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1.
Front Endocrinol (Lausanne) ; 15: 1357594, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38699384

RESUMO

In mammals, gonadal somatic cell lineage differentiation determines the development of the bipotential gonad into either the ovary or testis. Sertoli cells, the only somatic cells in the spermatogenic tubules, support spermatogenesis during gonadal development. During embryonic Sertoli cell lineage differentiation, relevant genes, including WT1, GATA4, SRY, SOX9, AMH, PTGDS, SF1, and DMRT1, are expressed at specific times and in specific locations to ensure the correct differentiation of the embryo toward the male phenotype. The dysregulated development of Sertoli cells leads to gonadal malformations and male fertility disorders. Nevertheless, the molecular pathways underlying the embryonic origin of Sertoli cells remain elusive. By reviewing recent advances in research on embryonic Sertoli cell genesis and its key regulators, this review provides novel insights into sex determination in male mammals as well as the molecular mechanisms underlying the genealogical differentiation of Sertoli cells in the male reproductive ridge.


Assuntos
Diferenciação Celular , Linhagem da Célula , Células de Sertoli , Células de Sertoli/citologia , Células de Sertoli/metabolismo , Células de Sertoli/fisiologia , Masculino , Humanos , Animais , Reprodução/fisiologia , Espermatogênese/fisiologia , Processos de Determinação Sexual/fisiologia
2.
Int J Oncol ; 64(6)2024 06.
Artigo em Inglês | MEDLINE | ID: mdl-38695241

RESUMO

Cancer remains a formidable adversary, challenging medical advancements with its dismal prognosis, low cure rates and high mortality rates. Within this intricate landscape, long non­coding RNAs (lncRNAs) emerge as pivotal players, orchestrating proliferation and migration of cancer cells. Harnessing the potential of lncRNAs as therapeutic targets and prognostic markers holds immense promise. The present comprehensive review delved into the molecular mechanisms underlying the involvement of lncRNAs in the onset and progression of the top five types of cancer. By meticulously examining lncRNAs across diverse types of cancer, it also uncovered their distinctive roles, highlighting their exclusive oncogenic effects or tumor suppressor properties. Notably, certain lncRNAs demonstrate diverse functions across different cancers, confounding the conventional understanding of their roles. Furthermore, the present study identified lncRNAs exhibiting aberrant expression patterns in numerous types of cancer, presenting them as potential indicators for cancer screening and diagnosis. Conversely, a subset of lncRNAs manifests tissue­specific expression, hinting at their specialized nature and untapped significance in diagnosing and treating specific types of cancer. The present comprehensive review not only shed light on the intricate network of lncRNAs but also paved the way for further research and clinical applications. The unraveled molecular mechanisms offer a promising avenue for targeted therapeutics and personalized medicine, combating cancer proliferation, invasion and metastasis.


Assuntos
Biomarcadores Tumorais , Regulação Neoplásica da Expressão Gênica , Neoplasias , RNA Longo não Codificante , RNA Longo não Codificante/genética , Humanos , Neoplasias/genética , Neoplasias/patologia , Biomarcadores Tumorais/genética , Proliferação de Células/genética , Prognóstico , Progressão da Doença
3.
Artigo em Inglês | MEDLINE | ID: mdl-38625452

RESUMO

We examined the integrity of flash-frozen and cryo-sectioned cardiac muscle preparations (introduced by Feng and Jin, 2020) by assessing tension transients in response to sinusoidal length changes at varying frequencies (1-100 Hz) at 25 °C. Using 70-µm-thick sections, we isolated fiber preparations to study cross-bridge (CB) kinetics: preparations were activated by saturating Ca2+ as well as varying concentrations of ATP and phosphate (Pi). Our results showed that, compared to ordinary skinned fibers, in-series stiffness decreased to 1/2, which resulted in a decrease of isometric tension to 62%, but CB kinetics and Ca2+ sensitivity were little affected. The pCa study demonstrated that the rate constant of the force generation step (2πb) is proportionate to [Ca2+] at < 5 µM, suggesting that the activation mechanism can be described by a simple second order reaction. We also found that tension, stiffness, and magnitude parameters are related to [Ca2+] by the Hill equation, with a cooperativity coefficient of 4-5, which is consistent with the fact that Ca2+ activation mechanisms involve cooperative multimolecular interactions. Our results support the long-held hypothesis that Process C (Phase 2) represents the CB detachment step, and Process B (Phase 3) represents the force generation step. Moreover, we discovered that constant H may represent the work-performing step in cardiac preparations. Our experiments demonstrate excellent CB kinetics with two well-defined exponentials that can be more distinguished than those found using ordinary skinned fibers. Flash-frozen and cryo-sectioned preparations are especially suitable for multi-institutional collaborations nationally and internationally because of their ease of transportation.

4.
Heliyon ; 10(5): e27207, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38463803

RESUMO

Cancer drug resistance stands as a formidable obstacle in the relentless fight against the top five prevalent cancers: breast, lung, colorectal, prostate, and gastric cancers. These malignancies collectively account for a significant portion of cancer-related deaths worldwide. In recent years, long non-coding RNAs (lncRNAs) have emerged as pivotal players in the intricate landscape of cancer biology, and their roles in driving drug resistance are steadily coming to light. This comprehensive review seeks to underscore the paramount significance of lncRNAs in orchestrating resistance across a spectrum of different cancer drugs, including platinum drugs (DDP), tamoxifen, trastuzumab, 5-fluorouracil (5-FU), paclitaxel (PTX), and Androgen Deprivation Therapy (ADT) across the most prevalent types of cancer. It delves into the multifaceted mechanisms through which lncRNAs exert their influence on drug resistance, shedding light on their regulatory roles in various facets of cancer biology. A comprehensive understanding of these lncRNA-mediated mechanisms may pave the way for more effective and personalized treatment strategies, ultimately improving patient outcomes in these challenging malignancies.

5.
Heart Rhythm ; 2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38395244

RESUMO

BACKGROUND: Diabetes mellitus (DM) is a major risk factor for atrial structural remodeling and atrial fibrillation (AF). Calpain activity is hypothesized to promote atrial remodeling and AF. OBJECTIVE: The purpose of this study was to investigate the role of calpain in diabetes-associated AF, fibrosis, and calcium handling dysfunction. METHODS: DM-associated AF was induced in wild-type (WT) mice and in mice overexpressing the calpain inhibitor calpastatin (CAST-OE) using high-fat diet feeding followed by low-dose streptozotocin injection (75 mg/kg). DM and AF outcomes were assessed by measuring blood glucose levels, fibrosis, and AF susceptibility during transesophageal atrial pacing. Intracellular Ca2+ transients, spontaneous Ca2+ release events, and intracellular T-tubule membranes were measured by in situ confocal microscopy. RESULTS: WT mice with DM had significant hyperglycemia, atrial fibrosis, and AF susceptibility with increased atrial myocyte calpain activity and Ca2+ handling dysfunction relative to control treated animals. CAST-OE mice with DM had a similar level of hyperglycemia as diabetic WT littermates but lacked significant atrial fibrosis and AF susceptibility. DM-induced atrial calpain activity and downregulation of the calpain substrate junctophilin-2 were prevented by CAST-OE. Atrial myocytes of diabetic CAST-OE mice exhibited improved T-tubule membrane organization, Ca2+ handling, and reduced spontaneous Ca2+ release events compared to littermate controls. CONCLUSION: This study confirmed that DM promotes calpain activation, atrial fibrosis, and AF in mice. CAST-OE effectively inhibits DM-induced calpain activation and reduces atrial remodeling and AF incidence through improved intracellular Ca2+ homeostasis. Our results support calpain inhibition as a potential therapy for preventing and treating AF in DM patients.

6.
Signal Transduct Target Ther ; 9(1): 12, 2024 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-38185705

RESUMO

Ischemia-reperfusion (I/R) injury paradoxically occurs during reperfusion following ischemia, exacerbating the initial tissue damage. The limited understanding of the intricate mechanisms underlying I/R injury hinders the development of effective therapeutic interventions. The Wnt signaling pathway exhibits extensive crosstalk with various other pathways, forming a network system of signaling pathways involved in I/R injury. This review article elucidates the underlying mechanisms involved in Wnt signaling, as well as the complex interplay between Wnt and other pathways, including Notch, phosphatidylinositol 3-kinase/protein kinase B, transforming growth factor-ß, nuclear factor kappa, bone morphogenetic protein, N-methyl-D-aspartic acid receptor-Ca2+-Activin A, Hippo-Yes-associated protein, toll-like receptor 4/toll-interleukine-1 receptor domain-containing adapter-inducing interferon-ß, and hepatocyte growth factor/mesenchymal-epithelial transition factor. In particular, we delve into their respective contributions to key pathological processes, including apoptosis, the inflammatory response, oxidative stress, extracellular matrix remodeling, angiogenesis, cell hypertrophy, fibrosis, ferroptosis, neurogenesis, and blood-brain barrier damage during I/R injury. Our comprehensive analysis of the mechanisms involved in Wnt signaling during I/R reveals that activation of the canonical Wnt pathway promotes organ recovery, while activation of the non-canonical Wnt pathways exacerbates injury. Moreover, we explore novel therapeutic approaches based on these mechanistic findings, incorporating evidence from animal experiments, current standards, and clinical trials. The objective of this review is to provide deeper insights into the roles of Wnt and its crosstalk signaling pathways in I/R-mediated processes and organ dysfunction, to facilitate the development of innovative therapeutic agents for I/R injury.


Assuntos
Traumatismo por Reperfusão , Animais , Traumatismo por Reperfusão/genética , Reperfusão , Via de Sinalização Wnt/genética , Apoptose/genética , Isquemia
7.
DNA Cell Biol ; 43(2): 61-73, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38153369

RESUMO

Vitiligo is one of the common chronic autoimmune skin diseases in clinic, which is characterized by localized or generalized depigmentation and seriously affects the physical and mental health of patients. At present, the pathogenesis of vitiligo is not clear; mainly, heredity, autoimmunity, oxidative stress, melanocyte (MC) self-destruction, and the destruction, death, or dysfunction of MCs caused by various reasons are always the core of vitiligo. Regulatory cell death (RCD) is an active and orderly death mode of cells regulated by genes, which widely exists in various life activities, plays a pivotal role in maintaining the homeostasis of the organism, and is closely related to the occurrence and development of many diseases. With the deepening of the research and understanding of RCD, people gradually found that there are many different forms of RCD in the lesions and perilesional skin of vitiligo patients, such as apoptosis, autophagy, pyroptosis, ferroptosis, and so on. Different cell death modes have different mechanisms in vitiligo, and different RCDs can interact and regulate each other. In this article, the mechanism related to RCD in the pathogenesis of vitiligo is reviewed, which provides new ideas for exploring the pathogenesis and targeted treatment of vitiligo.


Assuntos
Vitiligo , Humanos , Vitiligo/genética , Vitiligo/patologia , Melanócitos , Pele , Autoimunidade , Apoptose
8.
Nutrients ; 15(24)2023 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-38140398

RESUMO

BACKGROUND/AIM: The impact of myocardial stressors such as high-fat diet (HFD) and pressure overload has been extensively studied. Toll-like receptor 4 (TLR4) deficiency has been suggested to have a protective role in response to these stressors, although some conflicting data exist. Furthermore, there is limited information about the role of TLR4 on cardiac remodeling in response to long-term exposure to stressors. This study aims to investigate the effects of TLR4 deficiency on cardiac histology and physiology in response to chronic stressors. METHODS: TLR4-deficient (TLR4-/-) and wild-type (WT) mice were subjected to either HFD or a normal diet (ND) for 28 weeks. Another group underwent abdominal aortic constriction (AAC) or a sham procedure and was monitored for 12 weeks. Inflammatory markers, histology, and echocardiography were used to assess the effects of these interventions. RESULTS: TLR4-/- mice exhibited reduced cardiac hypertrophy and fibrosis after long-term HFD exposure compared to ND without affecting cardiac function. On the other hand, TLR4 deficiency worsened cardiac function in response to AAC, leading to decreased ejection fraction (EF%) and increased end-systolic volume (ESV). CONCLUSIONS: TLR4 deficiency provided protection against HFD-induced myocardial inflammation but impaired hemodynamic cardiac function under pressure overload conditions. These findings highlight the crucial role of TLR4 and its downstream signaling pathway in maintaining cardiac output during physiologic cardiac hypertrophy in response to pressure overload.


Assuntos
Cardiomegalia , Dieta Hiperlipídica , Receptor 4 Toll-Like , Animais , Camundongos , Cardiomegalia/genética , Cardiomegalia/metabolismo , Dieta Hiperlipídica/efeitos adversos , Coração , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/metabolismo
9.
Res Sq ; 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37961283

RESUMO

The use of frozen and cryo-sectioned cardiac muscle preparations, introduced recently by (Feng & Jin, 2020), offers promising advantages of easy transport and exchange of muscle samples among collaborating laboratories. In this report, we examined integrity of such preparation by studying tension transients in response to sinusoidal length changes and following concomitant amplitude and phase shift in tension time courses at varying frequencies. We used sections with 70 µm thickness, isolated fiber preparations, and studied cross-bridge (CB) kinetics: we activated the preparations with saturating Ca2+, and varying concentrations of ATP and phosphate (Pi). Our experiments have demonstrated that this preparation has the normal active tension and elementary steps of the CB cycle. Furthermore, we investigated the effect of Ca2+ on the rate constants and found that the rate constant r4 of the force generation step is proportionate to [Ca2+] when it is <5 µM. This observation suggests that the activation mechanism can be described by a simple second order reaction. As expected, we found that magnitude parameters including tension and stiffness are related to [Ca2+] by the Hill equation with cooperativity of 4-5, consistent to the fact that Ca2+ activation mechanisms involve cooperative multimolecular interactions. Our results are consistent with a long-held hypothesis that process C (phase 2 of step analysis) represents the CB detachment step, and process B (phase 3) represents the force generation step. In this report, we further found that constant H may also represent work performance step. Our experiments have demonstrated excellent CB kinetics with reduced noise and well-defined two exponentials, which are better than skinned fibers, and easier to handle and study than single myofibrils.

10.
Ann Med ; 55(2): 2279748, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37983519

RESUMO

The intricate web of cancer biology is governed by the active participation of long non-coding RNAs (lncRNAs), playing crucial roles in cancer cells' proliferation, migration, and drug resistance. Pioneering research driven by machine learning algorithms has unveiled the profound ability of specific combinations of lncRNAs to predict the prognosis of cancer patients. These findings highlight the transformative potential of lncRNAs as powerful therapeutic targets and prognostic markers. In this comprehensive review, we meticulously examined the landscape of lncRNAs in predicting the prognosis of the top five cancers and other malignancies, aiming to provide a compelling reference for future research endeavours. Leveraging the power of machine learning techniques, we explored the predictive capabilities of diverse lncRNA combinations, revealing their unprecedented potential to accurately determine patient outcomes.


lncRNAs play crucial roles in cancer biology, regulating proliferation, migration, and drug resistance.Emerging evidence suggests that machine learning can predict cancer prognosis using specific lncRNA combinations.Comprehensive information on the predictive abilities of lncRNA combinations in oncology concerning machine learning is lacking.This review offers up-to-date vital references on diverse lncRNA combinations pertinent to future research and clinical trials.


Assuntos
Neoplasias , RNA Longo não Codificante , Humanos , RNA Longo não Codificante/genética , Neoplasias/diagnóstico , Neoplasias/genética , Prognóstico , Aprendizado de Máquina
11.
Free Radic Biol Med ; 208: 846-858, 2023 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-37776918

RESUMO

Cardiovascular diseases (CVDs) are leading causes of global mortality; however, their underlying mechanisms remain unclear. The tumor suppressor factor p53 has been extensively studied for its role in cancer and is also known to play an important role in regulating CVDs. Abnormal p53 expression levels and modifications contribute to the occurrence and development of CVDs. Additionally, mounting evidence underscores the critical involvement of mitochondrial dysfunction in CVDs. Notably, studies indicate that p53 abnormalities directly correlate with mitochondrial dysfunction and may even interact with each other. Encouragingly, small molecule inhibitors targeting p53 have exhibited remarkable effects in animal models of CVDs. Moreover, therapeutic strategies aimed at mitochondrial-related molecules and mitochondrial replacement therapy have demonstrated their advantageous potential. Therefore, targeting p53 or mitochondria holds immense promise as a pioneering therapeutic approach for combating CVDs. In this comprehensive review, we delve into the mechanisms how p53 influences mitochondrial dysfunction, including energy metabolism, mitochondrial oxidative stress, mitochondria-induced apoptosis, mitochondrial autophagy, and mitochondrial dynamics, in various CVDs. Furthermore, we summarize and discuss the potential significance of targeting p53 or mitochondria in the treatment of CVDs.


Assuntos
Doenças Cardiovasculares , Proteína Supressora de Tumor p53 , Apoptose , Autofagia/genética , Doenças Cardiovasculares/genética , Doenças Cardiovasculares/metabolismo , Mitocôndrias/metabolismo , Estresse Oxidativo , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Humanos
12.
J Ovarian Res ; 16(1): 46, 2023 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-36829196

RESUMO

Epithelial ovarian cancer (EOC) is a gynecological disease with the highest mortality. With the lack of understanding of its pathogenesis, no accurate early diagnosis and screening method has been established for EOC. Studies revealed the multi-faceted function of Wilms' tumor (Wt1) genes in cancer, which may be related to the existence of multiple alternative splices. Our results show that Wt1 (+KTS) or Wt1 (-KTS) overexpression can significantly promote the proliferation and migration of human ovarian epithelial cells HOSEpiC, and Wt1 (+KTS) effects were more evident. To explore the Wt1 (+/-KTS) variant mechanism in HOSEpiC proliferation and migration and ovarian cancer (OC) occurrence and development, this study explored the differential regulation of Wt1 (+/-KTS) in HOSEpiC proliferation and migration by transcriptome sequencing. OC-related hub genes were screened by bioinformatics analysis to further explore the differential molecular mechanism of Wt1 (+/-KTS) in the occurrence of OC. Finally, we found that the regulation of Wt1 (+/-KTS) variants on the proliferation and migration of HOSEpiC may act through different genes and signaling pathways and screened out key genes and differentially regulated genes that regulate the malignant transformation of ovarian epithelial cells. The implementation of this study will provide new clues for the early diagnosis and precise treatment of OC.


Assuntos
Neoplasias Renais , Tumor de Wilms , Humanos , Proteínas WT1/genética , Proteínas WT1/metabolismo , Tumor de Wilms/genética , Células Epiteliais/metabolismo , Neoplasias Renais/genética , Biologia Computacional , Proliferação de Células
13.
Phytomedicine ; 109: 154590, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36610170

RESUMO

BACKGROUND: Heart failure (HF), caused by stress cardiomyopathy, is a major cause of mortality. Cardiac fibrosis is an essential structural remodeling associated with HF; therefore, preventing cardiac fibrosis is crucial to decelerating the progression of HF. Sodium houttuyfonate (SH), an extract of Houttuynia cordata, has a potent therapeutic effect on hypoxic cardiomyocytes in a myocardial infarction model. PURPOSE: To investigate the preventative and therapeutic effects of SH during isoproterenol (ISO)-induced HF and explore the pharmacological mechanism of SH in alleviating HF. METHODS: We analyzed the overlapping target genes between SH and cardiac fibrosis or HF using a network pharmacology analytical method. We verified the suppressive effect of SH on ISO-induced proliferation and activation of cardiac fibroblasts by immunohistochemical staining and histological analysis in an isoproterenol-induced HF mouse model. Additionally, we investigated the effect of SH by evaluating fibrosis and cardiac remodeling markers. To further decipher the pharmacological mechanism of SH against cardiac fibrosis and HF, we performed a molecular docking analysis between SH and hub common target genes. RESULTS: There were 20 overlapping target genes between SH and cardiac fibrosis and 32 overlapping target genes between SH and HF. The 16 common target genes of SH against cardiac fibrosis and HF included MMP2 (matrix metalloproteinase 2), and p38. SH significantly inhibited the ISO- or TGF-ß-induced expression of Col1α (collagen 1), α-SMA (smooth muscle actin), MMP2, TIMP2 (tissue inhibitor of metalloproteinase 2), TGF-ß (transforming growth factor), and Smad2 phosphorylation. Moreover, both ISO- and TGF-ß-induced p38 phosphorylation was inhibited. Molecular docking analysis showed that SH forms a stable complex with MMP2 and p38. CONCLUSIONS: In addition to protecting cardiomyocytes, SH directly inhibits cardiac fibroblast activation and proliferation by binding to MMP2 and p38, subsequently delaying cardiac fibrosis and HF progression. Our prevention- and intervention-based approaches in this study showed that SH inhibited the development of stress cardiomyopathy-mediated cardiac fibrosis and HF when SH was administered before or after the initiation of cardiac stress.


Assuntos
Cardiomiopatias , Insuficiência Cardíaca , Cardiomiopatia de Takotsubo , Camundongos , Animais , Metaloproteinase 2 da Matriz , Isoproterenol , Inibidor Tecidual de Metaloproteinase-2 , Cardiomiopatia de Takotsubo/patologia , Simulação de Acoplamento Molecular , Insuficiência Cardíaca/induzido quimicamente , Insuficiência Cardíaca/tratamento farmacológico , Insuficiência Cardíaca/patologia , Miócitos Cardíacos/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Fibrose , Fator de Crescimento Transformador beta1/metabolismo , Miocárdio/metabolismo
14.
Front Neurosci ; 16: 966772, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36213746

RESUMO

Optogenetics is an emerging bioengineering technology that has been rapidly developed in recent years by cross-integrating optics, genetic engineering, electrophysiology, software control, and other disciplines. Since the first demonstration of the millisecond neuromodulation ability of the channelrhodopsin-2 (ChR2), the application of optogenetic technology in basic life science research has been rapidly progressed, especially in neurobiology, which has driven the development of the discipline. As the optogenetic tool protein, microbial rhodopsins have been continuously explored, modified, and optimized, with many variants becoming available, with structural characteristics and functions that are highly diversified. Their applicability has been broadened, encouraging more researchers and clinicians to utilize optogenetics technology in research. In this review, we summarize the species and variant types of the most important class of tool proteins in optogenetic techniques, the microbial rhodopsins, and review the current applications of optogenetics based on rhodopsin qualitative light in biology and other fields. We also review the challenges facing this technology, to ultimately provide an in-depth technical reference to support the application of optogenetics in translational and clinical research.

15.
Front Public Health ; 10: 965631, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36106167

RESUMO

Pseudophosphatases are a class of phosphatases that mutate at the catalytically active site. They play important parts in many life processes and disorders, e.g., cell apoptosis, stress reaction, tumorigenesis, axon differentiation, Charcot-Marie-Tooth, and metabolic dysfunction. The present review considers the structures and action types of pseudophosphatases in four families, protein tyrosine phosphatases (PTPs), myotube protein phosphatases (MTMs), phosphatases and tensin homologues (PTENs) and dual specificity phosphatases (DUSPs), as well as their mechanisms in signaling and disease. We aimed to provide reference material for the research and treatment of related diseases.


Assuntos
Proteínas Tirosina Fosfatases , Transdução de Sinais , Humanos , Proteínas Tirosina Fosfatases/química , Proteínas Tirosina Fosfatases/metabolismo
16.
J Muscle Res Cell Motil ; 43(4): 157-172, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-35994221

RESUMO

The effect of obesity on cross-bridge (CB) function was investigated in mice lacking functional Melanocortin-4 Receptor (MC4R-/-), the loss of which causes dilated cardiomyopathy (DCM) in humans and mice. Skinned cardiac muscle fibers from male and female mice were used, and activated in the presence of Ca2+. To characterize CB kinetics, we changed the length of fibers in sinewaves (15 frequencies: 1‒187 Hz) at a small amplitude (0.2%L0), studied concomitant tension transients, and deduced the kinetic constants of the CB cycle from the ATP and Pi effects. In males, active tension and stiffness during full activation and rigor were ~ 1.5X in WT compared to MC4R-/- mice. This effect was not observed in females. We also observed that ATP binding and subsequent CB detachment steps were not altered by the mutation/gender. The equilibrium constant of the force generation step (K4) and Pi release step (association constant: K5) were not affected by the mutation, but there was a gender difference in WT mice: K4 and K5 were ~ 2.2X in males than in females. Concomitantly, the forward rate constant (r4) and backward rate constant (r-4) of the force generation step were 1.5-2.5X in muscles from female MC4R-/- mice relative to male MC4R-/- mice. However, these effects did not cause a significant difference in CB distributions among six CB states. In both genders, Ca2+ sensitivity decreased slightly (0.12 pCa unit) in mutants. We conclude that the CB functions are differentially affected both by obesity induced in the absence of functional MC4R-/- and gender.


Assuntos
Trifosfato de Adenosina , Fosfatos , Humanos , Feminino , Masculino , Camundongos , Animais , Difosfato de Adenosina/metabolismo , Trifosfato de Adenosina/metabolismo , Fosfatos/metabolismo , Cinética , Miócitos Cardíacos/metabolismo , Obesidade , Cálcio/metabolismo
17.
Front Cardiovasc Med ; 9: 808163, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35265680

RESUMO

Familial hypertrophic cardiomyopathy (FHCM), an autosomal dominant disease, is caused by mutations in genes encoding cardiac sarcomeric proteins. E22K, a mutation in the myosin regulatory light chain sarcomere gene, is associated with the development of FHCM. However, the molecular mechanisms by which E22K mutation promotes septal hypertrophy are still elusive. The hypertrophic markers, including beta-myosin heavy chain, atrial natriuretic peptide and B-type natriuretic peptide, were upregulated, as detected by fluorescence quantitative PCR. The gene expression profiles were greatly altered in the left ventricle of E22K mutant mice. Among these genes, nuclear factor of activated T cells (NFAT) and protein kinase C-alpha (PKC-α) were upregulated, and their protein expression levels were also verified to be elevated. The fibrosis markers, such as phosphorylated Smad and transforming growth factor beta receptor, were also elevated in transgenic E22K mice. After receiving 6 weeks of procedural exercise training, the expression levels of PKC-α and NFAT were reversed in E22K mouse hearts. In addition, the expression levels of several fibrosis-related genes such as transforming growth factor beta receptor 1, Smad4, and alpha smooth muscle actin in E22K mouse hearts were also reversed. Genes that associated with cardiac remodeling such as myocyte enhancer factor 2C, extracellular matrix protein 2 and fibroblast growth factor 12 were reduced after exercising. Taken together, our results indicate that exercise can improve hypertrophy and fibrosis-related indices in transgenic E22K mice via PKC-α/NFAT pathway, which provide new insight into the prevention and treatment of familial hypertrophic cardiomyopathy.

18.
Front Cell Dev Biol ; 9: 701547, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35059392

RESUMO

Diabetic nephropathy (DN) is a serious kidney-related complication of both type 1 and type 2 diabetes mellitus (T1DM, T2DM) and the second major cause of end-stage kidney disease. DN can lead to hypertension, edema, and proteinuria. In some cases, DN can even progress to kidney failure, a life-threatening condition. The precise etiology and pathogenesis of DN remain unknown, although multiple factors are believed to be involved. The main pathological manifestations of DN include mesangial expansion, thickening of the glomerular basement membrane, and podocyte injury. Eventually, these pathological manifestations will lead to glomerulosclerosis, thus affecting renal function. There is an urgent need to develop new strategies for the prevention and treatment of DN. Existing evidence shows that the Wnt signaling cascade plays a key role in regulating the development of DN. Previous studies focused on the role of the Wnt canonical signaling pathway in DN. Subsequently, accumulated evidence on the mechanism of the Wnt non-canonical signaling indicated that Wnt/Ca2+ and Wnt/PCP also have essential roles in the progression of DN. In this review, we summarize the specific mechanisms of Wnt signaling in the occurrence and development of DN in podocyte injury, mesangial cell injury, and renal fibrosis. Also, to elucidate the significance of the Wnt canonical pathway in the process of DN, we uncovered evidence supporting that both Wnt/PCP and Wnt/Ca2+ signaling are critical for DN development.

19.
Front Cardiovasc Med ; 8: 808115, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35237671

RESUMO

Mitochondria is a ubiquitous, energy-supplying (ATP-based) organelle found in nearly all eukaryotes. It acts as a "power plant" by producing ATP through oxidative phosphorylation, providing energy for the cell. The bioenergetic functions of mitochondria are regulated by nuclear genes (nDNA). Mitochondrial DNA (mtDNA) and respiratory enzymes lose normal structure and function when nuclear genes encoding the related mitochondrial factors are impaired, resulting in deficiency in energy production. Massive generation of reactive oxygen species and calcium overload are common causes of mitochondrial diseases. The mitochondrial depletion syndrome (MDS) is associated with the mutations of mitochondrial genes in the nucleus. It is a heterogeneous group of progressive disorders characterized by the low mtDNA copy number. TK2, FBXL4, TYPM, and AGK are genes known to be related to MDS. More recent studies identified new mutation loci associated with this disease. Herein, we first summarize the structure and function of mitochondria, and then discuss the characteristics of various types of MDS and its association with cardiac diseases.

20.
BMC Cardiovasc Disord ; 19(1): 278, 2019 12 02.
Artigo em Inglês | MEDLINE | ID: mdl-31791258

RESUMO

BACKGROUND: Diabetes mellitus (DM) has been demonstrated to be a strong risk factor for development and perpetuation of atrial fibrillation (AF). However, how DM and glycemic control affect the pathogenesis of AF has not been sufficiently investigated, especially for the atrial structural remodeling. METHODS: A total of 86 patients undergoing coronary artery bypass graft surgery were enrolled in this study, with atrium sample collected in the operation. The patients were divided into the DM group (n = 40) and the control group (n = 46) accordingly. Demographics, clinical data were collected and compared. Echocardiography, Masson staining and Western blotting were conducted to evaluate atrial structural remodeling. RESULTS: There was no significant difference between the two groups in baseline characteristics (all P > 0.05). Fast blood glucose and HbA1c of DM group were significantly higher than the control group (P < 0.001). Echocardiography results demonstrated that the left atrium diameter (LAD) and left atrium volume index (LAVI) of DM group was significantly higher than the control group (P < 0.001). Masson staining showed that the collagen volume fraction (CVF), a quantitative indicator of fibrosis, was significantly higher in DM patients (P = 0.03). Western blot results indicated that the Collagen I of DM group was more expressed in the DM group than the control group (P < 0.001). Univariate linear regression revealed that the HbA1c level was significantly associated with both LAD (Y = 1.139X + 25.575, P < 0.001, R2 = 0.291) and CVF (Y = 0.444X + 29.648, P = 0.009, R2 = 0.078). CONCLUSIONS: DM was associated with atrial structural remodeling, including atrium enlargement and atrial fibrosis, which might be attributed to poor glycemic control.


Assuntos
Fibrilação Atrial/fisiopatologia , Função do Átrio Esquerdo , Remodelamento Atrial , Glicemia/metabolismo , Diabetes Mellitus Tipo 2/sangue , Idoso , Fibrilação Atrial/diagnóstico por imagem , Fibrilação Atrial/etiologia , Biomarcadores/sangue , Estudos de Casos e Controles , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/diagnóstico , Feminino , Fibrose , Hemoglobinas Glicadas/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Fatores de Risco
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