scholarly journals α-Lipoic Acid Increases Collagen Synthesis and Deposition in Nondiabetic and Diabetic Rat Kidneys

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Nevena Grdović ◽  
Jovana Rajić ◽  
Jelena Arambašić Jovanović ◽  
Svetlana Dinić ◽  
Anja Tolić ◽  
...  

α-Lipoic acid (ALA) is widely used as a nutritional supplement and therapeutic agent in diabetes management. Well-established antioxidant and hypoglycemic effects of ALA were considered to be particularly important in combating diabetic complications including renal injury. The present study evaluated the potential of ALA to affect profibrotic events in kidney that could alter its structure and functioning. ALA was administered intraperitoneally (10 mg/kg) to nondiabetic and streptozotocin-induced diabetic male Wistar rats for 4 and 8 weeks. The effects of ALA were assessed starting from structural/morphological alterations through changes that characterize profibrotic processes, to regulation of collagen gene expression in kidney. Here, we demonstrated that ALA improved systemic glucose and urea level, reduced formation of renal advanced glycation end products (AGEs), and maintained renal structural integrity in diabetic rats. However, profibrotic events provoked in diabetes were not alleviated by ALA since collagen synthesis/deposition and expression of transforming growth factor-β1 (TGF-β1) and α-smooth muscle actin (α-SMA) remained elevated in ALA-treated diabetic rats, especially after 8 weeks of diabetes onset. Moreover, 8 weeks treatment of nondiabetic rats with ALA led to the development of profibrotic features reflected in increased collagen synthesis/deposition. Besides the TGF-β1 downstream signaling, the additional mechanism underlying the upregulation of collagen IV in nondiabetic rats treated with ALA involves decreased DNA methylation of its promoter that could arise from increased Tet1 expression. These findings emphasize the therapeutic caution in the use of ALA, especially in patients with renal diabetic complication.

2019 ◽  
Vol 39 (4) ◽  
pp. 440-450 ◽  
Author(s):  
WH El-Maadawy ◽  
OA Hammam ◽  
SH Seif el-Din ◽  
NM El-Lakkany

Autophagy and apoptosis are important players in the progression of hepatic fibrosis via activation of hepatic stellate cells (HSCs). Despite the recently depicted antifibrotic effects of alpha-lipoic acid (ALA), however, its modulatory effects on HSCs autophagy remain unverified. Our study aimed to elucidate the underlying antifibrotic mechanisms through which ALA mediates HSC autophagy and apoptosis. Liver fibrosis was induced via thioacetamide (TAA) intoxication in rats; TAA-intoxicated rats were treated with either silymarin or ALA. Effect of ALA on biochemical parameters and immunohistopathological examinations was measured and compared to silymarin. ALA restored normal hepatic architecture (S1 vs. S4), liver functions, hepatic glutathione, and transforming growth factor-β1 levels. ALA ameliorated hepatic levels of malondialdehyde, platelet-derived growth factor, tissue inhibitor metalloproteinases-1, hydroxyproline, and expression of alpha-smooth muscle actin. Moreover, ALA significantly reduced messenger RNA expression of LC3-II genes and triggered caspase-3 expression. Interestingly, ALA exhibited superior activities over silymarin regarding suppression of proliferation, activation and autophagy of HSCs, collagen deposition, and induction of HSCs apoptosis. In conclusion, treatment of TAA-intoxicated rats with ALA inhibited autophagy and induced apoptotic clearance of activated HSCs. Accordingly, this study provides mechanistic insights into the possible applicability of ALA in the treatment of hepatic fibrosis.


Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Shouguo Yang ◽  
Guanggen Cui ◽  
Ramin Beygui ◽  
Fardad Esmailian ◽  
Abbas Ardehali ◽  
...  

Background The underlying mechanism of thoracic aortic aneurysm (TAA) and dissection(TAD) was undetermined, and one controversy lies in whether they represent the different dvelopement period of the same disorder or totally diferent diseases. This study is in aim to compare the expression and distribution of Transforming Growth Factors(TGF) β1 in the aortic wall of TAA versus TAD patients. Method Aortic specimens were obtained from patients underwent to aortic procedures for TAA (n=38) and TAD (n=20) at UCLA , and control aorta (CN) from organ donnor (n=20). Double immunofluorescent stainning of TGF-β1 and α-smooth muscle actin were performed with paraffin embeded slides for all aortic samples and semiquantified by fluorescent intensity analysis. Histopathologic examination were performed with HE, Verhoeff van-Gieson and Masson’s trichrome stain. Results TAA and TAD patients exhibited an up-regulation of TGF-β1 to 120.3% and 109.6% compared with CN separately (P<0.05), with TAA higher than TAD (P<0.05). TGF-β1 distributed unevenly across aortic wall with the highest levels expression in tunica media, followed by intima then adventitia. In intima, TGF-β1 was expressed at the same level for TAD as CN, but was increased to 115.2% for TAA compared to CN (P<0.05). In media, TGF-β1 increased by 127.2% in TAA and 116.1% in TAD compared to CN (P<0.01), with TAA being higher than TAD (P<0.05). In adventitia, TGF- β1 was up-regulated to 119.6% and 116.7% for TAA and TAD compared to CN (P<0.05). Nucleus density analysis showed cellular plasia in adventitia of TAA and TAD than CN (P<0.05 ), while TAD patients demonstrated a higher nucleus density than TAA in intima and adventitia (P<0.05). α-actin was increased in media of TAA and TAD to 164.5% and 120% than CN (P<0.01 and P<0.05). Attenuated and interrupted elastin and mild to severe cystic medial degeneration were characteristic histopathologic finding in 29 (76.3%) TAA and 17(85%) TAD patients. Conclusions TGF- β1 expression was up-regulated in aortic wall of TAA and TAD compared to CN. The significant higher levels of TGF- β1 in intima and media in TAA versus TAD patients implicated a probable positive effect of TGF- β1 to maintain aortic wall integrity, and/or greater comsamption of TGF- β1 in the aortic dissection.


2017 ◽  
Vol 28 (05) ◽  
pp. 420-425 ◽  
Author(s):  
Xiao-Hui Tan ◽  
Chun-Lan Long ◽  
De-Ying Zhang ◽  
Tao Lin ◽  
Da-Wei He ◽  
...  

Introduction Several urethroplasties have been employed in the surgical treatment of hypospadias. Neourethral strictures are among the most common postoperative complications that often require reoperation. Materials and Methods We created a hypospadias model in New Zealand white male rabbits through a hypospadias-like defect and acute repair. A total of 24 animals were randomly allocated into three groups: tubularized incised-plate urethroplasty (TIPU) group (8), perimeatal-based flap urethroplasty (Mathieu) group (8), onlay island flap urethroplasty (onlay) group (8), and corresponding surgical procedures were immediately performed to reconstruct neourethra. The rabbits were killed postoperatively at 5 days, 2 weeks, 6 weeks, and 3 months, respectively. The penile tissue was harvested for histological and biochemical investigations to evaluate the expressions of transforming growth factor β1 (TGF-β1) and α-smooth muscle actin (α-SMactin) in all groups. Results All rabbits were operated on uneventfully. The amount of collagen content was increased in the Mathieu and onlay groups than in the TIPU group (p < 0.05). Biochemical analysis showed that the expression of TGF-β1 in the TIPU group was decreased compared with the two other groups at 2 or 6 weeks postoperatively (p < 0.01). The expression pattern regarding α-SMactin was similar at 6 weeks or 3 months postoperatively (p < 0.01). Conclusion The neourethra repaired by TIPU was practically resumed to normal anatomy and scarring was less apparent than the two other groups. Therefore, TIPU is considered as a relatively rational approach for hypospadias repair. The activity of fibroblasts has been increased in the long term, which may be the pathogenesis of neourethral stricture following hypospadias repair.


Biomolecules ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1682
Author(s):  
Vincent Yeung ◽  
Sriniwas Sriram ◽  
Jennifer A. Tran ◽  
Xiaoqing Guo ◽  
Audrey E. K. Hutcheon ◽  
...  

Corneal fibrosis (or scarring) occurs in response to ocular trauma or infection, and by reducing corneal transparency, it can lead to visual impairment and blindness. Studies highlight important roles for transforming growth factor (TGF)-β1 and -β3 as modulators in corneal wound healing and fibrosis, leading to increased extracellular matrix (ECM) components and expression of α-smooth muscle actin (αSMA), a myofibroblast marker. In this study, human corneal fibroblasts (hCF) were cultured as a monolayer culture (2D) or on poly-transwell membranes to generate corneal stromal constructs (3D) that were treated with TGF-β1, TGF-β3, or TGF-β1 + FAK inhibitor (FAKi). Results show that hCF 3D constructs treated with TGF-β1 or TGF-β3 impart distinct effects on genes involved in wound healing and fibrosis—ITGAV, ITGB1, SRC and ACTA2. Notably, in the 3D construct model, TGF-β1 enhanced αSMA and focal adhesion kinase (FAK) protein expression, whereas TGF-β3 did not. In addition, in both the hCF 2D cell and 3D construct models, we found that TGF-β1 + FAKi attenuated TGF-β1-mediated myofibroblast differentiation, as shown by abrogated αSMA expression. This study concludes that FAK signaling is important for the onset of TGF-β1-mediated myofibroblast differentiation, and FAK inhibition may provide a novel beneficial therapeutic avenue to reduce corneal scarring.


2009 ◽  
Vol 88 (8) ◽  
pp. 757-761 ◽  
Author(s):  
K. Jinno ◽  
T. Takahashi ◽  
K. Tsuchida ◽  
E. Tanaka ◽  
K. Moriyama

Wound healing is a well-orchestrated complex process leading to the repair of injured tissues. It is suggested that transforming growth factor (TGF)-β/Smad3 signaling is involved in wound healing. The purpose of this study was to investigate the role of TGF-β/Smad3 signaling in palatal wound healing in Smad3-deficient (Smad3−/−) mice. Histological examination showed that wound closure was accelerated by the proliferation of epithelium and dermal cells in Smad3−/− mice compared with wild-type (WT) mice. Macrophage/monocyte infiltration at wounded regions in Smad3−/− mice was decreased in parallel with the diminished production of TGF-β1, monocyte chemoattractant protein-1, and macrophage inflammatory protein-1α compared with WT mice. Fibrocytes, expressing hematopoietic surface marker and fibroblast products, were recruited and produced α-smooth-muscle actin in WT mice, but were not observed in Smad3−/− mice. These results suggest that TGF-β/Smad3 signaling may play an important role in the regulation of palatal wound healing.


Cardiology ◽  
2015 ◽  
Vol 131 (2) ◽  
pp. 97-106 ◽  
Author(s):  
Weili Qiao ◽  
Cheng Wang ◽  
Bing Chen ◽  
Fan Zhang ◽  
Yaowu Liu ◽  
...  

Objective: To investigate the effects of ibuprofen on cardiac fibrosis in a rat model of type 1 diabetes. Methods: The diabetic model was established by injecting streptozotocin into the rats. Then, ibuprofen or pioglitazone was given by gavage for 8 weeks. The cardiac fibrosis was assessed, and the major components of the renin-angiotensin system, the transforming growth factor β1 (TGF-β1) and the mammalian target of rapamycin (mTOR), were evaluated by histopathological, immunohistochemical, Western blot analysis or ELISA assay. Results: Obvious cardiac fibrosis was detected in the diabetic group and was alleviated by ibuprofen treatment. Angiotensin-converting enzyme (ACE), angiotensin (Ang) II and AngII type 1 receptor (AT1-R) levels were higher, and ACE2, Ang(1-7) and Mas receptor (Mas-R) were lower in the diabetic group. The ratio of ACE to ACE2 was raised in the diabetic group. All these changes were ameliorated by ibuprofen. TGF-β1 and mTOR were raised in the hearts of the diabetic group and were attenuated by ibuprofen treatment. There was no significant difference between the ibuprofen and the pioglitazone groups. Conclusion: Ibuprofen could ameliorate the cardiac fibrosis in diabetic rats by reduction of the ACE/AngII/AT1-R axis and enhancement of the ACE2/Ang(1-7)/Mas-R axis, leading to a decrease in TGF-β1 and mTOR.


2018 ◽  
Vol 315 (6) ◽  
pp. G954-G965 ◽  
Author(s):  
Murli Manohar ◽  
Hemanth Kumar Kandikattu ◽  
Alok Kumar Verma ◽  
Anil Mishra

Pancreatitis is an inflammatory disease characterized by the induction of several proinflammatory cytokines like interleukin (IL)-6, IL-8, IL-1β, and IL-1. Recently, the multifunctional innate cytokine IL-15 has been implicated in the protection of several diseases, including cancer. Tissue fibrosis is one of the major problems in successfully treating chronic pancreatitis pathogenesis. Therefore, we tested the hypothesis that recombinant IL-15 (rIL-15) treatment may induce innate tissue responses and its overexpression will improve the pathogenesis of cerulein-induced chronic pancreatitis, associated remodeling, and fibrosis. We observed atrophy of acinar cells, increased inflammation, and increased deposition of perivascular collagen, the upregulated protein level of transforming growth factor (TGF)-β1, α-smooth muscle actin (α-SMA), and collagen-1 in cerulein-induced chronic pancreatitis in mice. Furthermore, we reported that rIL-15 treatment protects mice from the cerulein-induced chronic pancreatitis pathogenesis, including acinar cell atrophy, and perivascular accumulation of tissue collagen followed by downregulation of profibrotic genes such as TGF-β1, α-SMA, collagen-1, collagen-3, and fibronectin in cerulein-induced chronic pancreatitis in mice. Mechanistically, we show that IL-15-mediated increase of interferon-γ-responsive invariant natural killer T (iNKT) cells in the blood and tissue protects cerulein-induced pancreatic pathogenesis in mice. Of note, a reduction in iNKT cells was also observed in human chronic pancreatitis compared with normal individuals. Taken together, these data suggest that IL-15 treatment may be a novel therapeutic strategy for treating chronic pancreatitis pathogenesis. NEW & NOTEWORTHY Pancreatic fibrosis is a major concern for the successful treatment of chronic pancreatitis and pancreatic cancer. Therefore, restriction in the progression of fibrosis is the promising approach to manage the pancreatitis pathogenesis. Herein, we present in vivo evidences that pharmacological treatment of recombinant interleukin-15 improves remodeling and fibrosis in cerulein-induced chronic pancreatitis in mice. Our observations indicate that interleukin-15 immunotherapy may be a possible and potential strategy for restricting the progression of fibrosis in chronic pancreatitis.


Marine Drugs ◽  
2018 ◽  
Vol 16 (9) ◽  
pp. 323 ◽  
Author(s):  
Hyun Jung ◽  
Dae-Sung Lee ◽  
Seong Park ◽  
Jung Choi ◽  
Won-Kyo Jung ◽  
...  

Nasal polyps (NPs) are a multifactorial disorder associated with a chronic inflammatory state of the nasal mucosa. Fucoxanthin (Fx) is a characteristic orange carotenoid obtained from brown algae and has diverse immunological properties. The present study investigated whether Fx inhibits fibrosis-related effects in nasal polyp-derived fibroblasts (NPDFs) and elucidated the molecular signaling pathways involved. The production of collagen type I (Col-1) was investigated in NP tissue via immunohistochemistry and western blot analysis. NPDFs were treated with transforming growth factor (TGF)-β1 (1 ng/mL) in the presence or absence of Fx (5–30 µM). The levels of α-smooth muscle actin (α-SMA), Col-1, and phosphorylated (p)-Smad 2/3, signal protein-1 (SP-1), MAPKs (mitogen-activated protein kinases), and Akt were measured by western blot analysis. The expression of Col-1 was detected in NP tissues. TGF-β1 stimulated the production of α-SMA and Col-1, and stimulated the contraction of collagen gel. However, pretreatment with Fx attenuated these effects. Furthermore, these inhibitory effects were mediated through modulation of both Smad 2/3 and Akt/SP-1 signaling pathways in TGF-β1-induced NPDFs. The results from the present study suggest that Fx may be a novel anti-fibrotic agent for the treatment of NP formation.


Biomolecules ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 525 ◽  
Author(s):  
Edith Sierra-Mondragon ◽  
Rafael Rodríguez-Muñoz ◽  
Carmen Namorado-Tonix ◽  
Eduardo Molina-Jijon ◽  
Daniel Romero-Trejo ◽  
...  

Diabetic nephropathy (DN) involves damage associated to hyperglycemia and oxidative stress. Renal fibrosis is a major pathologic feature of DN. The aim of this study was to evaluate anti-fibrogenic and renoprotective effects of all-trans retinoic acid (ATRA) in isolated glomeruli and proximal tubules of diabetic rats. Diabetes was induced by single injection of streptozotocin (STZ, 60 mg/Kg). ATRA (1 mg/Kg) was administered daily by gavage, from days 3–21 after STZ injection. ATRA attenuated kidney injury through the reduction of proteinuria, renal hypertrophy, increase in natriuresis, as well as early markers of damage such as β2-microglobulin, kidney injury molecule-1 (KIM-1), and neutrophil gelatinase-associated lipocalin (NGAL). The following parameters increased: macrophage infiltration, localization of alpha-smooth muscle actin (αSMA)-positive cells in renal tissue, and pro-fibrotic proteins such as transforming growth factor-β (TGF-β1), laminin beta 1 (LAM-β1), and collagens IV and I. Remarkably, ATRA treatment ameliorated these alterations and attenuated expression and nuclear translocation of Smad3, with increment of glomerular and tubular Smad7. The diabetic condition decreased expression of retinoic acid receptor alpha (RAR-α) through phosphorylation in serine residues mediated by the activation of c-Jun N-terminal kinase (JNK). ATRA administration restored the expression of RAR-α and inhibited direct interactions of JNK/RAR-α. ATRA prevented fibrogenesis through down-regulation of TGF-β1/Smad3 signaling.


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