scholarly journals mTOR inhibitors potentially reduce TGF-β2-induced fibrogenic changes in trabecular meshwork cells

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nozomi Igarashi ◽  
Megumi Honjo ◽  
Makoto Aihara

AbstractWe examined the effects of mTOR inhibitors on the fibrotic response induced by transforming growth factor-beta2 (TGF-β2) in cultured human trabecular meshwork (hTM) cells. TGF-β2-induced expression of fibronectin, collagen type I, alpha 1 chain (COL1A1), and alpha-smooth muscle actin (αSMA) in hTM cells was examined in the presence or absence of mTOR inhibitors using quantitative real-time polymerase chain reaction, Western blotting, and immunohistochemistry. The migration rates of hTM cells were examined in the presence of TGF-β2 with or without mTOR inhibitors. An in vitro study showed that the expression of fibronectin, COL1A1, and αSMA was upregulated by TGF-β2 treatment of hTM cells; such upregulation was significantly suppressed by mTOR inhibitors. The inhibitors significantly reduced the migration rate of TGF-β2-stimulated hTM cells. mTOR inhibitors may usefully reduce the fibrotic response of hTM cells and we may have to explore if it is also effective in in vivo model.

2021 ◽  
Vol 11 ◽  
Author(s):  
Jianwei Fan ◽  
Lifang Duan ◽  
Nan Wu ◽  
Xiaofan Xu ◽  
Jiaqi Xin ◽  
...  

Pancreatic inflammation and fibrosis are typical pathological features in chronic pancreatitis (CP). Activated pancreatic stellate cells (PSCs) have been regarded as the core event in the development of pancreatic fibrosis and are considered to be the key target for treatment of CP. Baicalin (C21H18O11), the main chemical composition of Baikal skullcap in the traditional Chinese medicines Dachaihu decoction (DCHD) and Xiaochaihu decoction (XCHD), has shown significant effects in the treatment of pancreatic fibrosis in CP mice; however, whether baicalin can inhibit the activation of PSCs and its underlying mechanism remain unclear. In this study, the influence of baicalin on activated PSCs in vitro and in vivo was investigated, and the results showed that Baicalin could significantly ameliorate the degree of pancreatic inflammation and fibrosis, while decreasing the levels of alpha-smooth muscle actin (α-SMA), F4/80 (surface markers of mouse macrophages), nuclear factor kappa-B (NF-κB), monocyte chemotactic protein 1 (MCP-1), and collagen type I alpha 1 (COL1A1)in the pancreas. Moreover, NF-κB and α-SMA were co-expressed in the pancreas of CP mice. Baicalin treatment markedly reduced the expression of co-location of α-SMA and NF-κB. In vitro, the protein expression levels of transforming growth factor-β receptor 1 (TGF-βR1), phosphorylated TGF-β activated kinase 1 p-TAK 1, and NF-κBp65 in PSCs were all remarkably reduced after treatment with baicalin. In addition, baicalin could inhibit MCP-1 mRNA expression in supernatant of activated PSCs, as well as the excessive migration of macrophages. Taken together, our findings indicated that baicalin could inhibit the TGF-β1/TGF-βR1/TAK1/NF-κB signaling pathway of activated PSCs, reduce the secretion of MCP-1, and further decrease the infiltration of macrophages and inflammation cells of the local microenvironment of the pancreas. Thus, this study provides a reliable experimental basis for baicalin in the prevention and treatment of CP.


2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Hui Dai ◽  
Liang Chen ◽  
Dongyue Gao ◽  
Aihua Fei

The present study was designed to further explore the role and the underlying molecular mechanism of phosphocreatine (PCr) for cardiac fibrosis in vivo. Isoproterenol (ISO) was used to induce cardiac fibrosis in rats. PCr administration ameliorated fibrosis by reducing collagen accumulation and fibrosis-related signals, including transforming growth factor beta 1 (TGF-β1), alpha smooth muscle actin (α-SMA), collagen type I, and collagen type III. Mitogen-activated protein kinases (MAPKs) and nuclear factor kappa B (NF-κB) signaling pathways, including p38, extracellular signal regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p65, were highly activated by ISO and blocked by PCr. Moreover, PCr decreased ISO-induced matrix metalloproteinase-9 (MMP-9) and increased the tissue inhibitor of metalloproteinase-1 (TIMP-1) expression. Furthermore, PCr suppressed cardiomyocyte apoptosis induced by ISO, as shown by downregulated expression of the proapoptotic caspase-3, Bax, and upregulated expression of the antiapoptotic Bcl-2. Taken together, PCr can be an effective agent for preventing cardiac fibrosis and cardiomyocyte apoptosis.


2017 ◽  
Vol 45 (05) ◽  
pp. 1061-1074 ◽  
Author(s):  
Jiamei Chen ◽  
Xuewei Li ◽  
Yonghong Hu ◽  
Wei Liu ◽  
Qun Zhou ◽  
...  

Gypenosides (GPs), the predominant components of Gynostemma pentaphyllum, exert antifibrotic effects; however, the mechanisms underlying their ability to ameliorate liver fibrosis are unclear. Liver fibrosis was induced in C57BL/6 mice via subcutaneous injection of 10% carbon tetrachloride (CCl[Formula: see text] three times a week for two weeks. Then, CCl4 was administered in conjunction with intragastric GPs for another three weeks. For in vitro analyses, WB-F344, hepatatic progenitor cells (HPCs) were treated with transforming growth factor beta 1 (TGF-[Formula: see text]1) with or without GPs for 48[Formula: see text]h. The results showed that alanine aminotransferase (ALT) and aspartate transaminase (AST) activity, deposition of collagen, hydroxyproline content, and expression of alpha-smooth muscle actin ([Formula: see text]-SMA) and collagen type I (Col I) were significantly decreased after treatment with GPs ([Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text]). In the 5M CCl4 group, the expression of HPC markers, Sox9 and cytokeratin 19 (CK19), was significantly increased compared with the normal or GPs-treated group ([Formula: see text], [Formula: see text]). Immunostaining showed that the number of Sox9 and [Formula: see text]-SMA double-positive cells was higher in the 5M CCl4 group than in the normal group, but the addition of GPs caused this cell number to decrease. In WB-F344 cells, the expression of [Formula: see text]-SMA and Col I was significantly increased after treatment with TGF-[Formula: see text], whereas in the GPs treatment group, expression was markedly decreased ([Formula: see text]). The levels of TGF-[Formula: see text] and TGF-[Formula: see text]R1 were markedly reduced after GPs treatment both in vivo and in vitro. In conclusion, GPs ameliorated CCl4-induced liver fibrosis via the inhibition of TGF-[Formula: see text] signaling, consequently inhibiting the differentiation of HPCs into myofibroblasts.


2021 ◽  
Vol 22 (4) ◽  
pp. 1861
Author(s):  
Jemima Seidenberg ◽  
Mara Stellato ◽  
Amela Hukara ◽  
Burkhard Ludewig ◽  
Karin Klingel ◽  
...  

Background: Pathological activation of cardiac fibroblasts is a key step in development and progression of cardiac fibrosis and heart failure. This process has been associated with enhanced autophagocytosis, but molecular mechanisms remain largely unknown. Methods and Results: Immunohistochemical analysis of endomyocardial biopsies showed increased activation of autophagy in fibrotic hearts of patients with inflammatory cardiomyopathy. In vitro experiments using mouse and human cardiac fibroblasts confirmed that blockade of autophagy with Bafilomycin A1 inhibited fibroblast-to-myofibroblast transition induced by transforming growth factor (TGF)-β. Next, we observed that cardiac fibroblasts obtained from mice overexpressing transcription factor Fos-related antigen 2 (Fosl-2tg) expressed elevated protein levels of autophagy markers: the lipid modified form of microtubule-associated protein 1A/1B-light chain 3B (LC3BII), Beclin-1 and autophagy related 5 (Atg5). In complementary experiments, silencing of Fosl-2 with antisense GapmeR oligonucleotides suppressed production of type I collagen, myofibroblast marker alpha smooth muscle actin and autophagy marker Beclin-1 in cardiac fibroblasts. On the other hand, silencing of either LC3B or Beclin-1 reduced Fosl-2 levels in TGF-β-activated, but not in unstimulated cells. Using a cardiac hypertrophy model induced by continuous infusion of angiotensin II with osmotic minipumps, we confirmed that mice lacking either Fosl-2 (Ccl19CreFosl2flox/flox) or Atg5 (Ccl19CreAtg5flox/flox) in stromal cells were protected from cardiac fibrosis. Conclusion: Our findings demonstrate that Fosl-2 regulates autophagocytosis and the TGF-β-Fosl-2-autophagy axis controls differentiation of cardiac fibroblasts. These data provide a new insight for the development of pharmaceutical targets in cardiac fibrosis.


Author(s):  
Joon M. Jung ◽  
Hae K. Yoon ◽  
Chang J. Jung ◽  
Soo Y. Jo ◽  
Sang G. Hwang ◽  
...  

Cold plasma can be beneficial for promoting skin wound healing and has a high potential of being effectively used in treating various wounds. Our aim was to verify the effect of cold plasma in accelerating wound healing and investigate its underlying mechanism in vitro and in vivo. For the in vivo experiments, 2 full-thickness dermal wounds were created in each mouse (n = 30). While one wound was exposed to 2 daily plasma treatments for 3 min, the other wound served as a control. The wounds were evaluated by imaging and histological analyses at 4, 7, and 11 days post the wound infliction process. Immunohistochemical studies were also performed at the same time points. In vitro proliferation and scratch assay using HaCaT keratinocytes and fibroblasts were performed. The expression levels of wound healing–related genes were analyzed by real-time polymerase chain reaction and western blot analysis. On day 7, the wound healing rates were 53.94% and 63.58% for the control group and the plasma-treated group, respectively. On day 11, these rates were 76.05% and 93.44% for the control and plasma-treated groups, respectively, and the difference between them was significant ( P = .039). Histological analysis demonstrated that plasma treatment promotes the formation of epidermal keratin and granular layers. Immunohistochemical studies also revealed that collagen 1, collagen 3, and alpha-smooth muscle actin appeared more abundantly in the plasma-treated group than in the control group. In vitro, the proliferation of keratinocytes was promoted by plasma exposure. Scratch assay showed that fibroblast exposure to plasma increased their migration. The expression levels of collagen 1, collagen 3, and alpha-smooth muscle actin were elevated upon plasma treatment. In conclusion, cold plasma can accelerate skin wound healing and is well tolerated.


2019 ◽  
Vol 39 (10) ◽  
pp. 2168-2191 ◽  
Author(s):  
Bronson A. Haynes ◽  
Li Fang Yang ◽  
Ryan W. Huyck ◽  
Eric J. Lehrer ◽  
Joshua M. Turner ◽  
...  

Objective: Endothelial cells (EC) in obese adipose tissue (AT) are exposed to a chronic proinflammatory environment that may induce a mesenchymal-like phenotype and altered function. The objective of this study was to establish whether endothelial-to-mesenchymal transition (EndoMT) is present in human AT in obesity and to investigate the effect of such transition on endothelial function and the endothelial particulate secretome represented by extracellular vesicles (EV). Approach and Results: We identified EndoMT in obese human AT depots by immunohistochemical co-localization of CD31 or vWF and α-SMA (alpha-smooth muscle actin). We showed that AT EC exposed in vitro to TGF-β (tumor growth factor-β), TNF-α (tumor necrosis factor-α), and IFN-γ (interferon-γ) undergo EndoMT with progressive loss of endothelial markers. The phenotypic change results in failure to maintain a tight barrier in culture, increased migration, and reduced angiogenesis. EndoMT also reduced mitochondrial oxidative phosphorylation and glycolytic capacity of EC. EVs produced by EC that underwent EndoMT dramatically reduced angiogenic capacity of the recipient naïve ECs without affecting their migration or proliferation. Proteomic analysis of EV produced by EC in the proinflammatory conditions showed presence of several pro-inflammatory and immune proteins along with an enrichment in angiogenic receptors. Conclusions: We demonstrated the presence of EndoMT in human AT in obesity. EndoMT in vitro resulted in production of EV that transferred some of the functional and metabolic features to recipient naïve EC. This result suggests that functional and molecular features of EC that underwent EndoMT in vivo can be disseminated in a paracrine or endocrine fashion and may induce endothelial dysfunction in distant vascular beds.


2018 ◽  
Vol 51 (5) ◽  
pp. 2111-2122 ◽  
Author(s):  
Yi-Bing Hu ◽  
Xiao-Ting Ye ◽  
Qing-Qing Zhou ◽  
Rong-Quan Fu

Background/Aims: Sestrin 2 is associated with the pathophysiology of several diseases. The aim of this study was to investigate the effects and potential mechanisms of Sestrin 2 in rat hepatic stellate cells (HSCs) during liver fibrogenesis. Methods: In this study, Sestrin 2 protein expression was detected in rat HSC-T6 cells challenged with transforming growth factor-β (TGF-β) and in mice treated with carbon tetrachloride (CCl4), a well-known model of hepatic fibrosis. Next, HSC-T6 cells and fibrotic mice were transfected with lentivirus. The mRNA expression levels of markers of liver fibrosis [alpha-smooth muscle actin (α-SMA) and collagen 1A1 (Col1A1)] were analyzed by quantitative reverse transcription–polymerase chain reaction (RT-PCR). Cell death and proliferation were evaluated by the MTT assay, and biochemical markers of liver damage in serum [alanine transaminase (ALT) and aspartate transaminase (AST)] were also measured using a biochemical analyzer. Histopathological examination was used to evaluate the degree of liver fibrosis, and protein expression [phospho-adenosine monophosphate-activated protein kinase (p-AMPK), AMPK, phospho-mammalian target of rapamycin (p-mTOR), and mTOR] was determined by western blotting. Results: We found that Sestrin 2 was elevated in both the HSC-T6 cell and hepatic fibrosis models. In vitro, overexpression of Sestrin 2 attenuated the mRNA levels of α-SMA and Col1A1, suppressed α-SMA protein expression, and modulated HSC-T6 cell proliferation. In vivo, overexpression of Sestrin 2 reduced the ALT and AST levels as well as the α-SMA and Col1A1 protein expression in the CCl4 model of liver fibrosis. Moreover, the degree of liver fibrosis was ameliorated. Interestingly, overexpression of Sestrin 2 increased p-AMPK but decreased p-mTOR protein expression. Conclusion: Our findings indicate that Sestrin 2 may attenuate the activation of HSCs and ameliorate liver fibrosis, most likely via upregulation of AMPK phosphorylation and suppression of the mTOR signaling pathway.


Author(s):  
Qiao You Lau ◽  
Fuad Gandhi Torizal ◽  
Marie Shinohara ◽  
Yasuyuki Sakai

During chronic liver injury, inflammation leads to the development of liver fibrosis— particularly due to the activation of hepatic stellate cells (HSCs). However, the involvement of inflammatory cytokines in HSC activation is unclear. Many existing in vitro liver models do not include these non-parenchymal cells (NPCs), and hence, do not represent the physiological relevance found in vivo. Herein, we demonstrated the hierarchical coculture of primary rat hepatocytes with NPCs such as the human-derived HSC line (LX-2) and the human-derived liver sinusoidal endothelial cell line (TMNK-1). The coculture tissue had higher albumin production and hepatic cytochrome P450 3A4 activity compared to the monoculture. We then further studied the effects of stimulation by both oxygen tension and key pro-fibrogenic cytokines, such as the transforming growth factor beta (TGF-β), on HSC activation. Gene expression analysis revealed that lower oxygen tension and TGF-β1 stimulation enhanced collagen type I, III, and IV, alpha-smooth muscle actin, platelet-derived growth factor, and matrix metallopeptidase expression from LX-2 cells in the hierarchical coculture after fibrogenesis induction. This hierarchical in vitro cocultured liver tissue could, therefore, provide an improved platform as a disease model for elucidating the interactions of various liver cell types and biochemical signals in liver fibrosis studies.


2003 ◽  
Vol 95 (2) ◽  
pp. 771-780 ◽  
Author(s):  
Yi-Sheng Chan ◽  
Yong Li ◽  
William Foster ◽  
Takashi Horaguchi ◽  
George Somogyi ◽  
...  

Muscle injuries are very common in traumatology and sports medicine. Although muscle tissue can regenerate postinjury, the healing process is slow and often incomplete; complete recovery after skeletal muscle injury is hindered by fibrosis. Our studies have shown that decreased fibrosis could improve muscle healing. Suramin has been found to inhibit transforming growth factor (TGF)-β1 expression by competitively binding to the growth factor receptor. We conducted a series of tests to determine the antifibrotic effects of suramin on muscle laceration injuries. Our results demonstrate that suramin (50 μg/ml) can effectively decrease fibroblast proliferation and fibrotic-protein expression (α-smooth muscle actin) in vitro. In vivo, direct injection of suramin (2.5 mg) into injured murine muscle resulted in effective inhibition of muscle fibrosis and enhanced muscle regeneration, which led to efficient functional muscle recovery. These results support our hypothesis that prevention of fibrosis could enhance muscle regeneration, thereby facilitating more efficient muscle healing. This study could significantly contribute to the development of strategies to promote efficient muscle healing and functional recovery.


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