Cardiac hypertrophy caused by hyperthyroidism in rats: the role of ATF-6 and TRPC1 channels.

Hyperthyroidism influences the development of cardiac hypertrophy. Transient receptor potential canonical channels (TRPCs) and endoplasmic reticulum (ER) stress are regarded as critical pathways in cardiac hypertrophy. Hence, we aimed to identify the TRPCs associated with ER stress in hyperthyroidism-induced cardiac hypertrophy. Twenty adult Wistar albino male rats were used in the study. The control group was fed with standard food and tap water. The group with hyperthyroidism was also fed with standard rat food, along with tap water that contained 12 mg/L of thyroxine (T4) for 4 weeks. At the end of the fourth week, the serum-free triiodothyronine (T3), T4, and thyroid-stimulating hormone (TSH) levels of the groups were measured. The left ventricle of each rat was used for histochemistry, immunohistochemistry, Western blot, total antioxidant capacity (TAC), and total oxidant status (TOS) analysis. As per our results, activating transcription factor 6 (ATF-6), inositol-requiring kinase 1 (IRE-1), and TRPC1, which play a significant role in cardiac hypertrophy caused by hyperthyroidism, showed increased activation. Moreover, TOS and serum-free T3 levels increased, while TAC and TSH levels decreased. With the help of the literature review in our study, we could, for the first time, indicate that the increased activation of ATF-6, IRE-1, and TRPC1-induced deterioration of the Ca2+ ion balance leads to hypertrophy in hyperthyroidism due to heart failure.

The role of anakinra in the modulation of intestinal cell apoptosis and inflammatory response during ischemia/reperfusion

Background/aim: Even though interleukin-1 receptor antagonist, IL-1Ra, is used in certain inflammatory diseases, its effect on ischemia-reperfusion injury is a current research topic. We aimed to investigate the protective effects of anakinra, an IL-1Ra, on the I/R induced intestinal injury. Materials and methods: The rat model of intestinal ischemia-reperfusion was induced. Rats were randomized into 4 groups: (group 1) control group, (group 2) I/R group, (group 3 and 4) treatment groups (50 mg/kg and 100 mg/kg, respectively). Gene expressions of caspase-3, TNF-α, IL-1α, IL-6, and apoptotic cells in tissue samples were evaluated by PCR and TUNEL methods, respectively. Plasma levels of superoxide dismutase (SOD), catalase (CAT), and malondialdehyde (MDA) were studied by the ELISA method and tissue samples were examined histopathologically as well. Results: Anakinra inhibited the expression of IL-1α, IL-6, and TNF-α and decreased the SOD, CAT, and MDA caused by ischemia- reperfusion injury in both treatment groups. Caspase-3 expression and TUNEL-positive cell number in treatment groups were also less. Histopathologically, anakinra better preserved the villous structure of the small intestine at a dose of 100 mg/kg than 50 mg/kg. Conclusion: Anakinra decreased the intestinal damage caused by ischemia-reperfusion and a dose of 100 mg/kg was found to be histopathologically more effective.

Investigation of the effect of hyperthyroidism on endoplasmic reticulum stress and tran- sient receptor potential canonical 1 channel in the kidney

Background/aim: Hyperthyroidism is associated with results in increased glomerular filtration rate as well as increased renin-angio- tensin-aldosterone activation. The disturbance of Ca2+ homeostasis in the endoplasmic reticulum (ER) is associated with many diseases, including diabetic nephropathy and hyperthyroidism. Transient receptor potential canonical 1 (TRPC1) channel is the first cloned TRPC family protein. Although it is expressed in many places in the kidney, its function is uncertain. TRPC1 is involved in regulating Ca2+ homeostasis, and its upregulation increases ER Ca2+ level, activates the unfolded protein response, which leads to cellular damage in the kidney. This study investigated the role of TRPC1 in the kidneys of hyperthyroid rats in terms of ER stress markers that are gluco- se-regulated protein 78 (GRP78), activating transcription factor 6 (ATF6), (protein kinase R (PKR)-like endoplasmic reticulum kinase) (PERK), Inositol-requiring enzyme 1 (IRE1). Materials and methods: Twenty male rats were assigned into control and hyperthyroid groups (n = 10). Hyperthyroidism was induced by adding 12 mg/L thyroxine into the drinking water of rats for 4 weeks. The serum-free T3 and T4 (fT3, fT4), TSH, blood urea nitrogen (BUN), and creatinine levels were measured. The histochemical analysis of kidney sections for morphological changes and also im- munohistochemical and western blot analysis of kidney sections were performed for GRP78, ATF6, PERK, IRE1, TRPC1 antibodies. Results: TSH, BUN, and creatinine levels decreased while fT3 and fT4 levels increased in the hyperthyroid rat. The morphologic analy- sis resulted in the capillary basal membrane thickening in glomeruli and also western blot, and immunohistochemical results showed an increase in TRPC1, GRP78, and ATF6 in the hyperthyroid rat (p < 0.05). Conclusion: In conclusion, in our study, we showed for the first time that the relationship between ER stress and TRPC1, and their increased expression caused renal damage in hyperthyroid rats.

Silymarin attenuated nonalcoholic fatty liver disease through the regulation of endoplasmic reticulum stress proteins GRP78 and XBP-1 in mice.

Nonalcoholic fatty liver disease (NAFLD) is an important health problem. The prevalence of NAFLD is increasing, especially in the Western countries. Although there are several intracellular pathways in NAFLD, endoplasmic reticulum (ER) stress has recently gained importance. Silymarin is an important liver-protective biological molecule. In light of this information, we investigated mice for the effect of silymarin on ER stress in the NAFLD model. In our study, the mice were randomly divided into six groups: Control, silymarin 100 and 200 mg/kg sham, fructose-induced NAFLD, and NAFLD + silymarin groups. After the last administrations, liver and blood samples were taken and hematoxylin-eosin, as well as Oil red O staining, were performed. As a result, the body and liver weights, lipid profile, AST, ALT, and glucose levels, along with the ER stress markers, increased in the NAFLD-only group. Silymarin treatments reversed most of these changes. Particularly, 200 mg/kg silymarin was more effective. PRACTICAL APPLICATIONS: According to the results, silymarin attenuated NAFLD by decreasing the ER stress proteins GRP78 and XBP-1. Silymarin may be therapeutic in the treatment of NAFLD as well as other ER-stress-based diseases. Silymarin can also be taken with food for prophylactic purposes.

Silymarin inhibited DU145 cells by activating SLIT2 protein and suppressing expression of CXCR4.

Among other cancers, prostate cancer is globally the second most rampant one with the incidence of 29.4% among men. SLIT2/ROBO1 signaling is very crucial pathway causally implicated in many cancers and reported to inhibit a variety of cancer cell types. CXCR4 is a chemokine receptor implicated in cancer progression. Silymarin is a phytochemical, of which anti-carcinogenic activity was suggested in various cancers, including prostate cancer. However, there are no studies examining the effect of silymarin on SLIT2-Robo1-CXCR4 axis. Herein, our goal is to explore cytotoxic and morphological effects of silymarin on DU145 cells and to reveal its role in Slit2/Robo and CXCR1 pathway. First, 24, 48 and 72 h-long cytotoxicity tests were performed for dose analysis of silymarin, followed H-E stain for morphological evaluation with varying doses of silymarin. Afterward, western blot and immunocytochemistry analyses were carried out for SLIT2, ROBO1 and CXCR4 proteins. According to MTT analysis, IC50 concentrations for silymarin were 315, 126 and 70 µM against DU145 cells for 24, 48 and 72 h treatments. In H-E, several apoptotic hallmarks, including, condensed, kidney-shaped and eccentric nuclei, membrane blebbings and apoptotic body formations were observed. Silymarin increased the expressions of SLIT2 and ROBO1 while decreased CXCR4 when compared to control group in immunocytochemistry and Western blot. To summarize, silymarin inhibited DU145 cells dose-dependently by activating SLIT2 protein and inhibiting expression of CXCR4. This study is the first examining the interplay between Slit2-Robo1-CXCR4 proteins and silymarin in DU145 cells. We believe that our study will provide new insights for future studies.

Silymarin suppresses HepG2 hepatocarcinoma cell progression through downregulation of Slit-2/Robo-1 pathway.

BACKGROUND: 14 million people are diagnosed with new cancer and approximately 8 million people die from cancer every year. Hepatocellular carcinoma is the most common type of liver cancer and covers almost 5-6% of cancer deaths worldwide. Silybum marianum, a plant that contains silymarin, has been used traditionally in the treatment of liver diseases for centuries. The antioxidant, anti-inflammatory and anti-fibrotic anti-cancer properties of silymarin have been demonstrated in several studies in vivo and in vitro. The Slit/Robo signaling pathway plays a role in many processes such as neurogenesis, angiogenesis, cell proliferation, cell movement, cancer progression, cell invasion, migration and metastasis. In this study, we aimed to investigate the effects of silymarin on HepG2 Hepatocellular carcinoma cells on Slit-2/Robo-1 signaling pathway and CXCR-4 which plays a role in the metastasis process. METHODS: HepG2 Hepatocellular carcinoma cells were used in the study. Different doses of silymarin's effect on HepG2 cells were observed by hematoxylin and eosin staining. Immunoblotting techniques were used to test the expression of Slit-2/Robo-1 and CXCR4 protein level. Immunocytochemistry was used to visualize the localization of Slit-2/Robo-1 and CXCR4 protein within the cells. RESULTS: Silymarin caused apoptosis in HepG2 cells, decreased the level of CXCR-4 protein dose-dependently, and decreased the Slit-2/Robo-1 protein level at low doses and increased it at high doses. CONCLUSIONS: Silymarin doses showed anti-carcinogenic, anti-metastatic and apoptotic effects in a dose-dependent manner on HepG2 cells through the Slit-2/Robo-1 pathway.