Metabolic basis of solute carrier transporters in treatment of type 2 diabetes mellitus

Solute carriers (SLCs) constitute the largest superfamily of membrane transporter proteins. These transporters, present in various SLC families, play a vital role in energy metabolism by facilitating the transport of diverse substances, including glucose, fatty acids, amino acids, nucleotides, and ions. They actively participate in the regulation of glucose metabolism at various steps, such as glucose uptake (e.g., SLC2A4/GLUT4), glucose reabsorption (e.g., SLC5A2/SGLT2), thermogenesis (e.g., SLC25A7/UCP-1), and ATP production (e.g., SLC25A4/ANT1 and SLC25A5/ANT2). The activities of these transporters contribute to the pathogenesis of type 2 diabetes mellitus (T2DM). Notably, SLC5A2 has emerged as a valid drug target for T2DM due to its role in renal glucose reabsorption, leading to groundbreaking advancements in diabetes drug discovery. Alongside SLC5A2, multiple families of SLC transporters involved in the regulation of glucose homeostasis hold potential applications for T2DM therapy. SLCs also impact drug metabolism of diabetic medicines through gene polymorphisms, such as rosiglitazone (SLCO1B1/OATP1B1) and metformin (SLC22A1-3/OCT1-3 and SLC47A1, 2/MATE1, 2). By consolidating insights into the biological activities and clinical relevance of SLC transporters in T2DM, this review offers a comprehensive update on their roles in controlling glucose metabolism as potential drug targets.

Sodium butyrate activates HMGCS2 to promote ketone body production through SIRT5-mediated desuccinylation / 医学前沿

Ketone bodies have beneficial metabolic activities, and the induction of plasma ketone bodies is a health promotion strategy. Dietary supplementation of sodium butyrate (SB) is an effective approach in the induction of plasma ketone bodies. However, the cellular and molecular mechanisms are unknown. In this study, SB was found to enhance the catalytic activity of 3-hydroxy-3-methylglutaryl-CoA synthase 2 (HMGCS2), a rate-limiting enzyme in ketogenesis, to promote ketone body production in hepatocytes. SB administrated by gavage or intraperitoneal injection significantly induced blood ß-hydroxybutyrate (BHB) in mice. BHB production was induced in the primary hepatocytes by SB. Protein succinylation was altered by SB in the liver tissues with down-regulation in 58 proteins and up-regulation in 26 proteins in the proteomics analysis. However, the alteration was mostly observed in mitochondrial proteins with 41% down- and 65% up-regulation, respectively. Succinylation status of HMGCS2 protein was altered by a reduction at two sites (K221 and K358) without a change in the protein level. The SB effect was significantly reduced by a SIRT5 inhibitor and in Sirt5-KO mice. The data suggests that SB activated HMGCS2 through SIRT5-mediated desuccinylation for ketone body production by the liver. The effect was not associated with an elevation in NAD+/NADH ratio according to our metabolomics analysis. The data provide a novel molecular mechanism for SB activity in the induction of ketone body production.

NF-κB regulates brown adipocyte function through suppression of ANT2

The transcription factor nuclear factor of kappa-light-chain-enhancer of activated B cells (NF-κB) is expressed in brown adipocytes, but its role remains largely unknown in the cells. This issue was addressed in current study by examining NF-κB in brown adipocytes in vitro and in vivo. NF-κB activity was increased by differentiation of brown adipocytes through elevation of p65 (RelA) expression. The transcriptional activity of NF-κB was induced by the cold stimulation with an elevation in S276 phosphorylation of p65 protein. Inactivation of NF-κB in brown adipocytes made the knockout mice [uncoupling protein 1 (Ucp1)-CreER-p65f/f, U-p65-KO] intolerant to the cold environment. The brown adipocytes exhibited an increase in apoptosis, a decrease in cristae density and uncoupling activity in the interscapular brown adipose tissue (iBAT) of p65-KO mice. The alterations became severer after cold exposure of the KO mice. The brown adipocytes of mice with NF-κB activation (p65 overexpression, p65-OE) exhibited a set of opposite alterations with a reduction in apoptosis, an increase in cristae density and uncoupling activity. In mechanism, NF-κB inhibited expression of the adenine nucleotide translocase 2 (ANT2) in the control of apoptosis. Data suggest that NF-κB activity is increased in brown adipocytes by differentiation and cold stimulation to protect the cells from apoptosis through down-regulation of ANT2 expression.

Exploration and construction of the new generation of intelligent ICU unit based on 5G and artificial intelligence technology / 中华急诊医学杂志

Objective:To explore the new generation of intelligent ICU Unit based on 5G and artificial intelligence technology.Methods:This study was conducted at the Second Affiliated Hospital, Zhejiang University School of Medicine from May 2019 to August 2020. Based on a multidisciplinary team including medical, nursing, hospital management, clinical medical engineering, 5G technology, information technology, artificial intelligence technology, logistics service, etc, was assembled to intelligently design and reconstruct an intelligent ICU Unit of Emergency ICU.Results:Based on 5G technology, a new intelligent ICU unit environment was constructed to realize remote and high-speed interaction of multi-dimensional information in ICU, including intelligent assistance of remote monitoring, remote ward rounds, remote consultation and family visits. An intelligent hospital infection prevention and control system was established including automatic identification and alarm of hand hygiene and personal protection.Conclusions:The new generation of intelligent ICU unit combined with 5G and artificial intelligence technology has changed the mode of medical service for critically ill patients and improved the service level, which is worthy of further exploration and application.

Mitochondrial protein IF1 is a potential regulator of glucagon-like peptide (GLP-1) secretion function of the mouse intestine

IF1 (ATPIF1) is a nuclear DNA-encoded mitochondrial protein whose activity is inhibition of the F

Mechanism of insulin resistance in obesity: a role of ATP / 医学前沿

Obesity increases the risk of type 2 diabetes through the induction of insulin resistance. The mechanism of insulin resistance has been extensively investigated for more than 60 years, but the essential pathogenic signal remains missing. Existing hypotheses include inflammation, mitochondrial dysfunction, hyperinsulinemia, hyperglucagonemia, glucotoxicity, and lipotoxicity. Drug discoveries based on these hypotheses are unsuccessful in the development of new medicines. In this review, multidisciplinary literature is integrated to evaluate ATP as a primary signal for insulin resistance. The ATP production is elevated in insulin-sensitive cells under obese conditions independent of energy demand, which we have named "mitochondrial overheating." Overheating occurs because of substrate oversupply to mitochondria, leading to extra ATP production. The ATP overproduction contributes to the systemic insulin resistance through several mechanisms, such as inhibition of AMPK, induction of mTOR, hyperinsulinemia, hyperglucagonemia, and mitochondrial dysfunction. Insulin resistance represents a feedback regulation of energy oversupply in cells to control mitochondrial overloading by substrates. Insulin resistance cuts down the substrate uptake to attenuate mitochondrial overloading. The downregulation of the mitochondrial overloading by medicines, bypass surgeries, calorie restriction, and physical exercise leads to insulin sensitization in patients. Therefore, ATP may represent the primary signal of insulin resistance in the cellular protective response to the substrate oversupply. The prevention of ATP overproduction represents a key strategy for insulin sensitization.

NF- B/HDAC1/SREBP1c pathway mediates the inflammation signal in progression of hepatic steatosis

The transcription factor nuclear factor kappa B (NF-B) is activated in hepatocytes in the pathogenesis of hepatic steatosis. However, the action mechanism of NF-B remains to be established in the hepatic steatosis. In this study, the subunit of NF-B was found to promote the hepatic steatosis through regulation of histone deacetylase 1 (HDAC1) in hepatocytes. The activity was supported by the phenotypes of knockout (-KO) mice and knockout (-KO) mice. Hepatic steatosis was reduced in the -KO mice, but not in the -KO mice. The reduction was a result of inhibition of HDAC1 activity in the -KO cells. Knockdown of gene led to suppression of hepatocyte steatosis in HepG2 cells. A decrease in sterol-regulatory element binding protein 1c (SREBP1c) protein was observed in the liver of -KO mice and in cell with knockdown. The decrease was associated with an increase in succinylation of SREBP1c protein. The study suggests that stabilizes HDAC1 to support the SREBP1c activity in hepatic steatosis in the pathophysiological condition. Interruption of this novel pathway in the -KO, but not the -KO mice, may account for the difference in hepatic phenotypes in the two lines of transgenic mice.

Regulation of microbiota-GLP1 axis by sennoside A in diet-induced obese mice

Sennoside A (SA) is a bioactive component of Chinese herbal medicines with an activity of irritant laxative, which is often used in the treatment of constipation and obesity. However, its activity remains unknown in the regulation of insulin sensitivity. In this study, the impact of SA on insulin sensitivity was tested in high fat diet (HFD)-induced obese mice through dietary supplementation. At a dosage of 30 mg/kg/day, SA improved insulin sensitivity in the mice after 8-week treatment as indicated by HOMA-IR (homeostatic model assessment for insulin resistance) and glucose tolerance test (GTT). SA restored plasma level of glucagon-like peptide 1 (GLP1) by 90% and mRNA expression of by 80% in the large intestine of HFD mice. In the mechanism, SA restored the gut microbiota profile, short chain fatty acids (SCFAs), and mucosal structure in the colon. A mitochondrial stress was observed in the enterocytes of HFD mice with ATP elevation, structural damage, and complex dysfunction. The mitochondrial response was induced in enterocytes by the dietary fat as the same responses were induced by palmitic acid in the cell culture. The mitochondrial response was inhibited in HFD mice by SA treatment. These data suggest that SA may restore the function of microbiota-GLP1 axis to improve glucose metabolism in the obese mice.

Effect of tumor volume and radiation dose on the prognosis of hepatocellular carcinoma patients treated with whole body gamma knife / 中华放射肿瘤学杂志

Objective To examine the effects of gross tumor volume (GTV) and radiation dose on the prognosis of hepatocellular carcinoma (HCC) patients treated with whole body gamma knife.Methods The clinical data of 69 HCC patients who underwent body gamma knife treatment from January 2012 to June 2015 in the Radiotherapy Center of the PLA General Hospital were retrospectively reviewed.Based on a 50% or 60% isodose coverage of the planning target volume (PTV), patients were treated with a radiation dose of 4-5 Gy per fraction, and a total marginal dose of 36-50 Gy (median dose 45 Gy).Short-term efficacy, overall survival (OS), and the adverse effect of the treatment were evaluated.The optimal cut-off tumor volume was identified using the receiver operating characteristic curve, and survival was determined by the Kaplan-Meier method.Univariate and multivariate analyses were performed using the log-rank test and Cox proportional hazards regression model, respectively.Results The overall short-term response rate of the 69 patients was 67%.The 1-and 2-year OS rates were 62% and 40%, respectively, with a median survival of 18.6 months.The multivariate analysis showed that gross tumor volume (GTV)93 cm3(P=0.665).Conclusions GTV is an independent prognostic factor for overall survival of HCC patients.Although high-dose radiotherapy provides survival benefits to patients with small GTV, it is not necessarily suitable for patients with large GTV.

Mitochondrial inhibitor as a new class of insulin sensitizer

Insulin resistance is a major risk factor for type 2 diabetes. AMP-activated protein kinase (AMPK) is a drug target in the improvement of insulin sensitivity. Several insulin-sensitizing medicines are able to activate AMPK through inhibition of mitochondrial functions. These drugs, such as metformin and STZ, inhibit ATP synthesis in mitochondria to raise AMP/ATP ratio in the process of AMPK activation. However, chemicals that activate AMPK directly or by activating its upstream kinases have not been approved for treatment of type 2 diabetes in humans. In an early study, we reported that berberine inhibited oxygen consumption in mitochondria, and increased AMP/ATP ratio in cells. The observation suggests an indirect mechanism for AMPK activation by berberine. Berberine stimulates glycolysis for ATP production that offsets the cell toxicity after mitochondria inhibition. The study suggests that mitochondrial inhibition is an approach for AMPK activation. In this review article, literature is critically reviewed to interpret the role of mitochondria function in the mechanism of insulin resistance, which supports that mitochondria inhibitors represent a new class of AMPK activator. The inhibitors are promising candidates for insulin sensitizers. This review provides a guideline in search for small molecule AMPK activators in the drug discovery for type 2 diabetes.

Challenges in Drug Discovery for Thiazolidinedione Substitute / 药学学报

Thiazolidinedione (TZD) is a powerful insulin sensitizer in the treatment of type 2 diabetes. It acts as a ligand to the nuclear receptor PPARγ (peroxisome proliferator-activated receptor-gamma) and induces transcription of PPARγ responsive genes. TZD controls lipid synthesis and storage in adipose tissue, liver and many other tissues through PPARγ. Derivatives of TZD, such as rosiglitazone (Avandia) and pioglitazone (Actos), are more powerful than metformin or berberine in insulin sensitization. Although they have common side effects such as weight gain and edema, these did not influence the side effects in general. However, recent findings of risk for congestive heart failure and bladder cancer have indeed significantly impaired their future in many countries. European countries have prohibited those drugs and in 2011, US will terminate application of rosiglitazone in clinics and hospitals. The multiple country actions may mark the end of TZD era. As a result, there is a strong demand for identification of TZD substitute in the treatment of type 2 diabetes. In this regard, literature about PPARγ ligands and potential TZD substitute are reviewed in this article. Histone deacetylase (HDAC) inhibitor is emphasized as a new class of insulin sensitizer here. Regulators of SIRT1, CREB, NO, p38, ERK and Cdk5 are discussed in the activation of PPARγ.

Challenges in Drug Discovery for Thiazolidinedione Substitute / 药学学报

Thiazolidinedione (TZD) is a powerful insulin sensitizer in the treatment of type 2 diabetes. It acts as a ligand to the nuclear receptor PPARγ (peroxisome proliferator-activated receptor-gamma) and induces transcription of PPARγ responsive genes. TZD controls lipid synthesis and storage in adipose tissue, liver and many other tissues through PPARγ. Derivatives of TZD, such as rosiglitazone (Avandia) and pioglitazone (Actos), are more powerful than metformin or berberine in insulin sensitization. Although they have common side effects such as weight gain and edema, these did not influence the side effects in general. However, recent findings of risk for congestive heart failure and bladder cancer have indeed significantly impaired their future in many countries. European countries have prohibited those drugs and in 2011, US will terminate application of rosiglitazone in clinics and hospitals. The multiple country actions may mark the end of TZD era. As a result, there is a strong demand for identification of TZD substitute in the treatment of type 2 diabetes. In this regard, literature about PPARγ ligands and potential TZD substitute are reviewed in this article. Histone deacetylase (HDAC) inhibitor is emphasized as a new class of insulin sensitizer here. Regulators of SIRT1, CREB, NO, p38, ERK and Cdk5 are discussed in the activation of PPARγ.

Protective effects of Glutamine on intestinal mucosa barrier dysfunction following traumatic brain injury in rats / 中华创伤杂志

Objective To observe the effect of Glutsmine on intestinal barrier function after traumatic brain injury in rats. Methods A total of 54 adult male Wistar rats were divided randomly into 3 groups, ie, normal group (Group N, 6 rats), TBI group (Group T, 24 rats) and Giutamine intervention group (Group G, 24 rats). Group T and Group G were subdivided into 4 groups according to detection time at days 1,3, 5 and 7 respectively. Meanwhile, 6 rats were enlisted in each group. The intestinal mucosa structure was detected by histopathological examination and electron microscopy. Apoptosis was detected by in situ immunohistochemical staining (TUNEL). Results Glutamine could relieve the pathological lesion of gut mucosa and decrease intestinal mucosa cell apoptosis after traumatic brain injury. Conclusion Glutamine can protect intestinal mucosa barrier function following traumatic brain injury.

Construction, characterization, and chromosomal mapping of a fosmid library of the white-cheeked gibbon (Nomascus leucogenys) / 基因组蛋白质组与生物信息学报·英文版

Gibbons have experienced extensive karyotype rearrangements during evolution and represent an ideal model for studying the underlying molecular mechanism of evolutionary chromosomal rearrangements. It is anticipated that the cloning and sequence characterization of evolutionary chromosomal breakpoints will provide vital insights into the molecular force that has driven such a radical karyotype reshuffle in gibbons. We constructed and characterized a high-quality fosmid library of the white-cheeked gibbon (Nomascus leucogenys) containing 192,000 non- redundant clones with an average insert size of 38 kb and 2.5-fold genome coverage. By end sequencing of 100 randomly selected fosmid clones, we generated 196 sequence tags for the library. These end-sequenced fosmid clones were then mapped onto the chromosomes of the white-cheeked gibbon by fluorescence in situ hybridization, and no spurious chimeric clone was detected. BLAST search against the human genome showed a good correlation between the number of hit clones and the number of chromosomes, an indication of unbiased chromosomal distribution of the fosmid library. The chromosomal distribution of the mapped clones is also consistent with the BLAST search result against human and white-cheeked gibbon genomes. The fosmid library and the mapped clones will serve as a valuable resource for further studying gibbons' chromosomal rearrangements and the underlying molecular mechanism as well as for comparative genomic study in the lesser apes.

THE NON-AUDITORIAL AFFERENTS OF THE INFERIOR COLLICULUS IN THE RAT——WGA-HRP METHOD / 解剖学报

WGA-HRP was injected into the inferior colliculus in the rat in order to study the non-auditorial afferents of the inferior colliculus. In the diencephalon and truncus encephali, retrograde labeling was observed in many non-auditorial regions: bilateral (with contralateral predominance) cuneate nucleus, gracile nucleus, nucleus of spinal tract of trigeminal nerve, nucleus medullae oblongatae centralis dorsalis; bilateral (with homolateral predominance) locus ceruleus, nucleus reticularis pontis oralis, laterodorsal tegmental nucleus, substantia nigra, sub-parafascicular nucleus, perifornical nucleus; bilateral medial parabrachial nucleus, deep tegmental nucleus of midbrain, lateral hypothalamic area; homolateral deep layer of superior colliculus, zona incerta; contralateral nucleus of solitary tract; and posteromedian septum, central tegmental nucleus, dorsal nucleus of the raphe. The afferent neurons from cuneate nucleus, gracile nucleus, nucleus of spinal tract of trigeminal nerve, nucleus of solitary tract mainly located below the level of obex. The results mentioned above suggested that the inferior colliculus is not only an auditorial relay nucleus, but also a complex body which is of different functions.