Bletilla striata polysaccharide attenuated the progression of pulmonary fibrosis by inhibiting TGF-β1/Smad signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Bletilla striata, a traditional medicinal plant, has been utilized as a folk medicine for many years because of its superior biological activity in China. However, Bletilla striata polysaccharide (BSP) has received less attention, and its specific mechanism for ameliorating pulmonary fibrosis is completely unclear.

AIMS OF THE STUDY

In this study, we aim to assess BSP on the treatment of PF and explore potential mechanisms.

MATERIALS AND METHODS

BSP was successfully extracted and purified from Bletilla striata. The mechanisms were assessed in bleomycin-induced pulmonary fibrosis model and lung fibroblasts activated by transforming growth factor-β1 (TGF-β1). Histological analysis, immunofluorescence, Western blot and flow cytometry were used to explore the alterations after BSP intervention.

RESULTS

The results in vivo showed an anti-PF effect of BSP treatment, which reduced pathogenic damages. Furthermore, TGF-β1-induced abnormal migration and upregulated expression of collagen I (COL1A1), vimentin and α-smooth muscle actin (α-SMA) were suppressed by BSP in L929 cells. Moreover, the abnormal proliferation was retarded by inhibiting the cell cycle of G1 to S phase. Immunofluorescence assay showed that BSP activated autophagy and played an antifibrotic role by inhibiting the expression of p62 and phospho-mammalian target of rapamycin (p-mTOR). Last but not least, the suppression of TGF-β1/Smad signaling pathway was critical for BSP to perform therapeutic effects in vitro and in vivo.

CONCLUSION

The possible mechanisms were involved in improving ECM deposition, regulating cell migration and proliferation, and promoting cellular autophagy. Briefly, all of the above revealed that BSP might be a novel therapy for treating pulmonary fibrosis.

Icariin improves cardiac function and remodeling via the TGF-β1/Smad signaling pathway in rats following myocardial infarction

BACKGROUND

Postinfarction cardiac remodeling presents a compensatory mechanism aimed at mitigating congestive heart failure. It is distinguished by progressive dilatation and hypertrophy of the ventricular chambers, fibrotic alterations, and prolonged apoptosis of cardiomyocytes. The primary objective of this study was to assess the effects of icariin on myocardial fibrosis and ventricular remodeling in rats subjected to myocardial infarction (MI).

METHODS

Male Sprague‒Dawley (SD) rats were subjected to randomization and subsequently divided into distinct groups: the control group, the sham group (undergoing sham operation), the MI group (experiencing ligation of the left anterior descending artery), and the icariin group. Within the icariin group, rats were further categorized into three different dose groups based on the administered icariin dosage: the MI30 group (30 mg/kg/day), the MI60 group (60 mg/kg/day), and the MI120 group (120 mg/kg/day). Cardiac function evaluation was carried out using echocardiography. Histological examinations, including hematoxylin and eosin (HE) staining, Masson staining, and immunohistochemistry studies, were conducted 90 days after the occurrence of MI. Additionally, Western blotting was employed to assess TGF-β1, p-Smad2, and p-Smad3 levels.

RESULTS

The administration of icariin revealed a noteworthy enhancement in cardiac function among rats afflicted with left anterior descending coronary artery (LAD) ligation. In comparison to the icariin groups, the MI group exhibited reduced EF and FS, along with elevated LVEDD and LVESD. Furthermore, the cardiac fibrosis levels in the MI group rats exhibited a considerable increase compared to those in the icariin group. Notably, the levels of Collagen I, Collagen III, MMP2, and MMP9 were significantly higher in the MI group than in the icariin group, with evident distinctions. Moreover, the expression levels of TGF-β, IL-13, p-Smad2, and p-Smad3 were notably upregulated in the MI group compared to the icariin group.

CONCLUSIONS

In an experimental rat model of MI, the administration of icariin resulted in the amelioration of both cardiac function and remodeling processes, operating through the intricate TGF-β1/Smad signaling pathway.

Kinetin inhibits hepatic stellate cell activation and induces apoptosis via interactions with the TGF-β1/Smad signaling pathway

Hepatic fibrosis is the pathological repair response of the liver to chronic injury; hepatic stellate cell (HSC) activation is the central link in the pathogenesis of hepatic fibrosis. Previously, we showed that kinetin, a plant cytokinin hormone, has a protective effect on CCl4-induced liver injury in mice. However, the role of kinetin in liver fibrosis remains unclear. We aimed to study these protective effects and to determine the mechanisms by which kinetin mediates HSC activation and apoptosis. For this purpose, the human HSC line LX-2 was treated with 10 ng/ml transforming growth factor-β1 (TGF-β1) for 24 h to stimulate activation. We found that treatment with kinetin at the sub-cytotoxic dose of 40 μg/ml for 48 h reduced the expression of the HSC activation marker α-SMA and inhibited the secretion of extracellular matrix proteins. In addition, kinetin was found to inhibit the proliferation and migration of LX-2 cells. We found that kinetin induced apoptosis in LX-2 cells by increasing the level of cleaved-caspase 3 and the Bax-to-Bcl-2 ratio. Interestingly, these effect were not observed in quiescent HSCs, suggesting that they are activation-dependent. Further study showed that kinetin attenuates activation and promotes apoptosis of LX-2 cells in vitro in part by suppressing the TGF-β1/Smad signaling pathway.

Metformin reduces myogenic contracture and myofibrosis induced by rat knee joint immobilization via AMPK-mediated inhibition of TGF-β1/Smad signaling pathway

PURPOSE

The two structural components contributing to joint contracture formation are myogenic and arthrogenic contracture, and myofibrosis is an important part of myogenic contracture. Myofibrosis is a response to long-time immobilization and is described as a condition with excessive deposition of endomysial and perimysial connective tissue components in skeletal muscle. The purpose of this study was to confirm whether metformin can attenuate the formation of myogenic contracture and myofibrosis through the phosphorylation level of adenosine monophosphate-activated protein kinase (AMPK) and inhabitation of subsequent transforming growth factor beta (TGF-β) 1/Smad signaling pathway.

MATERIALS AND METHODS

An immobilized rat model was used to determine whether metformin could inhibit myogenic contracture and myofibrosis. The contents of myogenic contracture of knee joint was calculated by measuring instrument of range of motion (ROM), and myofibrosis of rectus femoris were determined by ultrasound shear wave elastography and Masson staining. Protein expression of AMPK and subsequent TGF-β1/Smad signaling pathway were determined by western blot. Subsequently, Compound C, a specific AMPK inhibitor, was used to further clarify the role of the AMPK-mediated inhibition of TGF-β1/Smad signaling pathway.

RESULTS

We revealed that the levels of myogenic contracture and myofibrosis were gradually increased during immobilization, and overexpression of TGF-β1-induced formation of myofibrosis by activating Smad2/3 phosphorylation. Activation of AMPK by metformin suppressed overexpression of TGF-β1 and TGF-β1-induced Smad2/3 phosphorylation, further reducing myogenic contracture and myofibrosis during immobilization. In contrast, inhibition of AMPK by Compound C partially counteracted the inhibitory effect of TGF-β1/Smad signaling pathway by metformin.

CONCLUSION

Notably, we first illustrated the therapeutic effect of metformin through AMPK-mediated inhibition of TGF-β1/Smad signaling pathway in myofibrosis, which may provide a new therapeutic strategy for myogenic contracture.

Loss of Proximal Tubular Sirtuin 6 Aggravates Unilateral Ureteral Obstruction-Induced Tubulointerstitial Inflammation and Fibrosis by Regulation of β-Catenin Acetylation

Renal fibrosis is a significant pathologic change associated with progressive kidney disease. Sirt6 is an NAD⁺-dependent deacetylase and mono-ADP ribosyltransferase known to play diverse roles in the processes attendant to aging, metabolism, and carcinogenesis. However, the role of proximal tubule-specific Sirt6 in renal fibrosis remains elusive. This study investigates the effect of proximal tubule-specific Sirt6 knockdown on unilateral ureteral obstruction (UUO)-induced renal tubulointerstitial inflammation and fibrosis. Renal fibrosis in wild type and PT-Sirt6KO (Sirt6^flox/flox; Ggt1-Cre⁺) mice was induced by UUO surgery. After seven days, histologic examination and Western blot analysis were performed to examine extracellular matrix (ECM) protein expression. We evaluated inflammatory cytokine and cell adhesion molecule expression after ureteral obstruction. The therapeutic effect of Sirt6 activator MDL-800 on UUO-induced tubulointerstitial inflammation and fibrosis was assessed. The loss of Sirt6 in the proximal tubules aggravated UUO-induced tubular injury, ECM deposition, F4/80 positive macrophage infiltration, and proinflammatory cytokine and chemokine expression. Sirt6 activator MDL-800 mitigated UUO-induced renal tubulointerstitial inflammation and fibrosis. In an in vitro experiment, MDL-800 decreases the transforming growth factor (TGF)-β1-induced activation of myofibroblast and ECM production by regulating Sirt6-dependent β-catenin acetylation and the TGF-β1/Smad signaling pathway. In conclusion, proximal tubule Sirt6 may play an essential role in UUO-induced tubulointerstitial inflammation and fibrosis by regulating Sirt6-dependent β-catenin acetylation and ECM protein promoter transcription.

Blueberry Juice Attenuates Pulmonary Fibrosis via Blocking the TGF-β1/Smad Signaling Pathway

Idiopathic pulmonary fibrosis (IPF) is a progressive, fatal, and chronic lung disease, lacking a validated and effective therapy. Blueberry has demonstrated multiple pharmacological activities including anti-inflammatory, antioxidant, and anticancer. Therefore, the objective of this study was to investigate whether blueberry juice (BBJ) could ameliorate IPF. Experiments in vitro revealed that BBJ could significantly reduce the expressions of TGF-β1 modulated fibrotic protein, which were involved in the cascade of fibrosis in NIH/3T3 cells and human pulmonary fibroblasts. In addition, for rat primary lung fibroblasts (RPLFs), BBJ promoted the cell apoptosis along with reducing the expressions of α-SMA, vimentin, and collagen I, while increasing the E-cadherin level. Furthermore, BBJ could reverse epithelial–mesenchymal transition (EMT) phenotypic changes and inhibit cell migration, along with inducing the upregulation of E-cadherin in A549 cells. Compared with the vehicle group, BBJ treatment alleviated fibrotic pathological changes and collagen deposition in both bleomycin-induced prevention and treatment pulmonary fibrosis models. In fibrotic lung tissues, BBJ remarkably suppressed the expressions of collagen I, α-SMA, and vimentin and improved E-cadherin, which may be related to its inhibition of the TGF-β1/Smad pathway and anti-inflammation efficacy. Taken together, these findings comprehensively proved that BBJ could effectively prevent and attenuate idiopathic pulmonary fibrosis via suppressing EMT and the TGF-β1/Smad signaling pathway.

The EIF4A3/CASC2/RORA Feedback Loop Regulates the Aggressive Phenotype in Glioblastomas

Glioblastoma (GBM) is a common and refractory subtype of high-grade glioma with a poor prognosis. The epithelial-mesenchymal transition (EMT) is an important cause of enhanced glioblastoma invasiveness and tumor recurrence. Our previous study found that retinoic acid receptor-related orphan receptor A (RORA) is a nuclear receptor and plays an important role in inhibiting proliferation and tumorigenesis of glioma. We further confirmed RORA was downregulated in GBM. Thus, we determined whether RORA was involved in the migration, invasion, and EMT of GBM. Human GBM cell lines, U87 and T98G, and patient-derived glioma stem cells (GSCs), GSC2C and GSC4D, were used for in vitro and in vivo experiments. The expressions of RORA, CASC2, and EIF4A3 in GBM cells and GSCs were detected by RT-qPCR and western blotting. The biological effects of RORA, CASC2, and EIF4A3 on GBM migration, invasion, and EMT were evaluated using the migration assay, transwell assay, immunofluorescence staining, and xenograft experiments. We found that RORA inhibited the migration, invasion, and EMT of GBM. CASC2 could bind to, maintain the stability, and promote the nuclear translocation of RORA protein. EIF4A3 could downregulate CASC2 expression via inducing its cleavage, while RORA transcriptionally inhibited EIF4A3 expression, which formed a feedback loop among EIF4A3/CASC2/RORA. Moreover, gene set enrichment analysis (GSEA) and in vitro and in vivo experiments showed RORA inhibited the aggressiveness of GBM by negatively regulating the TGF-β1/Smad signaling pathway. Therefore, The EIF4A3/CASC2/RORA feedback loop regulated TGF-β1/Smad signaling pathway might become a promising therapeutic strategy for GBM treatment.

[Effect of regulating TGF-β1/Smad signaling pathway on apoptosis of hepatocellular carcinoma HepG2 cells under endoplasmic reticulum stress]

Objective: To investigate the effect of TGF-β1/Smad signaling pathway on the apoptosis of HepG2 cells under endoplasmic reticulum stress (ERS). Methods: An ERS model was established firstly. Human hepatocellular carcinoma HepG2 cells were treated with 3 μmol/L tunicamycin (TM) for 24 h to induce ERS. Cells were divided into 6 groups, each with 3 replicate holes, and the experiment was repeated 3 times. The 6 groups included untreated group, TM group (3 μmol/L TM treatment group), TM + NC group(3 μmol/L TM + si-TGF-β1 negative control group), TM + si-TGF-β1 group(3 μmol/L TM + si-TGF-β1 group), TM + pEX-3 group(3 μmol/L TM + plasmid control group), and TM + TGF-β1 pEX-3 group(3 μmol/L TM + TGF-β1 overexpressed plasmid group). HepG2 cells were transfected with TGF-β1 small interfering RNA (TGF-β1 si-RNA) and TGF-β1 overexpressed plasmids (TGF-β1 pEX-3) by Lipofectamine. Twenty-four hours after transfection, RT-qPCR and Western blot were used to detect the expression of TGF-β1 and p-Smad2 in HepG2 cells of each group. CCK-8 and flow cytometry were used to analyze changes in the proliferation inhibition rate and apoptosis rate of HepG2 cells in each group. Results: Compared with the untreated group, the expressions of TGF-β1 and p-Smad2 in TM group were significantly reduced (P＜0.05). Compared with the TM group, the expressions of TGF-β1 and p-Smad2, as well as the cell proliferation inhibition rate and apoptosis rate in TM + si-TGF-β1 group were obviously decreased (P＜ 0.01), while the expressions of TGF-β1 and p-Smad2, cell proliferation inhibition rate and apoptosis rate of TM + TGF-β1 pEX-3 group were significantly increased (P＜0.01). Conclusion: The TGF-β1/Smad signaling pathway was inhibited in hepatocellular carcinoma HepG2 cells under ERS, when this pathway was activated, the apoptosis rate of HepG2 cells under ERS was increased significantly.

Fibroblastic galectin-1-fostered invasion and metastasis are mediated by TGF-β1-induced epithelial-mesenchymal transition in gastric cancer

Background The gastric cancer (GC) microenvironment has important effects on biological behaviors, such as tumor cell invasion and metastasis. However, the mechanism by which the GC microenvironment promotes GC cell invasion and metastasis is unknown. The present study aimed to clarify the effects and mechanism of galectin-1 (GAL-1, encoded by LGALS1) on GC invasion and metastasis in the GC microenvironment. Methods The expression of GAL-1/ LGALS1 was determined using western blotting, immunohistochemistry, and quantitative real-time reverse transcription PCR in GC tissues. Besides, methods including stable transfection, Matrigel invasion and migration assays, and wound-healing assays in vitro; and metastasis assays in vivo, were also conducted. Results GAL-1 from cancer-associated fibroblasts (CAFs) induced the epithelial-mesenchymal transition (EMT) of GC cells though the transforming growth factor beta (TGF-β1)/ Sma- and mad-related protein (Smad) pathway, and affected the prognosis of patients with GC. The level of GAL-1 was high in CAFs, and treating MGC-803 and SGC -7901 cell line with the conditioned medium from CAFs promoted their invasion and metastasis abilities. Overexpression of LGALS1 promoted the expression of TGF-β1 and induced EMT of GC cell lines. A TGF-β1 antagonist inhibited the invasion and migration of GC cells. In vivo, overexpression of LGALS1 promoted GC growth and metastasis, and the TGF-β1 antagonist dramatically reversed these events. Conclusions These findings suggested that high expression of GAL-1 in the GC microenvironment predicts a poor prognosis in patients with GC by promoting the migration and invasion of GC cells via EMT through the TGF-β1/Smad signaling pathway. The results might provide new therapeutic targets to treat GC.

Glycyrrhizic acid restrains airway inflammation and remodeling in asthma via the TGF-β1/Smad signaling pathway

The anti-inflammatory effects of glycyrrhizic acid (GA) against asthma have previously been reported; however, the underlying molecular mechanism of GA in asthma has not yet been elucidated. Thus, the present study aimed to determine the function and potential molecular mechanism of GA for modulating the transforming growth factor-β1 (TGF-β1)/Smad signaling pathway in asthma-associated airway inflammation and remodeling. In order to study the mechanism of GA on airway inflammation and airway remodeling in asthmatic mice, a mouse model of chronic asthma was constructed. A total of 50 female mice were randomly assigned into five groups (10 mice/group), as follows: Blank group, asthma group, GA group, dexamethasone group and GA + TGF-β1 group. Hematoxylin and eosin, and Masson staining were performed to assess the airway inflammation and remodeling in mice with ovalbumin (OVA)-induced asthma. The serum levels of interleukin (IL)-4, IL-5, IL-13 and IL-17 in mice were assessed via the enzyme-linked immunosorbent assay. Reverse transcription-quantitative PCR and western blot analyses were performed to detect the levels of TGF-β1 and Smads in lung tissues of each group of mice. The results demonstrated that GA and dexamethasone treatment mitigated airway inflammation, inflammatory cell infiltration and airway remolding, with a concomitant decrease in the expression levels of IL-4, IL-5, IL-13 and IL-17, in mice with OVA-induced asthma. In addition, the levels of TGF-β1 and Smad2 notably decreased, while Smad7 expression increased in the GA and dexamethasone groups compared with the asthma group. Furthermore, histopathological morphometry exhibited significantly elevated inflammatory cell infiltration, airway wall and smooth muscle, collagen secretion and inflammatory cytokines in the serum of mice in the GA + TGF-β1 group compared with the GA group. Taken together, the results of the present study suggest that GA ameliorates airway inflammation and remodeling via the TGF-β1/Smad signaling pathway in mice with asthma.

MiR-195 promotes myocardial fibrosis in MI rats via targeting TGF-β1/Smad

The aim of this study was to investigate the effect of micro ribonucleic acid (miR)-195 on myocardial infarction (MI) in rats via regulating the transforming growth factor-β1 (TGF-β1)/Smad signaling pathway. A total of 36 Sprague-Dawley rats were randomly divided into a normal group (n=12), a model group (n=12) and an miR-195 antagomir group (n=12). In the normal group, the heart was exposed only, and normal saline was intraperitoneally injected after operation. In the model group, the acute MI model was established. In the miR-195 antagomir group, the acute MI model was also established, and miR- 195 antagomir was intraperitoneally injected. The samples were collected at 2 weeks after surgery. Then cardiac function was detected via echocardiography, and the morphology of heart tissues was observed via hematoxylin and eosin (H&E) staining. Moreover, the expression of Collagen I was determined using immunohistochemistry, the protein expressions of TGF-β1, Smad3 and Smad7 were detected using Western blotting, and the expression of miR-195 was detected via quantitative polymerase chain reaction (qPCR). It was found by echocardiography that, compared with those in the normal group, left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS) significantly declined, while left ventricular end-diastolic diameter (LVDd) and left ventricular end-systolic diameter (LVDs) significantly rose in the other two groups (P<0.05). In comparison with the model group, the miR-195 antagomir group had significantly increased LVEF and LVFS, and significantly decreased LVDd and LVDs (P<0.05). The immunohistochemistry results showed that the mean optical density of tissues with positively expressed Collagen I was obviously higher in the other two groups than that in the normal group (P<0.05), while it was obviously lower in the miR-195 antagomir group than that in the model group (P<0.05). According to the results of Western blotting, the protein expressions of TGF-β1 and Smad3 were evidently increased, while the protein expression of Smad7 was evidently decreased in the other two groups compared with those in the normal group (P<0.05). The opposite results were found in the miR-195 antagomir group compared with those in the model group (P<0.05). The results of qPCR manifested that the expression of miR-195 was markedly higher in the other two groups than that in the normal group (P<0.05), while it was markedly lower in the miR-195 antagomir group than in the model group (P<0.05). Moreover, it was observed using H&E staining that the myocardial fibers in the normal group had normal arrangement and intact structure, without obvious morphological abnormalities. In the model group, the myocardial fibers were arranged disorderly, and there were massive proliferating fibrous tissues, with a high degree of fibrosis. In themiR-195 antagomir group, the myocardial fibers were damaged and arranged less disorderly, and proliferation and fibrosis could be seen in some fibrous tissues, but to a lesser extent than the model group. In conclusion, miR-195 promotes myocardial fibrosis in MI rats via up-regulating the TGF-β1/Smad signaling pathway.

miR-363 Alleviates Detrusor Fibrosis via the TGF-β1/Smad Signaling Pathway by Targeting Col1a2 in Rat Models of STZ-Induced T2DM

Dysregulated expression of microRNAs (miRNAs or miRs) has been implicated in the pathophysiology of type 2 diabetes mellitus (T2DM). However, their underlying role in the complication of detrusor fibrosis remains poorly understood. Therefore, this study aimed to examine the potential functional relevance of miR-363 in detrusor fibrosis of rats with streptozotocin (STZ)-induced T2DM through the predicted target gene collagen type I alpha 2 (Col1a2). Immunohistochemical analysis found an increase in the positive expression of collagen type III alpha 1 (Col3a1) and Col1a2 in detrusor tissues, where miR-363 expression was decreased. Next, gain- and loss-of-function experiments were performed to clarify the effects of miR-363 and Col1a2 on the activities of bladder detrusor cells. Of note, binding affinity between miR-363 and Col1a2 was verified by a dual-luciferase reporter gene assay and RNA immunoprecipitation (RIP) assay. Upregulated miR-363 inhibited Col1a2 expression, which led to increased expression of B-cell lymphoma 2 (Bcl-2) and Smad7 and accelerated cell viability, along with decreases in cell apoptosis and Col3a1, Bcl-2-associated X protein (Bax), transforming growth factor (TGF)-β1, and Smad4 expressions. In conclusion, miR-363 upregulation reduces detrusor fibrosis in rats with STZ-induced T2DM through suppression of the TGF-β1/Smad signaling pathway by targeting Col1a2. Therefore, our study provided further insights for the development of new therapeutic targets for T2DM.

Destruction of the blood-retina barrier in diabetic retinopathy depends on angiotensin-converting enzyme-mediated TGF-β1/Smad signaling pathway activation

Diabetes mellitus (DM) is a systemic, chronic metabolic disease that is related to heredity and autoimmunity and is often accompanied by complications of retinopathy. However, the causative mechanism involved in the pathological process remains unclear. In this research, treatment with fosinopril or LY2109761 was found to be responsible for the improvement of the pathological processes, serum biochemical indexes and retinopathy in rats with streptozotocin-induced diabetes. In addition, the upregulation of angiotensin-converting enzyme (ACE) in the serum and the increased expression of TGF-β1 in the pathological outer nuclear layer (ONL) and inner nuclear layer (INL) of the retina were also reduced. In vitro experiments demonstrated that ACE enhanced cell damage and TGF-β1/Smad signaling pathway activation in retinal capillary endothelial cells (RCECs) under high glucose conditions. In addition, the activity of ACE was also considered to be related to the increasing levels of activated TGF-β1 in both rat retinal Müller cells (RMCs) and RCECs, but ACE activity had no effect on the high glucose-mediated upregulation of total TGF-β1 in RMCs. Coculture experiments with RCECs and RMCs showed that the barrier that was established under normal conditions was significantly impaired when exposed to high glucose combined with ACE, and damage of barrier can be prevented by adding fosinopril or LY2109761. Finally, a similar auxiliary effect of ACE was also observed in the activated TGF-β1-mediated barrier damage in blood-retinal barrier model in vitro. In summary, ACE-mediated TGF-β1/Smad signaling pathway activation was found to be involved in the destruction of the blood-retina barrier during diabetic retinopathy in a model of streptozotocin-induced diabetes, and these data may provide evidence to guide the treatment of the complications of diabetes mellitus.

Adipocytokine expression, platelet-to-lymphocyte ratio and TGF-1/Smad signaling activity in diabetic patients complicated with pulmonary infection

OBJECTIVE

To investigate adipocytokine expression levels, platelet-to-lymphocyte ratio (PLR) and transforming growth factor (TGF)-β1/Smad signaling activity in diabetic patients with pulmonary infection.

METHODS

Eighty-two type 2 diabetic patients with pulmonary infection were included in the observation group and 75 patients with simple type 2 diabetes were recruited into the control group. The fasting blood glucose (FBG), glycated hemoglobin (HbA1c), and PLR in the two groups were compared. Complement-C1q/tumor necrosis factor related protein 3 (CTRP-3), complement-C1q/tumor necrosis factor related protein 9 (CTRP-9), leptin, adiponectin, and TGF-β1/Smad signaling pathway activity in peripheral blood mononuclear cells (PBMCs) was detected.

RESULTS

Compared with patients in the control group, patients in the observation group presented with increased levels of FGB, HbA1c, and leptin, an increase in the PLR, and decreased serum CTRP-3, CTRP-9, and adiponectin levels. TGF-β1, p-Smad2, and p-Smad3 protein expression levels were up-regulated in PBMCs from patients in the observation group compared with the control group.

CONCLUSIONS

These results show that in type 2 diabetic patients with pulmonary infection, adipocytokine expression is altered, PLR is disturbed, and the TGF-β1/Smad signaling pathways in PBMCs are significantly activated.

Effect of octreotide on pancreatic fibrosis in rats with high-fat diet-induced obesity

BACKGROUND/AIMS

To explore the effect of octreotide on pancreatic fibrosis induced by high-fat diet (HFD) and its mechanism of action.

METHODS

Sprague-Dawley (SD) rats were assigned to control, HFD, or octreotide treatment groups. Glucose and insulin tolerance tests (GTT and ITT), fasting plasma glucose (FPG), and fasting insulin (FINS), serum and pancreatic lipid levels, were measured, and the Lee's index and the homeostatic model assessment (HOMA) index were calculated. The expression levels of alpha-smooth muscle actin (α-SMA), desmin, connective tissue growth factor (CTGF), transforming growth factor beta1 (TGF-β1), Smad3, and Smad7 in the pancreas were quantified. The LTC-14 cell line, which has features of primary rat pancreatic stellate cells (PSCs), was used for in vitro studies.

RESULTS

The AUC of ipGTT and ipITT, and FPG, FINS, lipid levels, were elevated after HFD feeding; however, they decreased after octreotide administration. The expression of α-SMA, CTGF, TGF-β1, and Smad3 in the HFD group were increased relative to the control group, but Smad7 expression was decreased. After treatment with octreotide, α-SMA, CTGF, TGF-β1, and Smad3 expression decreased, whereas the expression of Smad7 increased. In vitro studies showed that the expression of CTGF, TGF-β1, and Smad3 increased with palmitate treatment (PA), which mimics HFD treatment; and octreotide treatment decreased the expression of these proteins. The α-SMA and Smad7 expression levels remained unchanged among the three groups.

CONCLUSIONS

Octreotide can ameliorate pancreatic fibrosis and improve pancreatic beta-cell function induced in HFD treated rats, possibly by inhibiting PSC activation and by decreasing pancreatic extracellular matrix (ECM) through the TGF-β1/Smad signaling pathway.

Overexpression of lncRNA ANRIL promoted the proliferation and migration of prostate cancer cells via regulating let-7a/TGF-β1/ Smad signaling pathway

Long non-coding RNAs (lncRNAs) were playing critical roles in tumorigenesis. However, in prostate cancer, the roles and mechanisms of lncRNAs especially ANRIL were largely unknown. We investigated the effects of ANRIL on the proliferation and migration of prostate cancer cells using CCK-8 assay and Transwell migration assay. Real-time PCR and western blotting assays were used to analyze the levels of ANRIL, let-7a, TGF-β1, p-Smad2 and p-Smad7. Our results showed that ANRIL was significantly overexpressed in prostate cancer tissues compared with corresponding normal tissues. Knockdown of ANRIL significantly inhibited the proliferation and migration of prostate cancer LNCap, PC3 and DU145 cells. Knockdown of ANRIL significantly decreased the levels of TGF-β1 and p-Smad2, and increased the level of p-Smad7 in prostate cancer LNCap cells. We further found that knockdown of ANRIL significantly enhanced the expression of let-7a, and rescue experiment found that let-7a inhibitor recovered the suppressive effects of ANRIL silencing on the proliferation and migration of prostate cancer LNCap, PC3 and DU145 cells. And let-7a inhibitor recovered the suppressive effects of ANRIL silencing on the activity of TGF-β1/Smad signaling pathway in prostate cancer LNCap cells. Taken together, our findings indicated that overexpression of lncRNA ANRIL promoted the proliferation and migration of prostate cancer cells via regulating let-7a/TGF-β1/Smad signaling pathway.

Taxus chinensis ameliorates diabetic nephropathy through down-regulating TGF-β1/Smad pathway

Diabetic nephropathy (DN) is one of the common microvascular complications of diabetes mellitus. Renal fibrosis is closely related to the deterioration of renal function. The present study aimed to investigate protective effect of Taxus chinensis on high-fat diet/streptozotocin-induced DN in rats and explore the underlying mechanism of action. The rat DN model was established via feeding high fat diet for 4 weeks and subsequently injecting streptozotocin (30 mg·kg^-1 body weight) intraperitoneally. The rats with blood glucose levels higher than 16.8 mmol·L^-1 were selected for experiments. The DN rats were treated with Taxus chinensis orally (0.32, 0.64, and 1.28 g·kg^-1) once a day for 8 weeks. Taxus chinensis significantly improved the renal damage, which was indicated by the decreases in 24-h urinary albumin excretion rate, blood serum creatinine, and blood urea nitrogen. Histopathological examination confirmed the protective effect of Taxus chinensis. The thickness of glomerular basement membrane was reduced, and proliferation of mesangial cells and podocytes cells and increase in mesangial matrix were attenuated. Further experiments showed that Taxus chinensis treatment down-regulated the expression of TGF-β1 and α-SMA, inhibited phosphorylation of Smad2 and Smad3. These results demonstrated that Taxus chinensis alleviated renal injuries in DN rats, which may be associated with suppressing TGF-β1/Smad signaling pathway.

Comparison Study of Bone Defect Healing Effect of Raw and Processed Pyritum in Rats

To evaluate and compare the effect of raw and processed pyritum on tibial defect healing, 32 male Sprague Dawley rats were randomly divided into four groups. After tibial defect, animals were produced and grouped: sham and control group were orally administrated with distilled water (1 mL/100 g), while treatment groups were given aqueous extracts of raw and processed pyritum (1.5 g/kg) for successive 42 days. Radiographic examination showed that bone defect healing effect of the treatment groups was obviously superior compared to that of the control group. Bone mineral density of whole tibia was increased significantly after treating with pyritum. Inductively coupled plasma-optical emission spectrometry showed that the contents of Ca, P, and Mg in callus significantly increased in the treatment groups comparing with the control. Moreover, serological analysis showed that the concentration of serum phosphorus of the treatment groups significantly increased compared with that of the control group. By in vitro study, we have evaluated the effects of drug-containing serum of raw and processed pyritum on osteoblasts. It was manifested that both the drug-containing sera of raw and processed pyritum significantly increased the mRNA levels of alkaline phosphatase and collagen type I. Protein levels of phosphorylated Smad2/3 also increased. The mRNA levels of osteocalcin and transforming growth factor β (TGF-β) type I and II receptors, as well as the protein levels of TGF-β1 in the processed groups, were higher than those in the control. In summary, both raw and processed pyritum-containing sera exhibited positive effects on osteoblasts, which maybe via the TGF-β1/Smad signaling pathway. Notably, the tibia defect healing effect of pyritum was significantly enhanced after processing.

MicroRNA-142-3p inhibits high-glucose-induced endothelial-to-mesenchymal transition through targeting TGF-β1/Smad pathway in primary human aortic endothelial cells

Myocardial fibrosis is an important pathological feature of diabetic cardiomyopathy (DCM) and endothelial-to-mesenchymal transition (EndMT) is an essential process for myocardial fibrosis. Recent studies have demonstrated an association between miRs and DCM. Therefore, the aim of this study is to investigate the role and the mechanism of miRNAs in the process of EndMT. We simulated the conditions occurring in EndMT by application of high glucose in primary human aortic endothelial cells (HAECs). Firstly, we compared the expression profiles of miRNAs in HAECs with or without HG treatment using microarray. Then, after addition of miR-142-3p mimics, the expression levels of EndMT markers were assessed by qRT-PCR and Western Blot. Moreover, bioinformatics analysis and luciferase assay were used to confirm the direct regulation of miR-142-3p to TGF-β1. Furthermore, the role of TGF-β1 in the inhibitory effect of miR-142-3p on EndMT was evaluated. In addition, the expressions of TGF-β1/Smad signaling signatures were measured by Western Blot. MiR-142-3p screened by miRNA microarray was significantly down-regulated in HAECs under HG stimulation in a dose and time dependent manner. Subsequently, we found that overexpression of miR-142-3p could inhibit HG-induced EndMT, as evidenced by decreased α-SMA and vimentin expression, and increased CD31 and VE-cadherin expression. Of note, transforming growth factor beta 1 (TGF-β1), one of the molecular mediators implicated in the progression of EndMT, was confirmed to be downstream target gene of miR-142-3p in HAECs. Moreover, TGF-β1 overexpression remarkably abolished the inhibitory effects of miR-142-3p overexpression on HG induced EndMT. Finally, miR-142-3p also mediated its anti-EndMT action by inactivation of TGF-β1/Smad pathway, as demonstrated by downregulation of TGF-β1, phospho-Smad2 and phospho-Smad2. Our findings demonstrated that miR-142-3p could attenuate HG-induced EndMT in HAECs, the mechanism of which may be at least partly through blocking TGF-β1/Smad signaling pathway. This might provide a potential therapeutic target for DCM in future.

Overexpression of RACK1 inhibits collagen synthesis in keloid fibroblasts via inhibition of transforming growth factor-β1/Smad signaling pathway

Keloids are benign skin tumors characterized by collagen accumulation and hyperproliferation of fibroblasts. The receptor for activated C-kinase 1 (RACK1) was involved in liver fibrosis. However, the role of RACK1 in dermal fibrosis keloids is still unclear. Therefore, in this study, we investigated the effects of RACK1 on keloid fibroblasts (KFs) and transforming growth factor-β1 (TGF-β1)-induced collagen expression and explored the underlying mechanism. We found that RACK1 was decreased in KFs, overexpression of RACK1 significantly inhibited TGF-β1-induced KFs proliferation. RACK1 also obviously inhibited the expression of TGF-β1-induced TGF-β receptor I, II, type I collagen and α-smooth muscle actin (α-SMA) in human KFs. In addition, RACK1 suppressed the expression of TGF-β1-induced Smad2 and Smad3 phosphorylation in human KFs. Taken together, our study suggested that RACK1 inhibits collagen synthesis in KFs via inhibition the TGF-β1/Smad signaling pathway, and RACK1 is a potential target for treatment of the keloid disease.

Ubiquitination and regulation of Smad7 in the TGF-β1/Smad signaling of aristolochic acid nephropathy

Aristolochic acid I (AAI) affects TGF-β1/Smad signaling, which causes AA nephropathy (AAN), but the mechanisms are not fully understood. We aimed to clarify whether Arkadia and UCH37 participate in TGF-β1/Smad signaling via Smad7, and the regulatory mechanisms of Smad7. One side, mice and cultured mouse renal tubular epithelial cells (RTECs) were treated with various AAI doses and concentrations, respectively; on the other side, RTECs were transfected with small interfering RNA (siRNA) expression vectors against Arkadia and UCH37 and then treated with 10 µg/ml AAI. And then detect the mRNA and protein levels of Smad7, UCH37, Arkadia and any other relative factors by RT-PCR and Western blotting. In kidney tissues and RTECs, the mRNA and protein levels of Smad7 decreased with increasing AAI doses concentrations by real-time PCR and Western blotting, whereas those of Arkadia, UCH37, Smad2, Smad3 and TβRI increased. Cells transfected with the Arkadia siRNA expression vector showed reduced mRNA and protein levels of vimentin, α-SMA, Smad2, Smad3 and TβRI after AAI treatment, while those of CK18 and Smad7 increased compared with those of untransfected RTECs. Conversely, cells transfected with the UCH37 siRNA expression vector showed the opposite effect on analyzed signaling molecules after AAI treatment. Arkadia and UCH37 participate in TGF-β1/Smad signaling-mediated renal fibrosis, and Smad7 blocks TGF-β1 signaling by inhibiting Smad2/Smad3 phosphorylation and enhancing the degradation of TβRI.

Modulation of IKKβ/NF-κB and TGF-β1/Smad via Fuzheng Huayu recipe involves in prevention of nutritional steatohepatitis and fibrosis in mice

OBJECTIVES

Fuzheng Huayu recipe (FZHY) exerts significant protective effects against liver fibrosis by strengthening the body's resistance and removing blood stasis. However, the molecular mechanisms through which FZHY affects liver fibrosis are still unclear. In this study, we examined the expression levels of factors involved in the inhibitor κB kinase-β (IKK-β)/nuclear factor-κB (NF-κB) and transforming growth factor beta 1 (TGF-β1)/Smad signaling pathways to elucidate whether FZHY could attenuate nutritional steatohepatitis and fibrosis in mice.

MATERIALS AND METHODS

C57BL/6J mice were fed with methionine-choline deficient (MCD) diet for 8 weeks to induce fibrotic steatohepatitis. FZHY and/or heme oxygenase-1 (HO-1) chemical inducer (hemin) were administered to mice. The effects of FZHY alone and in combination with hemin were assessed by comparing the severity of hepatic injury, activation of hepatic stellate cells (HSCs), and the expression of oxidative stress, inflammation and fibrogenesis related genes.

RESULTS

Administration of FZHY, hemin and FZHY plus hemin significantly ameliorated liver injury. Additionally, our analysis indicated that administration of these agents significantly attenuated oxidative stress, downregulated the expression of pro-inflammatory and pro-fibrotic genes, including IKK-β, NF-κB, monocyte chemoattractant protein-1 (MCP-1), α-smooth muscle actin (α-SMA), TGF-β1, Smad3 and Smad4, and upregulated the expression of the antifibrogenic gene Smad7 (P< 0.001).

CONCLUSION

FZHY-containing therapies prevented nutritional steatohepatitis and fibrosis through modulating the expression of factors associated with the IKKβ/NF-κB and TGF-β1/Smad signaling pathways and oxidative stress related genes.

TGF-β1/Smad signaling, MMP-14, and MSC markers in arterial injury: discovery of the molecular basis of restenosis

Transforming growth factor (TGF)-β1 has been suggested to be involved in the recruitment of mesenchymal stem cells (MSCs) following arterial injury, but the role of downstream signaling and the contribution of the recruited MSCs are still unknown. The release of latent TGF-β1 from latent TGF-binding protein (LTBP) by matrix metallopeptidase-14 (MMP-14) proteolysis was demonstrated, which contributed to neointima formation, but the relationship between MMP-14 and activated TGF-β1 in the process of restenosis has yet to be explored. In this study, we observed the change in expression and distribution of TGF-β1/Smad signaling pathway proteins, MMP-14, and MSC markers in the process of neointima formation using a rat model for balloon-induced carotid artery injury. We found that the increase in downstream Smad signaling was consistent with the elevation of TGF-β1 levels and MSCs accumulated at the lumen side of neointima. Furthermore, the activation of MMP-14 in the injured artery was preceded by the increase in TGF-β1 levels. Herein, we conclude that MMP-14 induces an elevation in the levels of TGF-β1/Smad signaling proteins in injured arteries, and that MSCs are recruited by TGF-β1/Smad signaling and MMP-14, possibly differentiating into vascular smooth muscle cell (VSMC)-like cells and VSMC via modulation of TGF-β1/Smads signaling and MMP-14.