Activation of cardiac fibroblasts by ethanol is blocked by TGF-β inhibition

Blockade of thromboxane A2 signaling attenuates ethanol-induced myocardial inflammatory response in mice

BACKGROUND

Alcohol-associated cardiomyopathy (ACM) is a cardiac muscle disease characterized by inflammation and oxidative stress. Thromboxane-prostanoid receptor (TP-R) plays an important role in the pathogenesis of cardiovascular disease. Herein, we hypothesize that TP-R mediates alcohol-induced early cardiac injury.

METHODS

Eight-week-old male C57BL/6 wild-type mice were fed a chronic ethanol (ET) or control diet (CON) for 10 days followed by a single binge of ethanol or maltose-dextrin through oral gavage. A cohort of ethanol-fed mice received SQ 29,548 (SQ), a TP-R antagonist. RNA sequencing, real-time PCR, and western blot analysis were performed on left ventricle to investigate alterations in genes and/or proteins mediating oxidative stress, inflammation, and cardiac remodeling. Sirius Red staining was performed to measure myocardial fibrosis.

RESULTS

RNA-sequencing analysis of myocardium from CON and ET groups identified 142 genes that were significantly altered between the two groups. In particular, the gene expression of thioredoxin-interacting protein (TXNIP), a component of NLR family pyrin domain containing 3 (NLRP3) signaling, which mediates oxidative stress and inflammatory response, was upregulated in response to ethanol exposure. The myocardial protein levels of TP-R and thromboxane A2 synthase were increased upon alcohol exposure. Ethanol increased the levels of 4-hydroxynonenal, a marker of oxidative stress, with a concomitant increase in the protein levels of TXNIP and NLRP3, and administration of SQ attenuated these effects. Additionally, ethanol increased the protein levels of pro-inflammatory mediators, including tumor necrosis factor alpha and the NLRP3 downstream product, secretory interleukin 1 beta, and SQ blunted these effects. Finally, the Sirius red staining of the myocardium revealed an increase in collagen deposition in ethanol-fed mice which was attenuated by TP-R antagonism.

CONCLUSION

This study demonstrates that ethanol promotes the NLRP3 signaling pathway within the myocardium, leading to a pro-inflammatory milieu that potentially initiates early myocardial remodeling, and TP-R antagonism attenuates this effect.

Generation of a human iPSC-derived cardiomyocyte/fibroblast engineered heart tissue model

Animal models have proven integral to broadening our understanding of complex cardiac diseases but have been hampered by significant species-dependent differences in cellular physiology. Human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) have shown great promise in the modelling of cardiac diseases despite limitations in functional and structural maturity. 3D stem cell-derived cardiac models represent a step towards mimicking the intricate microenvironment present in the heart as an in vitro model. Incorporation of non-myocyte cell types, such as cardiac fibroblasts, into engineered heart tissue models (EHTs) can help better recapitulate the cell-to-cell and cell-to-matrix interactions present in the human myocardium. Integration of human-induced pluripotent stem cell-derived cardiac fibroblasts (hiPSC-CFs) and hiPSC-CM into EHT models enables the generation of a genetically homogeneous modelling system capable of exploring the abstruse structural and electrophysiological interplay present in cardiac pathophysiology. Furthermore, the construction of more physiologically relevant 3D cardiac models offers great potential in the replacement of animals in heart disease research. Here we describe efficient and reproducible protocols for the differentiation of hiPSC-CMs and hiPSC-CFs and their subsequent assimilation into EHTs. The resultant EHT consists of longitudinally arranged iPSC-CMs, incorporated alongside hiPSC-CFs. EHTs with both hiPSC-CMs and hiPSC-CFs exhibit slower beating frequencies and enhanced contractile force compared to those composed of hiPSC-CMs alone. The modified protocol may help better characterise the interplay between different cell types in the myocardium and their contribution to structural remodelling and cardiac fibrosis.

Abstinence Restores Cardiac Function in Mice with Established Alcohol-Induced Cardiomyopathy

Alcohol-induced cardiomyopathy (ACM) has a poor prognosis with up to a 50% chance of death within four years of diagnosis. There are limited studies investigating the potential of abstinence for promoting repair after alcohol-induced cardiac damage, particularly in a controlled preclinical study design. Here, we developed an exposure protocol that led to significant decreases in cardiac function in C57BL6/J mice within 30 days; dP/dt max decreased in the mice fed alcohol for 30 days (8054 ± 664.5 mmHg/s compared to control mice: 11,188 ± 724.2 mmHg/s, p < 0.01), and the dP/dt min decreased, as well (-7711 ± 561 mmHg/s compared to control mice: -10,147 ± 448.2 mmHg/s, p < 0.01). Quantitative PCR was used to investigate inflammatory and fibrotic biomarkers, while histology was used to depict overt changes in cardiac fibrosis. We observed a complete recovery of function after abstinence (dP/dt max increased from 8054 ± 664 mmHg/s at 30 days to 11,967 ± 449 mmHg/s after abstinence, p < 0.01); further, both inflammatory and fibrotic biomarkers decreased after abstinence. These results lay the groundwork for future investigation of the molecular mechanisms underlying recovery from alcohol-induced damage in the heart.

Maternal Ethanol Exposure-Induced Cardiac Fibrosis is Associated with Changes in TGF-β and SIRT1/FOXO3a Signaling in Male Rat Offspring: A Three-Month Follow-up Study

Ethanol exposure during pregnancy induces cardiac fibrosis in the fetal heart. However, the mechanisms by which consumption of ethanol induces fibrotic changes are not known. Pregnant rats were received ethanol 4.5 g/kg BW once per day from the 7th day of pregnancy (GD7) throughout lactation. Our findings demonstrated that, area of fibrosis increased in cardiac tissue in the pups on both postnatal day twenty one (PN21) and postnatal day ninety (PN90) after prenatal and early postnatal period ethanol treatment compared with the controls. It was accompanied by a decline in the expression of SIRT1 protein along with the elevation of FOXO3a and TGF-β protein expressions which were determined by western blot. Overall, our data reveal that prenatal alcohol usage increase in fibrotic regions in the pup hearts possibly by regulating TGF-β, FOXO3a and SIRT1 protein levels. These are potential therapeutic molecular targets that can be modulated to protect heart against maternal ethanol exposure.

Myocardial tissue and metabolism characterization in men with alcohol consumption by cardiovascular magnetic resonance and 11C-acetate PET/CT

BACKGROUND

Chronic alcohol consumption initially leads to asymptomatic left ventricular dysfunction, but can result in myocardial impairment and heart failure if ongoing. This study sought to characterize myocardial tissues and oxidative metabolism in asymptomatic subjects with chronic alcohol consumption by quantitative cardiovascular magnetic resonance (CMR) and 11C-acetate positron emission tomography (PET)/computed tomography (CT).

METHODS

Thirty-four male subjects (48.8 ± 9.1 years) with alcohol consumption > 28 g/day for > 10 years and 35 age-matched healthy male subjects (49.5 ± 9.7 years) underwent CMR and 11C-acetate PET/CT. Native and post T1 values and extracellular volume (ECV) from CMR and Kmono and K1 from PET imaging were measured. Quantitative measurements by CMR and PET imaging were compared between subjects with moderate to heavy alcohol consumption and healthy controls, and their correlations were also analyzed.

RESULTS

Compared to healthy controls, subjects with alcohol consumption showed significantly shorter native T1 (1133 ± 65 ms vs. 1186 ± 31 ms, p < 0.001) and post T1 (477 ± 42 ms vs. 501 ± 38 ms, p = 0.008) values, greater ECV (28.2 ± 2.2% vs. 26.9 ± 1.3%, p = 0.003), marginally lower Kmono (57.6 ± 12.1 min- 1 × 10- 3 vs. 63.0 ± 11.7 min- 1 × 10- 3, p = 0.055), and similar K1 (0.82 ± 0.13 min- 1 vs. 0.83 ± 0.15 min- 1, p = 0.548) after adjusting for confounding factors. There were no significant differences in CMR measurements and K1 between subjects with heavy and moderate alcohol consumption (all p > 0.05). In contrast, subjects with heavy alcohol consumption showed significantly lower Kmono values compared to those with moderate alcohol consumption (52.9 ± 12.1 min- 1 × 10- 3 vs. 63.7 ± 9.2 min- 1 × 10- 3, p = 0.012). Strong and moderate correlations were found between K1 and ECV in healthy controls (r = 0.689, p = 0.013) and subjects with moderate alcohol consumption (r = 0.518, p = 0.048), respectively.

CONCLUSION

Asymptomatic men with heavy alcohol consumption have detectable structural and metabolic changes in myocardium on CMR and 11C-acetate PET/CT. Compared with quantitative CMR, 11C-acetate PET/CT imaging may be more sensitive for detecting differences in myocardial damage among subjects with moderate to heavy alcohol consumption.

(Pro)renin Receptor is Involved in Myocardial Damage in Alcoholic Cardiomyopathy

BACKGROUND

(Pro)renin receptor (PRR), a novel member of the renin-angiotensin system, participates in various cardiovascular diseases. However, the role of PRR in alcoholic cardiomyopathy (ACM), which is caused by alcohol intake and manifests as myocardial damage and cardiac dysfunction, remains unclear.

METHODS

PRR gene silencing was achieved by transfecting recombinant adenovirus expressing anti-PRR short hairpin RNA (PRR-shRNA). In vitro, primary rat cardiac fibroblasts (CFs) were cultured with the stimulation of alcohol (200 mM), with or without PRR-shRNA and PD98059. Immunofluorescence, RT-PCR, and Western blot were used to measure the protein and messenger (mRNA) expression of PRR, fibrotic factors, and members of related signaling pathways. In vivo, Wistar rats were fed a diet containing 9% (v/v) alcohol or a normal diet for 3 months, with or without PRR-shRNA. Sirius Red staining, immunohistochemical staining, and toluidine blue staining were used to evaluate myocardial fibrosis, oxidative stress, and inflammation response.

RESULTS

Alcohol markedly increased PRR mRNA and protein expression in a time- and concentration-dependent manner in CFs. The increased expression of fibrotic factors induced by alcohol was prevented by PRR-shRNA and PD98059. Moreover, PRR-shRNA decreased the phosphorylation of extracellular regulated protein kinases (ERK) 1/2 in CFs. Furthermore, PRR-shRNA decreased cardiac fibrosis, reduced oxidative stress, and alleviated inflammation response in the myocardial tissue.

CONCLUSIONS

Our results show that PRR-ERK1/2 signaling was involved in the development of ACM and that PRR could be a new target for the treatment of ACM.

Prenatal Alcohol Exposure Causes Adverse Cardiac Extracellular Matrix Changes and Dysfunction in Neonatal Mice

Fetal alcohol syndrome (FAS) is the most severe condition of fetal alcohol spectrum disorders (FASD) and is associated with congenital heart defects. However, more subtle defects such as ventricular wall thinning and cardiac compliance may be overlooked in FASD. Our studies focus on the role of cardiac fibroblasts in the neonatal heart, and how they are affected by prenatal alcohol exposure (PAE). We hypothesize that PAE affects fibroblast function contributing to dysregulated collagen synthesis, which leads to cardiac dysfunction. To investigate these effects, pregnant C57/BL6 mice were intraperitoneally injected with 2.9 g EtOH/kg dose to achieve a blood alcohol content of approximately 0.35 on gestation days 6.75 and 7.25. Pups were sacrificed on neonatal day 5 following echocardiography measurements of left ventricular (LV) chamber dimension and function. Hearts were used for primary cardiac fibroblast isolation or protein expression analysis. PAE animals had thinner ventricular walls than saline exposed animals, which was associated with increased LV wall stress and decreased ejection fraction. In isolated fibroblasts, PAE decreased collagen I/III ratio and increased gene expression of profibrotic markers, including α-smooth muscle actin and lysyl oxidase. Notch1 signaling was assessed as a possible mechanism for fibroblast activation, and indicated that gene expression of Notch1 receptor and downstream Hey1 transcription factor were increased. Cardiac tissue analysis revealed decreased collagen I/III ratio and increased protein expression of α-smooth muscle actin and lysyl oxidase. However, Notch1 signaling components decreased in whole heart tissue. Our study demonstrates that PAE caused adverse changes in the cardiac collagen profile and a decline in cardiac function in the neonatal heart.

Effects of the (Pro)renin Receptor on Cardiac Remodeling and Function in a Rat Alcoholic Cardiomyopathy Model via the PRR-ERK1/2-NOX4 Pathway

Alcoholic cardiomyopathy (ACM) caused by alcohol consumption manifests mainly as by maladaptive myocardial function, which eventually leads to heart failure and causes serious public health problems. The (pro)renin receptor (PRR) is an important member of the local tissue renin-angiotensin system and plays a vital role in many cardiovascular diseases. However, the mechanism responsible for the effects of PRR on ACM remains unclear. The purpose of this study was to determine the role of PRR in myocardial fibrosis and the deterioration of cardiac function in alcoholic cardiomyopathy. Wistar rats were fed a liquid diet containing 9% v/v alcohol to establish an alcoholic cardiomyopathy model. Eight weeks later, rats were injected with 1 × 10⁹v.g./100 μl of recombinant adenovirus containing EGFP (scramble-shRNA), PRR, and PRR-shRNA via the tail vein. Cardiac function was assessed by echocardiography. Cardiac histopathology was measured by Masson's trichrome staining, immunohistochemical staining, and dihydroethidium staining. In addition, cardiac fibroblasts (CFs) were cultured to evaluate the effects of alcohol stimulation on the production of the extracellular matrix and their underlying mechanisms. Our results indicated that overexpression of PRR in rats with alcoholic cardiomyopathy exacerbates myocardial oxidative stress and myocardial fibrosis. Silencing of PRR expression with short hairpin RNA (shRNA) technology reversed the myocardial damage mediated by PRR. Additionally, PRR activated phosphorylation of ERK1/2 and increased NOX4-derived reactive oxygen species and collagen expression in CFs with alcohol stimulation. Administration of the ERK kinase inhibitor (PD98059) significantly reduced NOX4 protein expression and collagen production, which indicated that PRR increases collagen production primarily through the PRR-ERK1/2-NOX4 pathway in CFs. In conclusion, our study demonstrated that PRR induces myocardial fibrosis and deteriorates cardiac function through ROS from the PRR-ERK1/2-NOX4 pathway during ACM development.

Pharmacological Inhibition of Soluble Epoxide Hydrolase Ameliorates Chronic Ethanol-Induced Cardiac Fibrosis by Restoring Autophagic Flux

BACKGROUND

Chronic drinking leads to myocardial contractile dysfunction and dilated cardiomyopathy, and cardiac fibrosis is a consequence of these alcoholic injuries. Soluble epoxide hydrolase (sEH) hydrolyzes epoxyeicosatrienoic acids (EETs) to less bioactive diols, and EETs have cardioprotective properties. However, the effects of sEH inhibition in ethanol (EtOH)-induced cardiac fibrosis are unknown.

METHODS

This study was designed to investigate the role and underlying mechanisms of sEH inhibition in chronic EtOH feeding-induced cardiac fibrosis. C57BL/6J mice were fed a 4% Lieber-DeCarli EtOH diet for 8 weeks, and the sEH inhibitor 1-trifluoromethoxyphenyl-3-(1-propionylpiperidin-4-yl) urea (TPPU) was administered throughout the experimental period.

RESULTS

The results showed that chronic EtOH intake led to cardiac dilatation, collagen deposition, and autophagosome accumulation, while TPPU administration ameliorated these effects. In vitro, treating primary cardiac fibroblasts (CFs) with EtOH resulted in CF activation, including alpha smooth muscle actin overexpression, collagen synthesis, and cell migration. Moreover, EtOH disturbed CF autophagic flux, as evidenced by the increased LC3 II/I ratio and SQSTM1 expression, and by the enhanced autophagosome accumulation. TPPU treatment prevented the activation of CF induced by EtOH and restored the impaired autophagic flux by suppressing mTOR activation.

CONCLUSIONS

Taken together, these findings suggest that sEH pharmacological inhibition may be a unique therapeutic strategy for treating EtOH-induced cardiac fibrosis.

Impact of Alcohol Consumption on Atrial Fibrillation Outcomes Following Pulmonary Vein Isolation

Background

Moderate to heavy alcohol use has been shown to be associated with increased atrial fibrillation (AF) incidence. However, the relationship between alcohol use and AF recurrence after pulmonary vein isolation (PVI) is not well known.

Objective

We sought to study the impact of different alcohol consumption levels on outcomes after AF ablation.

Methods

A retrospective analysis was performed of 226 consecutive patients undergoing first time PVI for AF. Clinical data were collected including alcohol intake classified into 3 groups: none-rare (< 1 drink/ week), moderate (1-7 drinks/ week), and heavy (> 7 drinks/ week). Patients were followed for recurrences within the first 3 months (blanking period; early recurrence) and after 3 months up to 1 year (late recurrence) after the ablation.

Results

Paroxysmal and persistent AF had early recurrence rates of 29.1% and 32.2%, and late recurrence rates of 30.2% and 44.1%, respectively. The none-rare alcohol group had a higher frequency of diabetes mellitus (p=0.007). Neither moderate or heavy alcohol consumption, in reference to the none-rare group, was significantly predictive of early or late AF recurrence on adjusted multivariate logistic regression analysis (p>0.05).

Conclusion

Despite known associations between alcohol and incidence of AF, alcohol consumption is not associated with early or late AF recurrence after PVI in this cohort.

Serelaxin inhibits differentiation and fibrotic behaviors of cardiac fibroblasts by suppressing ALK-5/Smad2/3 signaling pathway

Serelaxin, a recombinant form of human relaxin-2, is currently regarded as a novel drug for treatment of acute heart failure. However, whether therapeutic effects of serelaxin are achieved by inhibiting cardiac fibrosis remains unclear. In this study, we investigate effects of serelaxin on inhibiting cardiac fibrosis. Cardiac fibroblasts (CFs) were isolated from the hearts of adult rats. Effects of serelaxin on differentiation of CFs towards myofibroblasts (MFs) and their fibrotic behaviors after induction with TGF-β1 were examined. Synthesis and degradation of collagens, secretion of IL-10, and expression of ALK-5 and p-Smad2/3 of TGF-β1-induced cells were assessed after treatment with serelaxin. Serelaxin inhibited differentiation of TGF-β1-induced CFs towards MFs, and reduced proliferation and migration of the induced cells. Moreover, serelaxin down-regulated expression of collagen I/III and TIMP-2, and up-regulated expression of MMP-2 and MMP-9 in the cells. After treatment with serelaxin, activity of MMP-2 and MMP-9 and secretion of IL-10 increased, expression of ALK-5 and the level of Smad2/3 phosphorylation was reduced significantly. These results suggest that serelaxin can inhibit differentiation of TGF-β1-induced CFs towards MFs, reduce production of collagens by suppressing ALK-5/Smad2/3 signaling pathway, and enhance extracellular matrix degradation by increasing MMP-2/TIMP-2 ratio and IL-10 secretion. Serelaxin may be a potential therapeutic drug for inhibiting cardiac fibrosis.

Etiology of alcoholic cardiomyopathy: Mitochondria, oxidative stress and apoptosis

Putative mechanisms leading to the development of alcoholic cardiomyopathy (ACM) include the interrelated cellular processes of mitochondria metabolism, oxidative stress and apoptosis. As mitochondria fuel the constant energy demands of this continually contracting tissue, it is not surprising that alcohol-induced molecular changes in this organelle contribute to cardiac dysfunction and ACM. As the causal relationship of these processes with ACM has already been established, the primary objective of this review is to provide an update of the experimental findings to more completely understand the aforementioned mechanisms. Accordingly, recent data indicate that alcohol impairs mitochondria function assessed by membrane potential and respiratory chain activity. Indictors of oxidative stress including superoxide dismutase, glutathione metabolites and malondialdehyde are also adversely affected by alcohol oftentimes in a sex-dependent manner. Additionally, myocardial apoptosis is increased based on assessment of TUNEL staining and caspase activity. Recent work has also emerged linking alcohol-induced oxidative stress with apoptosis providing new insight on the codependence of these interrelated mechanisms in ACM. Attention is also given to methodological differences including the dose of alcohol, experimental model system and the use of males versus females to highlight inconsistencies and areas that would benefit from establishment of a consistent model.

Ginger extract protects rat's kidneys against oxidative damage after chronic ethanol administration

Chronic alcohol ingestion is associated with pronounced detrimental effects on the renal system. In the current study, the protective effect of ginger extract on ethanol-induced damage was evaluated through determining 8-OHdG, cystatin C, glomerular filtration rate, and pathological changes such as cell proliferation and fibrosis in rats' kidneys. Male wistar rats were randomly divided into three groups and were treated as follows: (1) control, (2) ethanol and (3) ginger extract treated ethanolic (GETE) groups. After a six weeks period of treatment, the results revealed proliferation of glomerular and tubular cells, fibrosis in glomerular and peritubular and a significant rise in the level of 8-OHdG, cystatin C, plasma urea and creatinine. Moreover, compared to the control group, the ethanol group showed a significant decrease in the urine creatinine and creatinine clearance. In addition, significant amelioration of changes in the structure of kidneys, along with restoration of the biochemical alterations were found in the ginger extract treated ethanolic group, compared to the ethanol group. These findings indicate that ethanol induces kidneys abnormality by oxidative DNA damage and oxidative stress, and that these effects can be alleviated using ginger as an antioxidant and anti-inflammatory agent.

Adamts1 mediates ethanol-induced alterations in collagen and elastin via a FoxO1-sestrin3-AMPK signaling cascade in myocytes

A variety of stressors including alcohol (EtOH) are known to induce collagen production and fibrotic diseases. Matrix metalloproteinases (MMP) play an important role in regulating fibrosis, but little is known regarding the relationship between EtOH and MMPs. In addition, the signaling cascades involved in this process have not been elucidated. We have identified the MMP Adamts1 as a target of EtOH regulation. To characterize the function of Adamts1, we examined EtOH-induced alterations in collagen I and elastin protein levels in C2C12 myocytes. Incubation of myocytes with 100 mM EtOH decreased elastin and increased collagen content, respectively, and these changes were associated with increased O-GLcNAc modification of Adamts1. Conversely, silencing of Adamts1 by siRNA blocked the adverse effects of EtOH on collagen and elastin levels. Similar results were obtained after treatment with a pharmacological inhibitor of MMP. Changes in collagen were due, at least in part, to a decreased interaction of Adamts1 with its endogenous inhibitor TIMP3. The AMPK inhibitor compound C blocked the EtOH-induced stimulation of collagen and O-GLcNAc Adamts1 protein. Changes in AMPK appear linked to FoxO1, since inhibition of FoxO1 blocked the effects of EtOH on AMPK phosphorylation and O-GLcNAc levels. These FoxO-dependent modifications were associated with an upregulation of the FoxO1 transcription target sestrin 3, as well as increased binding of sestrin 3 with AMPK. Collectively, these data indicate that EtOH regulates the collagen I and elastin content in an Adamts1-dependent manner in myocytes. Furthermore, Adamts1 appears to be controlled by the FoxO1-sestrin 3-AMPK signaling cascade.

Alcohol effects on cardiac function

The consumption of ethanol can have both beneficial and detrimental effects on the function of the heart and cardiovascular system, depending on the amount consumed. Low-to-moderate amounts of ethanol intake are associated with improvements in cardiac function and vascular health. On the other hand, ethanol chronically consumed in large amounts acts as a toxin to the heart and vasculature. The cardiac injury produced by chronic alcohol abuse can progress to heart failure and eventual death. Furthermore, alcohol abuse may exacerbate preexisting heart conditions, such as hypertension and cardiomyopathy. This article focuses on the molecular mechanisms and pathophysiology of both the beneficial and detrimental cardiac effects of alcohol.

Liver cell injury caused by bad habits

Apoptosis and necrosis of liver cells induced by environmental or genetic factors are the main features of liver injury. Liver injury is usually caused by apoptosis of liver cells, which is controlled by a complex regulatory system involved in liver damage and secondary inflammation. This article aims to review liver injury caused by bad habits and the underlying molecular mechanisms.

Berberine regulates proliferation, collagen synthesis and cytokine secretion of cardiac fibroblasts via AMPK-mTOR-p70S6K signaling pathway

OBJECTIVE

The traditional Chinese medicinal berberine has long been used to treat cardiovascular diseases; however, the mechanism underlying its effects remains unclear. Here, this study would to investigate the effects of berberine on proliferation, collagen synthesis and cytokine secretion of cardiac fibroblasts.

METHODS

We assessed proliferation, collagen synthesis and cytokine secretion in cardiac fibroblasts subjected to angiotensin II (Ang II) subsequent to the consumption of berberine or a control treatment. And then we detected the role of AMPK/mTOR signaling pathway in berberine treatment of cardiac fibroblasts.

RESULTS

In the present study, the cellular behaviors of cardiac fibroblasts induced by Ang II were significantly activated including proliferation, transformation into myofibroblasts and collagen synthesis. Additionally, the ability of cytokine secretion was enhanced obviously. It was demonstrated that treatment of cardiac fibroblasts with berberine resulted in deceased proliferation, and attenuated fibroblast α-smooth muscle actin expression and collagen synthesis. And the protein secretion of TGFβ1 was inhibited; however, the protein secretion of IL-10 was increased in cardiac fibroblasts with berberine treatment. Mechanistically, the phosphorylation level of AMPK was increased; and the phosphorylation levels of mTOR and p70S6K were decreased in berberine treatment group.

CONCLUSION

These results illustrated that the protective effects of berberine on cellular behaviors of cardiac fibroblasts were at least in part due to activate AMPK signaling pathway and downregulate mTOR/p70S6K signaling pathway. Berberine might become a new strategy for treating cardiac fibrosis in the future.

Alcohol Differentially Alters Extracellular Matrix and Adhesion Molecule Expression in Skeletal Muscle and Heart

BACKGROUND

The production of fibrosis in response to chronic alcohol abuse is well recognized in liver but has not been fully characterized in striated muscle and may contribute to functional impairment. Therefore, the purpose of this study was to use an unbiased discovery-based approach to determine the effect of chronic alcohol consumption on the expression profile of genes important for cell-cell and cell-extracellular matrix (ECM) interactions in both skeletal and cardiac muscle.

METHODS

Adult male rats were pair-fed an alcohol-containing liquid diet or control diet for 24 weeks, and skeletal muscle (gastrocnemius) and heart were collected in the freely fed state. A pathway-focused gene expression polymerase chain reaction array was performed on these tissues to assess mRNA content for 84 ECM proteins, and selected proteins were confirmed by Western blot analysis.

RESULTS

In gastrocnemius, alcohol feeding up-regulated the expression of 11 genes and down-regulated the expression of 1 gene. Alcohol increased fibrosis as indicated by increased mRNA and/or protein for collagens α1(I), α2(I), α1(III), and α2(IV) as well as hydroxyproline. Alcohol also increased α-smooth muscle actin protein, an index of myofibroblast activation, but no concomitant change in transforming growth factor-β was detected. The mRNA and protein content for other ECM components, such as integrin-α5, L-selectin, PECAM, SPARC, and ADAMTS2, were also increased by alcohol. Only laminin-α3 mRNA was decreased in gastrocnemius from alcohol-fed rats, while 66 ECM- or cell adhesion-related mRNAs were unchanged by alcohol. For heart, expression of 16 genes was up-regulated, expression of 3 genes was down-regulated, and 65 mRNAs were unchanged by alcohol; there were no common alcohol-induced gene expression changes between heart and skeletal muscle. Finally, alcohol increased tumor necrosis factor-α and interleukin (IL)-12 mRNA in both skeletal and cardiac muscle, but IL-6 mRNA was increased and IL-10 mRNA decreased only in skeletal muscle.

CONCLUSIONS

These data demonstrate a fibrotic response in striated muscle from chronic alcohol-fed rats which is tissue specific in nature, suggesting different regulatory mechanisms.

Molecular mechanisms of ethanol-associated oro-esophageal squamous cell carcinoma

Alcohol drinking is a major etiological factor of oro-esophageal squamous cell carcinoma (OESCC). Both local and systemic effects of ethanol may promote carcinogenesis, especially among chronic alcoholics. However, molecular mechanisms of ethanol-associated OESCC are still not well understood. In this review, we summarize current understandings and propose three mechanisms of ethanol-associated OESCC: (1) Disturbance of systemic metabolism of nutrients: during ethanol metabolism in the liver, systemic metabolism of retinoids, zinc, iron and methyl groups is altered. These nutrients are known to be associated with the development of OESCC. (2) Disturbance of redox metabolism in squamous epithelial cells: when ethanol is metabolized in oro-esophageal squamous epithelial cells, reactive oxygen species are generated and produce oxidative damage. Meanwhile, ethanol may also disturb fatty-acid metabolism in these cells. (3) Disturbance of signaling pathways in squamous epithelial cells: due to its physico-chemical properties, ethanol changes cell membrane fluidity and shape, and may thus impact multiple signaling pathways. Advanced molecular techniques in genomics, epigenomics, metabolomics and microbiomics will help us elucidate how ethanol promotes OESCC.

Alcohol modulation of cardiac matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs favors collagen accumulation

BACKGROUND

Chronic alcohol consumption has been shown in human and animal studies to result in collagen accumulation, myocardial fibrosis, and heart failure. Cardiac fibroblasts produce collagen and regulate extracellular matrix (ECM) homeostasis through the synthesis and activity of matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs), with the balance of MMPs/TIMPs determining the rate of collagen turnover. Dynamic changes of MMP and TIMP expression were reported in alcohol-induced hepatic fibrosis; however, the effect of alcohol on MMP/TIMP balance in the heart and cardiac fibroblasts is unknown. We hypothesized that alcohol exposure alters cardiac fibroblast MMP and TIMP expression to promote collagen accumulation in the heart.

METHODS

Cardiac fibroblasts isolated from adult rats were cultured in the presence of alcohol (12.5 to 200 mM) for 48 hours. MMP, TIMP, and collagen type I and III expression were assayed by Western blot analysis. Hydroxyproline (HPro) was used as a marker of collagen production. The in vivo cardiac effects of ethanol (EtOH) were determined using rats exposed to EtOH vapor for 2 weeks, resulting in blood alcohol levels of 150 to 200 mg/dl. Cardiac collagen volume fraction (CVF), as well as MMP, TIMP, and collagen expression, was assessed.

RESULTS

EtOH-exposed rats exhibited up-regulation of TIMP-1, TIMP-3 and TIMP-4 in the heart, with no significant increases in MMPs. Cardiac fibroblasts exhibited transformation to a profibrotic phenotype following exposure to alcohol. These changes were reflected by increased α-smooth muscle actin and collagen I and III expression, as well as increased collagen secretion. In vivo EtOH exposure also produced fibrosis, indicated by increased CVF and expression of collagens.

CONCLUSIONS

Alcohol exposure modulates cardiac fibroblast MMP/TIMP expression favoring a profile associated with collagen accumulation. Our data suggest that this disrupted MMP/TIMP profile may contribute to the development of myocardial fibrosis and cardiac dysfunction resulting from chronic alcohol abuse.