ABI3BP promotes renal aging through Klotho-mediated ferroptosis.

The aging process of the kidneys is accompanied with several structural diseases. Abnormal fiber formation disrupts the balance of kidney structure and function, causing to end-stage renal disease and subsequent renal failure. Despite this, the precise mechanism underlying renal damage in aging remains elusive. In this study, ABI3BP gene knockout mice were used to investigate the role of ABI3BP in renal aging induced by irradiation. The results revealed a significant increase in ABI3BP expression in HK2 cells and kidney tissue of aging mice, with ABI3BP gene knockout demonstrating a mitigating effect on radiation-induced cell aging. Furthermore, the study observed a marked decrease in Klotho levels and an increase in ferroptosis in renal tissue and HK2 cells following irradiation. Notably, ABI3BP gene knockout not only elevated Klotho expression but also reduced ferroptosis levels. A significant negative correlation between ABI3BP and Klotho was established. Further experiments demonstrated that Klotho knockdown alleviated the aging inhibition caused by ABI3BP downregulation. This study identifies the upregulation of ABI3BP in aged renal tubular epithelial cells, indicating a role in promoting ferroptosis and inducing renal aging by inhibiting Klotho expression.

NSUN2 relies on ALYREF to regulate Nrf2-mediated oxidative stress and alleviate Dox-induced liver injury.

BACKGROUND: Doxorubicin (Dox) is associated with various liver injuries, limiting its clinical utility. This study investigates whether NSUN2 participates in Dox-induced liver injury and the associated molecular mechanism. METHODS: In vivo and in vitro liver cell injury models were constructed based on Dox therapy. The protein levels of NSUN2 and oxidative stress indicators Nrf2, HO-1, and NQO1 were evaluated by Western blot. The RNA binding potential was detected by RNA methylation immunoprecipitation (RIP). Additionally, the effect of NSUN2 on Nrf2 mRNA synthesis and localization was evaluated using an RNA fluorescence probe. RESULTS: NSUN2 was downregulated, and liver tissue suffered significant pathological damage in the Dox group. The levels of ALT and AST significantly increased. NSUN2 interference exacerbated Dox-induced liver cell damage, which was reversed by NSUN2 overexpression. RIP demonstrated that NSUN2 recognized and bound to Nrf2 mRNA. Western blot analysis showed the protein level of Nrf2 in the NSUN2-WT group was significantly higher than that of the control group, whereas there was no significant change in Nrf2 level in the mutant NSUN2 group. Luciferase analysis demonstrated that NSUN2 could recognize and activate the Nrf2 5'UTR region of LO2 cells. In addition, RIP analysis revealed that ALYREF could recognize and bind to Nrf2 mRNA and that ALYREF controls the regulatory effect of NSUN2 on Nrf2. CONCLUSION: NSUN2 regulates Dox-induced liver cell damage by increasing Nrf2 mRNA m5C methylation to inhibit inhibiting antioxidant stress. The regulatory effect of NSUN2 on Nrf2 depends on ALYREF.

Ameliorated biomechanical properties of carotid arteries by puerarin in spontaneously hypertensive rats.

BACKGROUND: An emerging body of evidence indicates that puerarin (PUE) plays an important role in the treatment of angina pectoris, myocardial ischemia-reperfusion injury, hypertension and other cardiovascular diseases, but how PUE affects the vascular remodeling of hypertensive rats has not been reported yet. This study aimed to investigate the effect and mechanism of PUE on carotid arteries of spontaneously hypertensive rats (SHR) to provide the basis for the clinical application of PUE. METHODS: Thirty male SHR and six male Wistar Kyoto rats (WKY) aged 3 months were used in this study, SHR rats were randomly divided into 5 groups, PUE(40 or 80 mg/kg/d, ip) and telmisartan (TELMI) (30 mg/kg/d, ig) were administrated for 3 months. We use DMT myography pressure-diameter system to investigate biomechanical properties of carotid arteries, 10 µM pan-classical transient receptor potential channels (TRPCs) inhibitor SKF96365, 200 nM specific TRPC6 inhibitor SAR7334 and 100 µM Orai1 inhibitor ANCOA4 were used in the mechanical test. RESULTS: PUE can significantly decrease systolic and diastolic blood pressure, long-term administration of PUE resulted in a mild reduction of thickness and inner diameter of carotid artery. PUE ameliorate NE-response and vascular remodeling mainly through inhibiting TRPCs channel activities of VSMC. CONCLUSION: PUE can ameliorate biomechanical remodeling of carotid arteries through inhibiting TRPCs channel activities of VSMC in spontaneously hypertensive rats.

Qiliqiangxin reduced cardiomyocytes apotosis and improved heart function in infarcted heart through Pink1/Parkin -mediated mitochondrial autophagy.

BACKGROUND: Qiliqiangxin (QLQX) is a preparation refined from a traditional Chinese medicine compound. It plays an important role in protecting cardiac function after myocardial infarction (MI). However, the underline mechanism of QLQX action is not clear. The purpose of this study was to detect the effects of QLQX on mitophagy after MI. METHODS: Male FVB/NJ mice aged 8-10 weeks were underwent left coronary artery ligation and were orally administered either QLQX (0.25 g/kg/d) or saline. Twenty-eight days after surgical operation, the cardiac function of mice was detected by echocardiography. Electron Microscopy was used to observe the microstructure of cardiomyocytes. Myocardial apoptosis was examined by TdT-mediated dUTP Nick-End Labeling (TUNEL) and western blot. H9c2 cells were cultured in a hypoxic incubator chamber (5% CO2, 1% O2, 94% N2) for 12 h and pretreated with or without QLQX (0.5 mg/mL). The cell apoptosis, reactive oxygen species (ROS), mitochondrial membrane potential and mitophagy were detected. RESULTS: When compared to sham group, the cardiac function of MI mice decreased significantly, and their cardiomyocyte apoptosis and mitochondrial damage were more serious. These MI-induced cardiac changes could be reversed by QLQX treatment. In vitro experiments also confirmed that QLQX could protect cardiomyocytes from hypoxia-induced apoptosis and mitochondrial damage. Further study indicated that QLQX could increase the expression of Pink1 and Parkin in cardiomyocytes. CONCLUSION: Qiliqiangxin could reduce cardiomyocytes apotosis and improved heart function in infarcted heart through Pink1-mediated mitochondrial autophagy.

A Selective TRPC3 Inhibitor Pyr3 Attenuates Myocardial Ischemia/Reperfusion Injury in Mice.

An emerging body of evidence indicates that transient receptor potential TRP channels act as important mediators for a wide variety of physiological functions and are potential targets for drug discovery. Our previous study has identified transient receptor potential channel 3 (TRPC3) and TRPC6 as cation channels through which most of the damaging calcium enters, aggravates pathological changes in vivo and increases ischemia/reperfusion (I/R) injury in mice. This study aimed to verify the effects of TRPC3 inhibitor Pyr3 on myocardial I/R injury in mice. C57BL/6J wild-type male mice (8 to 12 weeks old) were anesthetized with 3.3% chloral hydrate. A murine I (30 min)/R (24 h) injury model was established by temporary occlusion of the left anterior descending (LAD) coronary artery. Pyr3 was administered at concentrations of 0, 2.5, 5, or 10 mg/kg via the right jugular vein 5 min before reperfusion. We observed that the selective TRPC3 inhibitor, 10 mg/kg Pyr3, significantly decreased the infarct size of left ventricle, and reduced the myocardial cell apoptosis rate and inflammatory response in mice. In a conclusion, TRPC3 can function as a candidate target for I/R injury prevention, and Pyr3 may directly bind to TRPC3 channel protein, inhibit TRPC3 channel activity, and improve TRPC3-related myocardial I/R injury. Pyr3 may be used for clarification of TRPC3 functions and for treatments of TRPC3-mediated diseases.

TDCPP protects cardiomyocytes from H2O2-induced injuries via activating PI3K/Akt/GSK3ß signaling pathway.

Tris (1, 3-dichloro-2-propyl) phosphate (TDCPP) is a major type of organophosphorus flame retardants, and long-term exposure to TDCPP to normal cells or tissues under physiological conditions can induce toxic effects. But how TDCPP leads to the adverse effects is not yet clear, and the effect of TDCPP under pathological conditions such as reactive oxygen species assault is not well understood. The present study aimed to explore the potential effect of TDCPP against H2O2-induced oxidative stress in H9c2 cardiomyoblasts and rat neonatal cardiomyocytes. We found that H2O2-treatment decreased cell viability and increased lactate dehydrogenase and malondialdehyde generation of H9c2 cells. However, TDCPP could alleviate these effects. TDCPP alleviated Ca2+-overload caused by H2O2 through decreasing store-operated calcium entry. More importantly, TDCPP remarkably decreased H2O2-induced dephosphorylation of Akt and GSK3ß, and through this pathway TDCPP mitigated the H2O2-induced apoptosis and detrimental autophagy. Collectively, via mitigating Ca2+-overload and activating the Akt/GSK3ß signaling pathway, TDCPP may have a role in protecting cardiomyocytes from oxidative stress.

TDCPP protects cardiomyocytes from hypoxia-reoxygenation injury induced apoptosis through mitigating calcium overload and promotion GSK-3ß phosphorylation.

TDCPP, Tris (1, 3-dichloro-2-propyl) phosphate belongs to a group of chemicals known as triester organophosphate flame retardants, It can alter calcium homeostasis at much lower concentrations in normal conditions, but the mechanism is unclear till now. Calcium overload is a leading cause of apoptosis in myocardial ischemia/reperfusion (I/R) injury, thus how to mitigate Ca2+-overload is deserved to be investigated. We therefore hypothesized that TDCPP could attenuate cardiomyocytes apoptosis in I/R injury. H/R (hypoxia/reoxygenation) experiments in vitro were used to simulate in vivo I/R injury. The present study aimed to explore the potential effect of TDCPP in cardiomyocytes after H/R injury, Ca2+ imaging technique was used to explore SOCE(store-operated calcium entry) and Ca2+-overload levels, western blot technique was used to explore the potential target, the cell morphology, cell viability and mitochondrial membrane potential were also detected. The results have shown that: TDCPP could decrease SOCE, restore H9c2 cell viability, mitigate Ca2+-overload in H/R injury and reduce the mitochondrial membrane potential. Furthermore, TDCPP decreased STIM1 expression and promoted GSK3ß phosphorylation. Collectively, for the first time, this study suggest the antiapoptosis roles of TDCPP in H/R injury are via mitigation Ca2+-overload and promoting GSK-3ß phosphorylation.

Major contribution of the 3/6/7 class of TRPC channels to myocardial ischemia/reperfusion and cellular hypoxia/reoxygenation injuries.

The injury phase after myocardial infarcts occurs during reperfusion and is a consequence of calcium release from internal stores combined with calcium entry, leading to cell death by apoptopic and necrotic processes. The mechanism(s) by which calcium enters cells has(ve) not been identified. Here, we identify canonical transient receptor potential channels (TRPC) 3 and 6 as the cation channels through which most of the damaging calcium enters cells to trigger their death, and we describe mechanisms activated during the injury phase. Working in vitro with H9c2 cardiomyoblasts subjected to 9-h hypoxia followed by 6-h reoxygenation (H/R), and analyzing changes occurring in areas-at-risk (AARs) of murine hearts subjected to a 30-min ischemia followed by 24-h reperfusion (I/R) protocol, we found: (i) that blocking TRPC with SKF96365 significantly ameliorated damage induced by H/R, including development of the mitochondrial permeability transition and proapoptotic changes in Bcl2/BAX ratios; and (ii) that AAR tissues had increased TUNEL+ cells, augmented Bcl2/BAX ratios, and increased p(S240)NFATc3, p(S473)AKT, p(S9)GSK3ß, and TRPC3 and -6 proteins, consistent with activation of a positive-feedback loop in which calcium entering through TRPCs activates calcineurin-mediated NFATc3-directed transcription of TRPC genes, leading to more Ca2+ entry. All these changes were markedly reduced in mice lacking TRPC3, -6, and -7. The changes caused by I/R in AAR tissues were matched by those seen after H/R in cardiomyoblasts in all aspects except for p-AKT and p-GSK3ß, which were decreased after H/R in cardiomyoblasts instead of increased. TRPC should be promising targets for pharmacologic intervention after cardiac infarcts.

Deletion of diacylglycerol-responsive TRPC genes attenuates diabetic nephropathy by inhibiting activation of the TGFß1 signaling pathway.

TRPC6 plays a critical role in proteinuric kidney diseases, and TRPC3 is involved in tubulointerstitial damage and renal fibrosis in obstructed kidneys. Podocyte loss is a characteristic event in diabetic nephropathy (DN). The aim of this study was to examine whether deletion of the closely related diacylglycerol (DAG)-responsive TRPCs in mice (TRPC3/6/7-/-) affects diabetes-induced renal dysfunction and podocyte loss. We compared urine volume, kidney hypertrophy, glomerular enlargement, albuminuria and podocyte loss between wild type (WT) and TRPC3/6/7-/- diabetic mice. Finally, we examined whether the TGFß1 signaling pathway is changed in diabetic WT and TRPC3/6/7-/- mice. TRPC6 protein in the renal cortex was increased in WT diabetic mice. High glucose (HG) treatment increased TRPC6 expression in human podocytes. TRPC3 protein, however, was not altered in either diabetic mice or HG-treated human podocytes. Although diabetic WT and TRPC3/6/7-/- mice had similar levels of hyperglycemia, the TRPC3/6/7-/- diabetic mice showed less polyuria, kidney hypertrophy, glomerular enlargement, albuminuria, and had lost less podocytes compared with WT diabetic mice. In addition, we observed decreased expression of anti-apoptotic Bcl2 and increased expression of pro-apoptotic cleaved caspase 3 in WT diabetic mice, but such changes were not significant in TRPC3/6/7-/- diabetic mice. Western blot and immunohistochemistry revealed that TGFß1, p-Smad2/3, and fibronectin were upregulated in WT diabetic mice; however, expression of these signaling molecules was not changed in TRPC3/6/7-/- diabetic mice. In conclusion, deletion of DAG-responsive TRPCs attenuates diabetic renal injury via inhibiting the upregulation of TGFß1 signaling in diabetic kidneys.

TRPC3/6/7 Knockdown Protects the Brain from Cerebral Ischemia Injury via Astrocyte Apoptosis Inhibition and Effects on NF-кB Translocation.

Ischemia contributes significantly to morbidity and mortality associated with many common neurological diseases. Calcium overload is an important mechanism of cerebral ischemia and reperfusion (I/R) injury. Despite decades of intense research, an effective beneficial treatment of stroke remains limited; few therapeutic strategies exist to combat the consequences of cerebral ischemia. Traditionally, a "neurocentric" view has dominated research in this field. Evidence is now accumulating that glial cells, especially astrocytes, play an important role in the pathophysiology of cerebral ischemia. Here, we show that transient receptor potential (TRP)C3/6/7 knockout (KO) mice subjected to an I/R procedure demonstrate ameliorated brain injury (infract size), compared to wild-type (WT) control animals. This is accompanied by reduction of NF-кB phosphorylation and an increase in protein kinase B (AKT) phosphorylation in I/R-injured brain tissues in TRPC3/6/7 KO mice. Also, the expression of pro-apoptotic protein Bcl-2 associated X (Bax) is down-regulated and that of anti-apoptotic protein Bcl-2 is upregulated in TRPC3/6/7-/- mice. Astrocytes isolated from TRPC3/6/7 KO mice and subjected to oxygen/glucose deprivation and subsequent reoxygenation (OGD-R, mimicking in vivo I/R injury) also exhibit enhanced Bcl-2 expression, reduced Bax expression, enhanced AKT phosphorylation, and reduced NF-кB phosphorylation. Furthermore, apoptotic rates of TRPC3/6/7 KO astrocytes cultured in OGD-R conditions were reduced significantly compared to WT control. These findings suggest TRPC3/6/7 channels play a detrimental role in brain I/R injury. Deletion of these channels can interfere with the activation of NF-кB (pro-apoptotic), promote activation of AKT (anti-apoptotic), and ultimately, ameliorate brain damage via inhibition of astrocyte apoptosis after cerebral ischemia/reperfusion injury.

Effect of sex on biomechanical properties of the proper hepatic artery in pigs and humans for liver xenotransplant.

OBJECTIVES: This study investigated the relation between biomechanical properties of the proper hepatic artery and sex in pigs and humans to provide the theoretical basis for selecting suitable donor in pig-to-human liver xenotransplant. MATERIALS AND METHODS: The proper hepatic arteries of 32 Chinese Hubei white pigs (8 males, 8 females, 8 castrated males, and 8 ovariectomized females) and 10 deceased donors (5 human men, 5 human women) were obtained. The pressure-diameter relations of the proper hepatic arteries were measured on biomechanical test equipment to calculate the incremental elastic modulus (Einc), pressure-strain elastic modulus (Ep), volume elastic modulus (Ev), and compliance. Each sample was sliced into 5-µm frozen sections and stained with hematoxylin-eosin. RESULTS: There were significant differences in Einc (F=10.24; P = .001), Ep (F=3.75; P = .001), and Ev (F=3.41; P = .002) of the proper hepatic arteries of female, male, and gonadectomized pigs; females had the lowest elastic modulus and the gonadectomized group had the highest (P < .01). There was a significant difference in compliance of the porcine proper hepatic arteries between the sexes, highest in the female group and lowest in the gonadectomized group (P < .01). No difference in the elastic modulus and compliance of the proper hepatic artery between the male pig and the human man. There was no difference between the female pig and the human woman. CONCLUSIONS: There were differences in the biomechanical properties of the proper hepatic arteries of the female, male, and gonadectomized pigs. The biomechanical properties of the human men/women proper hepatic artery match those of the porcine male/female hepatic artery. The correlation between sex and biomechanical properties of the proper hepatic artery in pigs could imply that a pig of the same sex should be chosen for pig-to-human liver xenotransplant.

Morphological and biomechanical remodeling of the hepatic portal vein in a swine model of portal hypertension.

OBJECTIVES: To obtain the morphological and biomechanical remodeling of portal veins in swine with portal hypertension (PHT), so as to provide some mechanical references and theoretical basis for clinical practice about PHT. METHODS: Twenty white pigs were used in this study, 14 of them were subjected to both carbon tetrachloride- and pentobarbital-containing diet to induce experimental liver cirrhosis and PHT, and the remaining animals served as the normal controls. The morphological remodeling of portal veins was observed. Endothelial nitric oxide synthase expression profile in the vessel wall was assessed at both mRNA and protein level. The biomechanical changes of the hepatic portal veins were evaluated through assessing the following indicators: the incremental elastic modulus, pressure-strain elastic modulus, volume elastic modulus, and the incremental compliance. RESULTS: The swine PHT model was successfully established. The percentages for the microstructural components and the histological data significantly changed in the experimental group. Endothelial nitric oxide synthase expression was significantly downregulated in the portal veins of the experimental group. Three incremental elastic moduli (the incremental elastic modulus, pressure-strain elastic modulus, and volume elastic modulus) of the portal veins from PHT animals were significantly larger than those of the controls (P < 0.05), whereas the incremental compliance of hepatic portal vein decreased. CONCLUSIONS: Our study suggests that the morphological and biomechanical properties of swine hepatic portal veins change significantly during the PHT process, which may play a critical role in the development of PHT and serve as potential therapeutic targets during clinical practice.

Morphological and biomechanical remodelling of the hepatic artery in a swine model of portal hypertension.

OBJECTIVES: To obtain the biomechanical and morphological remodelling of hepatic arteries in swine with portal hypertension. METHODS: A number of 20 white pigs was used, of which 14 were subjected to liver cirrhosis and portal hypertension (PHT) induced by carbon tetrachloride and pentobarbital; the rest were used as the control group. The biomechanical remodelling of the hepatic arteries was measured, namely, the incremental elastic modulus (E inc), pressure-strain elastic modulus (E p), volume elastic modulus (E v), the incremental compliance (C), the opening angle and the stained microstructural components of the vessels. RESULTS: The percentages for the microstructural components and the histologic data significantly changed in the experimental group, three incremental elastic moduli (E inc, E p, and E v) of the experimental group were significantly larger than those of the control group (P < 0.05); the compliance of hepatic arteries decreased greatly (P < 0.05) too. The opening angle (OA) was considerably larger than that of control group (P < 0.05). CONCLUSIONS: The study suggests that the morphological and biomechanical properties of swine hepatic arteries have changed significantly during the process of portal hypertension and that from biomechanical aspects, the hepatic arteries have also suffered from extensive remodelling, which in turn deteriorates the existing portal hypertension.