Dietary cinnamaldehyde activation of TRPA1 antagonizes high-salt induced hypertension through restoring renal tubular mitochondrial dysfunction.

BACKGROUND: Renal proximal tubule plays a pivotal role in regulating sodium reabsorption and thus blood pressure. Transient receptor potential ankyrin 1 (TRPA1) has been reported to protect against renal injury by modulating mitochondrial function. We hypothesize that the activation of TRPA1 by its agonist cinnamaldehyde may mitigates high salt intake induced hypertension by inhibiting urinary sodium reabsorption through restoration of renal tubular epithelial mitochondrial function. METHODS: Trpa1-deficient (Trpa1-/-) mice and wild-type (WT) mice were fed standard laboratory chow [normal diet (ND) group, 0.4% salt], standard laboratory chow with 8% salt [high-salt diet (HS) group] or standard laboratory chow with 8% salt plus 0.015% cinnamaldehyde [high-salt plus cinnamaldehyde diet (HSC) group] for six months. Urinary sodium excretion, ROS production, mitochondrial function and the expression of NHE3 and Na+/K+-ATPase of renal proximal tubules were determined. RESULTS: Chronic dietary cinnamaldehyde supplementation reduced tail systolic blood pressure and 24-hour ambulatory arterial pressure in HS-fed WT mice. Compared with the mice fed HS, cinnamaldehyde supplementation significantly increased urinary sodium excretion, inhibited excess ROS production and alleviated mitochondrial dysfunction of renal proximal tubules in WT mice. However, these effects of cinnamaldehyde were absent in Trpa1-/- mice. Furthermore, chronic dietary cinnamaldehyde supplementation blunted HS-induced upregulation of NHE3 and Na+/K+-ATPase in WT mice but not Trpa1-/- mice. CONCLUSION: The present study demonstrated that chronic activation of Trpa1 attenuates HS-induced hypertension by inhibiting urinary sodium reabsorption through restoring renal tubular epithelial mitochondrial function. Renal TRPA1 may be a potential target for the management of excessive dietary salt intake-associated hypertension.

Sodium-glucose exchanger 2 inhibitor canagliflozin promotes mitochondrial metabolism and alleviates salt-induced cardiac hypertrophy via preserving SIRT3 expression.

INTRODUCTION: Excess salt intake is not only an independent risk factor for heart failure, but also one of the most important dietary factors associated with cardiovascular disease worldwide. Metabolic reprogramming in cardiomyocytes is an early event provoking cardiac hypertrophy that leads to subsequent cardiovascular events upon high salt loading. Although SGLT2 inhibitors, such as canagliflozin, displayed impressive cardiovascular health benefits, whether SGLT2 inhibitors protect against cardiac hypertrophy-related metabolic reprogramming upon salt loading remain elusive. OBJECTIVES: To investigate whether canagliflozin can improve salt-induced cardiac hypertrophy and the underlying mechanisms. METHODS: Dahl salt-sensitive rats developed cardiac hypertrophy by feeding them an 8% high-salt diet, and some rats were treated with canagliflozin. Cardiac function and structure as well as mitochondrial function were examined. Cardiac proteomics, targeted metabolomics and SIRT3 cardiac-specific knockout mice were used to uncover the underlying mechanisms. RESULTS: In Dahl salt-sensitive rats, canagliflozin showed a potent therapeutic effect on salt-induced cardiac hypertrophy, accompanied by lowered glucose uptake, reduced accumulation of glycolytic end-products and improved cardiac mitochondrial function, which was associated with the recovery of cardiac expression of SIRT3, a key mitochondrial metabolic regulator. Cardiac-specific knockout of SIRT3 not only exacerbated salt-induced cardiac hypertrophy but also abolished the therapeutic effect of canagliflozin. Mechanistically, high salt intake repressed cardiac SIRT3 expression through a calcium-dependent epigenetic modifications, which could be blocked by canagliflozin by inhibiting SGLT1-mediated calcium uptake. SIRT3 improved myocardial metabolic reprogramming by deacetylating MPC1 in cardiomyocytes exposed to pro-hypertrophic stimuli. Similar to canagliflozin, the SIRT3 activator honokiol also exerted therapeutic effects on cardiac hypertrophy. CONCLUSION: Cardiac mitochondrial dysfunction caused by SIRT3 repression is a critical promotional determinant of metabolic pattern switching underlying salt-induced cardiac hypertrophy. Improving SIRT3-mediated mitochondrial function by SGLT2 inhibitors-mediated calcium handling would represent a therapeutic strategy against salt-related cardiovascular events.

Leptin receptor deficiency impedes metabolic surgery related-weight loss through inhibition of energy expenditure in db/db mice.

BACKGROUND: Roux-en-Y gastric bypass (RYGB) surgery is an effective metabolic surgery against diabetes and obesity. Clinical evidence indicates that patients with severe obesity have a poor curative effect in losing weight if they suffer from leptin or its receptor deficiency, but the underlying mechanism remains elusive. Here, we investigated the effect of leptin receptor deficiency on metabolic dysfunction in db/db mice treated by RYGB surgery. METHODS: The db/db mice and their heterozygote control db/m mice were subjected to RYGB or sham surgery. Body weight, blood glucose, food intake and glucose tolerance were evaluated. Micro-PET/CT and histological analysis were performed to examine the glucose uptake of tissues and the fat changes in mice. The key factors in glucose and fatty acid metabolism were detected by western blot analysis. RESULTS: Compared with the sham group, the db/db mice in the RYGB group showed more significant weight regain after surgical recovery and improvement in hyperinsulinemia and glucose tolerance. However, the total body fat and multiple organ lipid deposition of RYGB-treated db/db mice was increased. The underlying mechanism studies suggested that the activation of AMPK regulated GLUT4 to increase glucose uptake, but AMPK could not promote fatty acid oxidation through the JAK2/STAT3 pathway under leptin receptor deficiency in db/db mice. CONCLUSION: We conclude that leptin receptor deficiency impedes the AMPK activation-mediated fat catabolism but does not affect AMPK-related glucose utilization after metabolic surgery in db/db mice. This result helps select surgical indications for patients with obesity and diabetes.

A high-salt diet promotes hypertrophic scarring through TRPC3-mediated mitochondrial Ca2+ homeostasis dysfunction.

Diet High in salt content have been associated with cardiovascular disease and chronic inflammation. We recently demonstrated that transient receptor potential canonical 3 (TRPC3) channels regulate myofibroblast transdifferentiation in hypertrophic scars. Here, we examined how high salt activation of TRPC3 participates in hypertrophic scarring during wound healing. In vitro, we confirmed that high salt increased the TRPC3 protein expression and the marker of myofibroblast alpha smooth muscle actin (α-SMA) in wild-type mice (WT) primary cultured dermal fibroblasts but not Trpc3-/- mice. Activation of TRPC3 by high salt elevated cytosolic Ca2+ influx and mitochondrial Ca2+ uptake in dermal fibroblasts in a TRPC3-dependent manner. High salt activation of TRPC3 enhanced mitochondrial respiratory dysfunction and excessive ROS production by inhibiting pyruvate dehydrogenase action, that activated ROS-triggered Ca2+ influx and the Rho kinase/MLC pathway in WT mice but not Trpc3-/- mice. In vivo, a persistent high-salt diet promoted myofibroblast transdifferentiation and collagen deposition in a TRPC3-dependent manner. Therefore, this study demonstrates that high salt enhances myofibroblast transdifferentiation and promotes hypertrophic scar formation through enhanced mitochondrial Ca2+ homeostasis, which activates the ROS-mediated pMLC/pMYPT1 pathway. TRPC3 deficiency antagonizes high salt diet-induced hypertrophic scarring. TRPC3 may be a novel target for hypertrophic scarring during wound healing.

Mitochondrial dysfunction caused by SIRT3 inhibition drives proinflammatory macrophage polarization in obesity.

OBJECTIVE: Metabolic reprogramming is a main feature of proinflammatory macrophage polarization, a process that leads to inflammation in dysfunctional adipose tissue. Therefore, the study aim was to explore whether sirtuin 3 (SIRT3), a mitochondrial deacetylase, participates in this pathophysiological process. METHODS: Macrophage-specific Sirt3 knockout (Sirt3-MKO) mice and wild-type littermates were treated with a high-fat diet. Body weight, glucose tolerance, and inflammation were evaluated. Bone marrow-derived macrophages and RAW264.7 cells were treated with palmitic acid to explore the mechanism of SIRT3 on inflammation. RESULTS: The expression of SIRT3 was significantly repressed in both bone marrow-derived macrophages and adipose tissue macrophages in mice fed with a high-fat diet. Sirt3-MKO mice exhibited accelerated body weight and severe inflammation, accompanied with reduced energy expenditure and worsened glucose metabolism. In vitro experiments showed that SIRT3 inhibition or knockdown exacerbated palmitic acid-induced proinflammatory macrophage polarization, whereas SIRT3 restoration displayed opposite effects. Mechanistically, SIRT3 deficiency resulted in hyperacetylation of succinate dehydrogenase that led to succinate accumulation, which suppressed the transcription of Kruppel-like factor 4 via increasing histone methylation on its promoter, thus evoking proinflammatory macrophages. CONCLUSIONS: This study emphasizes an important preventive role of SIRT3 in macrophage polarization and implies that SIRT3 is a promising therapeutic target for obesity.

Systematic analysis of lysine crotonylation in human macrophages responding to MRSA infection.

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most commonly encountered bacteria found in healthcare clinics and has been ranked a priority 2 pathogen. Research is urgently needed to develop new therapeutic approaches to combat the pathogen. Variations in the pattern of protein posttranslational modifications (PTMs) of host cells affect physiological and pathological events, as well as therapeutic effectiveness. However, the role of crotonylation in MRSA-infected THP1 cells remains unknown. In this study, we found that crotonylation profiles of THP1 cells were altered after MRSA infection. It was then confirmed that lysine crotonylation profiles of THP1 cells and bacteria were different; MRSA infection inhibited global lysine crotonylation (Kcro) modification but partially elevated Kcro of host proteins. We obtained a proteome-wide crotonylation profile of THP1 cells infected by MRSA further treated by vancomycin, leading to the identification of 899 proteins, 1384 sites of which were down-regulated, and 160 proteins with 193 sites up-regulated. The crotonylated down-regulated proteins were mainly located in cytoplasm and were enriched in spliceosome, RNA degradation, protein posttranslational modification, and metabolism. However, the crotonylated up-regulated proteins were mainly located in nucleus and significantly involved in nuclear body, chromosome, ribonucleoprotein complex, and RNA processing. The domains of these proteins were significantly enriched on RNA recognition motif, and linker histone H1 and H5 families. Some proteins related to protecting against bacterial infection were also found to be targets of crotonylation. The present findings point to a comprehensive understanding of the biological functions of lysine crotonylation in human macrophages, thereby providing a certain research basis for the mechanism and targeted therapy on the immune response of host cells against MRSA infection.

Cx43 acts as a mitochondrial calcium regulator that promotes obesity by inducing the polarization of macrophages in adipose tissue.

Metabolic reprogramming of macrophages initiates the polarization of pro-inflammatory macrophages that exacerbates adipocyte dysfunction and obesity. The imbalance of mitochondrial Ca2+ homeostasis impairs mitochondrial function and promotes inflammation. Connexin 43 (Cx43), a ubiquitous gap junction protein, has been demonstrated to regulate intracellular Ca2+ homeostasis. Here we explored whether macrophage Cx43 affects the obesity process by regulating the polarization of macrophage. HFD treatment induced obesity and exacerbated macrophages infiltration with upregulation of macrophages Cx43. Macrophage-specific knockout of Cx43 reduced HFD-induced obesity by alleviating inflammation in adipose tissue, with less pro-inflammatory M1 macrophage infiltration. Consistently, inhibition or knockdown of Cx43 improved palmitic acid (PA) induced mitochondrial dysfunction, as indicated by improved oxidative phosphorylation (OXPHOS), reduced formation of mitochondria-associated membranes (MAM) and mitochondrial Ca2+ overload. Mechanistically, Cx43 interacted with the mitochondrial Ca2+ uniporter (MCU) and knockdown of Cx43 alleviated PA-induced succinate dehydrogenase (SDH) oxidation by lowering MCU-mediated mitochondrial Ca2+ uptake, which then, promoting the polarization of pro-inflammatory M1 macrophages. Thus, this study identified Cx43 as a mitochondrial Ca2+ regulator that aggravates obesity via promoting macrophages polarized to M1 pro-inflammatory phenotype and suggests that Cx43 might be a promising therapeutic target antagonizing obesity.

Life cycle energy consumption, environmental impact, and costing assessment of coal to ethylene glycol processes via dimethyl oxalate and formaldehyde.

The popularization of conventional dimethyl oxalate to ethylene glycol (DMOtEG) has kept ongoing in the past decade in China. Recently, a northern China factory in construction attracts attention using alternative formaldehyde to ethylene glycol (FtEG) route. Thus, a question arises about the individual comparative advantages of these two processes. So, this paper conducts a systematic modeling analysis of DMOtEG and FtEG, and the life cycle assessment is performed by SimaPro v9 to compare their impact. The results indicate the inferiority of life cycle energy consumption and life cycle cost of FtEG to those of DMOtEG due to the high energy consumption and pollutant emissions. Moreover, most impact categories of FtEG are worse than the DMOtEG as global warming, and photochemical oxidant formation potential. Despite this, FtEG still wins for better potentials in ozone formation, fine particulate matter formation, and terrestrial acidification because of less nitride emissions. In addition, the decrease in energy consumption and external cost will significantly decrease the life cycle cost under controllable catalyst costs of FtEG. These results describe the impact categories of DMOtEG and FtEG and provide a basis to help decision-makers develop coal to ethylene glycol processes.

Molecular mechanisms of the antibacterial activity of polyimide fibers in a skin-wound model with Gram-positive and Gram-negative bacterial infection in vivo.

Recently, the need for antibacterial dressings has amplified because of the increase of traumatic injuries. However, there is still a lack of ideal, natural antibacterial dressings that show an efficient antibacterial property with no toxicity. Polyimide (PI) used as an implantable and flexible material has been recently reported as a mixture of particles showing more desirable antibacterial properties. However, we have identified a novel type of natural polyimide (PI) fiber that revealed antibacterial properties by itself for the first time. The PI fiber material is mainly composed of C, N, and O, and contains a small amount of Ca and Cl; the characteristic peaks of polyimide appear at 1774 cm-1, 1713 cm-1, 1370 cm-1, 1087 cm-1, and 722 cm-1. PI fibers displayed significant antibacterial activities against Escherichia coli (as a Gram-negative bacteria model) and methicillin-resistant Staphylococcus aureus (MRSA, as a Gram-positive bacteria model) according to the time-kill kinetics in vitro, and PI fibers damaged both bacterial cell walls directly. PI fibers efficiently ameliorated a local infection in vivo, inhibited the bacterial burden, decreased infiltrating macrophages, and accelerated wound healing in an E. coli- or MRSA-infected wound model. In conclusion, PI fibers used in the present study may act as potent antibacterial dressings protecting from MRSA or E. coli infections and as promising candidates for antimicrobial materials for trauma and surgical applications.

Sodium-Glucose Cotransporter 2 Inhibitor Canagliflozin Antagonizes Salt-Sensitive Hypertension Through Modifying Transient Receptor Potential Channels 3 Mediated Vascular Calcium Handling.

Background Salt-sensitive hypertension is highly prevalent and associated with cardiorenal damage. Large clinical trials have demonstrated that SGLT2 (sodium-glucose cotransporter 2) inhibitors exert hypotensive effect and cardiorenal protective benefits in patients with hypertension with and without diabetes. However, the underlying mechanism remains elusive. Methods and Results Dahl salt-sensitive rats and salt-insensitive controls were fed with 8% high-salt diet and some of them were treated with canagliflozin. The blood pressure, urinary sodium excretion, and vascular function were detected. Transient receptor potential channel 3 (TRPC3) knockout mice were used to explain the mechanism. Canagliflozin treatment significantly reduced high-salt-induced hypertension and this effect was not totally dependent on urinary sodium excretion in salt-sensitive hypertensive rats. Assay of vascular function and proteomics showed that canagliflozin significantly inhibited vascular cytoplasmic calcium increase and vasoconstriction in response to high-salt diet. High salt intake increased vascular expression of TRPC3 in salt-sensitive rats, which could be alleviated by canagliflozin treatment. Overexpression of TRPC3 mimicked salt-induced vascular cytosolic calcium increase in vitro and knockout of TRPC3 erased the antihypertensive effect of canagliflozin. Mechanistically, high-salt-induced activation of NCX1 (sodium-calcium exchanger 1) reverse mode increased cytoplasmic calcium level and vasoconstriction, which required TRPC3, and this process could be blocked by canagliflozin. Conclusions We define a previously unrecognized role of TRPC3/NCX1 mediated vascular calcium dysfunction in the development of high-salt-induced hypertension, which can be improved by canagliflozin treatment. This pathway is potentially a novel therapeutic target to antagonize salt-sensitive hypertension.

TRPC5 deletion in the central amygdala antagonizes high-fat diet-induced obesity by increasing sympathetic innervation.

Transient receptor potential channel 5 (TRPC5) is predominantly distributed in the brain, especially in the central amygdala (CeA), which is closely associated with pain and addiction. Although mounting evidence indicates that the CeA is related to energy homeostasis, the possible regulatory effect of TRPC5 in the CeA on metabolism remains unclear. Here, we reported that the expression of TRPC5 in the CeA of mice was increased under a high-fat diet (HFD). Specifically, the deleted TRPC5 protein in the CeA of mice using adeno-associated virus resisted HFD-induced weight gain, accompanied by increased food intake. Furthermore, the energy expenditure of CeA-specific TRPC5 deletion mice (TRPC5 KO) was elevated due to augmented white adipose tissue (WAT) browning and brown adipose tissue (BAT) activity. Mechanistically, deficiency of TRPC5 in the CeA boosted nonshivering thermogenesis under cold stimulation by stimulating sympathetic nerves, as the ß3-adrenoceptor (Adrb3) antagonist SR59230A blocked the effect of TRPC5 KO on this process. In summary, TRPC5 deletion in the CeA alleviated the metabolic deterioration of mice fed a HFD, and these phenotypic improvements were correlated with the increased sympathetic distribution and activity of adipose tissue.

Salt-Induced Hepatic Inflammatory Memory Contributes to Cardiovascular Damage Through Epigenetic Modulation of SIRT3.

BACKGROUND: High salt intake is the leading dietary risk factor for cardiovascular diseases. Although clinical evidence suggests that high salt intake is associated with nonalcoholic fatty liver disease, which is an independent risk factor for cardiovascular diseases, it remains elusive whether salt-induced hepatic damage leads to the development of cardiovascular diseases. METHODS: Mice were fed with normal or high-salt diet for 8 weeks to determine the effect of salt loading on liver histological changes and blood pressure, and salt withdrawal and metformin treatment were also conducted on some high-salt diet-fed mice. Adeno-associated virus 8, global knockout, or tissue-specific knockout mice were used to manipulate the expression of some target genes in vivo, including SIRT3 (sirtuin 3), NRF2 (NF-E2-related factor 2), and AMPK (AMP-activated protein kinase). RESULTS: Mice fed with a high-salt diet displayed obvious hepatic steatosis and inflammation, accompanied with hypertension and cardiac dysfunction. All these pathological changes persisted after salt withdrawal, displaying a memory phenomenon. Gene expression analysis and phenotypes of SIRT3 knockout mice revealed that reduced expression of SIRT3 was a chief culprit responsible for the persistent inflammation in the liver, and recovering SIRT3 expression in the liver effectively inhibits the sustained hepatic inflammation and cardiovascular damage. Mechanistical studies reveal that high salt increases acetylated histone 3 lysine 27 (H3K27ac) on SIRT3 promoter in hepatocytes, thus inhibiting the binding of NRF2, and results in the sustained inhibition of SIRT3 expression. Treatment with metformin activated AMPK, which inhibited salt-induced hepatic inflammatory memory and cardiovascular damage by lowering the H3K27ac level on SIRT3 promoter, and increased NRF2 binding ability to activate SIRT3 expression. CONCLUSIONS: This study demonstrates that SIRT3 inhibition caused by histone modification is the key factor for the persistent hepatic steatosis and inflammation that contributes to cardiovascular damage under high salt loading. Avoidance of excessive salt intake and active intervention of epigenetic modification may help to stave off the persistent inflammatory status that underlies high-salt-induced cardiovascular damage in clinical practice.

Water extract of Cayratia albifolia C.L.Li root relieves zymosan A-induced inflammation by restraining M1 macrophage polarization.

BACKGROUND: Cayratia albifolia C.L.Li (CAC) is a traditional Chinese herbal medicine used to treat inflammatory diseases. Our laboratory has firstly reported that the water extract from CAC relieved lipopolysaccharide (LPS)-induced inflammation, however stronger evidence is still needed to prove its anti-inflammatory effects and the mechanisms involved are also ambiguous. PURPOSE: This study sought to provide more evidence for the application of CAC in alleviating infectious inflammation and disclose novel pharmacological mechanisms. METHODS: Mice were injected with zymA into their paws or peritoneal cavities, and then treated with CAC. ELISA, immunofluorescence and flow cytometry were performed to detect the cytokines (IL-1ß, IL-6, TNF-α and IL-10) generation, the cell infiltration, and the CD86 or CD206 expression of macrophages. Then in vitro assays were performed on bone marrow-derived macrophages (BMDMs) and peritoneal macrophages (PMs) to detect their expression of iNOS, arg-1 and the cytokines above. On mechanisms, western blotting (WB), electrophoretic mobility shift assay (EMSA) and flow cytometry were carried out to measure NF-κB transcriptional activity, mitochondrial bioactivity and the mTORC1 activation when BMDMs were stimulated by zymA and treated with CAC. Finally, the chemical components consisted in the extract were analyzed by LC-MS. RESULTS: 200 mg/kg CAC clearly inhibited zymA induced mouse paw edema and reduced the contents of IL-1ß, IL-6 and TNF-α rather than IL-10 in local tissues. CAC also reduced CD86 but not CD206 in macrophages in situ. Through in vitro experiments, it was discovered that CAC reduced the protein and mRNA levels of IL-1ß, IL-6 and TNF-α, and also inhibited iNOS expression, but showed no influence on IL-10 and arg-1 in macrophages. We found CAC reduced NF-κB transcriptional activity, down-regulated mitochondrial membrane potential and ROS levels, and inhibited mTORC1 activity. Finally, we identified 15 major compounds in the extract, among which 4-guanidinobutyric acid and kynurenic acid were the most abundant. CONCLUSION: This study provides further evidence that CAC significantly reduces zymA induced infectious inflammation. In addition, this novel data revealed that CAC restrained M1 rather than promoting M2 macrophages polarization via multi-target inhibitory effects, based on its potentially active components.

Recurrent moderate hypoglycemia accelerates the progression of Alzheimer's disease through impairment of the TRPC6/GLUT3 pathway.

Currently, the most effective strategy for dealing with Alzheimer's disease (AD) is delaying the onset of dementia. Severe hypoglycemia is strongly associated with dementia; however, the effects of recurrent moderate hypoglycemia (RH) on the progression of cognitive deficits in patients with diabetes with genetic susceptibility to AD remain unclear. Here, we report that insulin-controlled hyperglycemia slightly aggravated AD-type pathologies and cognitive impairment; however, RH significantly increased neuronal hyperactivity and accelerated the progression of cognitive deficits in streptozotocin-induced (STZ-induced) diabetic APP/PS1 mice. Glucose transporter 3-mediated (GLUT3-mediated) neuronal glucose uptake was not significantly altered under hyperglycemia but was markedly reduced by RH, which induced excessive mitochondrial fission in the hippocampus. Overexpression of GLUT3, specifically in the dentate gyrus (DG) area of the hippocampus, enhanced mitochondrial function and improved cognitive deficits. Activation of the transient receptor potential channel 6 (TRPC6) increased GLUT3-mediated glucose uptake in the brain and alleviated RH-induced cognitive deficits, and inactivation of the Ca2+/AMPK pathway was responsible for TRPC6-induced GLUT3 inhibition. Taken together, RH impairs brain GLUT3-mediated glucose uptake and further provokes neuronal mitochondrial dysfunction by inhibiting TRPC6 expression, which then accelerates progression of cognitive deficits in diabetic APP/PS1 mice. Avoiding RH is essential for glycemic control in patients with diabetes, and TRPC6/GLUT3 represents potent targets for delaying the onset of dementia in patients with diabetes.

Circ_0007444 Inhibits the Progression of Ovarian Cancer via Mediating the miR-570-3p/PTEN Axis.

PURPOSE: Some circular RNAs have been found to be effective therapeutic targets for OC. However, the biological function of circ_0007444 in OC is still unknown. Thus, this study investigated the role of circ_0007444 in OC progression. METHODS: circ_0007444 expression was monitored in 87 OC patients and OC cells by quantitative real-time polymerase chain reaction. An in vitro study was performed to research the biological function of circ_0007444, including cell counting kit-8 assay, flow cytometry, wound healing assay, and transwell experiment. Luciferase reporter gene assay and RNA immunoprecipitation assay were used to reveal the interaction between circ_0007444, miR-570-3p, and PTEN. PTEN protein expression was determined by Western blot. In vivo study was performed using nude mice. Ki67, PTEN expression, and apoptosis in xenograft tumors was respectively researched by immunohistochemistry and Tunel assay. RESULTS: circ_0007444 was down-regulated in 87 OC patients, which was related to advanced tumor stage and grade, large tumor size, and low 60-month percent survival (P<0.05 or P<0.01). circ_0007444 inhibited proliferation, migration, and invasion, and promoted apoptosis of OC cells (P<0.01). circ_0007444 promoted PTEN expression via sponging miR-570-3p. miR-570-3p up-regulation and PTEN down-regulation reversed the inhibitory effect of circ_0007444 on OC cells malignant phenotype (P<0.01). circ_0007444 inhibited OC growth in vivo. In xenograft tumor, circ_0007444 decreased Ki67 expression but increased PTEN expression and apoptosis. CONCLUSION: circ_0007444 is a tumor suppressor in OC, which inhibits OC progression by mediating the miR-570-3p/PTEN. circ_0007444 can be a potential candidate for targeted therapy of OC.

Low-glucose-sensitive TRPC6 dysfunction drives hypoglycemia-induced cognitive impairment in diabetes.

BACKGROUND: Recurrent moderate hypoglycemia (RH), a major adverse effect of hypoglycemic therapy in diabetic patients, is one of the main risk factors for cognitive impairment and dementia. Transient receptor potential canonical channel 6 (TRPC6) is a potential therapeutic target for Alzheimer's disease (AD) and its expression is highly regulated by glucose concentration. OBJECTIVE: To investigate whether RH regulates the expression of TRPC6 in brain and whether TRPC6 dysfunction can drive hypoglycemia-associated cognitive impairment in diabetes, and reveal the underlying mechanism. METHODS: Histological staining, in vivo two-photon Ca2+ imaging, and behavioral tests were used to measure neuronal death, brain network activity, and cognitive function in mice, respectively. High-resolution respirometry and transmission electron microscope were used to assess mitochondrial structure and function. Intracellular calcium measurement and molecular biology techniques were conducted to uncover the underlying mechanism. RESULTS: Here, we report that the expression of TRPC6 in hippocampus was specifically repressed by RH in streptozocin-induced type 1 diabetic mice, but not in nondiabetic mice. TRPC6 knockout directly leads to neuron loss, neuronal activity, and cognitive function impairment under diabetic condition, the degree of which is similar to that of RH. Activation of TRPC6 with hyperforin substantially improved RH-induced cognitive impairment. Mechanistically, TRPC6 inhibited mitochondrial fission in the hippocampus of diabetic mice undergoing RH episodes by activating adenosine 5'-monophosphate-activated protein kinase, and TRPC6-mediated cytosolic calcium influx was required for this process. Clinically, dysfunction of TRPC6 was closely associated with cognitive impairment in type 2 diabetic patients with RH. CONCLUSIONS: Our results indicate that TRPC6 is a critical sensitive cation channel to hypoglycemia and is a promising target to prevent RH-induced cognitive impairment by properly orchestrating the mitochondrial dynamics in diabetic patients.

Reducing NADPH Synthesis Counteracts Diabetic Nephropathy through Restoration of AMPK Activity in Type 1 Diabetic Rats.

Diabetic nephropathy (DN) is a major complication of diabetes mellitus and a primary cause of end-stage renal failure. Clinical studies indicate that metabolic surgery improves DN; however, the mechanism remains unclear. Here, we report that Roux-en-Y Gastric Bypass (RYGB) surgery significantly blocked and reversed DN without affecting the insulin signaling pathway. This protective role of RYGB surgery is almost blocked by either inhibition or knockout of 5'AMP-activated protein kinase (AMPK) in podocytes. Furthermore, mRNA microarray data reveal that RYGB surgery obviously reduced the gene expression involved in nicotinamide adenine dinucleotide phosphate (NAPDH) synthesis. The expression of a key NADPH synthase, hexose-6-phosphate dehydrogenase (H6PD), was inhibited by the low plasma corticosterone level after surgery. In addition, blocking NAPDH synthesis by knocking down H6PD mimicked the beneficial role of RYGB surgery through activation of AMPK in podocytes. Therefore, this study demonstrates that reducing NADPH production is critical for renal AMPK activation in response to RYGB surgery.

Activation of the bitter taste sensor TRPM5 prevents high salt-induced cardiovascular dysfunction.

High salt intake is a known risk factor of cardiovascular diseases. Our recent study demonstrated that long-term high salt intake impairs transient receptor potential channel M5 (TRPM5)-mediated aversion to high salt concentrations, consequently promoting high salt intake and hypertension; however, it remains unknown whether TRPM5 activation ameliorates cardiovascular dysfunction. Herein we found that bitter melon extract (BME) and cucurbitacin E (CuE), a major compound in BME, lowered high salt-induced hypertension. Long-term BME intake significantly enhanced the aversion to high salt concentrations by upregulating TRPM5 expression and function, eventually decreasing excessive salt consumption in mice. Moreover, dietary BME ameliorated high salt-induced cardiovascular dysfunction and angiotensin II-induced hypertension in vivo. The mechanistic evidence demonstrated that dietary BME inhibited high salt-induced RhoA/Rho kinase pathway overactivation, leading to reduced phosphorylation levels of myosin light chain kinase and myosin phosphatase targeting subunit 1. Furthermore, CuE inhibited vasoconstriction by attenuating L-type Ca2+ channel-induced Ca2+ influx in vascular smooth muscle cells. To summarize, our findings indicate that dietary BME has a beneficial role in antagonizing excessive salt consumption and thus appears promising for the prevention of high salt-induced cardiovascular dysfunction.

Transient Receptor Potential Channel Canonical Type 3 Deficiency Antagonizes Myofibroblast Transdifferentiation In Vivo.

OBJECTIVE: Myofibroblast transformation has been shown to be associated with the reactive oxygen species- (ROS-) producing enzyme NADPH oxidase (Nox4). Inhibition of transient receptor potential channel canonical type 3 (TRPC3) attenuates mitochondrial calcium handling and ROS production in the vasculature of hypertensive rats. However, it remains elusive whether TRPC3 regulates mitochondrial calcium and ROS production and participates in myofibroblast transdifferentiation during wound healing. METHODS AND RESULTS: In this study, we demonstrated that activation of TRPC3 by transforming growth factor ß (TGFß (TGFαSMA). Inhibition of TRPC3 with its specific inhibitor, Pyr3, significantly decreased TGFß (TGFαSMA). Inhibition of TRPC3 with its specific inhibitor, Pyr3, significantly decreased TGFß (TGFß (TGFTrpc3-/- mice exhibited significantly attenuated myofibroblast transdifferentiation, as demonstrated by decreased αSMA). Inhibition of TRPC3 with its specific inhibitor, Pyr3, significantly decreased TGFß (TGFß (TGFTrpc3-/- mice exhibited significantly attenuated myofibroblast transdifferentiation, as demonstrated by decreased Trpc3+/+ mice. In addition, Trpc3-/- mice exhibited significantly attenuated myofibroblast transdifferentiation, as demonstrated by decreased. CONCLUSIONS: Our data indicate that TGFß1-mediated activation of TRPC3 enhances mitochondrial calcium and ROS production, which promotes myofibroblast transdifferentiation and HTS formation. Inhibition of the TRPC3-mediated Nox4/pSmad2/3 pathway may be a useful strategy to limit HTS formation after injury.ß (TGF.

Activation of TRPV1 channel antagonizes diabetic nephropathy through inhibiting endoplasmic reticulum-mitochondria contact in podocytes.

The impairment of podocyte protein filtration function caused by excessive mitochondrial calcium intake is a critical feature of diabetic nephropathy (DN). Ca2+ channel transient receptor potential cation channel subfamily V member 1 (TRPV1) has been reported to protect against ischemia-reperfusion induced acute renal injury, but there is no report about its role in DN. Here, we report that dietary capsaicin potently inhibits and reverses chronic renal structural and functional damages in db/db or streptozotocin (STZ)-induced diabetic mice in a TRPV1-dependent manner. Activation of TRPV1 by capsaicin alleviated hyperglycemia-induced mitochondrial dysfunction in podocytes, accompanied by reduced mitochondria-associated membranes (MAMs) formation and fewer Ca2+ transport from endoplasmic reticulum (ER) to mitochondria. Mechanistically, TRPV1-mediated transient Ca2+ influx activated 5' AMP-activated protein kinase (AMPK) that reduced the transcription of Fundc1, a key molecule participating in MAMs formation. Inhibition of AMPK or overexpression of Fundc1 obviously blocked the inhibitory effect of capsaicin on MAMs formation and functional decline in podocytes. These findings emphasize the critical role of mitochondrial Ca2+ homeostasis in the maintenance of normal renal function and suggest an effective intervention method to counteract DN.