Multiomics Approaches Identify Biomarkers for BAT Thermogenesis.

Brown adipose tissue (BAT) thermogenesis confers beneficial effects on metabolic diseases such as obesity and type-2 diabetes. Nevertheless, the mechanism and lipid driving the process that evokes this response have not been investigated yet. Here, a multiomics approach of integrative transcriptomics and lipidomics is used to explore the mechanism of regulating thermogenesis in BAT and providing promising lipid biomarkers and biomarker genes for thermogenic activators as antiobesity drugs. Lipidomics analysis demonstrated that a high abundance of glycerophospholipids and sphingolipids was more significant in BAT than in WAT. Enrichment analysis of upregulated DEGs between WAT and BAT screened suggested that the differences were mainly involved in lipid metabolism. Besides, ß3-adrenergic agonist stimulation reduced the levels of TAG and DAG and increased the content of PC, PE, CL, and LPC and expression of genes involved in thermogenesis, fatty acid elongation, and glycerophospholipid metabolism in BAT. In this study, based on interpreting the inherent characterization of BAT as thermogenic tissue through comparison with WAT as fat storage tissue, adrenergic stimulation-induced BAT thermogenesis further identified specific lipid biomarkers (7 TAG species, 10 PC species, 1 LPC species, and 1 CL species) and Elovl3 and Crat gene biomarkers, which may provide targets for combating obesity by boosting BAT thermogenesis.

Sex difference on fibroblast growth factors (FGFs) expression in skin and wound of streptozotocin(STZ)-induced type 1 diabetic mice.

BACKGROUND: Fibroblast growth factors (FGFs) are key factors affecting diabetic wound healing. However, the FGF family's expression patterns in skin and wounds influenced by both diabetes and sex are still unknown. METHODS AND RESULTS: In this study, normal and Streptozotocin (STZ)-induced type 1 diabetic C57BL/6J male and female mice were used to study the FGF family's expression in non-wound skin and wounds. We found that the expression patterns of Fgfs were affected by sex in both normal and diabetic animals during wound healing. In normal control mice, sex difference had a limited effect on basal skin Fgf expressions. However, it significantly influenced Fgf expressions in wounds. Type 1 diabetes reduced basal and wound-induced skin Fgf expressions. Female mice had far lower wound-induced skin Fgf expressions in diabetic mice. In addition, sex differently influenced Fibroblast growth factors receptor (Fgfr) expression patterns of non-wound skin and wounds in both normal and diabetic mice. Moreover, female mice had a lower relative level of Fibronectin leucine-rich repeat transmembrane protein 2 (FLRT2) - a FGFR activation marker gene - in wound and blood plasma. Correspondingly, the wound areas of female animals were larger than that of male animals in the early stage of wound healing (less than 3-day injury). CONCLUSION: Our research shows that the FGF family have different expression patterns in normal and diabetic wound healing in mice of different sex. Additionally, we also provide the signatures of individual FGFs in diabetic wound healing, which deserve further investigation.

Urotensin receptor acts as a novel target for ameliorating fasting-induced skeletal muscle atrophy.

Urotensin receptor (UT) is a G-protein-coupled receptor, whose endogenous ligand is urotensin-II (U-II). Skeletal muscle mass is regulated by various conditions, such as nutritional status, exercise, and diseases. Previous studies have pointed out that the urotensinergic system is involved in skeletal muscle metabolism and function, but its mechanism remains unclear, especially given the lack of research on the effect and mechanism of fasting. In this study, UT receptor knockout mice were generated to evaluate whether UT has effects on fasting induced skeletal muscle atrophy. Furthermore, the UT antagonist palosuran (3, 10, 30 mg/kg) was intraperitoneally administered daily for 5 days to clarify the therapeutic effect of UT antagonism. Our results found the mice that fasted for 48 h exhibited skeletal muscle atrophy, accompanied by enhanced U-II levels in both skeletal muscles and blood. UT receptor knockout effectively prevented fasting-induced skeletal muscle atrophy. The UT antagonist ameliorated fasting-induced muscle atrophy in mice as determined by increased muscle strengths, weights, and muscle fiber areas (including fast, slow, and mixed types). In addition, the UT antagonist reduced skeletal muscle atrophic markers, including F-box only protein 32 (FBXO32) and tripartite motif containing 63 (TRIM63). Moreover, the UT antagonist was also observed to enhance PI3K/AKT/mTOR while inhibiting autophagy signaling. In summary, our study provides the first evidence that UT antagonism may represent a novel therapeutic approach for the treatment of fasting-induced skeletal muscle atrophy.

Combination of Docking-Based and Pharmacophore-Based Virtual Screening Identifies Novel Agonists That Target the Urotensin Receptor.

The urotensin receptor (UT receptor), a G-protein-coupled receptor mediating urotensin-II and urotensin-II-related peptide signaling in the urotensinergic system, has multiple pharmacological activities. However, there is no drug targeting the UT receptor currently in clinical use, and the discovery of new leads is still important. The complete crystal structure of the UT receptor has not yet been resolved and a screening strategy combining multiple methods can improve the accuracy and efficiency of drug screening. This study aimed to identify novel UT receptor agonists using a combination of docking-based, pharmacophore-based, and cell-based drug screening. First, the three-dimensional structures of the UT receptor were constructed through single-template, multi-template homologous modeling and threading strategies. After structure evaluation and ligand enrichment analysis, a model from the threading modeling was selected for docking-based virtual screening based on stepwise filtering, and 1368 positive compounds were obtained from our compound library. Second, the pharmacophore models were constructed using known ligands targeting the UT receptor for pharmacophore-based virtual screening. A model was selected after model validation, and 300 positive compounds were retrieved. Then, after intersecting the results of two different virtual screening methods with 570 compound entities from our primary screening, 14 compounds were obtained. Finally, three hits were obtained after in vitro confirmation. Furthermore, preliminary evaluation of the hits showed that they influenced glucose consumption. In summary, by integrating docking-based, pharmacophore-based, and in vitro drug screening, three new agonists targeting the UT receptor were identified which may serve as promising therapeutic agents for urotensinergic system disorders.

Integration of Metabolomics and Transcriptomics Reveals Ketone Body and Lipid Metabolism Disturbance Related to ER Stress in the Liver.

Once protein synthesis is excessive or misfolded protein becomes aggregated, which eventually overwhelms the capacity of the endoplasmic reticulum (ER), a state named ER stress would be reached. ER stress could affect many tissues, especially the liver, in which nonalcoholic fatty liver disease, liver steatosis, etc. have been reported relative. However, there is still a lack of systematic insight into ER stress in the liver, which can be obtained by integrating metabolomics and transcriptomics of the tissue. Here, tunicamycin was utilized to induce ER stress in C57BL/6N mice. Microarray and untargeted metabolomics were performed to identify the genes and metabolites significantly altered in liver tissues. Surprisingly, apart from the predictable unfolded protein response, liver lipid, arginine, and proline metabolisms were affirmed to be related to ER stress. Also, the ketone body metabolism changed most prominently in response to ER stress, with few studies backing. What is more, succinate receptor 1 (Sucnr1) may be a novel marker and therapeutical target of liver ER stress. In this study, the combination of the metabolome and transcriptome provided reliable information about liver pathological processes, including key relative pathways, potential markers, and targets involved in ER stress of the liver.

Two new polycyclic polyprenylated acylphloroglucinols derivatives from Hypericum acmosepalum.

Polycyclic polyprenylated acylphloroglucinols (PPAPs) were mainly obtained from the plants of Hypericum genus of Guttiferae family, and possessed intriguing chemical structures and appealing biological activities. Two new PPAPs derivatives, hyperacmosin C (1) and hyperacmosin D (2) were isolated from H. acmosepalum. Their structures were established by NMR, HREIMS, and experimental electronic circular dichroism spectra. Besides, compound 1 showed significant hepatoprotective activity at 10 µM against paracetamol-induced HepG2 cell damage and compound 2 could moderately increase the relative glucose consumption.

Forkhead box protein O1 (FoxO1) regulates hepatic serine protease inhibitor B1 (serpinB1) expression in a non-cell-autonomous fashion.

FoxO proteins are major targets of insulin action, and FoxO1 mediates the effects of insulin on hepatic glucose metabolism. We reported previously that serpinB1 is a liver-secreted factor (hepatokine) that promotes adaptive ß-cell proliferation in response to insulin resistance in the liver-specific insulin receptor knockout (LIRKO) mouse. Here we report that FoxO1 plays a critical role in promoting serpinB1 expression in hepatic insulin resistance in a non-cell-autonomous manner. Mice lacking both the insulin receptor and FoxO1 (LIRFKO) exhibit reduced ß-cell mass compared with LIRKO mice because of attenuation of ß-cell proliferation. Although hepatic expression of serpinB1 mRNA and protein levels was increased in LIRKO mice, both the mRNA and protein levels returned to control levels in LIRFKO mice. Furthermore, liver-specific expression of constitutively active FoxO1 in transgenic mice induced an increase in hepatic serpinB1 mRNA and protein levels in refed mice. Conversely, serpinB1 mRNA and protein levels were reduced in mice lacking FoxO proteins in the liver. ChIP studies demonstrated that FoxO1 binds to three distinct sites located ∼9 kb upstream of the serpinb1 gene in primary mouse hepatocytes and that this binding is enhanced in hepatocytes from LIRKO mice. However, adenoviral expression of WT or constitutively active FoxO1 and insulin treatment are sufficient to regulate other FoxO1 target genes (IGFBP-1 and PEPCK) but not serpinB1 expression in mouse primary hepatocytes. These results indicate that liver FoxO1 promotes serpinB1 expression in hepatic insulin resistance and that non-cell-autonomous factors contribute to FoxO1-dependent effects on serpinB1 expression in the liver.

Effect of skeletal muscle phenotype and gender on fasting-induced myokine expression in mice.

Skeletal muscle secretes myokines, which are involved in metabolism and muscle function regulation. The role of fasting on myokine expression in skeletal muscle is largely unknown. In this study, we used gastrocnemius skeletal muscle RNA sequencing data from fasting male mice in the Gene Expression Omnibus (GEO) database. Adopted male and female C57BL/6J mice that fasted for 24 h were included to examine the effect of fasting on myokine expression in slow-twitch soleus and fast-twitch tiabialis anterior (TA) skeletal muscle. We found that fasting significantly affected many myokines in muscle. Fasting reduced Fndc5 and Igf1 gene expression in soleus and TA muscles in both male and female mice without muscle phenotype or gender differences, but Il6, Mstn and Erfe expression was influenced by fasting with fibre type- and gender-dependent effects. Fasting also induced muscle atrophy marker genes Murf1 and Fbxo32 and reduced myogenesis factor Mef2 expression without muscle fibre or gender differences. We further found that the expression of transcription factors Pgc1α, Pparα, Pparγ and Pparδ had muscle fibre type-dependent effects, and the expression of Pgc1α and Pparα had gender-dependent effects. The sophisticated expression pattern of myokines would partially explain the complicated cross-talk between skeletal muscle and other organs in different genders and muscles phenotypes, and it is worth further investigation.

Unusual cadinane-type sesquiterpene glycosides with α-glucosidase inhibitory activities from the fruit of Cornus officinalis Sieb. et Zuuc.

Five novel and rare cadinane-type sesquiterpene glycosides, cornucadinoside A-E (1-5) were isolated from water extract of the fruit of Cornus officinalis Sieb. et Zuuc.. The new chemical structures, together with their absolute configurations, were elucidated on the basis of extensive spectroscopic analysis, including a comparison of their experimental and calculated electronic circular dichroism (ECD) spectra. Their structures, which possess a naphthalene skeleton, are the first report on the occurrence of cadinane sesquiterpene glycosides in Cornus. Additionally, all the compounds exhibited marked α-glucosidase inhibitory activity except for 3in vitro.

Salvianolic Acid A Protects Against Diabetic Nephropathy through Ameliorating Glomerular Endothelial Dysfunction via Inhibiting AGE-RAGE Signaling.

BACKGROUND/AIMS: Glomerular endothelium dysfunction leads to the progression of renal architectonic and functional abnormalities in early-stage diabetic nephropathy (DN). Advanced glycation end products (AGEs) and receptor for AGEs (RAGE) are proved to play important roles in diabetic nephropathy. This study investigated the role of Salvianolic acid A (SalA) on early-stage DN and its possible underlying mechanism. METHODS: In vitro AGEs formation and breaking rate were measured to illustrate the effect of SalA on AGEs. Type 2 diabetic nephropathy rats were induced by high-fat diet and low-dose streptozocin (STZ). After eight-week treatment with SalA 1 mg/kg/day, 24h-urine protein, creatinine clearance was tested and renal structural injury was assessed by PAS and PASM staining. Primary glomerular endothelial cell permeability was evaluated after exposed to AGEs. AGEs-induced RhoA/ROCK and subsequently activated disarrange of cytoskeleton were assessed by western blot and immunofluorescence. RESULTS: Biochemical assay and histological examination demonstrated that SalA markedly reduced endothelium loss and glomerular hyperfiltration, suppressed glomerular hypertrophy and mesangial matrix expansion, eventually reduced urinary albumin and ameliorated renal function. Further investigation suggested that SalA exerted its renoprotective effects through inhibiting AGE-RAGE signaling. It not only inhibited formation of AGEs and increased its breaking in vitro, but also reduced AGEs accumulation in vivo and downregulated RAGE expression. SalA restored glomerular endothelial permeability through suppressing AGEs-induced rearrangement of actin cytoskeleton via AGE-RAGE-RhoA/ ROCK pathway. Moreover, SalA attenuated oxidative stress induced by AGEs, subsequently alleviated inflammation and restored the disturbed autophagy in glomerular endothelial cell and diabetic rats via AGE-RAGE-Nox4 axis. CONCLUSION: Our study indicated that SalA restored glomerular endothelial function and alleviated renal structural deterioration through inhibiting AGE-RAGE, thus effectively ameliorated early-stage diabetic nephropathy. SalA might be a promising therapeutic agent for the treatment of diabetic nephropathy.

Insulin regulates carboxypeptidase E by modulating translation initiation scaffolding protein eIF4G1 in pancreatic ß cells.

Insulin resistance, hyperinsulinemia, and hyperproinsulinemia occur early in the pathogenesis of type 2 diabetes (T2D). Elevated levels of proinsulin and proinsulin intermediates are markers of ß-cell dysfunction and are strongly associated with development of T2D in humans. However, the mechanism(s) underlying ß-cell dysfunction leading to hyperproinsulinemia is poorly understood. Here, we show that disruption of insulin receptor (IR) expression in ß cells has a direct impact on the expression of the convertase enzyme carboxypeptidase E (CPE) by inhibition of the eukaryotic translation initiation factor 4 gamma 1 translation initiation complex scaffolding protein that is mediated by the key transcription factors pancreatic and duodenal homeobox 1 and sterol regulatory element-binding protein 1, together leading to poor proinsulin processing. Reexpression of IR or restoring CPE expression each independently reverses the phenotype. Our results reveal the identity of key players that establish a previously unknown link between insulin signaling, translation initiation, and proinsulin processing, and provide previously unidentified mechanistic insight into the development of hyperproinsulinemia in insulin-resistant states.

Antidiabetic Effect of Salvianolic Acid A on Diabetic Animal Models via AMPK Activation and Mitochondrial Regulation.

BACKGROUND/AIMS: Diabetes mellitus (DM) characterized by hyperglycemia contributes to macrovascular and microvascular complications. Salvianolic acid A (SalA) is a polyphenolic compound isolated from the root of Salvia miltiorrhiza Bunge, which is a traditional Chinese medicine widely used to treat cardiovascular diseases. However, little is known about its antidiabetic effect. Our study aimed to investigate the in vivo and in vitro antidiabetic effect of SalA and the underlying mechanisms. METHODS: Alloxan-induced type 1 diabetic mice and high-fat diet (HFD) and low-dose streptozotocin (STZ)-induced type 2 diabetic rats received SalA treatment. Blood glucose, oral glucose tolerance test (OGTT), 24-h food and water intake were monitored. In vitro, glucose consumption and uptake were measured in HepG2 cells and L6 myotubes. Mitochondrial function was detected in hepatic and skeletal muscle mitochondria. AMP-activated protein kinase (AMPK) and Akt were analyzed by western blot. RESULTS: In both type 1 and type 2 diabetic animals, SalA lowered fasting blood glucose (FBG) and fed blood glucose in dose-dependent manner, as well as reduced 24-h food and water intake. In vitro, SalA caused dose-dependent increase in glucose consumption and enhanced glucose uptake. SalA significantly increased ATP production from 10 min to 12 h in HepG2 cells and L6 myotubes. Interestingly, SalA decreased mitochondrial membrane potential (MMP) in HepG2 cells. Furthermore, SalA improved hepatic and skeletal muscle mitochondrial function, increased ATP production, and concurrently decreased MMP. In particularly, SalA activated AMPK phosphorylation through Ca(2+)/calmodulin-dependent protein kinase kinase ß (CaMKKß)/AMPK signaling pathway, independent of liver kinase 1 (LKB1)/AMPK pathway. However, SalA didn't show any effect on insulin secretagogue and activation of PI3K/Akt signaling pathway. CONCLUSION: SalA exhibits the antidiabetic effects in diabetic animal models through improving mitochondrial function, increasing ATP production, and decreasing MMP via CaMKKß/AMPK signaling pathway.

A synthetic microbial consortium protects against obesity by regulating vitamin B6 metabolism.

Constructing synthetic microbial consortia is a challenging task but holds enormous potential for various applications. Our previous droplet-based microfluidic approach allowed for the isolation of bacteria that could utilize metabolites from an engineered bacterium BsS-RS06551 with anti-obesity potential, facilitating the construction of synthetic microbial consortia. Here, we identified a strain of Bifidobacterium pseudocatenulatum JJ3 that interacted with BsS-RS06551, and in vitro coculture showed that BsS-RS06551 was likely to interact with JJ3 through five dipeptides. Pathway analysis revealed that the vitamin B6 metabolism pathway was enriched in the coculture of BsS-RS06551 and JJ3 compared with the individual culture of BsS-RS06551. Additionally, we confirmed that the administration of JJ3 significantly alleviated obesity and related disorders in mice fed a high-fat diet. Notably, continuous ingestion of the synthetic microbial consortium comprising BsS-RS06551 and JJ3 not only exhibited a more pronounced impact on alleviating obesity compared to the individual administration of BsS-RS06551 or JJ3 but also enriched the population of Bifidobacterium longum and perturbed the vitamin B6 metabolism pathway in the gut. Synthetic microbial consortia represent a promising frontier for synthetic biology, and our strategy provides guidance for constructing and applying such consortia.

Identification of a novel hypoglycemic small molecule, trans-2, 4-dimethoxystilbene by rectifying gut microbiota and activating hepatic AMPKα-PPARγ pathway through gut-liver axis.

With the increasing prevalence of metabolic disorders, hyperglycemia has become a common risk factor that endangers people's lives and the need for new drug solutions is burgeoning. Trans-2, 4-dimethoxystilbene (TDMS), a synthetic stilbene, has been found as a novel hypoglycemic small molecule from glucose consumption test. Normal C57BL/6 J mice, mouse models of type 1 diabetes mellitus and diet-induced obesity subjected to TDMS gavage were found with lower glycemic levels and better glycemic control. TDMS significantly improved the symptoms of polydipsia and wasting in type 1 diabetic mice, and could rise their body temperature at the same time. It was found that TDMS could promote the expression of key genes of glucose metabolism in HepG2, as do in TDMS-treated liver, while it could improve the intestinal flora and relieve intestinal metabolic dysbiosis in hyperglycemic models, which in turn affected its function in the liver, forming the gut-liver axis. We further fished PPARγ by virtual screening that could be promoted by TDMS both in-vitro and in-vivo, which was regulated by upstream signaling of AMPKα phosphorylation. As a novel hypoglycemic small molecule, TDMS was proven to be promising with its glycemic improvements and amelioration of diabetes symptoms. It promoted glucose absorption and utilization by the liver and improved the intestinal flora of diabetic mice. Therefore, TDMS is expected to become a new hypoglycemic drug that acts through gut-liver axis via AMPKα-PPARγ signaling pathway in improving glycemic metabolism, bringing new hope to patients with diabetes and glucose metabolism disorders.

Uncovering the effect and mechanism of Panax notoginseng saponins on metabolic syndrome by network pharmacology strategy.

ETHNOPHARMACOLOGICAL RELEVANCE: Metabolic syndrome (MetS) is a cluster of disease centered on obesity, which is the result of stagnation of liver qi according to traditional Chinese medicine. Panax notoginseng is a traditional Chinese herbal medicine, entering liver and stomach meridians and dissipating blood stasis, in which panax notoginseng saponins (PNS) are the main active components. However, its effects and mechanism on metabolic syndrome has not been revealed yet. AIM OF STUDY: To evaluate the anti-MetS effect of PNS, including body weight and adiposity, glucose metabolism and non-alcoholic fatty liver disease (NAFLD), as well as to explore the mechanism and signaling pathway of PNS on MetS effect. MATERIALS AND METHODS: HPLC was utilized to affirm the percentages of saponins in PNS. In vivo, normal C57BL/6J mice and high-fat diet (HFD)-induced MetS mice were used to evaluate anti-MetS effect of PNS. Body weight, food and water intake were recorded. NMR imager was used for NMR imaging and lipid-water analysis. Blood glucose detection, glucose and insulin tolerance test were performed to evaluate glucose metabolism. Biochemical indexes analysis and histopathological staining were used to evaluate the effect on NAFLD. The expressions of mRNA and proteins related to thermogenesis in adipose tissue were determined using real-time PCR and Western blot. In silico, network pharmacology was utilized to predict potential mechanism. In vitro, matured 3T3-L1 adipocyte was used as subject to confirm the signaling pathway by Western blot. RESULTS: We determined the content of PNS component by HPLC. In vivo, PNS could improve metabolic syndrome with weight loss, reduction of adiposity, improvement of adipose distribution, correction of glucose metabolism disorder and attenuation of NAFLD. Mechanismly, PNS boosted energy exhaustion and dramatically enhanced thermogenesis in brown adipose tissue (BAT), induced white adipose tissue (WAT) browning. In silico, utilizing network pharmacology strategy, we identified 307 candidate targets which were enriched in MAPK signaling pathway specifically in liver tissue and adipocyte. In vitro validation confirmed ERK and p38MAPK mediated anti-MetS effects of PNS, not JNK signaling pathway. CONCLUSION: PNS exerted protective effect on metabolic syndrome through MAPK-mediated adipose thermogenic activation, which may serve as a prospective therapeutic drug for metabolic syndrome.

Kaempferol attenuates nonalcoholic fatty liver disease in type 2 diabetic mice via the Sirt1/AMPK signaling pathway.

Nonalcoholic fatty liver disease (NAFLD) is one of the most common liver diseases with limited treatment options. Moreover, its prevalence is doubled in type 2 diabetes mellitus (T2DM). Kaempferol (KAP) is a flavonoid compound that has been suggested to have beneficial effects on NAFLD, but studies on the mechanism are lacking, especially in the diabetic state. Herein, we investigated the effect of KAP on NAFLD associated with T2DM and its underlying mechanism in vitro and in vivo. The results of in vitro studies indicated that KAP treatment (10-8-10-6 M) significantly reduced lipid accumulation in oleic acid-induced HepG2 cells. Moreover, in the T2DM animal model of db/db mice, we confirmed that KAP (50 mg/kg) significantly reduced lipid accumulation and improved liver injury. Mechanistic studies in vitro and in vivo showed that Sirtuin 1 (Sirt1)/AMP-activated protein kinase (AMPK) signal was involved in KAP regulation of hepatic lipid accumulation. KAP treatment activated Sirt1 and AMPK, upregulated the levels of fatty acid oxidation-related protein proliferator activated receptor gamma coactivator 1α (PGC1α); and downregulated lipid synthesis-related proteins, including acetyl-coA carboxylase (ACC), fatty acid synthase (FASN), and sterol regulatory element-binding protein 1 (SREBP1). Furthermore, the curative effect of KAP on lipid accumulation was abolished by siRNA-mediated knockdown of either Sirt1 or AMPK. Collectively, these findings suggest that KAP may be a potential therapeutic agent for NAFLD associated with T2DM by regulating hepatic lipid accumulation through activation of Sirt1/AMPK signaling.

Anticancer peptides from induced tumor-suppressing cells for inhibiting osteosarcoma cells.

Osteosarcoma (OS) is the most frequent primary bone cancer, which is mainly suffered by children and young adults. While the current surgical treatment combined with chemotherapy is effective for the early stage of OS, advanced OS preferentially metastasizes to the lung and is difficult to treat. Here, we examined the efficacy of ten anti-OS peptide candidates from a trypsin-digested conditioned medium that was derived from the secretome of induced tumor-suppressing cells (iTSCs). Using OS cell lines, the antitumor capabilities of the peptide candidates were evaluated by assaying the alterations in metabolic activities, proliferation, motility, and invasion of OS cells. Among ten candidates, peptide P05 (ADDGRPFPQVIK), a fragment of aldolase A (ALDOA), presented the most potent OS-suppressing capabilities. Its efficacy was additive with standard-of-care chemotherapeutic agents such as cisplatin and doxorubicin, and it downregulated oncoproteins such as epidermal growth factor receptor (EGFR), Snail, and Src in OS cells. Interestingly, P05 did not present inhibitory effects on non-OS skeletal cells such as mesenchymal stem cells and osteoblast cells. Collectively, this study demonstrated that iTSC-derived secretomes may provide a source for identifying anticancer peptides, and P05 may warrant further evaluations for the treatment of OS.

Hyperglycemia in Diabetic Skin Infections Promotes Staphylococcus aureus Virulence Factor Aureolysin: Visualization by Molecular Imaging.

Bacterial skin infections are common in diabetic patients, with Staphylococcus aureus (S. aureus) being the most commonly isolated, causing comorbidities such as increased mortality and long-term hospitalization. While precise mechanisms remain to be determined, hyperglycemia represents an important pathogenetic factor responsible for the increased risk of S. aureus infection. Herein, we constructed a series of ratiometric fluorescent molecular probes for aureolysin (Aur), a major virulence factor in S. aureus. Using probe 1, we were able to determine specific Aur activity in both cells and tissues. We also observed that elevated glucose levels led to 2-fold higher Aur expression in S. aureus cultures. In a diabetic mouse model, we used molecular imaging to demonstrate that hyperglycemia tripled S. aureus Aur virulence compared to nondiabetic mice, resulting in more severe infections.

Secreted EMC10 is upregulated in human obesity and its neutralizing antibody prevents diet-induced obesity in mice.

Secreted isoform of endoplasmic reticulum membrane complex subunit 10 (scEMC10) is a poorly characterized secreted protein of largely unknown physiological function. Here we demonstrate that scEMC10 is upregulated in people with obesity and is positively associated with insulin resistance. Consistent with a causal role for scEMC10 in obesity, Emc10-/- mice are resistant to diet-induced obesity due to an increase in energy expenditure, while scEMC10 overexpression decreases energy expenditure, thus promoting obesity in mouse. Furthermore, neutralization of circulating scEMC10 using a monoclonal antibody reduces body weight and enhances insulin sensitivity in obese mice. Mechanistically, we provide evidence that scEMC10 can be transported into cells where it binds to the catalytic subunit of PKA and inhibits its stimulatory action on CREB while ablation of EMC10 promotes thermogenesis in adipocytes via activation of the PKA signalling pathway and its downstream targets. Taken together, our data identify scEMC10 as a circulating inhibitor of thermogenesis and a potential therapeutic target for obesity and its cardiometabolic complications.

Salvianolic acid A protects against vascular endothelial dysfunction in high-fat diet fed and streptozotocin-induced diabetic rats.

Salvianolic acid A (SalA) is one of the main active ingredients of Salvia miltiorrhizae. The objective of this study was to evaluate the effect of SalA on the diabetic vascular endothelial dysfunction (VED). The rats were given a high-fat and high-sucrose diet for 1 month followed by intraperitoneal injection of streptozotocin (30 mg/kg). The diabetic rats were treated with SalA (1 mg/kg, 90% purity) orally for 10 weeks after modeling, and were given a high-fat diet. Contractile and relaxant responses of aorta rings as well as the serum indications were measured. Our results indicated that SalA treatment decreased the level of serum Von Willebrand factor and ameliorated acetylcholine-induced relaxation and KCl-induced contraction in aorta rings of the diabetic rats. SalA treatment also reduced the serum malondialdehyde, the content of aortic advanced glycation end products (AGEs), and the nitric oxide synthase (NOS) activity as well as the expression of endothelial NOS protein in the rat aorta. Exposure of EA.hy926 cells to AGEs decreased the cell viability and changed the cell morphology, whereas SalA had protective effect on AGEs-induced cellular vitality. Our data suggested that SalA could protect against vascular VED in diabetes, which might attribute to its suppressive effect on oxidative stress and AGEs-induced endothelial dysfunction.