Suppression of TGF-β1/Smad signaling pathway by sesamin contributes to the attenuation of myocardial fibrosis in spontaneously hypertensive rats

The evaluation of the SMAD1 rs1016792 polymorphism and gene expression on pulmonary hypertension due to congenital heart disease in children: a preliminary study

Smad Family Member (SMAD), a protein family responsible for transducing the signal induced by TGF-β into the nucleus, is thought to play a role in the pathology of many heart diseases. Therefore, we aimed to evaluate the influence of the SMAD1 rs1016792 polymorphism and gene expression on pulmonary arterial hypertension (PAH) due to congenital heart disease (CHD) in children. A total of 90 children, 45 of whom were PAH-CHD children and 45 healthy children, were included in the study. Patients were selected from those who were diagnosed and followed in the Department of Pediatric Cardiology.The SMAD1 rs1016792 genotyping and expression analysis was performed using a real-time polymerase chain reaction (RT-PCR)-based system. It was determined that the left ventricular end-diastolic diameter (LVEDD) value was lower in the patient group than in the control group, while the pulmonary artery pressure (PAP) value was higher in the patient group than in the control group. When the SMAD1 gene expression level was examined, a statistically significant difference was found between the patient and control groups. Patients had decreased SMAD1 expression compared to controls (p˂0.001). We found no significant difference between the patient and control groups in terms of SMAD1 rs1016792 genotype distribution or allele frequency (p > 0.05). There was no difference between genotype distribution and SMAD1 expression levels in the groups. In this study, we showed for the first time that SMAD1 expression is decreased in children with PAH-CHD. These results will be a preliminary step toward understanding the role of SMAD1 in the etiopathogenesis of CHD.

Effects of sesame (Sesamum indicum L.) and bioactive compounds (sesamin and sesamolin) on inflammation and atherosclerosis: A review

Inflammation, oxidative stress, obesity, infection, hyperlipidemia, hypertension, and diabetes are the main causes of atherosclerosis, which in the long term lead to hardening of the arteries. In the current study, we reviewed recent findings of the mechanism of sesame and its active compounds of sesamin and sesamolin regulates on atherosclerosis. Sesame can decrease the lipid peroxidation and affect the enzymes, which control the balance of oxidative status in the body. Besides modulating the inflammatory cytokines, sesame regulates the main mediators of the signaling pathways in the process of inflammation, such as prostaglandin E2 (PGE2), nuclear factor kappa light-chain enhancer of activated B cells (NF-kB) and peroxisome proliferator-activated receptor gamma (PPAR-γ). Sesame decreases the growth of different pathogens. It fights against obesity and helps to reduce weight, body mass index (BMI), waist circumference, and lipid count of serum and liver. In addition to lowering fasting blood sugar (FBS), it decreases the hemoglobin A1c (HbA1c) and glucose levels and improves insulin function. With high content of linoleic acid, α-linolenic acid, and total polyunsaturated fatty acid (PUFA), sesame efficiently controls the blood plasma lipids and changes the lipid profile. In the case of hypertension, it maintains the health of endothelium through multiple mechanisms and conserves the response of the arteries to vasodilation. PUFA in sesame suppresses blood clotting and fibrinogen activity. All the mentioned properties combat atherosclerosis and hardening of blood vessels, which are detailed in the present review for sesame.

Lactacystin-induced kidney fibrosis: Protection by melatonin and captopril

Lactacystin is a specific proteasome inhibitor that blocks the hydrolysis of intracellular proteins by ubiquitin/proteasome system inhibition. The administration of lactacystin to rats induced hypertension and remodeling of the left ventricle and aorta. This study tested whether lactacystin induces structural and fibrotic rebuilding of the kidneys and whether melatonin and captopril can prevent these potential changes. Six weeks of lactacystin administration to rats increased their average systolic blood pressure (SBP). In the kidneys, lactacystin reduced glomerular density, increased the glomerular tuft area, and enhanced hydroxyproline concentrations. It also elevated the intraglomerular proportion including the amounts of collagen (Col) I and Col III. Lactacystin also raised the tubulointerstitial amounts of Col I and the sum of Col I and Col III with no effect on vascular/perivascular collagen. Six weeks of captopril treatment reduced SBP, while melatonin had no effect. Both melatonin and captopril increased glomerular density, reduced the glomerular tuft area, and lowered the hydroxyproline concentration in the kidneys. Both drugs reduced the proportion and total amounts of intraglomerular and tubulointerstitial Col I and Col III. We conclude that chronic lactacystin treatment stimulated structural and fibrotic remodeling of the kidneys, and melatonin and captopril partly prevented these alterations. Considering the effect of lactacystin on both the heart and kidneys, chronic treatment with this drug may be a prospective model of cardiorenal damage suitable for testing pharmacological drugs as protective agents.

Mesenchymal stem cells derived from the kidney can ameliorate diabetic nephropathy through the TGF-β/Smad signaling pathway

Diabetic nephropathy (DN) has been introduced as one of the main microvascular complications in diabetic patients, the most common cause of end-stage renal disease (ESRD). Based on the therapeutic potential of mesenchymal stem cells in tissue repair, we aimed to test the hypothesis that kidney stem cells (KSCs) might be effective in the kidney regeneration process. Stem cells from rat kidney were separated, and the surface stem cell markers were determined by flow cytometry analysis. Thirty-two Sprague Dawley rats were divided into four groups (control, control that received kidney stem cells, diabetic, diabetic treated with stem cells). To establish diabetic, model STZ (streptozotocin) (60 mg/kg) was used. The KSCs were injected into experimental groups via tail vein (2 × 10⁶ cells/rat). In order to determine the impact of stem cells on the function and structure of the kidney, biochemical and histological parameters were measured. Further, the expression of miRNA-29a, miR-192, IL-1β, and TGF-β was determined through the real-time PCR technique. Phosphorylation of Smad2/3 was evaluated by using the standard western blotting. The KSCs significantly reduced blood nitrogen (BUN), serum creatinine (Scr), and 24-h urinary proteins in DN (P < 0.05). IL-1β and TGF-β significantly increased in the kidney of diabetic rats. In addition, the expression of miR-29a is significantly increased, whereas miR-192 decreased after treatment with KSCs (P < 0.05). Diabetic rats showed an increased level of phosphorylation of both Smad2 and Smad3 (P < 0.05). Periodic acid-Schiff (PAS) staining showed improved histopathological changes in the presence of KSCs. Stem cells derived from adult rat kidney may be an option for treating the early DN to improve the functions and structure of kidneys in rats with DN.

Various aspects of inflammation in heart failure

Despite significant advances in the prevention and treatment of heart failure (HF), the prognosis in patients who have been hospitalised on at least one occasion due to exacerbation of HF is still poor. Therefore, a better understanding of the underlying pathophysiological mechanisms of HF is crucial in order to achieve better results in the treatment of this clinical syndrome. One of the areas that, for years, has aroused the interest of researchers is the activation of the immune system and the elevated levels of biomarkers of inflammation in patients with both ischaemic and non-ischaemic HF. Additionally, it is intriguing that the level of circulating pro-inflammatory biomarkers correlates with the severity of the disease and prognosis in this group of patients. Unfortunately, clinical trials aimed at assessing interventions to modulate the inflammatory response in HF have been disappointing, and the modulation of the inflammatory response has had either no effect or even a negative effect on the HF prognosis. The article presents a summary of current knowledge on the role of immune system activation and inflammation in the pathogenesis of HF. Understanding the immunological mechanisms pathogenetically associated with left ventricular remodelling and progression of HF may open up new therapeutic possibilities for HF.

Identification and Antihypertension Study of Novel Angiotensin I-Converting Enzyme Inhibitory Peptides from the Skirt of Chlamys farreri Fermented with Bacillus natto

The aim of this study was to isolate the angiotensin I-converting enzyme (ACE) inhibitory peptides from the skirt of Chlamys farreri fermented with Bacillus natto and to explore the antihypertension effect through in vivo studies. ACE inhibitory peptides were purified from the fermentation mixture by ultrafiltration, gel filtration chromatography, and reversed-phase high-performance liquid chromatography sequentially. The amino acids' sequence of the five novel ACE inhibitory peptides were identified by liquid chromatography-tandem mass spectrometry. Animal experiments demonstrated that the novel ACE inhibitory peptides significantly reduced the blood pressure in spontaneously hypertensive rats after a single or long-time treatment. Potential mechanisms were explored, and the results indicated that the novel peptides could regulate the renal renin-angiotensin system, improve vascular remodeling, inhibit myocardial fibrosis, and rebalance the gut microbial dysbiosis. Our results suggest that the fermentation products of the Chlamys farreri skirt by B. natto are potential sources of active peptides processing antihypertension activities.

LncRNA MHRT Promotes Cardiac Fibrosis via miR-3185 Pathway Following Myocardial Infarction

Long-chain noncoding RNA (lncRNA) is a new class of molecular regulators in heart development and disease. However, the role of specific lncRNA in cardiac fibrosis remains to be fully explored. This study aimed to investigate the role and potential mechanism of lncRNA MHRT in myocardial fibrosis after myocardial infarction (MI).Cardiac fibroblasts (CFs) were isolated from a mouse model of MI. The expression levels of MHRT and miR-3185 in the hearts of MI and CFs mice treated with transforming growth factor beta 1 (TGF-β1) were analyzed by qRT-PCR. The collagen expression was assessed using qRT-PCR and Western blot. Cell proliferation was assessed by performing MTT and EdU assays. The direct interaction between lncRNA and miRNA was analyzed by luciferase assay, RNA-binding protein immunoprecipitation (RIP) assay, and RNA pull-down assay.The expression levels of MHRT were raised in MI and CFs mice treated with TGF-β1. Overexpression of MHRT promoted collagen production and CF proliferation, while silencing of MHRT showed the opposite effect. MiR-3185 was a target gene of MHRT. In addition, overexpression of MHRT reduced the expression levels of miR-3185, and siMHRT reversed the inhibitory effect of TGF-β1 on the expression of miR-3185. Overexpression of miR-3185 inhibited the upregulation of Col I and Col III induced by TGF-β1.MHRT promoted cardiac fibrosis after MI through miR-3185 and increased myocardial collagen deposition and promoted myocardial fibrosis.

Sodium glucose cotransporter 2 inhibitors: mechanisms of action in heart failure

Diabetes is a key independent risk factor in the development of heart failure (HF) and a strong, adverse prognostic factor in HF patients. HF remains the primary cause of hospitalisation for diabetics and, as previous studies have shown, when HF occurs in these patients, intensive glycaemic control does not directly improve the prognosis. Recent clinical studies assessing a new class of antidiabetic drugs, sodium-glucose cotransporter 2 inhibitors (SGLT2is) showed some unexpected beneficial results. Patients treated with SGLT2is had a significant decrease in both cardiovascular (CV) and all-cause mortality and less hospitalisations due to HF compared to those given a placebo. These significant clinical benefits occurred quickly after the drugs were administered and were not solely due to improved glycaemic control. These groundbreaking clinical trials’ results have already changed clinical practice in the management of patients with diabetes at high CV risk. These trials have triggered numerous experimental studies aimed at explaining the mechanisms of action of this unique group of drugs. This article presents the current state of knowledge about the mechanisms of action of SGLT2is developed for the treatment of diabetes and which, thanks to their cardioprotective effects, may, in the future, become a treatment for patients with HF.

Atorvastatin attenuates TGF‑β1‑induced fibrogenesis by inhibiting Smad3 and MAPK signaling in human ventricular fibroblasts

Excessive proliferation and myofibroblasts transformation of cardiac fibroblasts play a critical role in the process of cardiac fibrosis. Atorvastatin (ATV), a 3‑hydroxy‑3‑methyl‑glutaryl‑coenzyme A reductase inhibitor, is commonly used to treat hypercholesterolemia. It has previously been shown that ATV has potential anti‑fibrotic effects. However, the underlying mechanisms of ATV against cardiac fibrosis remain to be fully elucidated, and to the best of our knowledge, there are no reports focusing on the effects of ATV on transforming growth factor‑β1 (TGF‑β1)‑induced human ventricular fibroblasts (hVFs) activation. In the present study, hVFs were stimulated with TGF‑β1 with or without pretreatment with ATV. Subsequently, hVF proliferation, cytotoxicity, myofibroblast differentiation and pro‑fibrotic gene expression were assessed. Canonical and non‑canonical signaling downstream of TGF‑β1, such as Smad3 and mitogen‑activated protein kinase (MAPK) signaling, were investigated by evaluating the phosphorylation levels of Smad3, extracellular signal‑regulated kinase 1/2, p38 MAPK and c‑Jun N‑terminal kinase. The results indicated that ATV significantly prevented TGF‑β1‑induced cell proliferation, myofibroblast differentiation and production of extracellular matrix proteins, such as matrix metalloproteinase‑2, collagen I and collagen III, in hVFs. Furthermore, ATV effectively inhibited TGF‑β1‑induced activation of Smad3 and MAPK signaling in hVFs. In conclusion, the present results demonstrated that ATV prevented TGF‑β1‑induced fibrogenesis in hVFs, at least in part by inhibiting the Smad3 and MAPK signaling pathways. Therefore, these results imply that ATV may be a promising agent to treat myocardial fibrosis.

The Role of Bone Morphogenetic Protein 7 (BMP-7) in Inflammation in Heart Diseases

Bone morphogenetic protein-7 is (BMP-7) is a potent anti-inflammatory growth factor belonging to the Transforming Growth Factor Beta (TGF-β) superfamily. It plays an important role in various biological processes, including embryogenesis, hematopoiesis, neurogenesis and skeletal morphogenesis. BMP-7 stimulates the target cells by binding to specific membrane-bound receptor BMPR 2 and transduces signals through mothers against decapentaplegic (Smads) and mitogen activated protein kinase (MAPK) pathways. To date, rhBMP-7 has been used clinically to induce the differentiation of mesenchymal stem cells bordering the bone fracture site into chondrocytes, osteoclasts, the formation of new bone via calcium deposition and to stimulate the repair of bone fracture. However, its use in cardiovascular diseases, such as atherosclerosis, myocardial infarction, and diabetic cardiomyopathy is currently being explored. More importantly, these cardiovascular diseases are associated with inflammation and infiltrated monocytes where BMP-7 has been demonstrated to be a key player in the differentiation of pro-inflammatory monocytes, or M1 macrophages, into anti-inflammatory M2 macrophages, which reduces developed cardiac dysfunction. Therefore, this review focuses on the molecular mechanisms of BMP-7 treatment in cardiovascular disease and its role as an anti-fibrotic, anti-apoptotic and anti-inflammatory growth factor, which emphasizes its potential therapeutic significance in heart diseases.

SMAD2 overexpression rescues the TGF-β3 null mutant mice cleft palate by increased apoptosis

During palatal development, medial edge epithelium (MEE) disappearance is one of the crucial steps in the process of fusion. The fate of these cells is still debated, and controversies remain. During secondary palate fusion, TGF-β3 signaling mediated in the cell through the SMAD2 protein plays an important role and leads to the disappearance of the midline epithelial seam (MES) and the confluence of the palatal mesenchyme. In mice, TGF-β3 knock-out is lethal and mice are born with a cleft in the secondary palate. This phenotype has been rescued by targeted overexpression of SMAD2 in the medial edge epithelium (MEE). The goal of this research was to understand the mechanism of palatal fusion in the rescue mice.

METHODS

The heads of embryos with four different genotypes (wild-type, K14-SMAD2/TGF-β3^(-/-), K14-SMAD2/TGF-β3^(±), and TGF-β3 null) were collected at embryonic day E14.5, genotyped, fixed and embedded in paraffin. Serial sections were studied for detection of apoptosis and epithelial mesenchymal transition using immunofluorescence.

RESULTS

TGF-β3 null mice developed a cleft in the secondary palate while both mice with K14-SMAD2 overexpression had fusion of the secondary palate. The MEE of both the rescue mice and K14-SMAD2 overexpression had a much higher ratio of apoptotic cells than wild-type mice. The increase in apoptosis was correlated with increased phospho-SMAD2 in the MEE.

CONCLUSION

SMAD2 overexpression rescued the cleft in the secondary palate by increasing apoptosis in the medial edge epithelium.

MicroRNA-663 participates in myocardial fibrosis through interaction with TGF-β1

MicroRNA-663 (miRNA-663) regulates the expression of transforming growth factor β1 (TGF-β1), which participates in the pathogenesis of myocardial fibrosis. Therefore, microRNA-663 may also serve a role in myocardial fibrosis. The present study aimed to determine whether miRNA-663 participates in myocardial fibrosis via interaction with TGF-β1. In the present study, the expression of miRNA-663 was significantly downregulated, whereas that of TGF-β1 was significantly upregulated in the endomyocardial biopsies of patients with myocardial fibrosis compared with those in control necropsies. Pearson's correlation analysis revealed that the expression levels of miRNA-663 were negatively correlated with those of TGF-β1 in patients with myocardial fibrosis, but not in the controls. Receiver operating characteristic curve analysis demonstrated that the downregulation of miRNA-663 distinguished patients with myocardial fibrosis from controls. In the AC16 human cardiomyocyte cell line, miRNA-663 overexpression resulted in downregulated TGF-β1 expression, whereas exogenous TGF-β1 treatment exhibited no significant effects on miRNA-663 expression. These results indicate that miRNA-663 may participate in myocardial fibrosis, possibly through interaction with TGF-β1.

Sesame Oil Attenuates Renal Oxidative Stress Induced by a High Fat Diet

The antioxidative effects of the bioactive compounds enriched sesame oil (e.g. lignans and tocopherols) are well established. This study aims to elucidate whether sesame oil could reduce renal oxidative stress induced by a high fat diet (HFD). Mice received HFD for 12 weeks (n=7 per group), which was prepared by adding 20% (w/w) lard (lard group) or sesame oil (sesame group) to the chow diet, respectively. Compared with mice in the lard group, renal lipid levels of those in the sesame group were reduced, shown by decreases in protein expression of transcription factors and enzymes involved in fatty acid synthesis (sterol regulatory element-binding protein-1 and acetyl coenzyme A carboxylase α) and an increase in β-oxidation (peroxisome proliferator-activated receptor α and carnitine palmitoyltransferase I) (P<0.05). In the sesame group, levels of peroxynitrite and thiobarbituric acid reactive substances were also reduced, whereas the level of glutathione was increased. In addition, there was elevated protein expression levels of antioxidant enzymes regulated by nuclear factor-like 2, such as superoxide dismutase, glutathione peroxidase, and glutathione S-transferase (P<0.05), and decreased expression for nuclear factor kappa B and cyclooxygenase 2 (P<0.05). These results suggest that sesame oil could ameliorate HFD-induced renal damage by suppressing oxidative stress and inflammation.

Stevioside attenuates isoproterenol-induced mouse myocardial fibrosis through inhibition of the myocardial NF-κB/TGF-β1/Smad signaling pathway

Stevioside, a natural glycoside compound, has many beneficial biological activities, but its protective effect on myocardial fibrosis has not been reported yet. This study aimed to investigate the effect of stevioside. The isoproterenol-induced model mice were orally given stevioside 75-300 mg kg-1 for 40 days. The results showed that after the administration of stevioside, the myocardial hydroxyproline, collagen accumulation, and protein expressions of collagen I/III, α-smooth muscle actin, transforming growth factor-β1 (TGF-β1), nuclear factor kappa B p65 (NF-κB p65), Smad2/3, and P-Smad2/3 were decreased, while the glutathione peroxidase and superoxide dismutase levels in serum and myocardial tissues and protein expressions of myocardial peroxisome proliferator-activated receptor γ (PPARγ) and Smad7 were increased. After the preincubation of isoproterenol-stimulated cardiac fibroblasts with the PPARγ antagonist GW9662, stevioside-reduced protein expressions were decreased, but stevioside-induced Smad7 was not affected. These findings demonstrated that stevioside could exert a protective effect on mouse myocardial fibrosis, and its mechanisms were associated with the increments of antioxidant ability, PPARγ activation, and Smad7 expression, which caused a synergistic inhibition of the NF-κB/TGF-β1/Smad signaling pathway.

Protective effect of Qishen Yiqi dropping pills on the myocardium of rats with chronic heart failure

Protective effect of Qishen Yiqi dropping pills on the myocardium of rats with chronic heart failure (CHF) was investigated. Sixty rats were divided into the sham operation (n=20), the model (n=20) and the Qishen Yiqi dropping pill treatment group (n=20) using the random table method. The treatment group received administration of Qishen Yiqi dropping pills. The model and the sham operation group were given the same amount of normal saline. Within 24 h after the last administration, the rats were sacrificed. The myocardia were used for reverse transcription-polymerase chain reaction, western blot analysis and histological examination. In the sham operation group, cardiomyocytes were stained evenly and arranged neatly and densely with clear structures. In the model group, the cell morphology was fuzzy, the myocytes were hypertrophied, the nuclear pyknosis was fragmented, the arrangement was disordered, the intercellular space was narrowed, and the cytoplasm was missing. The apoptosis rates of cardiomyocytes in the model and Qishen Yiqi dropping pill treatment group were significantly higher than that in the sham operation group (P<0.05). The myocardial infarction areas in the model group and the Qishen Yiqi dropping pill treatment group were larger than that in the sham operation group (P<0.05). The expression levels of transforming growth factor-β1, mothers against decapentaplegic homolog 2 (Smad2), Smad3, and caspase-3 messenger ribonucleic acids and proteins in the model group and the Qishen Yiqi dropping pill treatment group were higher than those in the sham operation group (P<0.05). Qishen Yiqi dropping pills have an obvious myocardial protective effect on CHF rats, which may enhance the degree of myocardial fibrosis by inhibiting the TGF-β1/Smads pathway and improve cardiomyocyte apoptosis by suppressing the caspase-3 signaling pathway, thus protecting the myocardium.

Regulatory Effect of 1,25(OH)2D3 on TGF-β1 and miR-130b Expression in Streptozotocin-Induced Diabetic Nephropathy in Rats

OBJECTIVE

To investigate the role of microRNA-130b in 1,25(OH)2D3 mediated improvement of renal fibrosis via transforming growth factor-beta 1 in a rat model of diabetic nephropathy (DN).

METHODS

DN was induced in 30 rats by intraperitoneal injection of streptozotocin. These rats were randomly allocated to the DN group, TGF-β1 overexpression group (in situ injection of TGF-β1 lentivirus to kidney tissues), and TGF-β1 siRNA group (in situ injection of TGF-β1 siRNA lentivirus to kidney tissues). Rats with different expression levels of TGF-β1 were administered 1,25(OH)2D3 (0.03 μg/kg/d) or peanut oil as control. DN rats were treated only with peanut oil. All rats were randomly divided into five groups (n = 6 per group): TGF-β1 overexpression + oil, TGF-β1 overexpression + 1,25(OH)2D3, TGF-β1 siRNA + oil, TGF-β1 siRNA + 1,25(OH)2D3, and DN + oil groups. After 37 days, kidney samples were collected and the expression of TGF-β1 and miR-130b was determined by real-time PCR, western blotting, and immunohistochemistry. Hematoxylin and eosin staining and Masson staining were used to evaluate kidney morphological and fibrogenic changes. Differences were determined using ANOVA and Student's t-test.

RESULTS

RT-PCR, western blotting, and immunohistochemistry revealed that interference of TGF-β1 significantly decreased mRNA and protein levels of TGF-β1 in renal tissues of DN rats compared to those in renal tissues of rats overexpressing TGF-β1 (p < 0.05). Histological analysis showed that upregulated TGF-β1 led to disorganized kidney structure and severe kidney fibrosis. The expression of miR-130b was significantly lowered upon lentivirus-mediated overexpression of TGF-β1 than upon downregulation of TGF-β1 (p < 0.05). Treatment with 1,25(OH)2D3 led to a significant reduction of TGF-β1 at the mRNA and protein levels (both p < 0.05), improvement of renal structure and fibrosis, and an increase in miR-130b expression (p < 0.05).

CONCLUSION

TGF-β1 can decrease the expression of miR-130b in kidney tissues of DN rats. Moreover, miR-130b may be involved in the protective effect of 1,25(OH)2D3 on renal fibrosis via TGF-β1.

Integrin ανβ5 in vitro inhibition limits pro-fibrotic response in cardiac fibroblasts of spontaneously hypertensive rats

Background

To date the TGF-β1 activation mediated by integrin ανβ5 during fibrosis is well-known. This process has been shown also in the heart, where cardiac fibroblasts (CF) differentiate into α-smooth muscle actin (α-SMA)-positive myofibroblasts (MyoFB). Here, we studied the effects on CF, isolated by spontaneously hypertensive rats (SHR), of integrin ανβ5 inhibition in MyoFB differentiation.

Methods

Staining and immunohistochemistry were performed on rat cardiac tissue. CF were isolated by enzymatic digestion from SHR (SHR-CF) and normotensive WKY (WKY-CF) rat hearts and then treated for in vitro evaluation.

Results

SHR heart tissues revealed a higher TGF-β1 expression vs. WKY samples. SHR-CF showed an enhanced SMAD2/3 activation and an up-regulated expression of α-SMA, a typical MyoFB marker, especially after TGF-β1 treatment. Immunostaining on cardiac tissues revealed a higher expression of integrin ανβ5 in SHR vs. WKY rat hearts. In vitro results confirmed the up-regulation of integrin ανβ5 expression in SHR-CF at basal condition and after TGF-β1 treatment, in comparison with WKY-CF. Inhibition of integrin ανβ5 by cilengitide treatment led a decreased expression of ανβ5, collagen I, and α-SMA in SHR-CF vs. WKY-CF, resulting in a diminished differentiation of CF into MyoFB. Taking together, results suggested that SHR-CF are more susceptible to TGF-β1, showing an up-regulated activation of SMAD2/3 signaling, and an increased ανβ5, α-SMA, and collagen I expression. Hypertension stimulus promoted an up-regulation of integrin ανβ5 on SHR cardiac tissue and its in vitro inhibition reverted pro-fibrotic events of SHR-CF.

Conclusion

Inhibition of integrin ανβ5 exerted by cilengitide strongly diminished SHR-CF differentiation into detrimental MyoFB. So, integrin ανβ5 might be considered a novel therapeutic target and cilengitide an effective pharmacological tool to limit the progression of hypertension-induced cardiac fibrosis.

Electronic supplementary material

The online version of this article (10.1186/s12967-018-1730-1) contains supplementary material, which is available to authorized users.

Epigallocatechingallate attenuates myocardial injury in a mouse model of heart failure through TGF‑β1/Smad3 signaling pathway

The present study aimed to assess the protective effect of epigallocatechingallate (EGCG) against myocardial injury in a mouse model of heart failure and to determine the mechanism underlying regulation of the transforming growth factor-β1/mothers against decapentaplegic homolog 3 (TGF-β1/Smad3) signaling pathway. Mouse models of heart failure were established. Alterations in ejection fraction, left ventricular internal diastolic diameter (LVIDd) and left ventricular internal systolic diameter (LVIDs) were measured by echocardiography. Pathological alterations of myocardial tissue were determined by hematoxylin and eosin, and Masson staining. The levels of serum brain natriuretic peptide (BNP), N-terminal-proBNP, interleukin (IL)-1β, IL-6, tumor necrosis factor-α, malondialdehyde, superoxide dismutase and glutathione peroxidase were detected with ELISA. Expression of collagen I, collagen III were detected by western blotting and reverse transcription quantitative polymerase chain reaction. Transforming growth factor-β1 (TGF-β1), Smad3, phosphorylated (p)-Smad3, apoptosis regulator BAX (Bax), caspase-3 and apoptosis regulator Bcl₂ in mouse cardiac tissue were measured by western blotting. P-smad3 and TGF-β1 were measured by immunofluorescence staining. EGCG reversed the alterations in LVIDd and LVIDs induced by establishment of the model of heart failure, increased ejection fraction, inhibited myocardial fibrosis, attenuated the oxidative stress, inflammatory and cardiomyocyte apoptosis and lowered the expression levels of collagen I and collagen III. Following treatment with TGF-β1 inhibitor, the protective effect of EGCG against heart failure was attenuated. The results of the present study demonstrated that EGCG can inhibit the progression and development of heart failure in mice through inhibition of myocardial fibrosis and reduction of ventricular collagen remodeling. This protective effect of EGCG is likely mediated through inhibition of TGF-β1/smad3 signaling pathway.

Sitagliptin ameliorates diabetic nephropathy by blocking TGF-β1/Smad signaling pathway

Diabetic nephropathy (DN) is the leading cause of end-stage failure of the kidney, but the efficacy of current strategies available for the prevention of DN remains unsatisfactory. The purpose of this study was to assess whether sitagliptin (SIT) has therapeutic potential for prevention of DN and to investigate its possible mechanism. The effects of SIT on DN were investigated in rats with type 2 diabetes mellitus (T2DM) and rat mesangial cells (MCs) induced by high glucose. T2DM rats were administered at a dose of 10 mg/kg SIT. The kidney index, 24 h urinary protein, blood urea nitrogen (BUN), serum creatinine (Cr), accumulation of glycogen and collagens were investigated by different methods. MCs were administered with SIT at doses of 0.1, 1 and 10 µmol/ml. The possible mechanism of SIT on protection of diabetic kidney injury was examined by expression of transforming growth factor-β1 (TGF-β1)/Smad pathway. The results showed that the SIT-treated diabetic rats significantly reduced diabetic kidney injury by inhibiting the kidney index and attenuating 24 h urinary protein, reducing BUN and serum creatinine, inhibiting progressive renal fibrosis and increassing extracellular matrix including collagen IV and fibronectin. Further studies showed that inhibition of renal fibrosis in SIT-treated diabetic rats and MCs were associated with rebalancing of TGF-β1/Smad pathway. Sitagliptin may be a potent agent for preventing the progression of DN through inhabiting TGF-β1/Smad-mediated renal fibrosis.

Exosomes derived from human umbilical cord mesenchymal stem cells improve myocardial repair via upregulation of Smad7

It has been previously reported that exosomes derived from human umbilical cord mesenchymal stem cells (hucMSC)‑exosomes exhibit cardioprotective effects on the rat acute myocardial infarction (AMI) models and cardiomyocyte hypoxia injury models in vitro, however the exact mechanisms involved require further investigation. The present study aimed to investigate the repair effects of hucMSC‑exosomes on myocardial injury via the regulation of mothers against decapentaplegic homolog 7 (Smad7) expression. Compared with sham or normoxia groups (in vivo and in vitro, respectively), western blotting demonstrated that Smad7 expression was significantly decreased in the borderline area of infraction myocardium and in H9C2(2‑1) cells following hypoxia‑induced injury. Additionally, microRNA (miR)‑125b‑5p expression was markedly increased using reverse transcription‑quantitative polymerase chain reaction, but was reversed by hucMSC‑exosomes. Trypan blue staining and lactate dehydrogenase release detection demonstrated that cell injury was significantly increased in the AMI + PBS and hypoxia group compared with in the sham and normoxia groups and was inhibited by hucMSC‑exosomes. A dual luciferase reporter gene assay confirmed that Smad7 is a target gene of miR‑125b‑5p. In addition, miR‑125b‑5p mimics promoted H9C2(2‑1) cell injury following 48 h exposure to hypoxia. Downregulation of Smad7 expression under hypoxia was increased by miR‑125b‑5p mimics compared with the mimic negative control, and hucMSC‑exosomes partially alleviated this phenomenon. In conclusion, hucMSC‑exosomes may promote Smad7 expression by inhibiting miR‑125b‑5p to increase myocardial repair. The present study may provide a potential therapeutic approach to improve myocardial repair following AMI.

Rosuvastatin improves myocardial hypertrophy after hemodynamic pressure overload via regulating the crosstalk of Nrf2/ARE and TGF-β/ smads pathways in rat heart

Left ventricular hypertrophy is more commonly associated with hemodynamic overload imposed by hypertension or volume overload. Transforming growth factor β (TGF-β) is involved in the cardiac hypertrophy and fibrosis of the left ventricle. The fact that TGF-β1 and the nuclear factor erythroid 2-related factor 2 (Nrf2) both become up-regulated upon persistent vessel overload suggests that these two factors may virtually impact on their signaling pathways. In this research, 40 rats were divided into sham group, model group, rosuvastatin low and high dose group. Rat models were established by incomplete constriction of abdominal aorta. After five weeks treatment, blood pressure, heart mass index (HMI), hemodynamic parameters and the average diameter of myocardium cell and collagen volume fraction (CVF) improved significantly in rosuvastatin groups, compared with the model group. Both rosuvastatin groups, increased in expression of Smad7, Nrf2, NAD (P) H dehydrogenase [quinone] 1 (Nqo1) and heme oxygenase 1(Ho1),and decreased in expression of TGF-βl、Smad3 compared with the model group. Results from co-immunoprecipitation and GST pull down showed that Nrf2 interacts with Smad7. Our results revealed the crosstalk between TGF-β1/Smads and Nrf2/ antioxidant response elements (ARE) pathways in myocardial remodeling through the interaction between Smad7 and Nrf2. Rosuvastatin can improve cardiac function and hypertrophy by regulating the crosstalk of the two signaling pathways.

C1q/TNF-Related Protein 3 (CTRP3) Function and Regulation

As the largest endocrine organ, adipose tissue secretes many bioactive molecules that circulate in blood, collectively termed adipokines. Efforts to identify such metabolic regulators have led to the discovery of a family of secreted proteins, designated as C1q tumor necrosis factor (TNF)-related proteins (CTRPs). The CTRP proteins, adiponectin, TNF-alpha, as well as other proteins with the distinct C1q domain are collectively grouped together as the C1q/TNF superfamily. Reflecting profound biological potency, the initial characterization of these adipose tissue-derived CTRP factors finds wide-ranging effects upon metabolism, inflammation, and survival-signaling in multiple tissue types. CTRP3 (also known as CORS26, cartducin, or cartonectin) is a unique member of this adipokine family. In this review we provide a comprehensive overview of the research concerning the expression, regulation, and physiological function of CTRP3. © 2017 American Physiological Society. Compr Physiol 7:863-878, 2017.

Ginsenoside Rb1 improves cardiac function and remodeling in heart failure

We investigated the effect of ginsenoside Rb1 on cardiac function and remodeling in heart failure (HF). Four weeks after HF induction, the rats were administrated with ginsenoside Rb1 (35 and 70 mg/kg) and losartan (4.5 mg/kg) for 8 weeks. Losartan was used as a positive control. Cardiac function was assessed by measuring hemodynamic parameters. Histological changes were analyzed by HE and Masson’s trichrome staining. Cardiac hypertrophy, fibrosis, mitochondrial membrane potential and glucose transporter type 4 (GLUT4) levels were evaluated. In the present study, high dose of (H−) ginsenoside Rb1 decreased heart rate, improved cardiac function and alleviated histological changes induced by HF. H-ginsenoside Rb1 attenuated cardiac hypertrophy and myocardial fibrosis by decreasing left ventricular (LV) weight/heart weight ratio and cardiomyocyte cross-sectional area and reducing the levels of atrial natriuretic factor (ANF), β-myosin heavy chain (β-MHC), periostin, collagen I, Angiotensin II (Ang II), Angiotensin converting enzyme (ACE) and Ang II type 1 (AT1) receptor. Moreover, H-ginsenoside Rb1 decreased mitochondrial membrane potential and enhanced the translocation of GLUT4 to plasma membrane. The TGF-β1/Smad and ERK signaling pathways were inhibited and the Akt pathway was activated. These findings suggest that ginsenoside Rb1 might restore cardiac/mitochondrial function, increase glucose uptake and protect against cardiac remodeling via the TGF-β1/Smad, ERK and Akt signaling pathways.

Traditional Chinese medicine baoxin decoction improves cardiac fibrosis of rats with dilated cardiomyopathy

We investigated the effect of baoxin decoction (BXD) on myocardial fibrosis and clarified the possible mechanism of action. Dilated myocardiopathy was induced by doxorubicin injected intraperitoneally for 6 weeks. Rats that demonstrated dilated myocardiopathy were randomly divided into five groups plus a control group. Three groups were treated with BXD (7.5/kg, 15 g/kg and 30 g/kg) daily for 4 weeks. One group was treated with 8.75 g/kg of captopril (positive control), and with physiologic saline (negative control). Cardiac function was evaluated using echocardiography. Hematoxylin and eosin, and Massons trichrome staining were performed, PICP and PIIINP were assessed by ELISA, the expression of galectin-3 and collagen types I and III was evaluated with reverse transcription-quantitative PCR, and interrelated proteins were detected by western blot analysis. BXD downregulated galectin-3, collagen I and III and was correlated with a high expression of fibrosis markers. It also significantly decreased myocardial collagen volume fraction (CVF), together with markedly preventing the upregulation of collagen I and III. In addition, BXD downregulated the expression of TGF-β1 and Smad3 in the myocardial fibrosis rats. Therefore, BXD treatment significantly improved cardiac function and alleviated myocardial fibrosis in a rat model of doxorubicin-induced dilated cardiomyopathy (DCM), which is the mechanism that may be associated with inhibiting the TGF-β1 signaling pathway.

The expression of Smad signaling pathway in myocardium and potential therapeutic effects

Myocardial infarction (MI) is a life-threatening disease. The expression of Smad proteins in the ischemic myocardium changes significantly following myocardial infarction, suggesting a close relationship between Smad proteins and heart remodeling. Moreover, it is known that the expression of Smads is regulated by transforming growth factor-β (TGF-β) and bone morphogenetic proteins (BMP). Based on these findings, regulating the expression of Smad proteins by targeting TGF-β and BMP in the ischemic myocardium may be considered to be a possible therapeutic strategy for the treatment of myocardial infarction.

Angiotensinase C mRNA and Protein Downregulations Are Involved in Ethanol-Deteriorated Left Ventricular Systolic Dysfunction in Spontaneously Hypertensive Rats

The influences of angiotensinase C on ethanol-induced left ventricular (LV) systolic function were assessed in spontaneously hypertensive rats (SHRs). SHRs were fed by a liquid diet with or without ethanol for 49 days. The normotensive Wistar Kyoto rats (WKY) were fed by the liquid diet without ethanol and used as control. We evaluated LV systolic function, angiotensinase C mRNA and protein expressions, activation of the renin-angiotensin system (RAS), and the gene expressions of LV collagen (Col) III a1 and matrix metalloproteinases- (MMP-) 9. Compared to the WKY, LV systolic dysfunction (expressed by decreased fractional shortening and ejection fraction) was observed in the SHRs before ethanol treatment and further deteriorated by ethanol treatment. In the ethanol-treated SHRs, the following were observed: downregulations of angiotensinase C mRNA and protein, increased RAS activity with low collagen production as evidenced by angiotensin II and angiotensin type 1 receptor (AT₁R) protein upregulation, AT_1aR mRNA downregulation, and an MMP-9 mRNA expression upregulation trend with the downregulation of Col III a1 mRNA expression in LV. We conclude that chronic ethanol regimen is sufficient to promote the enhanced RAS activity-induced decrease in the production of cardiac collagen via downregulated angiotensinase C, leading to the further deterioration of LV systolic dysfunction in SHRs.