Functions, Mechanisms, and therapeutic applications of the inositol pyrophosphates 5PP-InsP5 and InsP8 in mammalian cells.

Water-soluble myo-inositol phosphates have long been characterized as second messengers. The signaling properties of these compounds are determined by the number and arrangement of phosphate groups on the myo-inositol backbone. Recently, higher inositol phosphates with pyrophosphate groups were recognized as signaling molecules. 5-Diphosphoinositol 1,2,3,4,6-pentakisphosphate (5PP-InsP5) is the most abundant isoform, constituting more than 90% of intracellular inositol pyrophosphates. 5PP-InsP5 can be further phosphorylated to 1,5-bisdiphosphoinositol 2,3,4,6-tetrakisphosphate (InsP8). These two molecules, 5PP-InsP5 and InsP8, are present in various subcellular compartments, where they participate in regulating diverse cellular processes such as cell death, energy homeostasis, and cytoskeletal dynamics. The synthesis and metabolism of inositol pyrophosphates are subjected to tight regulation, allowing for their highly specific functions. Blocking the 5PP-InsP5/InsP8 signaling pathway by inhibiting the biosynthesis of 5PP-InsP5 demonstrates therapeutic benefits in preclinical studies, and thus holds promise as a therapeutic approach for certain diseases treatment, such as metabolic disorders.

Characteristics of the gut microbiome and metabolic profile in elderly patients with sarcopenia.

Introduction: There is growing evidence of research indicating that the gut microbiota is involved in the development of sarcopenia. Nevertheless, there exists a notable deficiency in comprehension concerning the connection between irregularities in the intestinal microbiome and metabolic processes in older individuals suffering from sarcopenia. Methods: To analyze fecal samples obtained from a cohort of 30 older patients diagnosed with sarcopenia as well as 30 older patients without sarcopenia, this study employed 16S rDNA sequencing and liquid chromatography-mass spectrometry (LC-MS)-based non-targeted metabolomics profiling techniques. Results: As a result, we found that 29 genera and 172 metabolites were significantly altered in the sarcopenic patients. Among them, Blautia, Lachnospiraceae_unclassified, and Subdoligranulum were the bacteria with a potential diagnostic value for sarcopenia diagnosis. Correlation analysis between clinical indices and these gut bacteria suggested that the IL-6 level was negatively correlated with Blautia. Function prediction analysis demonstrated that 17 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways differ significantly between sarcopenic and non-sarcopenic patients. The primary classes of metabolites identified in the study included lipids and lipid-like molecules, organic acids and derivatives, and organoheterocyclic compounds. KEGG enrichment analysis showed that purine metabolism, arginine and proline metabolism, alanine, aspartate, and glutamate metabolism, butanoate metabolism, and histidine metabolism may contribute to the development of sarcopenia. The correlation study on gut microbiota and metabolites found that Lachnospiraceae_unclassified was positively associated with seven metabolites that were more abundant in the non-sarcopenia group and negatively correlated with three metabolites that were more abundant in the sarcopenia group. In addition, Subdoligranulum was positively correlated with seven metabolites that were lacking in sarcopenia and negatively correlated with two metabolites that were enriching in sarcopenia. Moreover, Blautia was positively associated with xanthosine. Discussion: We conducted a study on the intestinal microbiota and metabolic profile of elderly individuals with sarcopenia, offering a comprehensive analysis of the overall ecosystem. Through this investigation, we were able to validate existing research on the gut-muscle axis and further investigate potential pathogenic processes and treatment options for sarcopenia.

Hispidin Inhibits Ferroptosis Induced by High Glucose via the miR-15b-5p/GLS2 Axis in Pancreatic Beta Cells.

Type 2 diabetes mellitus (T2DM) is a global health issue that lacks effective treatments. Dysfunction and/or death of pancreatic ß-cells (PBCs) are considered a major cause of T2DM. Therefore, elucidating the mechanisms underlying the death of PBCs might be helpful to develop novel strategies to treat T2DM. Ferroptosis is a newly identified form of cell death that has distinct features. However, knowledge regarding the role of ferroptosis in the death of PBCs remains limited. In the current study, we used high glucose (10 mM) (HG) levels to induce ferroptosis in PBC. We also observed that hispidin, a polyphenol compound that can be isolated from Phellinus linteus, could attenuate ferroptosis induced by HG in PBCs. Mechanistic investigations showed that hispidin led to the upregulation of miR-15b-5p, which directly inhibits the expression of glutaminase (GLS2) which plays an essential role in the glutamine metabolism. In addition, we found that overexpression of GLS2 could abrogate the protective effect of hispidin against ferroptosis caused by HG in PBCs. Therefore, our study provides novel insights into the mechanisms that regulate the death of PBCs.

Integrated genomics analysis highlights important SNPs and genes implicated in moderate-to-severe asthma based on GWAS and eQTL datasets.

BACKGROUND: Severe asthma is a chronic disease contributing to disproportionate disease morbidity and mortality. From the year of 2007, many genome-wide association studies (GWAS) have documented a large number of asthma-associated genetic variants and related genes. Nevertheless, the molecular mechanism of these identified variants involved in asthma or severe asthma risk remains largely unknown. METHODS: In the current study, we systematically integrated 3 independent expression quantitative trait loci (eQTL) data (N = 1977) and a large-scale GWAS summary data of moderate-to-severe asthma (N = 30,810) by using the Sherlock Bayesian analysis to identify whether expression-related variants contribute risk to severe asthma. Furthermore, we performed various bioinformatics analyses, including pathway enrichment analysis, PPI network enrichment analysis, in silico permutation analysis, DEG analysis and co-expression analysis, to prioritize important genes associated with severe asthma. RESULTS: In the discovery stage, we identified 1129 significant genes associated with moderate-to-severe asthma by using the Sherlock Bayesian analysis. Two hundred twenty-eight genes were prominently replicated by using MAGMA gene-based analysis. These 228 replicated genes were enriched in 17 biological pathways including antigen processing and presentation (Corrected P = 4.30 × 10- 6), type I diabetes mellitus (Corrected P = 7.09 × 10- 5), and asthma (Corrected P = 1.72 × 10- 3). With the use of a series of bioinformatics analyses, we highlighted 11 important genes such as GNGT2, TLR6, and TTC19 as authentic risk genes associated with moderate-to-severe/severe asthma. With respect to GNGT2, there were 3 eSNPs of rs17637472 (PeQTL = 2.98 × 10- 8 and PGWAS = 3.40 × 10- 8), rs11265180 (PeQTL = 6.0 × 10- 6 and PGWAS = 1.99 × 10- 3), and rs1867087 (PeQTL = 1.0 × 10- 4 and PGWAS = 1.84 × 10- 5) identified. In addition, GNGT2 is significantly expressed in severe asthma compared with mild-moderate asthma (P = 0.045), and Gngt2 shows significantly distinct expression patterns between vehicle and various glucocorticoids (Anova P = 1.55 × 10- 6). CONCLUSIONS: Our current study provides multiple lines of evidence to support that these 11 identified genes as important candidates implicated in the pathogenesis of severe asthma.

Challenges in diagnosing community-acquired carbapenem-susceptible Acinetobacter baumannii enterogenic sepsis: A case report.

INTRODUCTION: Community-acquired (CA) carbapenem-susceptible Acinetobacter baumannii (CSAB) enterogenic sepsis is very rare but has a high mortality. Although CA A. baumannii bloodstream infections have been known to develop from respiratory tract, urinary tract, and intravenous device-related infections, CA A. baumannii bloodstream infections from the gastrointestinal tract have not yet been reported. PATIENT CONCERNS: A 73-year-old male with the chief presentation of gastrointestinal symptoms was initially diagnosed with acute gastroenteritis and showed poor clinical response to empirical antibiotic therapy. DIAGNOSES: The diagnosis of CSAB enterogenic sepsis was established based on results of blood culture, elevated serum procalcitonin level, and specific hemodynamic changes related to septic shock. INTERVENTIONS: The patient initially received empirical antibiotic treatment (cefodizime 2.0 q12 hours plus moxifloxacin 0.4 qd); then, treatment was changed to the conventional dose of carbapenem (imipenem 0.5 q6 hour). OUTCOMES: Finally, CSAB was eliminated from the bloodstream, and the patient was discharged. LESSONS: Although severe, CA CSAB enterogenic sepsis is often misdiagnosed because of its clinical rarity. Early diagnosis and appropriate initial empirical antibiotic therapy are crucial for treating such cases.

Ulinastatin inhibits apoptosis induced by serum deprivation in mesenchymal stem cells.

Mesenchymal stem cells (MSCs) have exhibited great potential in the therapy of cardiovascular disease. However, the application of MSCs is hampered by apoptosis, which reduces the number of cells in the host cardiac microenvironment. Ulinastatin (UTI), a broad­spectrum protease inhibitor that can be purified from human urine, has attracted attention for its protective effects through its immunomodulatory and anti­inflammatory properties. The present study aimed to evaluate the effects of UTI on serum deprivation­induced apoptosis of MSCs and investigate its molecular mechanisms. Cell viability was determined by the MTT assay. Apoptosis was assessed by flow cytometric analysis with Annexin V/propidium iodide staining. The protein levels of cleaved caspase­3, B­cell lymphoma­2 (Bcl­2) family proteins, total­Akt and phospho­Akt were evaluated by western blot. The results of the present study demonstrated that UTI exhibited a protective effect in serum deprived MSCs, as indicated by increased cell viability, and a reduction in the rate of apoptosis and caspase­3 activation. In addition, treatment with UTI significantly decreased the expression levels of Bcl­2, Bcl­extra large and Bcl­associated X protein. Furthermore, activation of the Akt signaling pathway was involved in the UTI­induced anti­apoptotic effects. The present findings indicated that UTI is able to promote the survival of MSCs under serum deprivation conditions. The present study may be helpful in improving the therapeutic efficacy of MSC transplantation used to cure chronic ischemic heart disease.

[Risk factors analysis of renal replacement therapy after liver transplantation and prognosis effect of initial treatment time].

OBJECTIVE: To analyze the risk factors of renal replacement therapy (RRT) in acute kidney injury (AKI) patients after liver transplantation, and to investigate the prognosis effect of initial RRT treatment time. METHODS: Clinical data of 132 recipients undergoing organ donation for cardiac death (DCD) allograft orthotopic liver transplantation admitted to Ningbo Medical Center Lihuili Hospital and Ningbo Medical Center Lihuili Eastern Hospital from July 2014 to July 2018 was retrospectively analyzed. AKI was defined and staged by the criteria of Kidney Disease Improving Global Outcomes (KDIGO) guideline in the first 7 days. According to the implementation of RRT, the patients were divided into non-RRT group and RRT group. The differences in gender, age, body mass index (BMI), model for end-stage liver disease with serum sodium (MELD-Na) score, serum creatinine (SCr), and intraoperative norepinephrine (NE) dose, blood loss, fluid infusion, anhepatic phase time, duration of operation between two groups were compared. The statistically significant risk factors of AKI found by univariate analysis were selected and analyzed to find independent risk factors of RRT in AKI patients after liver transplantation with multivariate Logistic regression analysis. The receiver operating characteristic (ROC) curve was drawn to evaluate the test efficiency of all risk factors of RRT implementation. According to the implementation of RRT on KDIGO stage-2, all the patients on KDIGO stage-2 and stage-3 were divided into early group (initial RRT on KDIGO stage-2) and delayed group (including self-improvement without RRT on KDIGO stage-2 and initial RRT on KDIGO stage-3). The duration of mechanical ventilation, the length of intensive care unit (ICU) stay, AKI duration, incidence of catheter related bloodstream infection (CRBSI) and 28-day mortality were compared between the two groups. RESULTS: All 132 receptors were enrolled in the final analysis, and 77 patients developed AKI, accounting for 58.3%, among which 52 cases were in RRT group (67.5%) and 25 were in non-RRT group (32.5%). As shown by univariate analysis, the MELD-Na score (21.6±4.4 vs. 18.0±4.3), intraoperative NE dose (µg×kg-1×h-1: 7.5±1.2 vs. 5.2±1.7), blood loss [mL: 3 000 (2 200, 4 000) vs. 2 600 (1 800, 3 200)], fluid infusion [mL: 6 400 (4 500, 7 800) vs. 5 600 (4 200, 6 800)], and anhepatic period (minutes: 65.6±4.5 vs. 63.0±5.0) were significantly increased in RRT group as compared with those in non-RRT group (all P < 0.05). There was no significant difference in gender, age, BMI, SCr before operation or the duration of operation. It was shown by multivariate Logistic regression analysis that MELD-Na score before operation [odds ratio (OR) = 1.398, 95% confidence interval (95%CI) = 1.062-1.841, P = 0.017], intraoperative NE dose (OR = 4.724, 95%CI = 2.036-10.961, P = 0.000) and fluid infusion (OR = 1.002, 95%CI = 1.001-1.004, P = 0.010) were independent risk factors of RRT implementation in AKI patients after liver transplantation. It was shown by ROC curve analysis that the area under the ROC curve (AUC) of MELD-Na score, NE dose and fluid infusion for predicting the implementation of RRT in AKI patients after liver transplantation was 0.719, 0.867, and 0.670, respectively, which suggesting that NE dose had moderate predictive value, but MELD-Na score and fluid infusion had low predicative value. When the optimal cut-off value of NE dose was 6.5 µg×kg-1×h-1, the sensitivity was 84.6% and the specificity was 80.0%. The 28-day mortality was both 0 in early group (n = 25) and delayed group (n = 39). Compared with the early group, the duration of mechanical ventilation (hours: 41.0±1.0 vs. 35.8±6.7) and the length of ICU stay (hours: 98.8±6.6 vs. 94.2±7.3) were significantly increased in delayed group (both P < 0.05), there was no significant difference in AKI duration (days: 11.8±4.2 vs. 10.6±4.9) or the incidence of CRBSI [5.1% (2/39) vs. 4.0% (1/25), both P > 0.05]. CONCLUSIONS: MELD-Na score, intraoperative NE dose and fluid infusion were the independent risk factors of RRT implementation in AKI patients after liver transplantation. NE dose had moderate predictive value, but MELD-Na score and fluid infusion had low predicative value. Initial RRT on KDIGO stage-2 could reduce the duration of mechanical ventilation and the length of ICU stay.

[Effect of simvastatin on atherosclerosis and central aortic pressure in ApoE gene knockout mice].

OBJECTIVE: To investigate the effects of simvastatin on atherosclerosis and central aortic pressure in ApoE-knockout (ApoE-/-) mice. METHODS: Ten 5-week-old male ApoE-/- mice and 5 C57 mice were fed with high-lipid diet for 3 weeks, and then C57 mice (WT group) and 5 ApoE-/- mice (ApoE-/- group) were given 1% carboxymethyl cellulose solution (8 ml·kg-1·d-1), and another 5 ApoE-/- mice (ApoE-/-/S group) were given simvastatin solution (50 mg·kg-1·d-1) by gavege for 3 weeks. The areas of atherosclerotic lesion in aortic root, central aortic pressure and serum lipid levels were examined. RESULTS: No atherosclerotic plaques were observed in WT group. Compared with ApoE-/- group, simvastatin significantly decreased atherosclerotic lesion area in aortic root (89 818.05±16 980.93 µm2 vs 34 937.01±13 280.65 µm2, P<0.05). The systolic pressure (SP), mean arterial pressure (MAP), pulse pressure (PP) and diastolic pressure (DP) of central aortic pressure were significantly increased in ApoE-/- group compared with those in WT group (P<0.05). Compared to ApoE-/- group, the SP, MAP and PP of central aortic pressure were significantly reduced in ApoE-/-/S group (P<0.05). SP and MAP of central aortic pressure were positively correlated with atherosclerotic lesion area (SP: r=0.7152, P=0.0461; PP: r=0.7594， P=0.0288). Compared with WT group, serum triglyceride, total cholesterol and low-density lipoprotein levels were markedly increased in ApoE-/- group (P<0.05). Serum high-density lipoprotein level was decreased in ApoE-/- group compared with WT group. No differences in serum triglyceride, total cholesterol, low-density lipoprotein and high-density lipoprotein levels were found between ApoE-/- group and ApoE-/-/S group. CONCLUSION: Simvastatin can attenuate atherosclerosis of aorta in ApoE-/- mice, which is associated with the reduced central aortic systolic pressure but not with the serum lipids levels.

Lysophosphatidic acid protects mesenchymal stem cells against ischemia-induced apoptosis in vivo.

Lysophosphatidic acid (LPA), as an endogenous lipid mediator, has been revealed to regulate many important biological and pathophysiological processes via specific G-protein-coupled receptors termed LPA1-5. We have previously shown that LPA antagonized the apoptosis of mesenchymal stem cells (MSCs) induced by hypoxia and serum deprivation (hypoxia/SD), mimicking ischemic myocardium microenvironment. Whether LPA has the same potentially beneficial effect on MSCs in vivo is unknown. Here we demonstrated that LPA treatment improved graft MSC survival in ischemic myocardium assessed in a gender-mismatched transplantation model by real-time PCR, as well as by TUNEL assay. Moreover, transplantation of LPA-treated MSCs enhanced capillary density determined by immunostaining for platelet endothelial cell adhesion molecule (PECAM)-1, and it is also found that LPA enhanced vascular endothelial growth factor (VEGF) release from MSCs under hypoxia/SD in vitro. We did not get any improvement in left ventricular (LV) function at 1 week after transplantation of LPA-treated MSCs. These data suggest that LPA exerts both protective actions on MSC survival and enhancement on MSC paracrine in vivo and may represent a novel and effective treatment strategy in cell transplantation.

[Lovastatin protects mesenchymal stem cells against hypoxia and serum deprivation-induced apoptosis through activation of PI3K/Akt and ERK1/2 signaling pathways].

OBJECTIVE: To investigated the effect of lovastatin on hypoxia and serum deprivation (Hypoxia/SD) induced rat MSCs apoptosis in vitro and associated signaling pathway changes. METHODS: MSCs were isolated from Sprague-Dawley rats. The anti-apoptotic effects of lovastatin were detected using Hoechst33342 and annexin V-FITC/PI binding assay by Flow cytometric analysis. The phosphorylation of Akt and ERK1/2, the cytochrome C and the cleaved caspase-3 were detected by Western blot. RESULTS: Lovastatin (0.01 - 1 micromol/L) significantly reduced Hypoxia/SD-induced MSCs apoptosis and increased Akt phosphorylation, reduced caspase-3 activation and cytochrome c release from mitochondria to cytosol in a time dependent manner. These effects could be significantly blocked by both PI3K inhibitor, LY294002 and ERK1/2 inhibitor, U0126. CONCLUSIONS: Our results showed that lovastatin protects MSCs from Hypoxia/SD-induced apoptosis via activating PI3K/Akt and ERK1/2 signaling pathways suggesting a potential role of statins as an adjunct therapeutic agent during transplanting MSCs into damaged heart after myocardial infarction.

Lysophosphatidic acid protects mesenchymal stem cells against hypoxia and serum deprivation-induced apoptosis.

Bone marrow-derived mesenchymal stem cells (MSCs) have shown great promise for cardiac repair. However, poor viability of transplanted MSCs within the ischemic heart has limited their therapeutic potential. Our previous studies have documented that hypoxia and serum deprivation (hypoxia/SD), induced MSCs apoptosis through the mitochondrial apoptotic pathway. Since serum lysophosphatidic acid (LPA) levels are known to be significantly elevated after acute myocardial infarction and that LPA enhanced survival of other cell systems, we embarked on determining whether LPA protects MSCs against hypoxia/SD-induced apoptosis. We have also investigated the potential mechanism(s) that may mediate such actions of LPA. All experiments were carried out on rat bone marrow MSCs. Apoptosis was induced by exposure of cells to hypoxia/SD in a sealed GENbox hypoxic chamber. Effects of LPA were investigated in the absence and presence of inhibitors that target either G(i)proteins, the mitogen activated protein kinases ERK1/2, or phosphoinositide 3-kinase (PI3K). The data obtained showed that hypoxia/SD-induced apoptosis was significantly attenuated by LPA through Gi-coupled LPA(1) receptors linked to the downstream ERK1/2 and PI3K/Akt signaling pathways that function in parallel. Additional studies have demonstrated that hypoxia/SD-induced activation of mitochondrial dysfunction was virtually abolished by LPA treatment and that inhibition of the LPA(1) receptor, Gi proteins, the PI3K/Akt pathway, or ERKs effectively reversed this protective action of LPA. Taken together, our findings indicate that LPA is a novel, potent survival factor for MSCs and this may prove to be of considerable therapeutic significance in terms of exploiting MSC-based therapy in the infracted myocardium.