Oral administration of wild plant-derived minerals and red ginseng ameliorates insulin resistance in fish through different pathways.

Many kinds of fish are characterized by a limited efficiency to use carbohydrates. For this reason, raw fish and mixed feed containing a lot of fish meal have been used as feed for fish farming. However, continuing to use high-protein diets not only increases the cost of fish farming, but may also fuel animal protein shortages. Furthermore, carbohydrates are added to improve the texture of the feed and act as a binding agent and are usually contained at 20% in the feed. It makes sense, therefore, to find ways to make good use of carbohydrates rather than wasting them. The physiological mechanisms of glucose intolerance in fish are not yet well understood. Therefore, we investigated the glucose utilization of fish, omnivorous goldfish Carassius auratus and carnivorous rainbow trout Oncorhynchus mykiss. Furthermore, the effects of oral administration of wild plant-derived minerals and red ginseng on the glucose utilization in these fish muscle cells were investigated. As a result, we found the following. (1) An extremely high insulin resistance in fish muscle and the symptom was more pronounced in carnivorous rainbow trout. (2) Administration of wild plant-derived minerals promotes the translocation of the insulin-responsive glucose transporter GLUT4 to the cell surface of white muscle via activation of the PI3 kinase axis, whereas administration of red ginseng not only promotes GLUT4 transfer and translocation to the cell surface of white muscle via AMPK activation as well as promoting glucose uptake into muscle cells via a pathway separate from the insulin signaling system. (3) In fish, at least goldfish and rainbow trout, both PI3K/Akt and AMPK signaling cascades exist to promote glucose uptake into muscle cells, as in mammals.

Synthesis and Identification of Biologically Active Mono-Labelled FITC-Insulin Conjugate.

Fluorescently labelling proteins such as insulin have wide ranging applications in a pharmaceutical research and drug delivery. Human insulin (Actrapid®) was labelled with fluorescein isothiocyanate (FITC) and the synthesised conjugate identified using reverse phase high performance liquid chromatography (RP-HPLC) on a C18 column and a gradient method with mobile phase A containing 0.1% trifluoroacetic acid (TFA) in Millipore water and mobile phase B containing 90% Acetonitrile, 10% Millipore water and 0.1% TFA. Syntheses were carried out at varying reaction times between 4 and 20 h. Mono-labelled FITC-insulin conjugate was successfully synthesised with labelling at the B1 position on the insulin chain using a molar ratio of 2:1 (FITC:insulin) at a reaction time of 18 h and confirmed by electrospray mass spectroscopy. Reactions were studied across a pH range of 7-9.8 and the quantities switch from mono-labelled to di-labelled FITC-insulin conjugates at a reaction time of 2 h (2:1 molar ratio) at pH > 8. The conjugates isolated from the studies had biological activities in comparison to native insulin of 99.5% monoB1, 78% monoA1, 51% diA1B1 and 0.06% triA1B1B29 in HUVEC cells by examining AKT phosphorylation levels. MonoB1 FITC-insulin conjugate was also compared to native insulin by examining cell surface GLUT4 in C2C12 skeletal muscle cells. No significant difference in the cellular response was observed for monoB1 produced in-house compared to native insulin. Therefore mono-labelled FITC-insulin at the B1 position showed similar biological activity as native insulin and can potentially be used for future biomedical applications.

Carnosic Acid Attenuates the Free Fatty Acid-Induced Insulin Resistance in Muscle Cells and Adipocytes.

Elevated blood free fatty acids (FFAs), as seen in obesity, impair insulin action leading to insulin resistance and Type 2 diabetes mellitus. Several serine/threonine kinases including JNK, mTOR, and p70 S6K cause serine phosphorylation of the insulin receptor substrate (IRS) and have been implicated in insulin resistance. Activation of AMP-activated protein kinase (AMPK) increases glucose uptake, and in recent years, AMPK has been viewed as an important target to counteract insulin resistance. We reported previously that carnosic acid (CA) found in rosemary extract (RE) and RE increased glucose uptake and activated AMPK in muscle cells. In the present study, we examined the effects of CA on palmitate-induced insulin-resistant L6 myotubes and 3T3L1 adipocytes. Exposure of cells to palmitate reduced the insulin-stimulated glucose uptake, GLUT4 transporter levels on the plasma membrane, and Akt activation. Importantly, CA attenuated the deleterious effect of palmitate and restored the insulin-stimulated glucose uptake, the activation of Akt, and GLUT4 levels. Additionally, CA markedly attenuated the palmitate-induced phosphorylation/activation of JNK, mTOR, and p70S6K and activated AMPK. Our data indicate that CA has the potential to counteract the palmitate-induced muscle and fat cell insulin resistance.

Decreased miR-497-5p Suppresses IL-6 Induced Atrophy in Muscle Cells.

Interleukin-6 (IL-6) is a pro-inflammatory cytokine associated with skeletal muscle wasting in cancer cachexia. The control of gene expression by microRNAs (miRNAs) in muscle wasting involves the regulation of thousands of target transcripts. However, the miRNA-target networks associated with IL6-induced muscle atrophy remain to be characterized. Here, we show that IL-6 promotes the atrophy of C2C12 myotubes and changes the expression of 20 miRNAs (5 up-regulated and 15 down-regulated). Gene Ontology analysis of predicted miRNAs targets revealed post-transcriptional regulation of genes involved in cell differentiation, apoptosis, migration, and catabolic processes. Next, we performed a meta-analysis of miRNA-published data that identified miR-497-5p, a down-regulated miRNAs induced by IL-6, also down-regulated in other muscle-wasting conditions. We used miR-497-5p mimics and inhibitors to explore the function of miR-497-5p in C2C12 myoblasts and myotubes. We found that miR-497-5p can regulate the expression of the cell cycle genes CcnD2 and CcnE1 without affecting the rate of myoblast cellular proliferation. Notably, miR-497-5p mimics induced myotube atrophy and reduced Insr expression. Treatment with miR-497-5p inhibitors did not change the diameter of the myotubes but increased the expression of its target genes Insr and Igf1r. These genes are known to regulate skeletal muscle regeneration and hypertrophy via insulin-like growth factor pathway and were up-regulated in cachectic muscle samples. Our miRNA-regulated network analysis revealed a potential role for miR-497-5p during IL6-induced muscle cell atrophy and suggests that miR-497-5p is likely involved in a compensatory mechanism of muscle atrophy in response to IL-6.

Metformin and sodium dichloroacetate effects on proliferation, apoptosis, and metabolic activity tested alone and in combination in a canine prostate and a bladder cancer cell line.

An important approach in tumor therapy is combining substances with different action mechanisms aiming to enhance the antineoplastic effect, decrease the therapeutic dosage, and avoid resistance mechanisms. Moreover, evaluating compounds already approved for the treatment of non-neoplastic diseases is promising for new antineoplastic therapies. Sodium dichloroacetate (DCA) reactivates oxidative phosphorylation in the cancer cell mitochondria, reducing apoptosis resistance in cancer cells. Furthermore, metformin inhibits the proliferation of tumor cells and CD133+ cancer -stem-like cells. In the present study, we evaluated the independent and synergistic effect of metformin and DCA on the metabolic activity, cell proliferation, and apoptosis of a canine prostate adenocarcinoma (Adcarc1258) and a transitional cell carcinoma cell line (TCC1506) in comparison to a primary canine fibroblast culture. Determining metformin uptake in tumor cells was performed by quantitative HPLC. Depending on the dosage, metformin as a single agent inhibited the metabolic activity and cell proliferation of the tumor cells, showing only minor effects on the fibroblasts. Furthermore, 1 mM metformin increased apoptosis over 96 h in the tumor cell lines but not in fibroblasts. Additionally, metformin uptake into the tumor cells in vitro was measurable by quantitative HPLC. Synergistic effects for the combination therapy were observed in both neoplastic cell lines as well as in the fibroblasts. Based on these results, metformin might be a promising therapeutic agent for canine urogenital tumors. Further studies on kinetics, toxicology, bioavailability, and application of metformin in dogs are necessary.

Metformin Increases Protein Phosphatase 2A Activity in Primary Human Skeletal Muscle Cells Derived from Lean Healthy Participants.

OBJECTIVE: To investigate if PP2A plays a role in metformin-induced insulin sensitivity improvement in human skeletal muscle cells. Participants. Eight lean insulin-sensitive nondiabetic participants (4 females and 4 males; age: 21.0 ± 1.0 years; BMI: 22.0 ± 0.7 kg/m2; 2-hour OGTT: 97.0 ± 6.0 mg/dl; HbA1c: 5.3 ± 0.1%; fasting plasma glucose: 87.0 ± 2.0 mg/dl; M value; 11.0 ± 1.0 mg/kgBW/min). DESIGN: A hyperinsulinemic-euglycemic clamp was performed to assess insulin sensitivity in human subjects, and skeletal muscle biopsy samples were obtained. Primary human skeletal muscle cells (shown to retain metabolic characteristics of donors) were cultured from these muscle biopsies that included 8 lean insulin-sensitive participants. Cultured cells were expanded, differentiated into myotubes, and treated with 50 µM metformin for 24 hours before harvesting. PP2Ac activity was measured by a phosphatase activity assay kit (Millipore) according to the manufacturer's protocol. RESULTS: The results indicated that metformin significantly increased the activity of PP2A in the myotubes for all 8 lean insulin-sensitive nondiabetic participants, and the average fold increase is 1.54 ± 0.11 (P < 0.001). CONCLUSIONS: These results provided the first evidence that metformin can activate PP2A in human skeletal muscle cells derived from lean healthy insulin-sensitive participants and may help to understand metformin's action in skeletal muscle in humans.

The Effects of Marine Algal Polyphenols, Phlorotannins, on Skeletal Muscle Growth in C2C12 Muscle Cells via Smad and IGF-1 Signaling Pathways.

Skeletal muscle is an important tissue in energy metabolism and athletic performance. The use of effective synthetic supplements and drugs to promote muscle growth is limited by various side effects. Moreover, their use is prohibited by anti-doping agencies; hence, natural alternatives are needed. Therefore, we evaluated the muscle growth effect of substances that can act like synthetic supplements from edible marine algae. First, we isolated six marine algal polyphenols belonging to the phlorotannin class, namely dieckol (DK), 2,7″-phloroglucinol-6,6'-bieckol (PHB), phlorofucofuroeckol A (PFFA), 6,6'-bieckol (6,6-BK), pyrogallol-phloroglucinol-6,6'-bieckol (PPB), and phloroglucinol (PG) from an edible brown alga, Ecklonia cava and evaluated their effects on C2C12 myoblasts proliferation and differentiation. Of the six phlorotannin isolates evaluated, DK and PHB induced the highest degree of C2C12 myoblast proliferation. In addition, DK and PHB regulates myogenesis by down-regulating the Smad signaling, a negative regulator, and up-regulating the insulin-like growth factor-1 (IGF-1) signaling, a positive regulator. Interestingly, DK and PHB bind strongly to myostatin, which is an inhibitor of myoblast proliferation, while also binding to IGF-1 receptors. Moreover, they bind to IGF-1 receptor. These results suggest that DK and PHB are potential natural muscle building supplements and could be a safer alternative to synthetic drugs.

Ursolic Acid Lactone Obtained from Eucalyptus tereticornis Increases Glucose Uptake and Reduces Inflammatory Activity and Intracellular Neutral Fat: An In Vitro Study.

Obesity has a strong relationship to insulin resistance and diabetes mellitus, a chronic metabolic disease that alters many physiological functions. Naturally derived drugs have aroused great interest in treating obesity, and triterpenoids are natural compounds with multiple biological activities and antidiabetic mechanisms. Here, we evaluated the bioactivity of ursolic acid lactone (UAL), a lesser-known triterpenoid, obtained from Eucalyptus tereticornis. We used different cell lines to show for the first time that this molecule exhibits anti-inflammatory properties in a macrophage model, increases glucose uptake in insulin-resistant muscle cells, and reduces triglyceride content in hepatocytes and adipocytes. In 3T3-L1 adipocytes, UAL inhibited the expression of genes involved in adipogenesis and lipogenesis, enhanced the expression of genes involved in fat oxidation, and increased AMP-activated protein kinase phosphorylation. The range of biological activities demonstrated in vitro indicates that UAL is a promising molecule for fighting diabetes.

A Broad-Spectrum Chemokine Inhibitor Blocks Inflammation-Induced Myometrial Myocyte-Macrophage Crosstalk and Myometrial Contraction.

Prophylactic administration of the broad-spectrum chemokine inhibitor (BSCI) FX125L has been shown to suppress uterine contraction, prevent preterm birth (PTB) induced by Group B Streptococcus in nonhuman primates, and inhibit uterine cytokine/chemokine expression in a murine model of bacterial endotoxin (LPS)-induced PTB. This study aimed to determine the mechanism(s) of BSCI action on human myometrial smooth muscle cells. We hypothesized that BSCI prevents infection-induced contraction of uterine myocytes by inhibiting the secretion of pro-inflammatory cytokines, the expression of contraction-associated proteins and disruption of myocyte interaction with tissue macrophages. Myometrial biopsies and peripheral blood were collected from women at term (not in labour) undergoing an elective caesarean section. Myocytes were isolated and treated with LPS with/out BSCI; conditioned media was collected; cytokine secretion was analyzed by ELISA; and protein expression was detected by immunoblotting and immunocytochemistry. Functional gap junction formation was assessed by parachute assay. Collagen lattices were used to examine myocyte contraction with/out blood-derived macrophages and BSCI. We found that BSCI inhibited (1) LPS-induced activation of transcription factor NF-kB; (2) secretion of chemokines (MCP-1/CCL2 and IL-8/CXCL8); (3) Connexin43-mediated intercellular connectivity, thereby preventing myocyte-macrophage crosstalk; and (4) myocyte contraction. BSCI represents novel therapeutics for prevention of inflammation-induced PTB in women.

Berberine improves intralipid-induced insulin resistance in murine.

Insulin resistance (IR) is a major metabolic risk factor even before the onset of hyperglycemia. Recently, berberine (BBR) is found to improve hyperglycemia and IR. In this study, we investigated whether BBR could improve IR independent of hyperglycemia. Acute insulin-resistant state was induced in rats by systemic infusion of intralipid (6.6%). BBR was administered via different delivery routes before or after the beginning of a 2-h euglycemic-hyperinsulinemic clamp. At the end of experiment, rats were sacrificed, gastrocnemius muscle was collected for detecting mitochondrial swelling, phosphorylation of Akt and AMPK, as well as the mitochondrial permeability regulator cyclophilin D (CypD) protein expression. We showed that BBR administration markedly ameliorated intralipid-induced IR without affecting blood glucose, which was accompanied by alleviated mitochondrial swelling in skeletal muscle. We used human skeletal muscle cells (HSMCs), AML12 hepatocytes, human umbilical vein endothelial cells, and CypD knockout mice to investigate metabolic and molecular alternations. In either HSMCs or AML12 hepatocytes, BBR (5 µM) abolished palmitate acid (PA)-induced increase of CypD protein levels. In CypD-deficient mice, intralipid-induced IR was greatly attenuated and the beneficial effect of BBR was diminished. Furthermore, we demonstrated that the inhibitory effect of BBR on intralipid-induced IR was mainly mediated by skeletal muscle, but not by intestine, liver, or microvasculature; BBR administration suppressed intralipid-induced upregulation of CypD expression in skeletal muscle. These results suggest that BBR alleviates intralipid-induced IR, which is related to the inhibition of CypD protein expression in skeletal muscle.

The cardiovascular protective effect and mechanism of calycosin and its derivatives.

Cardiovascular disease is the main cause of mortality and morbidity in the world, especially in developing countries. Drug therapy is one of the main ways to treat cardiovascular diseases. Among them, great progress has been made in the treatment of cardiovascular diseases with traditional Chinese medicine. In terms of experimental research, the mechanism of traditional Chinese medicine in the treatment of cardiovascular diseases has been thoroughly discussed in vitro and in vivo. In terms of clinical treatment, traditional Chinese medicine with flavonoids, saponins and alkaloids as the main effective components has a definite effect on the treatment of cardiovascular diseases such as arrhythmia, myocardial ischemia, angina pectoris and myocardial infarction, with high safety and good application prospects. With the further research on the effective ingredients, mechanism and adverse reactions of traditional Chinese medicine, it will be beneficial to the effectiveness of traditional Chinese medicine, reduce side effects and promote the modernization of traditional Chinese medicine. Calycosin and its derivatives, the main bioactive flavonoids in Astragalus membranaceus have multiple biological effects, such as antioxidant, pro-angiogenesis, anti-tumour, and anti-inflammatory effects. Based on the above biological effects, calycosin has been shown to have good potential for cardiovascular protection. The potent antioxidant effect of calycosin may play an important role in the cardiovascular protective potential. For injured cardiac myocytes, calycosin and its derivatives can alleviate the cell damage mainly marked by the release of myocardial enzymes and reduce the death level of cardiac myocytes mainly characterized by apoptosis through various mechanisms. For vascular endothelial cells, calycosin also has multiple effects and multiple mechanisms, such as promoting vascular endothelial cell proliferation, exerting vasodilating effect and directly affecting the synthesis function of endothelial cells. The present review will address the bioactivity of calycosin in cardiovascular diseases such as protective effects on cardiac myocytes and vascular endothelial cells and elucidate main mechanism of calycosin and its derivatives to exert the above biological effects.

Vav2 catalysis-dependent pathways contribute to skeletal muscle growth and metabolic homeostasis.

Skeletal muscle promotes metabolic balance by regulating glucose uptake and the stimulation of multiple interorgan crosstalk. We show here that the catalytic activity of Vav2, a Rho GTPase activator, modulates the signaling output of the IGF1- and insulin-stimulated phosphatidylinositol 3-kinase pathway in that tissue. Consistent with this, mice bearing a Vav2 protein with decreased catalytic activity exhibit reduced muscle mass, lack of proper insulin responsiveness and, at much later times, a metabolic syndrome-like condition. Conversely, mice expressing a catalytically hyperactive Vav2 develop muscle hypertrophy and increased insulin responsiveness. Of note, while hypoactive Vav2 predisposes to, hyperactive Vav2 protects against high fat diet-induced metabolic imbalance. These data unveil a regulatory layer affecting the signaling output of insulin family factors in muscle.

Oleuropein Aglycone Peracetylated (3,4-DHPEA-EA(P)) Attenuates H2O2-Mediated Cytotoxicity in C2C12 Myocytes via Inactivation of p-JNK/p-c-Jun Signaling Pathway.

Oleuropein, a glycosylated secoiridoid present in olive leaves, is known to be an important antioxidant phenolic compound. We studied the antioxidant effect of low doses of oleuropein aglycone (3,4-DHPEA-EA) and oleuropein aglycone peracetylated (3,4-DHPEA-EA(P)) in murine C2C12 myocytes treated with hydrogen peroxide (H2O2). Both compounds were used at a concentration of 10 µM and were able to inhibit cell death induced by the H2O2 treatment, with 3,4-DHPEA-EA(P) being more. Under our experimental conditions, H2O2 efficiently induced the phosphorylated-active form of JNK and of its downstream target c-Jun. We demonstrated, by Western blot analysis, that 3,4-DHPEA-EA(P) was efficient in inhibiting the phospho-active form of JNK. This data suggests that the growth arrest and cell death of C2C12 proceeds via the JNK/c-Jun pathway. Moreover, we demonstrated that 3,4-DHPEA-EA(P) affects the myogenesis of C2C12 cells; because MyoD mRNA levels and the differentiation process are restored with 3,4-DHPEA-EA(P) after treatment. Overall, the results indicate that 3,4-DHPEA-EA(P) prevents ROS-mediated degenerative process by functioning as an efficient antioxidant.

Statins Stimulate New Myocyte Formation After Myocardial Infarction by Activating Growth and Differentiation of the Endogenous Cardiac Stem Cells.

The 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) exert pleiotropic effects on cardiac cell biology which are not yet fully understood. Here we tested whether statin treatment affects resident endogenous cardiac stem/progenitor cell (CSC) activation in vitro and in vivo after myocardial infarction (MI). Statins (Rosuvastatin, Simvastatin and Pravastatin) significantly increased CSC expansion in vitro as measured by both BrdU incorporation and cell growth curve. Additionally, statins increased CSC clonal expansion and cardiosphere formation. The effects of statins on CSC growth and differentiation depended on Akt phosphorylation. Twenty-eight days after myocardial infarction by permanent coronary ligation in rats, the number of endogenous CSCs in the infarct border zone was significantly increased by Rosuvastatin-treatment as compared to untreated controls. Additionally, commitment of the activated CSCs into the myogenic lineage (c-kitpos/Gata4pos CSCs) was increased by Rosuvastatin administration. Accordingly, Rosuvastatin fostered new cardiomyocyte formation after MI. Finally, Rosuvastatin treatment reversed the cardiomyogenic defects of CSCs in c-kit haploinsufficient mice, increasing new cardiomyocyte formation by endogenous CSCs in these mice after myocardial infarction. In summary, statins, by sustaining Akt activation, foster CSC growth and differentiation in vitro and in vivo. The activation and differentiation of the endogenous CSC pool and consequent new myocyte formation by statins improve myocardial remodeling after coronary occlusion in rodents. Similar effects might contribute to the beneficial effects of statins on human cardiovascular diseases.

Activity of Gas Transmitters in Vessels of the Anterior Abdominal Wall after Implantation of a Polypropylene Mesh.

The distribution of NO and H2S in the arterial vessels of the anterior abdominal wall after implantation of a polypropylene mesh was studied by immunohistochemical methods at different stages of healing of the surgical wound in mature male Wistar rats. The presence of enzymes of NO and H2S synthesis in the wall of arterial vessels of the soft tissues of the anterior abdominal wall has been established. It has been shown that endothelial NO synthase is localized exclusively in the endothelium of both large and small vessels. Cystathionine γ lyase in small vessels is located only in the endothelial lining, whereas in large arteries and vessels of medium caliber, it is located in the endothelium and in myocytes. Inducible NO synthase appears in the artery wall only in animals with implanted polypropylene mesh by day 5 of the postoperative period, reaching the maximum by day 10. The content and localization of cystathionine γ lyase in the vascular wall of sham-operated and experimental rats did not much differ from the control values.

Anti-Fibrotic Effect of Human Wharton's Jelly-Derived Mesenchymal Stem Cells on Skeletal Muscle Cells, Mediated by Secretion of MMP-1.

Extracellular matrix (ECM) components play an important role in maintaining skeletal muscle function, but excessive accumulation of ECM components interferes with skeletal muscle regeneration after injury, eventually inducing fibrosis. Increased oxidative stress level caused by dystrophin deficiency is a key factor in fibrosis in Duchenne muscular dystrophy (DMD) patients. Mesenchymal stem cells (MSCs) are considered a promising therapeutic agent for various diseases involving fibrosis. In particular, the paracrine factors secreted by MSCs play an important role in the therapeutic effects of MSCs. In this study, we investigated the effects of MSCs on skeletal muscle fibrosis. In 2-5-month-old mdx mice intravenously injected with 1 × 105 Wharton's jelly (WJ)-derived MSCs (WJ-MSCs), fibrosis intensity and accumulation of calcium/necrotic fibers were significantly decreased. To elucidate the mechanism of this effect, we verified the effect of WJ-MSCs in a hydrogen peroxide-induced fibrosis myotubes model. In addition, we demonstrated that matrix metalloproteinase-1 (MMP-1), a paracrine factor, is critical for this anti-fibrotic effect of WJ-MSCs. These findings demonstrate that WJ-MSCs exert anti-fibrotic effects against skeletal muscle fibrosis, primarily via MMP-1, indicating a novel target for the treatment of muscle diseases, such as DMD.

Attenuation of Free Fatty Acid (FFA)-Induced Skeletal Muscle Cell Insulin Resistance by Resveratrol is Linked to Activation of AMPK and Inhibition of mTOR and p70 S6K.

Insulin resistance, a main characteristic of type 2 diabetes mellitus (T2DM), is linked to obesity and excessive levels of plasma free fatty acids (FFA). Studies indicated that significantly elevated levels of FFAs lead to skeletal muscle insulin resistance, by dysregulating the steps in the insulin signaling cascade. The polyphenol resveratrol (RSV) was shown to have antidiabetic properties but the exact mechanism(s) involved are not clearly understood. In the present study, we examined the effect of RSV on FFA-induced insulin resistance in skeletal muscle cells in vitro and investigated the mechanisms involved. Parental and GLUT4myc-overexpressing L6 rat skeletal myotubes were used. [3H]2-deoxyglucose (2DG) uptake was measured, and total and phosphorylated levels of specific proteins were examined by immunoblotting. Exposure of L6 cells to FFA palmitate decreased the insulin-stimulated glucose uptake, indicating insulin resistance. Palmitate increased ser307 (131% ± 1.84% of control, p < 0.001) and ser636/639 (148% ± 10.1% of control, p < 0.01) phosphorylation of IRS-1, and increased the phosphorylation levels of mTOR (174% ± 15.4% of control, p < 0.01) and p70 S6K (162% ± 20.2% of control, p < 0.05). Treatment with RSV completely abolished these palmitate-induced responses. In addition, RSV increased the activation of AMPK and restored the insulin-mediated increase in (a) plasma membrane GLUT4 glucose transporter levels and (b) glucose uptake. These data suggest that RSV has the potential to counteract the FFA-induced muscle insulin resistance.

Active Compound of Pharbitis Semen (Pharbitis nil Seeds) Suppressed KRAS-Driven Colorectal Cancer and Restored Muscle Cell Function during Cancer Progression.

Kirsten rat sarcoma viral oncogene homolog (KRAS)-driven colorectal cancer (CRC) is notorious to target with drugs and has shown ineffective treatment response. The seeds of Pharbitis nil, also known as morning glory, have been used as traditional medicine in East Asia. We focused on whether Pharbitis nil seeds have a suppressive effect on mutated KRAS-driven CRC as well as reserving muscle cell functions during CRC progression. Seeds of Pharbitis nil (Pharbitis semen) were separated by chromatography and the active compound of Pharbitis semen (PN) was purified by HPLC. The compound PN efficiently suppressed the proliferation of mutated KRAS-driven CRC cells and their clonogenic potentials in a concentration-dependent manner. It also induced apoptosis of SW480 human colon cancer cells and cell cycle arrest at the G2/M phase. The CRC related pathways, including RAS/ERK and AKT/mTOR, were assessed and PN reduced the phosphorylation of AKT and mTOR. Furthermore, PN preserved muscle cell proliferation and myotube formation in cancer conditioned media. In summary, PN significantly suppressed mutated KRAS-driven cell growth and reserved muscle cell function. Based on the current study, PN could be considered as a promising starting point for the development of a nature-derived drug against KRAS-mutated CRC progression.

Atypical chemokine receptor ACKR3/CXCR7 controls postnatal vasculogenesis and arterial specification by mesenchymal stem cells via Notch signaling.

Mesenchymal stem cells (MSCs) are known to play a role in postnatal vasculogenesis and hold great promise for vascular regeneration. However, the mechanisms by which the endothelial differentiation and specification of MSCs remain unclear. We examined the potential role and molecular mechanisms of atypical chemokine receptor ACKR3/CXCR7 in MSC-mediated endothelial cell differentiation and specification. Here, we showed that vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF) activate CXCR7 expression on MSCs through PDGF receptors, PDGFRα and PDGFRß-mediated phosphoinositide 3-kinase (PI3K)/Akt signaling. Genetic and pharmacologic blockage of CXCR7 on MSCs suppressed the VEGF or stromal cell-derived factor 1 (SDF)-1-induced the capacity for vasculogenesis in vitro and in vivo. Moreover, CXCR7 gain of function markedly promoted vasculogenesis by MSCs in vitro and in vivo and induced endothelial differentiation along the arterial endothelial cell lineage via upregulation of Notch signaling. However, blockade of Notch signaling inhibited CXCR7-induced vasculogensis by MSCs. These results indicate CXCR7 is a critical regulator of MSC-mediated postnatal vasculogenesis and arterial specification via Notch signaling.

TNF-alpha regulates alternative splicing of genes participating in pathways of crucial metabolic syndromes; a transcriptome wide study.

BACKGROUND: TNF-α, a pro-inflammatory cytokine is one of the major contributors for metabolic syndromes including insulin resistance, obesity, type II diabetes etc. The role of alternative splicing, a post-transcriptional regulation of gene expression on the onset of these syndromes is poorly understood. However, the role of alternative splicing, which more than 95% of all exons in eukaryotic cells undergo in several other diseases including cancer and muscle dystrophy, has been elucidated. In this study we aim to investigate the role of alternative splicing in pathways leading to metabolic syndromes mediated by TNF-α. METHODS: A genome wide transcriptome analysis was carried out using Illumina platform. Results were validated using RT-PCR analysis. Various bioinformatics tools and databases (for example IPA, KEGG, STRING etc) were used for the pathway and interactome analysis. CURRENT FINDINGS: Transcriptome wide analysis revealed that TNF-α treatment in vitro causes a significant change in expression of 228 genes at the level of alternative splicing. Regulation of some of these genes was validated in different cell lines. Pathway analysis showed at least 15% of the alternatively spliced genes fall under the contributory pathways leading to different metabolic syndromes, among which the maximally interconnected genes were transcription regulators. CONCLUSION: These findings suggest that TNF-α.-mediated alternative splicing plays a crucial role in regulating various genes involved in pathways connected to metabolic syndromes.