OBJECTIVE: To explore the clinical and genetic characteristics of a child with spinocerebellar ataxia type 29 (SCA29) due to novel variant of the inositol 1,4,5-trisphosphate receptor type 1 (ITPR1) gene. METHODS: The child was subjected high-throughput sequencing, and candidate variant was verified by Sanger sequencing of his family members. RESULTS: The child was found to harbor a c.800C>T (p.T267M) variant of the ITPR1 gene, which was not found in his parents and their fetus. The variant has occurred in a hotspot of the ITPR1 gene variants and was unreported before in China. Based on his clinical and genetic characteristics, the child was diagnosed with SCA29. CONCLUSION The novel heterozygous c.800C>T (p.T267M) of the ITPR1 gene probably underlay the SCA29 in this child.
Child ; Humans ; Family ; Inositol 1,4,5-Trisphosphate Receptors/genetics* ; Mutation ; Spinocerebellar Ataxias/genetics* ; Spinocerebellar Degenerations

The purpose of the present study was to determine the role of inositol 1,4,5-trisphosphate receptor 3 (IP₃R3) in renal cyst development in autosomal dominant polycystic kidney disease (ADPKD). 2-aminoethoxy-diphenyl borate (2-APB) and shRNA were used to suppress the expression of IP₃R3. The effect of IP₃R3 on cyst growth was investigated in Madin-Darby canine kidney (MDCK) cyst model, embryonic kidney cyst model and kidney specific Pkd1 knockout (PKD) mouse model. The underlying mechanism of IP₃R3 in promoting renal cyst development was investigated by Western blot and immunofluorescence staining. The results showed that the expression level of IP₃R3 was significantly increased in the kidneys of PKD mice. Inhibiting IP₃R3 by 2-APB or shRNA significantly retarded cyst expansion in MDCK cyst model and embryonic kidney cyst model. Western blot and immunofluorescence staining results showed that hyperactivated cAMP-PKA signaling pathway in the growth process of ADPKD cyst promoted the expression of IP₃R3, which was accompanied by a subcellular redistribution process in which IP₃R3 was translocated from endoplasmic reticulum to intercellular junction. The abnormal expression and subcellular localization of IP₃R3 further promoted cyst epithelial cell proliferation by activating MAPK and mTOR signaling pathways and accelerating cell cycle. These results suggest that the expression and subcellular distribution of IP₃R3 are involved in promoting renal cyst development, which implies IP₃R3 as a potential therapeutic target of ADPKD.
Animals ; Dogs ; Mice ; Cysts/genetics* ; Inositol 1,4,5-Trisphosphate Receptors/pharmacology* ; Kidney/metabolism* ; Polycystic Kidney Diseases/metabolism* ; Polycystic Kidney, Autosomal Dominant/drug therapy* ; Madin Darby Canine Kidney Cells

Background: Myo-inositol has emerged as one of the preventive therapies for the development of gestational diabetes mellitus in at-risk populations. This systematic review and meta-analysis was conducted to determine the efficacy and safety of myo-inositol in decreasing the incidence of gestational diabetes in overweight and obese pregnant women. Methodology: This meta-analysis was conducted using the standard Cochrane methodology and reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) 2020 guidelines. Inclusion criteria were randomized controlled trials (RCTs) that enrolled overweight and obese pregnant women and used myo-inositol supplementation. The primary outcome was the incidence of gestational diabetes mellitus at 24-28 weeks. Secondary outcomes included cesarean section rate, the incidence of pregnancy-induced hypertension, macrosomia and preterm delivery. Risk ratios (RRs) and 95% confidence intervals (CIs) were used for dichotomous data. Results: Six RCTs were included. Compared to standard micronutrient supplementation, standard dose of myo-inositol (4 g) may reduce the incidence of GDM (RR 0.54; CI [0.30, 0.96]; n = 887 women), but the certainty of evidence is low to very low. With low-dose myo-inositol however, evidence is uncertain about its benefit on the incidence of gestational diabetes mellitus in overweight and obese women with RR 0.71; CI [0.14, 3.50]. No adverse effects were noted. For the secondary outcomes, standard dose myo-inositol appears to reduce the incidence of pregnancy-induced hypertension and preterm delivery, but the certainty of evidence is low to very low. Conclusion Current evidence is uncertain on the potential benefit of myo-inositol supplementation in overweight and obese pregnant women. While studies show that 4 g myo-inositol per day may decrease the incidence of GDM, pregnancy-induced hypertension and pre-term birth with no associated risk of serious adverse events, the certainty of evidence is low to very low. Future high-quality trials may provide more compelling evidence to support practice recommendations.
Diabetes, Gestational ; Obesity ; Inositol Phosphates

As an important dicarboxylic acids existing in nature, glucaric acid has been widely used in medical, health, and polymer materials industry, therefore it is considered as one of the "top value-added chemicals from biomass". In this study, using Saccharomyces cerevisiae as a chassis microorganism, the effects of overexpression of myo-inositol transporter Itr1, fusional expression of inositol oxygenase MIOX4 and uronate dehydrogenase Udh, and down-expression of glucose-6-phosphate dehydrogenase gene ZWF1 on the glucaric acid production were investigated. The results showed that the yield of glucaric acid was increased by 26% compared with the original strain Bga-3 under shake flask fermentation after overexpressing myo-inositol transporter Itr1. The yield of glucaric acid was increased by 40% compared with Bga-3 strain by expressing the MIOX4-Udh fusion protein. On these basis, the production of glucaric acid reached 5.5 g/L, which was 60% higher than that of Bga-3 strain. In a 5 L fermenter, the highest yield of glucaric acid was 10.85 g/L, which was increased 80% compared with that of Bga-3 strain. The application of the above metabolic engineering strategy improved the pathway efficiency and the yield of glucaric acid, which may serve as a reference for engineering S. cerevisiae to produce other chemicals.
Fermentation ; Glucaric Acid/metabolism* ; Inositol Oxygenase/genetics* ; Metabolic Engineering ; Saccharomyces cerevisiae/metabolism*

OBJECTIVE: To explore the mechanism by which inositol-requiring enzyme-1α (IRE1α) regulates autophagy function of chondrocytes through calcium homeostasis endoplasmic reticulum protein (CHERP). METHODS: Cultured human chondrocytes (C28/I2 cells) were treated with tunicamycin, 4μ8c, rapamycin, or both 4μ8c and rapamycin, and the expressions of endoplasmic reticulum (ER) stress- and autophagy-related proteins were detected with Western blotting. Primary chondrocytes from ERN1 knockout (ERN1 CKO) mice and wild-type mice were examined for ATG5 and ATG7 mRNA expressions, IRE1α and p-IRE1α protein expressions, and intracellular calcium ion content using qPCR, Western blotting and flow cytometry. The effect of bafilomycin A1 treatment on LC3 Ⅱ/LC3 Ⅰ ratio in the isolated chondrocytes was assessed with Western blotting. Changes in autophagic flux of the chondrocytes in response to rapamycin treatment were detected using autophagy dual fluorescent virus. The changes in autophagy level in C28/I2 cells overexpressing CHERP and IRE1α were detected using immunofluorescence assay. RESULTS: Tunicamycin treatment significantly up-regulated ER stress-related proteins and LC3 Ⅱ/LC3 Ⅰ ratio and down-regulated the expression of p62 in C28/I2 cells (P < 0.05). Rapamycin obviously up-regulated LC3 Ⅱ/LC3 Ⅰ ratio (P < 0.001) in C28/I2 cells, but this effect was significantly attenuated by co-treatment with 4μ8c (P < 0.05). Compared with the cells from the wild-type mice, the primary chondrocytes from ERN1 knockout mice showed significantly down-regulated mRNA levels of ERN1 (P < 0.01), ATG5 (P < 0.001) and ATG7 (P < 0.001), lowered or even lost expressions of IRE1α and p-IRE1α proteins (PP < 0.01), and increased expression of CHERP (P < 0.05) and intracellular calcium ion content (P < 0.001). Bafilomycin A1 treatment obviously increased LC3 Ⅱ/ LC3 Ⅰ ratio in the chondrocytes from both wild-type and ERN1 knockout mice (P < 0.01 or 0.05), but the increment was more obvious in the wild-type chondrocytes (P < 0.05). Treatment with autophagy dual-fluorescence virus resulted in a significantly greater fluorescence intensity of LC3-GFP in rapamycin-treated ERN1 CKO chondrocytes than in wild-type chondrocytes (P < 0.05). In C28/I2 cells, overexpression of CHERP obviously decreased the fluorescence intensity of LC3, and overexpression of IRE1α enhanced the fluorescence intensity and partially rescued the fluorescence reduction of LC3 caused by CHERP. CONCLUSION IRE1α deficiency impairs autophagy in chondrocytes by upregulating CHERP and increasing intracellular calcium ion content.
Animals ; Autophagy ; Calcium/metabolism* ; Chondrocytes ; Endoplasmic Reticulum/metabolism* ; Endoribonucleases/pharmacology* ; Homeostasis ; Inositol ; Mice ; Mice, Knockout ; Protein Serine-Threonine Kinases ; RNA, Messenger/metabolism* ; Sirolimus/pharmacology* ; Tunicamycin/pharmacology*

OBJECTIVE: To compare the analgesic effect of Jin Ling Zi Powder (JLZ) and its two single herbs. METHODS: The hot plate method was used to induce pain. Totally 36 mice were randomly divided into 6 groups by a complete random design, including control, model, aspirin (ASP, 0.14 g/kg body weight), JLZ (14 g/kg body weight), Corydalis yanhusuo (YHS, 14 g/kg body weight), and Toosendan Fructus (TF, 14 g/kg body weight) groups, 6 mice in each group. The mice in the control and model groups were given the same volume of saline, daily for 2 consecutive weeks. At 30, 60, 90, and 120 min after the last administration, the pain threshold of mice in each group was measured, and the improvement rate of pain threshold was calculated. Serum endogenous metabolites were analyzed by gas chromatography-mass spectrometry (GC-MS). RESULTS: There was no statistical difference in pain threshold among groups before administration (P>0.05). After 2 weeks of administration, compared with the model group, the pain threshold in JLZ, YHS, TF and ASP groups were increased to varying degrees (P<0.05). JLZ had the best analgesic effect and was superior to YHS and TF groups. A total of 14 potential biomarkers were screened in serum data analysis and potential biomarkers levels were all reversed to different degrees after the treatment with JLZ and its single herbs. These potential biomarkers were mainly related to glyoxylate and dicarboxylate metabolism, glycine, serine and threonine metabolism, valine, leucine and isoleucine biosynthesis, aminoacyl-tRNA biosynthesis and inositol phosphate metabolism. CONCLUSIONS The analgesic mechanism of JLZ and YHS was mainly due to the combination of glycine and its receptor, producing post-synaptic potential, reducing the excitability of neurons, and weakening the afferent effect of painful information.
Animals ; Mice ; Analgesics/therapeutic use* ; Aspirin/pharmacology* ; Biomarkers ; Body Weight ; Drugs, Chinese Herbal/therapeutic use* ; Glycine ; Glyoxylates ; Inositol Phosphates ; Isoleucine ; Leucine ; Metabolomics/methods* ; Powders ; RNA, Transfer ; Serine ; Threonine ; Valine

Inositol 1,4,5-trisphosphate receptor 1 (ITPR1) is an important intracellular channel for releasing Ca²⁺. In order to investigate the effects of the ITPR1 overexpression on Ca²⁺ concentration and lipid content in duck uterine epithelial cells and its effects on calcium transport-related genes, the structural domain of ITPR1 gene of duck was cloned into an eukaryotic expression vector and transfected into duck uterine epithelial cells. The overexpression of the ITPR1 gene, the concentration of Ca²⁺, the lipid content, and the expression of other 6 calcium transport-related genes was determined. The results showed that the concentration of Ca²⁺ in uterine epithelial cells was significantly reduced after transfection (P<0.05), the triglyceride content was significantly increased (P<0.01), and the high-density lipoprotein content was significantly decreased (P<0.01). The correlation analysis results showed that the overexpression of the C-terminal half of the ITPR1 gene was significantly positively correlated with the total cholesterol content (P<0.01), which was significantly positively correlated with the low-density lipoprotein content (P<0.05). The overexpression of the N-terminal half of the ITPR1 gene was significantly positively correlated with the triglyceride content (P<0.01), which was significantly negatively correlated with the concentration of Ca²⁺ (P<0.05). RT-qPCR results of 6 calcium transport-related genes showed that the overexpression of the C-terminal half of the ITPR1 gene significantly inhibited the expression of the IP3R2, VDAC2 and CAV1 genes, and the overexpression of the N-terminal half of the ITPR1 gene significantly promoted the expression of the IP3R3 and CACNA2D1 genes. In conclusion, the ITPR1 gene overexpression can promote Ca²⁺ release in duck uterus epithelial cells, promote the synthesis of triglyceride, low-density lipoprotein and cholesterol, and inhibit the production of high-density lipoprotein, and the ITPR1 gene overexpression affected the expression of all 6 calcium transport-related genes.
Animals ; Calcium/metabolism* ; Ducks/genetics* ; Epithelial Cells ; Female ; Inositol ; Inositol 1,4,5-Trisphosphate Receptors ; Lipids ; Uterus

The acrosome reaction is a prerequisite for fertilization, and its signaling pathway has been investigated for decades. Regardless of the type of inducers present, the acrosome reaction is ultimately mediated by the elevation of cytosolic calcium. Inositol 1,4,5-trisphosphate-gated calcium channels are important components of the acrosome reaction signaling pathway and have been confirmed by several researchers. In this study, we used a novel permeabilization tool BioPORTER^® and first demonstrated its effectiveness in spermatozoa. The inositol 1,4,5-trisphosphate type-1 receptor antibody was introduced into spermatozoa by BioPORTER^® and significantly reduced the calcium influx and acrosome reaction induced by progesterone, solubilized zona pellucida, and the calcium ionophore A23187. This finding indicates that the inositol 1,4,5-trisphosphate type-1 receptor antibody is a valid inositol 1,4,5-trisphosphate receptor inhibitor and provides evidence of inositol 1,4,5-trisphosphate-gated calcium channel involvement in the acrosome reaction in human spermatozoa. Moreover, we demonstrated that the transfer of 1,4,5-trisphosphate into spermatozoa induced acrosome reactions, which provides more reliable evidence for this process. In addition, by treating the spermatozoa with inositol 1,4,5-trisphosphate/BioPORTER^® in the presence or absence of calcium in the culture medium, we showed that the opening of inositol 1,4,5-trisphosphate-gated calcium channels led to extracellular calcium influx. This particular extracellular calcium influx may be the major process of the final step of the acrosome reaction signaling pathway.
Acrosome Reaction/physiology* ; Calcimycin/pharmacology* ; Calcium/pharmacology* ; Calcium Ionophores/pharmacology* ; Drug Delivery Systems ; Humans ; Inositol 1,4,5-Trisphosphate Receptors/metabolism* ; Male ; Progesterone/pharmacology* ; Spermatozoa/metabolism* ; Zona Pellucida/metabolism*

OBJECTIVE: Repetitive transcranial magnetic stimulation (rTMS) is an effective treatment for major depressive disorder (MDD). This study evaluated the antidepressant effect of rTMS and examined how it affected N-asetyl aspartate (NAA), choline (Cho), creatine (Cr), lactate (Lac), myoinositol (mIns), glutamate (Glu), glutathione (GSH), and glutamine (Gln) metabolite levels in the left dorsolateral prefrontal cortex (DLPFC) of MDD patients who were not receiving antidepressant medication. METHODS: In total, 18 patients (10 female, 8 male) were evaluated. Each patient underwent H magnetic resonance spectroscopy (H-MRS) before and within 3 days of completion of TMS therapy. All patients completed 20 sessions of rTMS directed at the left DLPFC over a 2-week period. The Hamilton Depression Scale (HAMD) scores of patients were calculated, and their responses to treatment were assessed within 1–3 days of completion of TMS. RESULTS: We found statistically significant differences in HAMD scores before and after rTMS. Moreover, the peak metabolite ratios of NAA/Cr, GSH/Cr, and Gln/Cr were significantly higher after rTMS compared to those before rTMS. CONCLUSION: Increased understanding of the mechanism of action of TMS will improve its application and may stimulate development of new-generation therapeutic agents.
Aspartic Acid ; Choline ; Creatine ; Depression ; Depressive Disorder, Major ; Female ; Glutamic Acid ; Glutamine ; Glutathione ; Humans ; Inositol ; Lactic Acid ; Magnetic Resonance Spectroscopy ; Prefrontal Cortex ; Transcranial Magnetic Stimulation

Gα(q)-coupled receptor stimulation was implied in the activation process of transient receptor potential canonical (TRPC)1/4 and TRPC1/5 heterotetrameric channels. The inactivation occurs due to phosphatidylinositol 4,5-biphosphate (PI(4,5)P₂) depletion. When PI(4,5)P₂ depletion was induced by muscarinic stimulation or inositol polyphosphate 5-phosphatase (Inp54p), however, the inactivation by muscarinic stimulation was greater compared to that by Inp54p. The aim of this study was to investigate the complete inactivation mechanism of the heteromeric channels upon Gα(q)-phospholipase C β (Gα(q)-PLCβ) activation. We evaluated the activity of heteromeric channels with electrophysiological recording in HEK293 cells expressing TRPC channels. TRPC1/4 and TRPC1/5 heteromers undergo further inhibition in PLCβ activation and calcium/protein kinase C (PKC) signaling. Nevertheless, the key factors differ. For TRPC1/4, the inactivation process was facilitated by Ca²⁺ release from the endoplasmic reticulum, and for TRPC1/5, activation of PKC was concerned mostly. We conclude that the subsequent increase in cytoplasmic Ca²⁺ due to Ca²⁺ release from the endoplasmic reticulum and activation of PKC resulted in a second phase of channel inhibition following PI(4,5)P₂ depletion.
Calcium ; Cytoplasm ; Endoplasmic Reticulum ; GTP-Binding Proteins ; HEK293 Cells ; Inositol ; Phosphatidylinositol 4,5-Diphosphate ; Phospholipases ; Phosphotransferases ; Protein Kinase C ; Transient Receptor Potential Channels ; Type C Phospholipases