About

Renate Pilz is a Professor In Residence in the Department of Medicine at UCSD. Her research focuses on basic tumor biology, signal transduction, and the control of cell growth, differentiation, and survival by Ras- and Rho-related proteins, which are small GTPases activated downstream of multiple receptors. These proteins regulate cellular processes such as cell cycle progression, apoptosis, motility, and differentiation, and are important targets for cancer therapy due to their role in promoting transformation and tumor metastasis. Her work investigates the effects of prenylation inhibitors on signaling in solid tumors and leukemic cells, and she has identified novel Rho effector proteins and their functions in cancer cells. Additionally, her research explores the cross-talk between Ras and Rho pathways, as well as the regulation of gene expression by NO/cGMP/cGMP-dependent protein kinases (PKGs), including their roles in vascular smooth muscle cells, osteoblasts, and mesenchymal stem cells. She has identified mechanisms whereby PKG isoforms influence cell survival, motility, and signaling pathways relevant to bone health and cancer invasiveness. Her extensive research activities are supported by multiple NIH grants, and she has contributed to the understanding of signaling mechanisms involved in osteoporosis, vascular pathology, and cancer.

Research topics

• Biology
• Chemistry
• Internal medicine
• Medicine
• Toxicology
• Anatomy
• Biochemistry
• Biophysics
• Endocrinology
• Pathology
• Medical emergency
• Cell biology

Selected publications

• Cobinamide, a Vitamin B12 Analog, Attenuates Benzo[a]pyrene and Pyrene Toxicity Through Selective Redox Modulation

  Toxics · 2026-05-15

  articleOpen access

  Polycyclic aromatic hydrocarbons (PAHs) are common environmental contaminants formed during the incomplete combustion of organic material. Their persistence, bioaccumulation, and metabolic activation contribute to mutagenic and cytotoxic outcomes. Among these are benzo[a]pyrene (B[a]P), the most studied PAH and a benchmark compound for PAH carcinogenicity, and pyrene, a PAH whose urinary metabolite 1-hydroxypyrene is widely used as a biomarker of PAH exposure. B[a]P undergoes CYP1A1-mediated oxidation to generate reactive oxygen species (ROS) via epoxide and quinone redox cycling, whereas pyrene produces ROS primarily through pyrene-quinone redox cycling. We investigated cobinamide, a vitamin B12/cobalamin analog with potent antioxidant properties, for mitigating benzo[a]pyrene- and pyrene-induced injury. In H9C2 rat embryonic cardiomyoblasts and A549 human lung epithelial cells exposed to B[a]P (10 μM) or pyrene (10–100 μM), cobinamide (5–10 μM) attenuated PAH-induced reductions in cell number in both models, while in H9C2 cells, it also attenuated decreases in metabolic activity and reduced apoptosis. Cobinamide also returned JNK/p38 phosphorylation to near baseline levels, decreased DNA and protein oxidation and DNA strand breaks. Transcriptionally, cobinamide suppressed inflammatory (TNF-α, IL-1β, and IL-6) and oxidative stress genes (HMOX1 and NOX4), while enhancing oxidative response (SOD2) and xenobiotic metabolism (CYP1A1). In Drosophila melanogaster exposed to 5 mM B[a]P/pyrene, 2 mM cobinamide improved survival and fully restored locomotion, outperforming cobalamin (minimal benefit) and N-acetylcysteine (partial rescue). Spectroscopic analyses showed no direct cobinamide-PAH binding. These findings demonstrate that cobinamide efficiently limits ROS-mediated PAH injury through redox modulation while preserving xenobiotic metabolism, suggesting its potential therapeutic use to mitigate PAH-induced toxicity.

  PublisherDOI

• Crosstalk between androgen receptor and protein kinase G signaling in bone: implications for osteoporosis therapy

  Trends in Pharmacological Sciences · 2025-02-25 · 8 citations

  reviewSenior author
  PublisherDOI

• Protein kinase G2 activation restores Wnt signaling and bone mass in glucocorticoid-induced osteoporosis in mice

  JCI Insight · 2024-06-17 · 11 citations

  articleOpen accessSenior author

  Osteoporotic fractures are a major complication of long-term glucocorticoid therapy. Glucocorticoids transiently increase bone resorption, but they predominantly inhibit bone formation and induce osteocyte apoptosis, leading to bone loss. Current treatments of glucocorticoid-induced osteoporosis aim mainly at reducing bone resorption and are, therefore, inadequate. We previously showed that signaling via the NO/cGMP/protein kinase G pathway plays a key role in skeletal homeostasis. Here, we show that pharmacological PKG activation with the guanylyl cyclase-1 activator cinaciguat or expression of a constitutively active, mutant PKG2R242Q restored proliferation, differentiation, and survival of primary mouse osteoblasts exposed to dexamethasone. Cinaciguat treatment of WT mice or osteoblast-specific expression of PKG2R242Q in transgenic mice prevented dexamethasone-induced loss of cortical bone mass and strength. These effects of cinaciguat and PKG2R242Q expression were due to preserved bone formation parameters and osteocyte survival. The basis for PKG2's effects appeared to be through recovery of Wnt/β-catenin signaling, which was suppressed by glucocorticoids but critical for proliferation, differentiation, and survival of osteoblast-lineage cells. Cinaciguat reduced dexamethasone activation of osteoclasts, but this did not occur in the PKG2R242Q transgenic mice, suggesting a minor role in osteoprotection. We propose that existing PKG-targeting drugs could represent a novel therapeutic approach to prevent glucocorticoid-induced osteoporosis.

  PublisherOA PDFDOI

• A plasma membrane–associated form of the androgen receptor enhances nuclear androgen signaling in osteoblasts and prostate cancer cells

  Science Signaling · 2024-01-30 · 12 citations

  articleOpen accessSenior authorCorresponding

  Androgen binding to the androgen receptor (AR) in the cytoplasm induces the AR to translocate to the nucleus, where it regulates the expression of target genes. Here, we found that androgens rapidly activated a plasma membrane–associated signaling node that enhanced nuclear AR functions. In murine primary osteoblasts, dihydrotestosterone (DHT) binding to a membrane-associated form of AR stimulated plasma membrane–associated protein kinase G type 2 (PKG2), leading to the activation of multiple kinases, including ERK. Phosphorylation of AR at Ser 515 by ERK increased the nuclear accumulation and binding of AR to the promoter of Ctnnb1 , which encodes the transcription factor β-catenin. In male mouse osteoblasts and human prostate cancer cells, DHT induced the expression of Ctnnb1 and CTNN1B , respectively, as well as β-catenin target genes, stimulating the proliferation, survival, and differentiation of osteoblasts and the proliferation of prostate cancer cells in a PKG2-dependent fashion. Because β-catenin is a master regulator of skeletal homeostasis, these results explain the reported male-specific osteoporotic phenotype of mice lacking PKG2 in osteoblasts and imply that PKG2-dependent AR signaling is essential for maintaining bone mass in vivo. Our results suggest that widely used pharmacological PKG activators, such as sildenafil, could be beneficial for male and estrogen-deficient female patients with osteoporosis but detrimental in patients with prostate cancer.

  PublisherOA PDFDOI

• Phosphatase regulatory subunit MYPT2 knockout partially compensates for the cardiac dysfunction in mice caused by lack of myosin light chain kinase 3

  Journal of Biological Chemistry · 2023-03-06 · 2 citations

  articleOpen access

  Cardiac contraction is modulated by the phosphorylation state of myosin regulatory light chain 2 (MLC-2v). The level of MLC-2v phosphorylation is dependent on the opposing activities of MLC kinases and phosphatases. The predominant MLC phosphatase found in cardiac myocytes contains Myosin Phosphatase Targeting Subunit 2 (MYPT2). Overexpression of MYPT2 in cardiac myocytes results in a decreased level of MLC phosphorylation, reduced left ventricular contraction, and induction of hypertrophy; however, the effect of knocking out MYPT2 on cardiac function is unknown. We obtained heterozygous mice containing a MYPT2 null allele from the Mutant Mouse Resource Center. These mice were produced in a C57BL/6N background which lack MLCK3, the main regulatory light chain kinase in cardiac myocytes. We found that mice null for MYPT2 were viable and had no obvious phenotypic abnormality when compared to WT mice. Additionally, we determined that WT C57BL/6N mice had a low basal level of MLC-2v phosphorylation, which was significantly increased when MYPT2 was absent. At 12-weeks, MYPT2 KO mice had smaller hearts and showed downregulation of genes involved in cardiac remodeling. Using cardiac echo, we found that 24-week-old male MYPT2 KO mice had decreased heart size with increased fractional shortening compared to their MYPT2 WT littermates. Collectively, these studies highlight the important role that MYPT2 plays in cardiac function in vivo and demonstrate that its deletion can partially compensate for the lack of MLCK3. Cardiac contraction is modulated by the phosphorylation state of myosin regulatory light chain 2 (MLC-2v). The level of MLC-2v phosphorylation is dependent on the opposing activities of MLC kinases and phosphatases. The predominant MLC phosphatase found in cardiac myocytes contains Myosin Phosphatase Targeting Subunit 2 (MYPT2). Overexpression of MYPT2 in cardiac myocytes results in a decreased level of MLC phosphorylation, reduced left ventricular contraction, and induction of hypertrophy; however, the effect of knocking out MYPT2 on cardiac function is unknown. We obtained heterozygous mice containing a MYPT2 null allele from the Mutant Mouse Resource Center. These mice were produced in a C57BL/6N background which lack MLCK3, the main regulatory light chain kinase in cardiac myocytes. We found that mice null for MYPT2 were viable and had no obvious phenotypic abnormality when compared to WT mice. Additionally, we determined that WT C57BL/6N mice had a low basal level of MLC-2v phosphorylation, which was significantly increased when MYPT2 was absent. At 12-weeks, MYPT2 KO mice had smaller hearts and showed downregulation of genes involved in cardiac remodeling. Using cardiac echo, we found that 24-week-old male MYPT2 KO mice had decreased heart size with increased fractional shortening compared to their MYPT2 WT littermates. Collectively, these studies highlight the important role that MYPT2 plays in cardiac function in vivo and demonstrate that its deletion can partially compensate for the lack of MLCK3. The sarcomere is the basic contractile unit in myocytes (1Sweeney H.L. Hammers D.W. Muscle contraction.Cold Spring Harb. Perspect. Biol. 2018; 10a023200Crossref Scopus (102) Google Scholar). An individual sarcomere is composed of both thin and thick filaments. The thin filament consists of two intertwined chains of actin with regulatory proteins troponin and tropomyosin, whereas the thick filament consists of organized bundles of myosin. One functional unit of myosin contains two myosin heavy chains, two essential myosin light chains (MLCs), and two regulatory MLCs, specifically ventricular regulatory myosin light chain 2 (MLC-2v) (2England J. Loughna S. Heavy and light roles: myosin in the morphogenesis of the heart.Cell Mol. Life Sci. 2013; 70: 1221-1239Crossref PubMed Scopus (129) Google Scholar). The phosphorylation state of MLC-2v alters the binding of the myosin heavy chain head to actin, modulating muscle contraction and relaxation (3Grassie M.E. Moffat L.D. Walsh M.P. MacDonald J.A. The myosin phosphatase targeting protein (MYPT) family: a regulated mechanism for achieving substrate specificity of the catalytic subunit of protein phosphatase type 1delta.Arch. Biochem. Biophys. 2011; 510: 147-159Crossref PubMed Scopus (185) Google Scholar, 4Kampourakis T. Irving M. Phosphorylation of myosin regulatory light chain controls myosin head conformation in cardiac muscle.J. Mol. Cell Cardiol. 2015; 85: 199-206Abstract Full Text Full Text PDF PubMed Scopus (47) Google Scholar). MLC-2v phosphorylation occurs in a gradient, with higher levels in the outer layers at the apex and lower phosphorylation toward the inner layers and the mid-cardiac region (5Davis J.S. Hassanzadeh S. Winitsky S. Lin H. Satorius C. Vemuri R. et al.The overall pattern of cardiac contraction depends on a spatial gradient of myosin regulatory light chain phosphorylation.Cell. 2001; 107: 631-641Abstract Full Text Full Text PDF PubMed Scopus (225) Google Scholar, 6Sheikh F. Ouyang K. Campbell S.G. Lyon R.C. Chuang J. Fitzsimons D. et al.Mouse and computational models link Mlc2v dephosphorylation to altered myosin kinetics in early cardiac disease.J. Clin. Invest. 2012; 122: 1209-1221Crossref PubMed Scopus (120) Google Scholar). This gradient may improve cardiac output by inducing cardiac torsion (5Davis J.S. Hassanzadeh S. Winitsky S. Lin H. Satorius C. Vemuri R. et al.The overall pattern of cardiac contraction depends on a spatial gradient of myosin regulatory light chain phosphorylation.Cell. 2001; 107: 631-641Abstract Full Text Full Text PDF PubMed Scopus (225) Google Scholar, 6Sheikh F. Ouyang K. Campbell S.G. Lyon R.C. Chuang J. Fitzsimons D. et al.Mouse and computational models link Mlc2v dephosphorylation to altered myosin kinetics in early cardiac disease.J. Clin. Invest. 2012; 122: 1209-1221Crossref PubMed Scopus (120) Google Scholar). The importance of MLC-2v phosphorylation is highlighted in mice carrying alanine mutations at the regulatory phosphorylation sites (Ser14/Ser15); these mice have a shorter lifespan, develop dilated cardiac myopathy, and show decreased cardiac function by 2 months of age (6Sheikh F. Ouyang K. Campbell S.G. Lyon R.C. Chuang J. Fitzsimons D. et al.Mouse and computational models link Mlc2v dephosphorylation to altered myosin kinetics in early cardiac disease.J. Clin. Invest. 2012; 122: 1209-1221Crossref PubMed Scopus (120) Google Scholar). In normal beating hearts, MLC-2v is approximately 40% phosphorylated (7Chang A.N. Kamm K.E. Stull J.T. Role of myosin light chain phosphatase in cardiac physiology and pathophysiology.J. Mol. Cell Cardiol. 2016; 101: 35-43Abstract Full Text Full Text PDF PubMed Scopus (23) Google Scholar). The phosphorylation of MLC-2v is dependent on the opposing activities of myosin light chain kinases (MLCKs) and myosin light chain phosphatases. The main MLCK in hearts is MLCK3 (aka cMLCK) (8Seguchi O. Takashima S. Yamazaki S. Asakura M. Asano Y. Shintani Y. et al.A cardiac myosin light chain kinase regulates sarcomere assembly in the vertebrate heart.J. Clin. Invest. 2007; 117: 2812-2824Crossref PubMed Scopus (126) Google Scholar). In mice lacking MLCK3, MLC-2v levels fall to approximately 10% (9Ding P. Huang J. Battiprolu P.K. Hill J.A. Kamm K.E. Stull J.T. Cardiac myosin light chain kinase is necessary for myosin regulatory light chain phosphorylation and cardiac performance in vivo.J. Biol. Chem. 2010; 285: 40819-40829Abstract Full Text Full Text PDF PubMed Scopus (101) Google Scholar), with the remaining phosphorylation likely mediated by MLCK4 or Zip kinase (10Chang A.N. Chen G. Gerard R.D. Kamm K.E. Stull J.T. Cardiac myosin is a substrate for zipper-interacting protein kinase (ZIPK).J. Biol. Chem. 2010; 285: 5122-5126Abstract Full Text Full Text PDF PubMed Scopus (27) Google Scholar, 11Chang A.N. Mahajan P. Knapp S. Barton H. Sweeney H.L. Kamm K.E. et al.Cardiac myosin light chain is phosphorylated by Ca2+/calmodulin-dependent and -independent kinase activities.Proc. Natl. Acad. Sci. U. S. A. 2016; 113: E3824-E3833Crossref PubMed Scopus (36) Google Scholar). Under basal conditions, MLCK3 KO mice (either germline or induced) develop enlarged hearts and show signs of cardiac dysfunction, including dilated ventricles and decreased fractional shortening (FA) (12Massengill M.T. Ashraf H.M. Chowdhury R.R. Chrzanowski S.M. Kar J. Warren S.A. et al.Acute heart failure with cardiomyocyte atrophy induced in adult mice by ablation of cardiac myosin light chain kinase.Cardiovasc. Res. 2016; 111: 34-43Crossref PubMed Scopus (26) Google Scholar, 13Warren S.A. Briggs L.E. Zeng H. Chuang J. Chang E.I. Terada R. et al.Myosin light chain phosphorylation is critical for adaptation to cardiac stress.Circulation. 2012; 126: 2575-2588Crossref PubMed Scopus (83) Google Scholar). MLCK3 KO mice are also susceptible to stress-induced heart failure (9Ding P. Huang J. Battiprolu P.K. Hill J.A. Kamm K.E. Stull J.T. Cardiac myosin light chain kinase is necessary for myosin regulatory light chain phosphorylation and cardiac performance in vivo.J. Biol. Chem. 2010; 285: 40819-40829Abstract Full Text Full Text PDF PubMed Scopus (101) Google Scholar, 12Massengill M.T. Ashraf H.M. Chowdhury R.R. Chrzanowski S.M. Kar J. Warren S.A. et al.Acute heart failure with cardiomyocyte atrophy induced in adult mice by ablation of cardiac myosin light chain kinase.Cardiovasc. Res. 2016; 111: 34-43Crossref PubMed Scopus (26) Google Scholar, 13Warren S.A. Briggs L.E. Zeng H. Chuang J. Chang E.I. Terada R. et al.Myosin light chain phosphorylation is critical for adaptation to cardiac stress.Circulation. 2012; 126: 2575-2588Crossref PubMed Scopus (83) Google Scholar); however, mice with cardiac-specific MLCK3 overexpression are protected (13Warren S.A. Briggs L.E. Zeng H. Chuang J. Chang E.I. Terada R. et al.Myosin light chain phosphorylation is critical for adaptation to cardiac stress.Circulation. 2012; 126: 2575-2588Crossref PubMed Scopus (83) Google Scholar). The predominant cardiac MLC phosphatase is thought to be a heterotrimer, composed of PP1Cδ (catalytic subunit), M21 (a 21 kDa subunit of relatively unknown function), and MYPT2 (a PP1Cδ regulatory and myosin-targeting subunit, which contains binding sites for PP1Cδ, myosin, and M21). MYPT2 was first described as a MYPT1 homolog that was highly expressed in heart (14Fujioka M. Takahashi N. Odai H. Araki S. Ichikawa K. Feng J. et al.A new isoform of human myosin phosphatase targeting/regulatory subunit (MYPT2): cDNA cloning, tissue expression, and chromosomal mapping.Genomics. 1998; 49: 59-68Crossref PubMed Scopus (70) Google Scholar). Much more is known about MYPT1 function, which is primarily found in smooth muscle cells (3Grassie M.E. Moffat L.D. Walsh M.P. MacDonald J.A. The myosin phosphatase targeting protein (MYPT) family: a regulated mechanism for achieving substrate specificity of the catalytic subunit of protein phosphatase type 1delta.Arch. Biochem. Biophys. 2011; 510: 147-159Crossref PubMed Scopus (185) Google Scholar, 7Chang A.N. Kamm K.E. Stull J.T. Role of myosin light chain phosphatase in cardiac physiology and pathophysiology.J. Mol. Cell Cardiol. 2016; 101: 35-43Abstract Full Text Full Text PDF PubMed Scopus (23) Google Scholar). MYPT1 and MYPT2 both bind the catalytic PP1Cδ subunit and target it to myosin (15Okamoto R. Kato T. Mizoguchi A. Takahashi N. Nakakuki T. Mizutani H. et al.Characterization and function of MYPT2, a target subunit of myosin phosphatase in heart.Cell Signal. 2006; 18: 1408-1416Crossref PubMed Scopus (50) Google Scholar, 16Scotto-Lavino E. Garcia-Diaz M. Du G. Frohman M.A. Basis for the isoform-specific interaction of myosin phosphatase subunits protein phosphatase 1c beta and myosin phosphatase targeting subunit 1.J. Biol. Chem. 2010; 285: 6419-6424Abstract Full Text Full Text PDF PubMed Scopus (31) Google Scholar). A conserved at the is phosphorylated by and the phosphorylated bind in the PP1Cδ catalytic phosphatase (15Okamoto R. Kato T. Mizoguchi A. Takahashi N. Nakakuki T. Mizutani H. et al.Characterization and function of MYPT2, a target subunit of myosin phosphatase in heart.Cell Signal. 2006; 18: 1408-1416Crossref PubMed Scopus (50) Google Scholar, J. M. Ichikawa K. N. M. et phosphorylation for kinase on smooth muscle myosin Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar, M. F. K. T. R. of protein phosphatase PubMed Scopus Google Scholar). is known about MYPT2 function in In Mizutani et H. R. N. K. M. S. et of myosin phosphatase of contraction and cardiac J. 2010; PubMed Scopus (36) Google found that cardiac MYPT2 overexpression to a in phosphorylated MLC-2v and of with increased and and reduced The of cardiac with the of MYPT2 the importance of the MLCK and myosin light chain phosphatase In we MYPT2 KO which were by the Mutant Mouse Resource and Center. The mice a deletion in the MYPT2 which a in the and a the These mice are in a C57BL/6N which to lack MLCK3 protein expression, to a that out of from the normal A. S. J. D. J. et null C57BL/6N mice develop whereas null mice Sci. Google Scholar). The C57BL/6N are known to be susceptible to heart failure M. N. S. F. D. et al.Cardiac or a of the in and Res. PubMed Scopus Google Scholar), and the lack of MLCK3 is likely a to In we found that the of MYPT2 increased MLC-2v phosphorylation levels and cardiac function in C57BL/6N mice. that MYPT1 KO mice are viable R. M. N. M. N. H. et al.The of the MYPT1 results in Res. PubMed Scopus Google Scholar), MYPT2 KO mice have We heterozygous MYPT2 KO mice obtained from the and found that MYPT2 KO mice were viable as determined by at the of and mice were at the and both male and MYPT2 KO mice were MYPT2 KO mice normal to at of age and showed no obvious or when compared to WT mice. MYPT2 is in and muscle (14Fujioka M. Takahashi N. Odai H. Araki S. Ichikawa K. Feng J. et al.A new isoform of human myosin phosphatase targeting/regulatory subunit (MYPT2): cDNA cloning, tissue expression, and chromosomal mapping.Genomics. 1998; 49: 59-68Crossref PubMed Scopus (70) Google Scholar). MYPT2 protein expression, we the a of we first the for its to MYPT2, and Cell from cells with for MYPT2, and were by and with by was a in that the of MYPT1 and MYPT2 proteins were the of was approximately the with the by we levels of MYPT1 and MYPT2 the was higher that of that the was toward We heart from MYPT2 and KO mice. MYPT2 was lower in heterozygous mice and in the KO mice and The of MYPT1 was of MYPT2 and was in no of MYPT1 and results were in from and muscle A and of the catalytic PP1Cδ subunit decreased in the MYPT2 KO mice to compared to from MYPT2 WT mice and In levels and In mice containing both MLCK3 and MYPT2, MLC-2v a basal phosphorylation level of (7Chang A.N. Kamm K.E. Stull J.T. Role of myosin light chain phosphatase in cardiac physiology and pathophysiology.J. Mol. Cell Cardiol. 2016; 101: 35-43Abstract Full Text Full Text PDF PubMed Scopus (23) Google Scholar), whereas in MLCK3 KO level is with the MLC-2v phosphorylation thought to be mediated by MLCK4 or (10Chang A.N. Chen G. Gerard R.D. Kamm K.E. Stull J.T. Cardiac myosin is a substrate for zipper-interacting protein kinase (ZIPK).J. Biol. Chem. 2010; 285: 5122-5126Abstract Full Text Full Text PDF PubMed Scopus (27) Google Scholar, 11Chang A.N. Mahajan P. Knapp S. Barton H. Sweeney H.L. Kamm K.E. et al.Cardiac myosin light chain is phosphorylated by Ca2+/calmodulin-dependent and -independent kinase activities.Proc. Natl. Acad. Sci. U. S. A. 2016; 113: E3824-E3833Crossref PubMed Scopus (36) Google Scholar). Using and we found that MLC-2v had a basal phosphorylation level of 10% in C57BL/6N which is with MLCK3 KO in these mice A and We that the MLCK3 which was to in a lack of MLCK3 protein A. S. J. D. J. et null C57BL/6N mice develop whereas null mice Sci. Google Scholar). In mice heterozygous for the MYPT2 MLC-2v phosphorylation to and when MYPT2 is the level of MLC-2v phosphorylation to A and Using we found that MLCK3 MLC-2v in in a phosphorylation be by or by a human MLC-2v phosphorylation was a MLCK3 and and MLC-2v have to from in we can that phosphorylation of MLC-2v can be the human MLC-2v We found a in MLC-2v phosphorylation in heart from heterozygous and MYPT2 KO mice when compared to from WT Cardiac troponin is a target of MLCK3 phosphorylation, which in the contractile to MLC-2v phosphorylation S. M. Irving M. Campbell et al.Cardiac myosin regulatory light chain kinase cardiac by both myosin regulatory light chain and troponin Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar). We found that the level of troponin phosphorylation at is in the and of MYPT2 in C57BL/6N mice lacking MLCK3 Cardiac contraction is also regulated by phosphorylation of protein A. of cardiac myosin binding a Signal. PubMed Scopus Google Scholar). MYPT2 alters phosphorylation, we E. E. K. T. a new to phosphorylated Cell 2006; Full Text Full Text PDF PubMed Scopus Google Scholar). We found that as a of phosphorylation, and no in the overall level of phosphorylation in the or of MYPT2 and MLCK3 KO mice have hearts WT mice (12Massengill M.T. Ashraf H.M. Chowdhury R.R. Chrzanowski S.M. Kar J. Warren S.A. et al.Acute heart failure with cardiomyocyte atrophy induced in adult mice by ablation of cardiac myosin light chain kinase.Cardiovasc. Res. 2016; 111: 34-43Crossref PubMed Scopus (26) Google Scholar, A.N. Battiprolu P.K. Chen G. Gerard R.D. et phosphorylation of cardiac myosin regulatory light chain in vivo.J. Biol. Chem. 2015; Full Text Full Text PDF PubMed Scopus Google Scholar). We the and in mice and found that was increased in MYPT2 KO with a in male mice The of heart to was significantly decreased in the MYPT2 KO mice the of and to were in We to of genes involved in cardiac myosin heavy chain and troponin We found that and levels significantly MYPT2 WT and KO mice levels of and were significantly decreased in the These results demonstrate in a MLCK3 null MYPT2 KO mice hearts and downregulation of genes involved in cardiac remodeling. the effect of MYPT2 in the we on 24-week-old male MYPT2 and KO mice in the C57BL/6N background In we also WT mice. mice MLCK3 and show no in the phosphorylation level of the main regulatory in MYPT1 or MYPT2 when compared to C57BL/6N mice was no in the heart or the A and We found a toward increased left ventricular in the C57BL/6N mice when compared to was a in in the MYPT2 KO mice compared to C57BL/6N mice to was decreased in the C57BL/6N mice and and significantly increased when MYPT2 was in the C57BL/6N background ventricular inner at and left ventricular inner to were in C57BL/6N both compared to mice and MYPT2 KO C57BL/6N mice and were no in the in or left ventricular in and results demonstrate that cardiac in the of MLCK3 can be by deletion of also highlight that MYPT2 plays a role in cardiac function in The results from can be as in In mice containing MLCK3 and MYPT2 with both kinase and phosphatase MLC-2v phosphorylation of 40% and cardiac function is In C57BL/6N which lack MLCK3 MLC-2v phosphorylation to 10% and cardiac function is knocking out MYPT2 phosphatase targeting in C57BL/6N mice to increased MLC-2v phosphorylation and cardiac The that C57BL/6N mice lack MLCK3 for to heart failure A. S. J. D. J. et null C57BL/6N mice develop whereas null mice Sci. Google Scholar, M. N. S. F. D. et al.Cardiac or a of the in and Res. PubMed Scopus Google Scholar). We also reduced cardiac function in C57BL/6N mice when compared to function was by MYPT2 with a of MLC In et (9Ding P. Huang J. Battiprolu P.K. Hill J.A. Kamm K.E. Stull J.T. Cardiac myosin light chain kinase is necessary for myosin regulatory light chain phosphorylation and cardiac performance in vivo.J. Biol. Chem. 2010; 285: 40819-40829Abstract Full Text Full Text PDF PubMed Scopus (101) Google Scholar). a MLCK3 allele to the of a which was of a In mice for allele MLCK3 was by and the of phosphorylated MLC-2v was reduced to to 40% in the WT mice which were in a and This level of MLC-2v phosphorylation is to we in the C57BL/6N mice. At to et (9Ding P. Huang J. Battiprolu P.K. Hill J.A. Kamm K.E. Stull J.T. Cardiac myosin light chain kinase is necessary for myosin regulatory light chain phosphorylation and cardiac performance in vivo.J. Biol. Chem. 2010; 285: 40819-40829Abstract Full Text Full Text PDF PubMed Scopus (101) Google found increased and cardiac function in mice for the allele WT mice In Warren et (13Warren S.A. Briggs L.E. Zeng H. Chuang J. Chang E.I. Terada R. et al.Myosin light chain phosphorylation is critical for adaptation to cardiac stress.Circulation. 2012; 126: 2575-2588Crossref PubMed Scopus (83) Google described mice with a germline MLCK3 basal at of the hearts were enlarged with increased and also showed reduced and increased left ventricular at and these mice were to were highly susceptible to heart failure with increased of the ventricles both and and reduced compared to WT mice. In mice with cardiac MLCK3 overexpression were protected from cardiac (13Warren S.A. Briggs L.E. Zeng H. Chuang J. Chang E.I. Terada R. et al.Myosin light chain phosphorylation is critical for adaptation to cardiac stress.Circulation. 2012; 126: 2575-2588Crossref PubMed Scopus (83) Google Scholar). are and MYPT1 and MYPT2 specifically with PP1Cδ, target it to myosin, and its (15Okamoto R. Kato T. Mizoguchi A. Takahashi N. Nakakuki T. Mizutani H. et al.Characterization and function of MYPT2, a target subunit of myosin phosphatase in heart.Cell Signal. 2006; 18: 1408-1416Crossref PubMed Scopus (50) Google Scholar). We found that MYPT2 to decreased levels of PP1Cδ in the This is with the that overexpression of MYPT2 in cardiac myocytes to increased PP1Cδ levels H. R. N. K. M. S. et of myosin phosphatase of contraction and cardiac J. 2010; PubMed Scopus (36) Google and that knocking out MYPT1 in smooth cells to decreased PP1Cδ levels Chen P. et al.Myosin phosphatase target subunit regulates the contraction and relaxation of smooth muscle and Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar). the of to PP1Cδ in the PP1Cδ deletion to decreased levels of MYPT2 E. N. A. Chang A.N. Myosin light chain phosphatase catalytic subunit cardiac myosin dependent and of the regulatory Biol. Chem. Full Text Full Text PDF Scopus Google Scholar). We a in expression, and be as the with MYPT2 (15Okamoto R. Kato T. Mizoguchi A. Takahashi N. Nakakuki T. Mizutani H. et al.Characterization and function of MYPT2, a target subunit of myosin phosphatase in heart.Cell Signal. 2006; 18: 1408-1416Crossref PubMed Scopus (50) Google Scholar). We found that hearts about as MYPT2 as results have by E. N. A. Chang A.N. Myosin light chain phosphatase catalytic subunit cardiac myosin dependent and of the regulatory Biol. Chem. Full Text Full Text PDF Scopus Google Scholar). MYPT2 for the of MLCK3, MLC-2v phosphorylation and cardiac were MLC-2v phosphorylation is that the remaining MLC-2v kinase or a more to MLC-2v or that MLC-2v was The remaining MLC-2v dephosphorylation may be mediated by PP1Cδ or by PP1Cδ of the The of these kinases and in MLC-2v phosphorylation to be determined and it is important to in that we determined the level of MLC-2v phosphorylation in heart are MLC-2v phosphorylation in and studies (5Davis J.S. Hassanzadeh S. Winitsky S. Lin H. Satorius C. Vemuri R. et al.The overall pattern of cardiac contraction depends on a spatial gradient of myosin regulatory light chain phosphorylation.Cell. 2001; 107: 631-641Abstract Full Text Full Text PDF PubMed Scopus (225) Google Scholar, 13Warren S.A. Briggs L.E. Zeng H. Chuang J. Chang E.I. Terada R. et al.Myosin light chain phosphorylation is critical for adaptation to cardiac stress.Circulation. 2012; 126: 2575-2588Crossref PubMed Scopus (83) Google Scholar). in WT levels of MLC-2v phosphorylation are likely higher 40% at the apex and lower the mid-cardiac et S. M. Irving M. Campbell et al.Cardiac myosin regulatory light chain kinase cardiac by both myosin regulatory light chain and troponin Biol. Chem. Full Text Full Text PDF PubMed Scopus Google that MLCK3 human and cardiac troponin troponin is a target of MLCK3, we troponin phosphorylation was altered in the MYPT2 KO we found that MYPT2 deletion had no We also phosphorylation in heart by for lack of E. E. K. T. a new to phosphorylated Cell 2006; Full Text Full Text PDF PubMed Scopus Google Scholar); we found no WT and MYPT2 KO mice. We two on phosphorylated of in heart obtained by tissue in containing a phosphatase In et O. S. J. of cardiac myosin binding phosphorylation in human heart muscle.J. Mol. Cell Cardiol. 2010; 49: Full Text Full Text PDF PubMed Scopus Google to on partially from heart in with as a phosphatase is that more to which the is also that the we for phosphorylated of We found that of and were decreased in C57BL/6N MYPT2 KO mice when compared to In and the predominant ventricular heavy chain is expressed from the in adult mice and the predominant is expressed from the C. A. M. J. of cardiac myosin J. PubMed Scopus Google Scholar). levels in models of heart (9Ding P. Huang J. Battiprolu P.K. Hill J.A. Kamm K.E. Stull J.T. Cardiac myosin light chain kinase is necessary for myosin regulatory light chain phosphorylation and cardiac performance in vivo.J. Biol. Chem. 2010; 285: 40819-40829Abstract Full Text Full Text PDF PubMed Scopus (101) Google Scholar, A. S. J. D. J. et null C57BL/6N mice develop whereas null mice Sci. Google Scholar). The decreased in MYPT2 KO mice is with the smaller heart size and cardiac for troponin and its to in human heart failure L.E. M.E. The muscle troponin is expressed in and human Cell Biochem. PubMed Scopus Google Scholar). et A. S. J. D. J. et null C57BL/6N mice develop whereas null mice Sci. Google found that and are higher in C57BL/6N mice in and are with the MYPT2 at partially the cardiac that occurs in the of MLCK3. et A. S. J. D. J. et null C57BL/6N mice develop whereas null mice Sci. Google Scholar), we no in and basal These genes for and and their is known to in to F. A of the regulatory role of kinase in cardiac physiology and Res. Cardiol. 2018; 113: PubMed Scopus Google Scholar). In to the of et A. S. J. D. J. et null C57BL/6N mice develop whereas null mice Sci. Google Scholar), et (9Ding P. Huang J. Battiprolu P.K. Hill J.A. Kamm K.E. Stull J.T. Cardiac myosin light chain kinase is necessary for myosin regulatory light chain phosphorylation and cardiac performance in vivo.J. Biol. Chem. 2010; 285: 40819-40829Abstract Full Text Full Text PDF PubMed Scopus (101) Google found increased with no in in to mice. In we reduced expression, and no in in MYPT2 KO mice compared to WT C57BL/6N in cardiac myocytes MYPT2, and both increased compared to controls H. R. N. K. M. S. et of myosin phosphatase of contraction and cardiac J. 2010; PubMed Scopus (36) Google Scholar). The results and the results of may be to in the in the age of the mice in the In is the first the cardiac of MYPT2 KO mice. that knocking out MYPT2 in background significantly increased MLC-2v phosphorylation, to cardiac both MYPT1 and MYPT2 are expressed in heart MYPT1 compensate for the of MYPT2 in MLC-2v highlight the important role MYPT2 plays in cardiac performance in

  PublisherOA PDFDOI

• The vitamin B₁₂ analog cobinamide ameliorates azide toxicity in cells, <i>Drosophila melanogaster</i>, and mice

  Clinical Toxicology · 2023-04-03 · 2 citations

  articleOpen access

  Context The azide anion (N3-) is highly toxic. It exists most commonly as sodium azide, which is used widely and is readily available, raising the potential for occupational incidents and use as a weapon of mass destruction. Azide-poisoned patients present with vomiting, seizures, hypotension, metabolic acidosis, and coma; death can occur. No specific azide antidote exists, with treatment being solely supportive. Azide inhibits mitochondrial cytochrome c oxidase and is likely oxidized to nitric oxide in vivo. Cytochrome c oxidase inhibition depletes intracellular adenosine triphosphate and increases oxidative stress, while increased nitric oxide causes hypotension and exacerbates oxidative damage. Here, we tested whether the cobalamin (vitamin B12) analog cobinamide, a strong and versatile antioxidant that also neutralizes nitric oxide, can reverse azide toxicity in mammalian cells, Drosophila melanogaster, and mice.Results We found cobinamide bound azide with a moderate affinity (Ka 2.87 × 105 M−1). Yet, cobinamide improved growth, increased intracellular adenosine triphosphate, and reduced apoptosis and malondialdehyde, a marker of oxidative stress, in azide-exposed cells. Cobinamide rescued Drosophila melanogaster and mice from lethal exposure to azide and was more effective than hydroxocobalamin. Azide likely generated nitric oxide in the mice, as evidenced by increased serum nitrite and nitrate, and reduced blood pressure and peripheral body temperature in the animals; the reduced temperature was likely due to reflex vasoconstriction in response to the hypotension. Cobinamide improved recovery of both blood pressure and body temperature.Conclusion We conclude cobinamide likely acted by neutralizing both oxidative stress and nitric oxide, and that it should be given further consideration as an azide antidote.

  PublisherOA PDFDOI

• The Antioxidant/Nitric Oxide-Quenching Agent Cobinamide Prevents Aortic Disease in a Mouse Model of Marfan Syndrome

  JACC Basic to Translational Science · 2023-10-04 · 7 citations

  articleOpen accessSenior authorCorresponding

  Major pathologic changes in the proximal aorta underlie the life-threatening aortic aneurysms and dissections in Marfan Syndrome; current treatments delay aneurysm development without addressing the primary pathology. Because excess oxidative stress and nitric oxide/protein kinase G signaling likely contribute to the aortopathy, we hypothesized that cobinamide, a strong antioxidant that can attenuate nitric oxide signaling, could be uniquely suited to prevent aortic disease. In a well-characterized mouse model of Marfan Syndrome, cobinamide dramatically reduced elastin breaks, prevented excess collagen deposition and smooth muscle cell apoptosis, and blocked DNA, lipid, and protein oxidation and excess nitric oxide/protein kinase G signaling in the ascending aorta. Consistent with preventing pathologic changes, cobinamide diminished aortic root dilation without affecting blood pressure. Cobinamide exhibited excellent safety and pharmacokinetic profiles indicating it could be a practical treatment. We conclude that cobinamide deserves further study as a disease-modifying treatment of Marfan Syndrome.

  PublisherDOI

• Author response for "Protein Kinase &lt;scp&gt;G2&lt;/scp&gt; Is Essential for Skeletal Homeostasis and Adaptation to Mechanical Loading in Male but not Female Mice"

  2022-08-19

  peer-reviewSenior author
  PublisherDOI

• Cobinamide is a strong and versatile antioxidant that overcomes oxidative stress in cells, flies, and diabetic mice

  PNAS Nexus · 2022-09-01 · 14 citations

  articleOpen access

  Abstract Increased oxidative stress underlies a variety of diseases, including diabetes. Here, we show that the cobalamin/vitamin B12 analog cobinamide is a strong and multifaceted antioxidant, neutralizing superoxide, hydrogen peroxide, and peroxynitrite, with apparent rate constants of 1.9 × 108, 3.7 × 104, and 6.3 × 106 M−1 s−1, respectively, for cobinamide with the cobalt in the +2 oxidation state. Cobinamide with the cobalt in the +3 oxidation state yielded apparent rate constants of 1.1 × 108 and 8.0 × 102 M−1 s−1 for superoxide and hydrogen peroxide, respectively. In mammalian cells and Drosophila melanogaster, cobinamide outperformed cobalamin and two well-known antioxidants, imisopasem manganese and manganese(III)tetrakis(4-benzoic acid)porphyrin, in reducing oxidative stress as evidenced by: (i) decreased mitochondrial superoxide and return of the mitochondrial membrane potential in rotenone- and antimycin A-exposed H9c2 rat cardiomyocytes; (ii) reduced JNK phosphorylation in hydrogen-peroxide-treated H9c2 cells; (iii) increased growth in paraquat-exposed COS-7 fibroblasts; and (iv) improved survival in paraquat-treated flies. In diabetic mice, cobinamide administered in the animals’ drinking water completely prevented an increase in lipid and protein oxidation, DNA damage, and fibrosis in the heart. Cobinamide is a promising new antioxidant that has potential use in diseases with heightened oxidative stress.

  PublisherOA PDFDOI

• Author response for "Protein Kinase &lt;scp&gt;G2&lt;/scp&gt; Is Essential for Skeletal Homeostasis and Adaptation to Mechanical Loading in Male but not Female Mice"

  2022-11-04

  peer-reviewSenior author
  PublisherDOI

Recent grants

• Regulation and Function of the Erythroid Transcription Factor NF-E2

  NSF · $281k · 1995–1998

• Targeting defective NO/cGMP signaling as novel therapy for diabetic osteoporosis

  NIH · $1.8M · 2016–2022

• PKG Regulation of Sirtuin 1 as a Novel Treatment Strategy for Age-related Osteoporosis

  NIH · $2.3M · 2021–2026

• NIH Grant K08CA001548

  NIH · $395k · 1995

• Testing novel NO/cGMP-based bone-anabolic agents in mouse models of osteoporosis

  NIH · $375k · 2015–2018

Frequent coauthors

• Gerry R. Boss

  University of California System

  89 shared

• Darren E. Casteel

  University of California, San Diego

  37 shared

• Shunhui Zhuang

  University of California, San Diego

  35 shared

• Matthew Brenner

  University of California, Irvine

  26 shared

• Sari Mahon

  University of California, Irvine

  26 shared

• Hema Kalyanaraman

  University of California, San Diego

  23 shared

• William Blackledge

  University of California, San Diego

  17 shared

• Adriano Chan

  University of California, San Diego

  17 shared

Education

• Ph.D., Molecular and Computational Biology

  University of California, San Diego

  2000

• M.S., Molecular and Computational Biology

  University of California, San Diego

  1996

• B.S., Biology

  University of California, San Diego

  1994