This study aimed to investigate the effects of acupuncture on dynamic changes in Ca²⁺, Na⁺, and H₂O₂ flux following eccentric exercise-induced muscle injury. The total of 324 healthy male Wistar rats were randomly divided into 6 groups: control group (C), eccentric exercise group (E), eccentric exercise with acupuncture group (EA), EA with TRP channel blocker group (EAT), EA with NOX2 blocker group (EAN) and EA with placebo group (EAP). Gastrocnemius muscles were subject to lengthening contractions with percutaneous electrical stimulation, followed by immediate pretreatment with blocking agents. After 30 min, acupuncture needling was administered to the gastrocnemius muscle, and real-time dynamic changes of Ca²⁺, Na⁺ and H₂O₂ flux were measured with non-invasive micro-test technique during the needle retention period, immediately, 3 h, 6 h, and 24 h post-extraction respectively. Results showed that compared with the E group, acupuncture significantly increased net Ca²⁺ efflux (P < 0.05), extended the period of net Na⁺ influx, and significantly decreased net H₂O₂ efflux (P < 0.05). However, these effects were significantly attenuated in the EAT and EAN groups, where excessive net H₂O₂ efflux was observed (P < 0.001). These findings indicate that acupuncture regulates the dynamic changes of Ca²⁺, Na⁺ and H₂O₂ flux by activating the TRP channels and interacting with NOX2 activity following eccentric exercise-induced skeletal muscle injury.
Animals ; Muscle, Skeletal/metabolism* ; Rats, Wistar ; Rats ; Male ; Calcium/metabolism* ; Hydrogen Peroxide/metabolism* ; Physical Conditioning, Animal ; Sodium/metabolism* ; Acupuncture Therapy ; NADPH Oxidase 2

Donors with a serum sodium concentration of >155 mmol/L are extended criteria donors for liver transplantation (LT). Elevated serum sodium of donors leads to an increased incidence of hepatic dysfunction in the early postoperative period of LT; however, the exact mechanism has not been reported. We constructed a Lewis rat model of 70% hepatic parenchymal area subjected to ischemia-reperfusion (I/R) with hypernatremia and a BRL-3A cell model of hypoxia-reoxygenation (H/R) with high-sodium (HS) culture medium precondition. To determine the degree of injury, biochemical analysis, histological analysis, and oxidative stress and apoptosis detection were performed. We applied specific inhibitors of the epithelial sodium channel (ENaC) and Na⁺/Ca²⁺ exchanger (NCX) in vivo and in vitro to verify their roles in injury. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH) levels and the area of hepatic necrosis were significantly elevated in the HS+I/R group. Increased reactive oxygen species (ROS) production, myeloperoxidase (MPO)‍-positive cells, and aggravated cellular apoptosis were detected in the HS+I/R group. The HS+H/R group of BRL-3A cells showed significantly increased cellular apoptosis and ROS production compared to the H/R group. The application of amiloride (Amil), a specific inhibitor of ENaC, reduced ischemia-reperfusion injury (IRI) aggravated by HS both in vivo and in vitro, as evidenced by decreased serum transaminases, inflammatory cytokines, apoptosis, and oxidative stress. SN-6, a specific inhibitor of NCX, had a similar effect to Amil. In summary, hypernatremia aggravates hepatic IRI, which can be attenuated by pharmacological inhibition of ENaC or NCX.
Animals ; Reperfusion Injury/drug therapy* ; Hypernatremia/complications* ; Rats ; Liver/metabolism* ; Rats, Inbred Lew ; Male ; Apoptosis ; Sodium-Calcium Exchanger/antagonists & inhibitors* ; Reactive Oxygen Species/metabolism* ; Oxidative Stress ; Epithelial Sodium Channel Blockers/pharmacology* ; Epithelial Sodium Channels ; Cell Line ; Liver Transplantation

Objective To investigate the effect of liquid-liquid phase separation(LLPS)of YTH domain family protein 2(YTHDF2)on the sodium arsenite-induced malignant transformation of skin cells,providing a new intervention target for the prevention and control of sodium arsenite-induced carcinogenesis.Methods The HaCaT cell model of malignant transformation was constructed by continuous treatment with 1 μmol/L sodium arsenite for 22 weeks,including cells with normal YTHDF2 LLPS(YTHDF2-wt)and cells with inhibited YTHDF2 LLPS(YTHDF2-mut).Confocal microscopy was employed to observe and characterize the LLPS droplets formed by YTHDF2 during sodium arsenite-induced malignant transformation of skin cells.Cell proliferation,scratch healing,and colony formation assays were performed to detect malignant phenotypes.Western blotting,quantitative reverse transcription PCR,and immunofluorescence experiments were conducted to examine the effects of YTHDF2 LLPS on the mRNA and protein levels of phosphatase and tensin homolog deleted on chromosome ten(PTEN)during sodium arsenite-induced malignant transformation of skin cells.Results After 4 weeks of sodium arsenite treatment,LLPS droplets of YTHDF2 appeared in YTHDF2-wt cells,and the number of droplets gradually increased as the treatment time was prolonged(F=35.252,P<0.001),while no phase-separated droplets were observed in YTHDF2-mut cells.Compared with YTHDF2-mut cells,YTHDF2-wt cells showed enhanced proliferation at the time points of 48 h(t=3.654,P=0.006)and 72 h(t=5.458,P<0.001)after 22 weeks of sodium arsenite treatment.The scratch healing rate of YTHDF2-wt cells was increased at the 8th(t=12.137,P<0.001)and 22th(t=4.484,P=0.011)weeks of sodium arsenite treatment.The number of colonies formed by YTHDF2-wt cells was higher at the 4th(t=3.365,P=0.027),8th(t=5.580,P=0.005),and 22th(t=3.328,P=0.029)weeks of sodium arsenite treatment.Compared with YTHDF2-mut cells,YTHDF2-wt cells showed down-regulated protein(t=-3.119,P=0.036)and mRNA(t=4.051,P=0.015) levels of PTEN after 22 weeks of sodium arsenite treatment.Immunofluorescence results showed that after 4 weeks of sodium arsenite treatment,YTHDF2 LLPS droplets in YTHDF2-wt cells were localized to stress granules,translation-related membrane-less organelles.Conclusions During sodium arsenite-induced malignant transformation of skin cells,YTHDF2 undergoes LLPS and localizes to stress granules,translation-related membrane-less organelles.YTHDF2 LLPS participates in sodium arsenite-induced malignant transformation of skin cells by down-regulating the mRNA level of the key tumor suppressor PTEN.
Arsenites/toxicity* ; Sodium Compounds/toxicity* ; Humans ; Cell Transformation, Neoplastic/drug effects* ; PTEN Phosphohydrolase/metabolism* ; Cell Proliferation ; Skin/cytology* ; RNA-Binding Proteins ; Skin Neoplasms/chemically induced* ; Cell Line

OBJECTIVE: To study effects of Shenmai Injection on hypertensive heart failure and its mechanism for inhibiting myocardial fibrosis. METHODS: Salt-sensitive (Dahl/SS) rats were fed with normal diet (0.3% NaCl) and the high-salt diet (8% NaCl) to observe the changes in blood pressure and heart function, as the control group and the model group. Salt-insensitive rats (SS-13BN) were fed with the high-salt diet (8% NaCl) as the negative control group. After modeling, the model rats were randomly divided into heart failure (HF) group, Shenmai Injection (SMI) group and pirfenidone (PFD) group by a random number table, with 6 rats in each group. They were given sterilized water, SMI and pirfenidone, respectively. Blood pressure, cardiac function, fibrosis and related molecular expression were detected by sphygmomanometer, echocardiogram, enzyme linked immunosorbent assay (ELISA), hematoxylin-eosin staining, Masson staining, immunofluorescence and qPCR analysis. RESULTS: After high-salt feeding, compared with the control and negative control group, in the model group the blood pressure increased significantly, the left ventricular ejection fraction (LVEF) and left ventricular fraction shortening (LVFS) were significantly reduced, and the serum NT-proBNP concentration increased significantly (all P<0.05); furthermore, the arrangement of myocardial cells was disordered, the edema was severe, and the degree of myocardial fibrosis was also significantly increased (P<0.05); the protein and mRNA expressions of collagen type I (Col I) were up-regulated (P<0.05), and the mRNA expressions of transforming growth factor β 1 (TGF- β 1), Smad2 and Smad3 were significantly up-regulated (P<0.05). Compared with HF group, after intervention of Shenmai Injection, LVEF and LVFS increased, myocardial morphology was improved, collagen volume fraction decreased significantly (P<0.05), and the mRNA expressions of Col I, TGF- β 1, Smad2 and Smad3, as well as Col I protein expression, were all significantly down-regulated (all P<0.05). CONCLUSION Myocardial fibrosis is the main pathological manifestation of hypertensive heart failure, and Shenmai Injection could inhibit myocardial fibrosis and effectively improve heart failure by regulating TGF-β 1/Smad signaling pathway.
Rats ; Animals ; Stroke Volume ; Sodium Chloride ; Rats, Inbred Dahl ; Ventricular Function, Left ; Heart Failure ; Transforming Growth Factor beta1/metabolism* ; Hypertension ; Fibrosis ; RNA, Messenger

PiT2 is an inorganic phosphate (Pi) transporter whose mutations are linked to primary familial brain calcification (PFBC). PiT2 mainly consists of two ProDom (PD) domains and a large intracellular loop region (loop7). The PD domains are crucial for the Pi transport, but the role of PiT2-loop7 remains unclear. In PFBC patients, mutations in PiT2-loop7 are mainly nonsense or frameshift mutations that probably cause PFBC due to C-PD1131 deletion. To date, six missense mutations have been identified in PiT2-loop7; however, the mechanisms by which these mutations cause PFBC are poorly understood. Here, we found that the p.T390A and p.S434W mutations in PiT2-loop7 decreased the Pi transport activity and cell surface levels of PiT2. Furthermore, we showed that these two mutations attenuated its membrane localization by affecting adenosine monophosphate-activated protein kinase (AMPK)- or protein kinase B (AKT)-mediated PiT2 phosphorylation. In contrast, the p.S121C and p.S601W mutations in the PD domains did not affect PiT2 phosphorylation but rather impaired its substrate-binding abilities. These results suggested that missense mutations in PiT2-loop7 can cause Pi dyshomeostasis by affecting the phosphorylation-regulated cell-surface localization of PiT2. This study helps understand the pathogenesis of PFBC caused by PiT2-loop7 missense mutations and indicates that increasing the phosphorylation levels of PiT2-loop7 could be a promising strategy for developing PFBC therapies.
Humans ; Cell Membrane ; Mutation, Missense ; Phosphates/metabolism* ; Sodium-Phosphate Cotransporter Proteins, Type III/genetics*

Renal outer medullary potassium (ROMK) channel is an important K⁺ excretion channel in the body, and K⁺ secreted by the ROMK channels is most or all source of urinary potassium. Previous studies focused on the ROMK channels of thick ascending limb (TAL) and collecting duct (CD), while there were few studies on the involvement of ROMK channels of the late distal convoluted tubule (DCT2) in K⁺ excretion. The purpose of the present study was mainly to record the ROMK channels current in renal DCT2 and observe the effect of high potassium diet on the ROMK channels by using single channel and whole-cell patch-clamp techniques. The results showed that a small conductance channel current with a conductance of 39 pS could be recorded in the apical membrane of renal DCT2, and it could be blocked by Tertiapin-Q (TPNQ), a ROMK channel inhibitor. The high potassium diet significantly increased the probability of ROMK channel current occurrence in the apical membrane of renal DCT2, and enhanced the activity of ROMK channel, compared to normal potassium diet (P < 0.01). Western blot results also demonstrated that the high potassium diet significantly up-regulated the protein expression levels of ROMK channels and epithelial sodium channel (ENaC), and down-regulated the protein expression level of Na⁺-Cl^- cotransporter (NCC). Moreover, the high potassium diet significantly increased urinary potassium excretion. These results suggest that the high potassium diet may activate the ROMK channels in the apical membrane of renal DCT2 and increase the urinary potassium excretion by up-regulating the expression of renal ROMK channels.
Potassium Channels, Inwardly Rectifying/metabolism* ; Kidney Tubules, Distal/metabolism* ; Potassium/metabolism* ; Epithelial Sodium Channels/metabolism* ; Diet

Virtually all of the dietary potassium intake is absorbed in the intestine, over 90% of which is excreted by the kidneys regarded as the most important organ of potassium excretion in the body. The renal excretion of potassium results primarily from the secretion of potassium by the principal cells in the aldosterone-sensitive distal nephron (ASDN), which is coupled to the reabsorption of Na⁺ by the epithelial Na⁺ channel (ENaC) located at the apical membrane of principal cells. When Na⁺ is transferred from the lumen into the cell by ENaC, the negativity in the lumen is relatively increased. K⁺ efflux, H⁺ efflux, and Cl^- influx are the 3 pathways that respond to Na⁺ influx, that is, all these 3 pathways are coupled to Na⁺ influx. In general, Na⁺ influx is equal to the sum of K⁺ efflux, H⁺ efflux, and Cl^- influx. Therefore, any alteration in Na⁺ influx, H⁺ efflux, or Cl^- influx can affect K⁺ efflux, thereby affecting the renal K⁺ excretion. Firstly, Na⁺ influx is affected by the expression level of ENaC, which is mainly regulated by the aldosterone-mineralocorticoid receptor (MR) pathway. ENaC gain-of-function mutations (Liddle syndrome, also known as pseudohyperaldosteronism), MR gain-of-function mutations (Geller syndrome), increased aldosterone levels (primary/secondary hyperaldosteronism), and increased cortisol (Cushing syndrome) or deoxycorticosterone (hypercortisolism) which also activate MR, can lead to up-regulation of ENaC expression, and increased Na⁺ reabsorption, K⁺ excretion, as well as H⁺ excretion, clinically manifested as hypertension, hypokalemia and alkalosis. Conversely, ENaC inactivating mutations (pseudohypoaldosteronism type 1b), MR inactivating mutations (pseudohypoaldosteronism type 1a), or decreased aldosterone levels (hypoaldosteronism) can cause decreased reabsorption of Na⁺ and decreased excretion of both K⁺ and H⁺, clinically manifested as hypotension, hyperkalemia, and acidosis. The ENaC inhibitors amiloride and Triamterene can cause manifestations resembling pseudohypoaldosteronism type 1b; MR antagonist spironolactone causes manifestations similar to pseudohypoaldosteronism type 1a. Secondly, Na⁺ influx is regulated by the distal delivery of water and sodium. Therefore, when loss-of-function mutations in Na⁺-K⁺-2Cl^- cotransporter (NKCC) expressed in the thick ascending limb of the loop and in Na⁺-Cl^- cotransporter (NCC) expressed in the distal convoluted tubule (Bartter syndrome and Gitelman syndrome, respectively) occur, the distal delivery of water and sodium increases, followed by an increase in the reabsorption of Na⁺ by ENaC at the collecting duct, as well as increased excretion of K⁺ and H⁺, clinically manifested as hypokalemia and alkalosis. Loop diuretics acting as NKCC inhibitors and thiazide diuretics acting as NCC inhibitors can cause manifestations resembling Bartter syndrome and Gitelman syndrome, respectively. Conversely, when the distal delivery of water and sodium is reduced (e.g., Gordon syndrome, also known as pseudohypoaldosteronism type 2), it is manifested as hypertension, hyperkalemia, and acidosis. Finally, when the distal delivery of non-chloride anions increases (e.g., proximal renal tubular acidosis and congenital chloride-losing diarrhea), the influx of Cl^- in the collecting duct decreases; or when the excretion of hydrogen ions by collecting duct intercalated cells is impaired (e.g., distal renal tubular acidosis), the efflux of H⁺ decreases. Both above conditions can lead to increased K⁺ secretion and hypokalemia. In this review, we focus on the regulatory mechanisms of renal potassium excretion and the corresponding diseases arising from dysregulation.
Humans ; Bartter Syndrome/metabolism* ; Pseudohypoaldosteronism/metabolism* ; Potassium/metabolism* ; Aldosterone/metabolism* ; Hypokalemia/metabolism* ; Gitelman Syndrome/metabolism* ; Hyperkalemia/metabolism* ; Clinical Relevance ; Epithelial Sodium Channels/metabolism* ; Kidney Tubules, Distal/metabolism* ; Sodium/metabolism* ; Hypertension ; Alkalosis/metabolism* ; Water/metabolism* ; Kidney/metabolism*

OBJECTIVES: Endothelium-dependent vasodilation dysfunction is the pathological basis of diabetic macroangiopathy. The utilization and adaptation of endothelial cells to high glucose determine the functional status of endothelial cells. Glycolysis pathway is the major energy source for endothelial cells. Abnormal glycolysis plays an important role in endothelium-dependent vasodilation dysfunction induced by high glucose. Pyruvate kinase isozyme type M2 (PKM2) is one of key enzymes in glycolysis pathway, phosphorylation of PKM2 can reduce the activity of pyruvate kinase and affect the glycolysis process of glucose. TEPP-46 can stabilize PKM2 in its tetramer form, reducing its dimer formation and phosphorylation. Using TEPP-46 as a tool drug to inhibit PKM2 phosphorylation, this study aims to explore the impact and potential mechanism of phosphorylated PKM2 (p-PKM2) on endothelial dependent vasodilation function in high glucose, and to provide a theoretical basis for finding new intervention targets for diabetic macroangiopathy. METHODS: The mice were divided into 3 groups: a wild-type (WT) group (a control group, C57BL/6 mice) and a db/db group (a diabetic group, db/db mice), which were treated with the sodium carboxymethyl cellulose solution (solvent) by gavage once a day, and a TEPP-46 group (a treatment group, db/db mice+TEPP-46), which was gavaged with TEPP-46 (30 mg/kg) and sodium carboxymethyl cellulose solution once a day. After 12 weeks of treatment, the levels of p-PKM2 and PKM2 protein in thoracic aortas, plasma nitric oxide (NO) level and endothelium-dependent vasodilation function of thoracic aortas were detected. High glucose (30 mmol/L) with or without TEPP-46 (10 μmol/L), mannitol incubating human umbilical vein endothelial cells (HUVECs) for 72 hours, respectively. The level of NO in supernatant, the content of NO in cells, and the levels of p-PKM2 and PKM2 protein were detected. Finally, the effect of TEPP-46 on endothelial nitric oxide synthase (eNOS) phosphorylation was detected at the cellular and animal levels. RESULTS: Compared with the control group, the levels of p-PKM2 in thoracic aortas of the diabetic group increased (P<0.05). The responsiveness of thoracic aortas in the diabetic group to acetylcholine (ACh) was 47% lower than that in the control group (P<0.05), and that in TEPP-46 treatment group was 28% higher than that in the diabetic group (P<0.05), while there was no statistically significant difference in the responsiveness of thoracic aortas to sodium nitroprusside (SNP). Compared with the control group, the plasma NO level of mice decreased in the diabetic group, while compared with the diabetic group, the phosphorylation of PKM2 in thoracic aortas decreased and the plasma NO level increased in the TEPP-46 group (both P<0.05). High glucose instead of mannitol induced the increase of PKM2 phosphorylation in HUVECs and reduced the level of NO in supernatant (both P<0.05). HUVECs incubated with TEPP-46 and high glucose reversed the reduction of NO production and secretion induced by high glucose while inhibiting PKM2 phosphorylation (both P<0.05). At the cellular and animal levels, TEPP-46 reversed the decrease of eNOS (ser1177) phosphorylation induced by high glucose (both P<0.05). CONCLUSIONS p-PKM2 may be involved in the process of endothelium-dependent vasodilation dysfunction in Type 2 diabetes by inhibiting p-eNOS (ser1177)/NO pathway.
Animals ; Humans ; Mice ; Carboxymethylcellulose Sodium/pharmacology* ; Diabetes Mellitus, Type 2/metabolism* ; Endothelium, Vascular/metabolism* ; Glucose/metabolism* ; Human Umbilical Vein Endothelial Cells ; Mice, Inbred C57BL ; Nitric Oxide/metabolism* ; Nitric Oxide Synthase Type III/metabolism* ; Phosphorylation ; Pyruvate Kinase/metabolism* ; Vasodilation

Humans ; Sodium-Calcium Exchanger ; Carrier Proteins ; Pain ; Calcium/metabolism*

This study aims to investigate the therapeutic effects and potential mechanisms of resveratrol(Res) on poor ovarian response(POR) in mice. The common target genes shared by Res and POR were predicted by network pharmacology, used for Gene Ontology(GO) annotation and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment, and then validated by animal experiments. The mice with regular estrous cycle after screening were randomized into normal, POR, and low-and high-dose(20 and 40 mg·kg~(-1), respectively) Res groups. The normal group was administrated with an equal volume of 0.9% sodium chloride solution by gavage, and the mice in other groups with tripterygium glycosides suspension(50 mg·kg~(-1)) by gavage for 2 weeks. After the modeling, the mice in low-and high-dose Res groups were treated with Res by gavage for 2 weeks, and the mice in normal and POR groups with an equal volume of 0.9% sodium chloride solution by gavage. Ovulation induction and sample collection were carried out on the day following the end of treatment. Vaginal smears were collected for observation of the changes in the estrous cycle, the counting of retrieved oocytes, and the measurement of ovarian wet weight and ovarian index. The enzyme-linked immunosorbent assay(ELISA) was employed to measure the levels of anti-mullerian hormone(AMH), follicle-stimulating hormone(FSH), estradiol(E_2), and luteinizing hormone(LH) in the serum. The ovarian tissue morphology and granulosa cell apoptosis were observed by hematoxylin-eosin(HE) staining and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling(TUNEL), respectively. Western blot was employed to determine the protein levels of phosphatidylinositol 3-kinase(PI3K), protein kinase B(AKT), forkhead box O(FOXO) 3a, hypoxia-inducible factor(HIF)-1α, B-cell lymphoma-2(Bcl-2), and Bcl-2-associated X protein(Bax). A total of 222 common targets shared by Res and POR were collected. GO annotation indicated that these targets were mainly involved in oxidative stress response. KEGG enrichment analysis revealed that Res can intervene in POR via PI3K/AKT, HIF-1, and FOXO signaling pathways. Animal experiments showed that the model group had higher rate of estrous cycle disorders, lower number and poorer morphology of normally developed follicles at all levels, more atretic follicles, higher apoptosis of ovarian granulosa cells, lower number of retrieved oocytes, lower ovarian wet weight and ovarian index, higher serum levels of FSH and LH, lower levels of AMH and E_2, higher expression levels of HIF-1α, FOXO3a and Bax, and lower expression levels of PI3K, AKT, and Bcl-2 in the ovarian tissue than the normal group. Compared with the POR group, low-and high-dose Res decreased the rate of estrous cycle disorders, improved the follicle number and morphology, reduced atretic follicles, promoted the apoptosis of ovarian granulosa cells, increased retrieved oocytes, ovarian wet weight and ovarian index, and lowered serum FSH and LH levels. Moreover, Res down-regulated the expression levels of HIF-1α, FOXO3a and Bax, and up-regulated the expression levels of PI3K, AKT and Bcl-2 in the ovarian tissue. In summary, Res can inhibit apoptosis and mitigate poor ovarian response in mice by regulating the PI3K/AKT/FOXO3a and HIF-1α pathways.
Female ; Mice ; Animals ; Proto-Oncogene Proteins c-akt/metabolism* ; Resveratrol/pharmacology* ; bcl-2-Associated X Protein ; Phosphatidylinositol 3-Kinases/metabolism* ; Sodium Chloride ; Follicle Stimulating Hormone ; Proto-Oncogene Proteins c-bcl-2