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1.
Gut Microbes ; 16(1): 2341457, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38630030

RESUMEN

With an increasing interest in dietary fibers (DFs) to promote intestinal health and the growth of beneficial gut bacteria, there is a continued rise in the incorporation of refined DFs in processed foods. It is still unclear how refined fibers, such as guar gum, affect the gut microbiota activity and pathogenesis of inflammatory bowel disease (IBD). Our study elucidated the effect and underlying mechanisms of guar gum, a fermentable DF (FDF) commonly present in a wide range of processed foods, on colitis development. We report that guar gum containing diet (GuD) increased the susceptibility to colonic inflammation. Specifically, GuD-fed group exhibited severe colitis upon dextran sulfate sodium (DSS) administration, as evidenced by reduced body weight, diarrhea, rectal bleeding, and shortening of colon length compared to cellulose-fed control mice. Elevated levels of pro-inflammatory markers in both serum [serum amyloid A (SAA), lipocalin 2 (Lcn2)] and colon (Lcn2) and extensive disruption of colonic architecture further affirmed that GuD-fed group exhibited more severe colitis than control group upon DSS intervention. Amelioration of colitis in GuD-fed group pre-treated with antibiotics suggest a vital role of intestinal microbiota in GuD-mediated exacerbation of intestinal inflammation. Gut microbiota composition and metabolite analysis in fecal and cecal contents, respectively, revealed that guar gum primarily enriches Actinobacteriota, specifically Bifidobacterium. Guar gum also altered multiple genera belonging to phyla Bacteroidota and Firmicutes. Such shift in gut microbiota composition favored luminal accumulation of intermediary metabolites succinate and lactate in the GuD-fed mice. Colonic IL-18 and tight junction markers were also decreased in the GuD-fed group. Importantly, GuD-fed mice pre-treated with recombinant IL-18 displayed attenuated colitis. Collectively, unfavorable changes in gut microbiota activity leading to luminal accumulation of lactate and succinate, reduced colonic IL-18, and compromised gut barrier function following guar gum feeding contributed to increased colitis susceptibility.


Guar gum increased susceptibility to colitisGuar gum-induced exacerbation of colitis is gut microbiota dependentGuar gum-induced shift in microbiota composition favored the accumulation of luminal intermediate metabolites succinate and lactateGuar gum-fed mice exhibited reduced colonic level of IL-18 and tight junction molecules.Exogenous IL-18 administration partly rescued mice from guar gum-induced colitis susceptibility.


Asunto(s)
Colitis , Galactanos , Microbioma Gastrointestinal , Mananos , Gomas de Plantas , Animales , Ratones , Interleucina-18 , Inflamación , Colitis/inducido químicamente , Fibras de la Dieta , Ácido Láctico , Succinatos
2.
Cytokine ; 171: 156354, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37672864

RESUMEN

AIM: Pancreastatin, a dysglycemic hormone that encourages inflammation and steatosis in a variety of metabolic disorder animal models. The purpose of this study is to determine the effect of the pancreastatin inhibitor PSTi8 on immunometabolic changes in the liver of MCD-induced NASH mice. MAIN METHODS: Methionine and choline-deficient (MCD) diet was used for the development of NASH. Liver enzymes like SGOT, SGPT, and ALP and lipid profiles were also performed in the serum. Further, immunophenotyping study was performed in the liver through flowcytometer. Subsequently, Hematoxylin and Eosin, Picro Sirius Red and Masson's Trichrome staining were done to check the liver morphology and collagen staining, respectively. Inflammatory cytokines were measured through ELISA and gene expression through RT-PCR. The expression of α-SMA was examined using immunohistochemistry and immunofluorescence staining. KEY FINDINGS: PSTi8 inhibited the expression of lipogenic genes in the liver and attenuated bad cholesterol, SGOT, SGPT, and ALP in the serum. PSTi8 improved the liver morphology and attenuated collagen deposition. Subsequently, PSTi8 attenuated inflammatory M1-macrophages, CD8+T, CD4+T cells and increased anti-inflammatory M2 macrophages, T-reg and eosinophil populations in the liver. It also attenuated the expression of pro-inflammatory genes like Mcp1, Tnfα, and Il6. Apart from this, PSTi8 attenuated the oxidative stress marker, like ROS, and MDA and fibrosis marker α-SMA in the liver. It also decreased the apoptosis and ROS and MDA level in the liver. SIGNIFICANCE: Overall, these compressive studies revealed that PSTi8 exhibited beneficial effect on the liver of MCD-induced NASH mice by attenuating inflammation and oxidative stress.

3.
J Biochem Mol Toxicol ; 37(6): e23336, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37009719

RESUMEN

Raspberry Ketone (RK) and Resveratrol (RSV) are natural phenolic antioxidants and anti-inflammatory agents. However, its combined pharmacokinetic and pharmacodynamics potentials are not reported. The study aims to assess the combined effect of RK with RSV to protect rats from carbon-tetrachloride (CCl4) induced oxidative stress and NASH. The toxicant CCl4 was employed at a concentration of 1 mL/kg as a 1:1 (v/v) mixture with olive oil twice weekly for 6 weeks to induce liver toxicity. Animal treatment was followed for 2 weeks. Silymarin was used as a standard control drug to compare the hepatoprotective effect of RK and RSV. Hepatic histology, oxidative stress, MMP, reduced glutathione (GSH), plasma levels of SGOT, SGPT, and lipid profile (total cholesterol and triglycerides) were measured. Anti-inflammation genes (IL-10), and fibrotic genes (TGF-ß) were also examined in liver tissue. Oral administration of combined RK with RSV (50 + 50 mg/kg for 2 weeks) showed significantly more hepatoprotection by significantly decreasing elevated plasma markers and lipid profile than alone RK and RSV (100 mg/kg daily for 2 weeks). It also significantly alleviated the hepatic lipid peroxidation, restoring the activities of GSH levels in the liver. RT-PCR and Immunoblotting studies confirmed that significantly upregulation of anti-inflammation genes and protein expression (MMP-9) ameliorated the disease. Pharmacokinetic studies confirmed more synergistic stability in simulated gastric-intestinal fluids (FaSSGF, FaSSIF) and rat liver microsomes (CYP-450, NADPH oxidation & glucuronidation. Moreover, coadministration of drugs augmented the relative bioavailability, Vd/ F (L/Kg), and MRT0-∞( h), which leads to more efficacy. This pharmacokinetic and pharmacodynamic reveals a new adjuvant therapy for the treatment of steatohepatitis.


Asunto(s)
Enfermedad Hepática Inducida por Sustancias y Drogas , Hígado Graso , Ratas , Animales , Resveratrol/farmacología , Antioxidantes/metabolismo , Estrés Oxidativo , Hígado/metabolismo , Hígado Graso/inducido químicamente , Hígado Graso/tratamiento farmacológico , Hígado Graso/metabolismo , Tetracloruro de Carbono , Antiinflamatorios/farmacología , Triglicéridos , Enfermedad Hepática Inducida por Sustancias y Drogas/metabolismo , Peroxidación de Lípido
4.
Bioanalysis ; 15(2): 83-98, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36916612

RESUMEN

Background: Raspberry ketone (RK), derived from red raspberry fruit (Rubus idaeus, family Rosaceae), is a reported potent antiobesity agent. This study aims to investigate method development, validation, and in vitro and in vivo pharmacokinetics in rats. Materials & methods: LC-MS/MS was used to conduct method development, validation, stability, and oral PK samples of RK in plasma analyses. Results: RK was highly soluble in Tris buffer and stable in gastrointestinal fluids as well as plasma. Rat liver microsomal stability of RK in phase I and II studies was 84.96 ± 2.39 and 69.98 ± 8.69%, respectively, after 60 min. Intestinal permeability was 4.39 ± 1.37 × 10-5 cm/s. Maximal concentration was 1591.02 ± 64.76 ng/ml, which was achieved after 1 h (time to maximal concentration), and absolute oral bioavailability was 86.28%. Conclusion: Pharmacokinetic data serve as a keystone for preclinical and clinical adjuvant therapy.


Using LC­MS/MS, a method was developed and validated for RK, and investigated the preclinical pharmacokinetics and bioavailability in Sprague Dawley rats.


Asunto(s)
Butanonas , Espectrometría de Masas en Tándem , Ratas , Animales , Cromatografía Liquida/métodos , Espectrometría de Masas en Tándem/métodos , Microsomas Hepáticos , Reproducibilidad de los Resultados
5.
Eur J Pharmacol ; 944: 175559, 2023 Apr 05.
Artículo en Inglés | MEDLINE | ID: mdl-36764353

RESUMEN

Elevated plasma glucose concentration, as a consequence of excessive hepatic glucose production, plays a pivotal role in the development of diabetes. A chromogranin A-derived diabetogenic peptide Pancreastatin (PST) enhances hepatic glucose output leading to diabetes. Therefore, here we probed the role of PSTi8, a PST inhibitor in ameliorating diabetes by investigating the effect of high glucose (HG) or PST on glucose metabolism. Further, we also explored the action mechanism of the underlying anti-hyperglycemic effect of PSTi8. PSTi8 treatment rescue cultured L6 and HepG2 cells from HG and PST-induced insulin resistance, respectively. It also enhances insulin receptor kinase activity by interacting with the insulin receptor and enhancing GLUT4 translocation and glucose uptake. Thus, our in-silico and in-vitro data support the PST-dependent and independent activity of PSTi8. Additionally, PSTi8 treatment in streptozotocin-induced diabetic rats improved glucose tolerance by lowering blood glucose and plasma PST levels. Concomitantly, the treated animals exhibited reduced hepatic glucose production accompanied by downregulation of hepatic gluconeogenic genes PEPCK and G6Pase. PSTi8-treated rats also exhibited enhanced hepatic glycogen in line with reduced plasma glucagon concentrations. Consistently, improved plasma insulin levels in PSTi8-treated rats enhanced skeletal muscle glucose disposal via enhanced P-Akt expression. In summary, these findings suggest PSTi8 has anti-hyperglycemic properties with enhanced skeletal muscle glucose disposal and reduced hepatic gluconeogenesis both PST dependent as well as independent.


Asunto(s)
Diabetes Mellitus Experimental , Resistencia a la Insulina , Ratas , Animales , Glucosa/metabolismo , Cromogranina A , Receptor de Insulina , Estreptozocina , Diabetes Mellitus Experimental/metabolismo , Hígado/metabolismo , Hipoglucemiantes , Insulina/metabolismo
6.
Life Sci ; 316: 121415, 2023 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-36690247

RESUMEN

AIMS: Pancreastatin (PST), an anti-insulin peptide derived from chromogranin A. Its levels increase in cases of obesity, which contributes to adipose tissue inflammation and insulin resistance. This study aims to investigate the immunometabolic effect of PST inhibitor (PSTi8) against PST by using in vitro and in vivo finding. MAIN METHODS: 3T3-L1 cells were differentiated with or without PSTi8, and Oil Red O staining was performed. J774A.1 cells were used for macrophage polarization study. The diet-induced obesity and T2DM model was developed in C57BL/6 mice through high-fat diet for 8 weeks. Alzet osmotic pumps were filled with PSTi8 (release rate: 2 mg/kg/day) and implanted in mice for eight weeks. Further, insulin and glucose tolerance tests were performed. Liver and eWAT sections were stained with hematoxylin and eosin. FACS was used to measure mitochondrial ROS and membrane potential, while Oroboros O2k was used to measure oxygen consumption rate. Immunocytochemistry and qRT-PCR were done for protein and gene expression, respectively. KEY FINDINGS: PSTi8 inhibited the expression of lipolytic genes and proteins in 3T3-L1 adipocytes. PSTi8 improved the inulin sensitivity, lipid profile, MMP, and OCR levels in the 3T3-L1 adipocyte and eWAT. It also increased the M1 to M2 macrophage polarization in J77A.1 cells and eWAT. Further, PSTi8 attenuated inflammatory CD4+ T, CD8+ T cells and increased the anti-inflammatory T-reg and eosinophil populations in the eWAT. It also reduced the expression of pro-inflammatory genes like Mcp1, Tnfα, and Il-6. SIGNIFICANCE: Collectively, PSTi8 exerted its beneficial effect on adipose tissue inflammation and restored energy expenditure against diet-induced obesity.


Asunto(s)
Linfocitos T CD8-positivos , Resistencia a la Insulina , Ratones , Animales , Cromogranina A/metabolismo , Ratones Obesos , Linfocitos T CD8-positivos/metabolismo , Ratones Endogámicos C57BL , Tejido Adiposo/metabolismo , Obesidad/tratamiento farmacológico , Obesidad/metabolismo , Insulina/metabolismo , Inflamación/tratamiento farmacológico , Inflamación/metabolismo , Dieta Alta en Grasa/efectos adversos , Células 3T3-L1
7.
Peptides ; 159: 170902, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36375661

RESUMEN

Pancreastatin (PST) is an endogenous bioactive peptide. PST is generated from chromogranin A (Chga) protein which is released by chromaffin and neuroendocrine cells. PST exhibits diabetogenic effect by antagonizing the action of insulin in adipocytes. The level of PST rises during obesity, resulting in persistent low-grade inflammation in adipocytes. Pancreastatin inhibitor 8 (PSTi8), which is developed by modification of PST sequence which antagonizes the action of PST. In this study, we investigated the immunometabolic effect of PSTi8 in the diet-induced obesity (DIO) model in C57BL/6 mice. Here we found PSTi8 decreased the body weight gain, fat mass and increased the lean mass in (DIO) mice. It also showed reduction of adipocyte hypertrophy in eWAT and lipid accumulation in liver of DIO mice. Immunoprofiling of stromal vascular fraction isolated from eWAT of PTSi8 treated mice showed increased anti-inflammatory M2 macrophages, Eosinophil, T-regulatory cells and reduced pro-inflammatory M1 macrophages, CD4 and CD8 T cell population. Apart from this, PSTi8 also improved the mitochondrial function by decreasing reactive oxygen species and increasing mitochondrial membrane potential, NADPH/NADP ratio and citrate synthase activity in eWAT of DIO mice. It also increased the protein expression of pAMPK, pAKT, Arginase -1 and decreased the expression of MHC-II and iNOS in eWAT of DIO mice. In conclusion, PSTi8 exerted its beneficial effect on restoring energy expenditure by reducing adipose tissue inflammation.


Asunto(s)
Dieta Alta en Grasa , Resistencia a la Insulina , Ratones , Animales , Cromogranina A , Dieta Alta en Grasa/efectos adversos , Ratones Endogámicos C57BL , Tejido Adiposo/metabolismo , Inflamación/tratamiento farmacológico , Inflamación/metabolismo , Obesidad/tratamiento farmacológico , Obesidad/metabolismo , Homeostasis
8.
Life Sci ; 289: 120221, 2022 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-34902437

RESUMEN

AIM: Free fatty acid-mediated obesity plays a crucial role in the pathogenesis of Type 2 Diabetes. FFA induced JNK activation acts as a central regulator in causing hepatic insulin resistance. Similarly, Pancreastatin, a chromogranin A peptide, serves as a crucial link between FFA-induced insulin resistance. Therefore, in the present work, we sought to test Pancreastatin inhibitor PSTi8 to ameliorate FFA-induced hepatic insulin resistance in in vitro and in vivo models. MATERIAL AND METHODS: To verify our objective, we exposed hepatocytes (HepG2 cells) with palmitate (0.3 mM) or palmitate + PSTi8 (200 nM). Parallelly mice were fed either HFD or HFD + PSTi8 (1 mg/kg). After 21 days animals were scanned for increased fat mass, along with GTT, ITT and PTT experiment to check glucose, and insulin tolerance. Furthermore, ROS generation and hepatic glycogen content was measured in FFA exposed hepatocytes. Gene expression and protein expression studies were further conducted to delineate the action mechanism of PSTi8. KEY FINDINGS: PSTi8 exposure decreased ROS accumulation, lipid accumulation, and reduced glycogen content in FFA-induced groups. It also enhances glucose uptake and reduces gluconeogenesis to combat the FFA effect. Furthermore, gene expression studies indicate that PSTi8 treatment reduces NADPH oxidase3 (NOX3) expression and inhibits JNK signaling, a predominant source of ROS-induced insulin resistance. SIGNIFICANCE: To summarize, the protective effect of PSTi8 on FFA-induced insulin resistance is mediated via inhibition of JNK signaling, which leads to decreased ROS generation and enhanced insulin sensitivity. Hence PSTi8 could be a therapeutic molecule to prevent western diet-induced insulin resistance.


Asunto(s)
Cromogranina A/antagonistas & inhibidores , Ácidos Grasos/metabolismo , Resistencia a la Insulina , MAP Quinasa Quinasa 4/metabolismo , Estrés Oxidativo/efectos de los fármacos , Transducción de Señal/efectos de los fármacos , Animales , Cromogranina A/metabolismo , Células Hep G2 , Humanos , Masculino , Ratones
9.
J Pharm Pharmacol ; 73(11): 1442-1450, 2021 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-34128987

RESUMEN

OBJECTIVES: Hyperglycemia-induced SIRT1, DNMT1, SODs, as well as oxidative stress, play a pivotal role in the progression of diabetic nephropathy. Cissus quadrangularis, holds antioxidant and hypoglycemic activity; however, a direct link between its activity and prevention of diabetic nephropathy has not been ascertained yet. Accordingly, we aimed to delineate the protective effect of ethanolic extract of Cissus quadrangularis (EECQ) against high-fat diet/streptozotocin (HFD/STZ) induced diabetic nephropathy rats. METHODS: The control group was fed with a normal chow diet. Rats kept on an HFD for 12 weeks with a single low dose of STZ manifested the features of diabetic nephropathy. The treatment was done by the oral administration of EECQ (200 mg/kg) for six weeks (six rats in each group). KEY FINDINGS: Treatment with EECQ demonstrated substantial attenuation of elevated insulin resistance, lipid profile and creatinine level. Additionally, EECQ restored albuminuria, glomerular filtration rate and creatinine clearance in diabetic nephropathy rats. Furthermore, HFD consumption in rats culminated in reduced SIRT1 and enhanced DNMT1 expression, nonetheless, rescued by EECQ. Moreover, EECQ augmented the SOD 1 and 3 levels, thereby safeguarded from oxidative damage and renal inflammation. Besides, treatment protected from renal fibrosis by downregulating TGFß, Smad2/3 and col1/3 expression in diseased rats. CONCLUSIONS: Thus, based on the above findings, we conclude that EECQ shows a protective effect against diabetic nephropathy.


Asunto(s)
Cissus , Diabetes Mellitus Experimental/metabolismo , Nefropatías Diabéticas/metabolismo , Riñón/efectos de los fármacos , Extractos Vegetales/farmacología , Proteínas Represoras/metabolismo , Sirtuina 1/metabolismo , Albuminuria , Animales , Antioxidantes/metabolismo , Antioxidantes/farmacología , Creatinina/sangre , Diabetes Mellitus Experimental/tratamiento farmacológico , Diabetes Mellitus Experimental/patología , Nefropatías Diabéticas/prevención & control , Dieta Alta en Grasa , Tasa de Filtración Glomerular , Hipoglucemiantes/farmacología , Hipoglucemiantes/uso terapéutico , Inflamación , Resistencia a la Insulina , Riñón/metabolismo , Riñón/patología , Lípidos/sangre , Masculino , Estrés Oxidativo/efectos de los fármacos , Fitoterapia , Extractos Vegetales/uso terapéutico , Ratas Sprague-Dawley , Proteínas Smad Reguladas por Receptores/metabolismo , Superóxido Dismutasa/metabolismo , Factor de Crecimiento Transformador beta/metabolismo
10.
Drug Dev Res ; 82(7): 927-944, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-33988872

RESUMEN

Advancement in biotechnology provided a notable expansion of peptide and protein therapeutics, used as antigens, vaccines, hormones. It has a prodigious potential to treat a broad spectrum of diseases such as cancer, metabolic disorders, bone disorders, and so forth. Protein and peptide therapeutics are administered parenterally due to their poor bioavailability and stability, restricting their use. Hence, research focuses on the oral delivery of peptides and proteins for the ease of self-administration. In the present review, we first address the main obstacles in the oral delivery system in addition to approaches used to enhance the stability and bioavailability of peptide/protein. We describe the physiochemical parameters of the peptides and proteins influencing bioavailability in the systemic circulation. It encounters, many barriers affecting its stability, such as poor cellular membrane permeability at the GIT site, enzymatic degradation (various proteases), and first-pass hepatic metabolism. Then describe the current approaches to overcome the challenges mentioned above by the use of absorption enhancers or carriers, structural modification, formulation and advance technology.


Asunto(s)
Sistemas de Liberación de Medicamentos , Péptidos , Administración Oral , Disponibilidad Biológica , Proteínas
11.
Eur J Pharmacol ; 901: 174079, 2021 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-33812885

RESUMEN

Metabolic Syndrome is a multifactorial disease associated with increased risk of cardiovascular disorders, type 2 diabetes mellitus, fatty liver disease, etc. Various stress stimuli such as reactive oxygen species, endoplasmic reticulum stress, mitochondrial dysfunction, increased cytokines, or free fatty acids are known to aggravate progressive development of hyperglycemia and hyperlipidemia. Although the exact mechanism contributing to altered metabolism is unclear. Evidence suggests stress kinase role to be a crucial one in metabolic syndrome. Stress kinase, c-jun N-terminal kinase activation (JNK) is involved in various metabolic manifestations including obesity, insulin resistance, fatty liver disease as well as cardiometabolic disorders. It emerged as a foremost mediator in regulating metabolism in the liver, skeletal muscle, adipose tissue as well as pancreatic ß cells. It has three isoforms each having a unique and tissue-specific role in altered metabolism. Current findings based on genetic manipulation or chemical inhibition studies identified JNK isoforms to play a central role in the regulation of whole-body metabolism, suggesting it to be a novel therapeutic target. Hence, it is imperative to elucidate its role in metabolic syndrome onset and progression. The purpose of this review is to elucidate in vitro and in vivo implications of JNK signaling along with the therapeutic strategy to inhibit specific isoform. Since metabolic syndrome is an array of diseases and complex pathway, carefully examining each tissue will be important for specific treatment strategies.


Asunto(s)
Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Enfermedades Metabólicas/tratamiento farmacológico , Transducción de Señal/efectos de los fármacos , Animales , Humanos , Síndrome Metabólico/tratamiento farmacológico
12.
Heliyon ; 6(10): e05133, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-33033766

RESUMEN

In the preceding study, we delineated that high-fat diet (HFD) consumption in mice increases the circulatory level of pancreastatin (PST), which additionally enhances the free fatty acid (FFA) concentration in circulation. Consequently, the aggravated FFA activates Fetuin-A, which facilitates hepatic lipid accumulation, insulin resistance (IR), and culminates in type 2 diabetes (T2D). Metformin (Met) is a widely known first-line drug for the treatment of T2D. We previously unveiled PSTi8, an inhibitor of PST, comprising antidiabetic property. Hence, we hypothesized that combination therapy of Met and PSTi8, at reduced therapeutic doses, would mitigate HFD-induced IR by inhibiting hepatic Fetuin-A in mice model of T2D. C57BL/6 mice were fed HFD for 12 weeks, followed by treatment with Met, PSTi8, and its combination for 10 days. Glucose and insulin tolerance tests were conducted. Circulatory levels of PST, Fetuin-A, and lipid markers were determined. Also, the mRNA and protein expression of Fetuin-A was assessed by qPCR, western blotting, and immunofluorescence. Moreover, the energy expenditure was measured by comprehensive laboratory animal monitoring system (CLAMS). Combination therapy displayed improved PST, Fetuin-A, and lipid profile in plasma. We also found reduced hepatic Fetuin-A, which reduced inhibitory phosphorylation of IRS and increased phosphorylation of AKT. Consequently, ameliorated hepatic lipogenesis, gluconeogenesis, and inflammation. Also, combination treatment attenuated Fetuin-A expression, lipid accumulation, and glucose production in palmitate-induced HepG2 cells. Altogether current study promulgates the beneficial effect of combination therapy of Met and PSTi8 (comparable to alone higher therapeutic doses) to ameliorate Fetuin-A activation, hepatic lipid accumulation, insulin resistance, and associated progressive pathophysiological alterations in T2D.

13.
Eur J Pharmacol ; 881: 173204, 2020 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-32439261

RESUMEN

Pancreastatin (PST), a chromogranin A (CHGA) derived peptide connects obesity with insulin resistance by inducing inflammation. Previously, we have evaluated potential activity of PST inhibitor (PSTi8) in liver and adipose tissue in type 2 diabetic mice model. In this study we further explore the therapeutic effect of PSTi8 on glucose metabolism in skeletal muscle cells/tissue and its effect on energy homeostasis in diet induced diabetic mice model. In in-vitro studies, we found that PSTi8 increases glucose uptake via enhanced GLUT4 translocation in L6 cells. This positive effect of PSTi8 led us to proceed with in-vivo studies in diabetic mice. C57BL/6 mice were fed HFD or HFrD diet for 12 weeks along with single STZ induction at 4th week followed by PSTi8 treatment. We found that HFD and HFrD model showed increased fat mass, caused glucose intolerance and insulin resistance, with accompanying proinflammatory effect on epididymal white adipose tissue (eWAT) together leading to skeletal muscle insulin resistance. Administration of PSTi8 protects from diet induced inflammatory response and enhances glucose tolerance and insulin sensitivity. PSTi8 improves circulating adipokine and lipid parameters, along with switch in macrophage polarisation from M1 to M2 in stromal vascular fraction of adipose tissue. In addition, treatment of PSTi8 also improves energy homeostasis, decreases circulatory non-esterified fatty acids level and inhibits ceramide deposition in muscle tissue. Overall this increased muscle insulin sensitivity is mediated via AKT/AS160/GLUT4 pathway activation. Our results reveal that PSTi8 inhibits the obesity mediated inflammation which enhances glucose disposal in skeletal muscle.


Asunto(s)
Glucemia/efectos de los fármacos , Cromogranina A/antagonistas & inhibidores , Diabetes Mellitus Experimental/tratamiento farmacológico , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Hipoglucemiantes/farmacología , Resistencia a la Insulina , Músculo Esquelético/efectos de los fármacos , Obesidad/tratamiento farmacológico , Tejido Adiposo Blanco/efectos de los fármacos , Tejido Adiposo Blanco/metabolismo , Tejido Adiposo Blanco/fisiopatología , Adiposidad/efectos de los fármacos , Animales , Biomarcadores/sangre , Glucemia/metabolismo , Cromogranina A/metabolismo , Diabetes Mellitus Experimental/inducido químicamente , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/fisiopatología , Diabetes Mellitus Tipo 2/inducido químicamente , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/fisiopatología , Dieta Alta en Grasa , Metabolismo Energético/efectos de los fármacos , Proteínas Activadoras de GTPasa/metabolismo , Transportador de Glucosa de Tipo 4/metabolismo , Humanos , Mediadores de Inflamación/metabolismo , Macrófagos/efectos de los fármacos , Macrófagos/metabolismo , Masculino , Ratones Endogámicos C57BL , Músculo Esquelético/metabolismo , Músculo Esquelético/fisiopatología , Obesidad/complicaciones , Obesidad/metabolismo , Obesidad/fisiopatología , Proteínas Proto-Oncogénicas c-akt/metabolismo , Estreptozocina , Células THP-1
14.
Heliyon ; 6(12): e05826, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-33426334

RESUMEN

AIMS: Hepatic steatosis in women confronting menopause is the manifestation of substantial fructose consumption and forms a positive feedback loop to develop endoplasmic reticulum (ER) stress. Previously pancreastatin inhibitor peptide-8 (PSTi8) and Metformin (Met) combination effectively ameliorated hepatic lipid accumulation in high fructose diet (HFrD) fed diabetic mice models at reduced doses. Moreover, SIRT-1 plays a crucial role in the regulation of SREBP-1c. Hence we hypothesized that Met and PSTi8 in combination (at therapeutic lower doses) could mitigate hepatic steatosis linked ER stress by activating SIRT-1 and precluding SREBP-1c in HFrD fed 4-Vinylcyclohexenediepoxide (HVCD) induced perimenopausal rats. MAIN METHODS: HVCD rats were fed HFrD for 12 weeks, accompanied by 14 days of treatment with Met, PSTi8, and combination. We confirmed model establishment by estrus cycle study, estradiol level, and intraperitoneal glucose tolerance test. Plasma lipid profile and liver function were determined. Also, mRNA and protein expressions were examined. Moreover, distribution of SIRT-1 and SREBP-1c was detected in HepG2 cells by immunofluorescence staining. KEY FINDINGS: HVCD group displayed augmented insulin resistance (IR), lipogenesis, and ER stress in the liver. Combination therapy improved the estrus cyclicity, estradiol, and lipid profile of HVCD rats. Met and PSTi8 combination reduced hepatic SREBP-1c and triggered SIRT-1 expression in high fructose-induced insulin-resistant HepG2 cells; consequently, combination therapy attenuated ER stress. SIGNIFICANCE: Succinctly, present research promotes impetus concerning the remedial impact of Met with PSTi8 at lower therapeutic doses to ameliorate hepatic IR, steatosis, and associated ER stress by revamping the SIRT-1/SREBP-1c axis in perimenopausal rats.

15.
Eur J Pharmacol ; 864: 172723, 2019 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-31586632

RESUMEN

Pancreastatin (PST), a chromogranin A derived peptide has anti-insulin effects and plays a significant role in obesity-induced insulin resistance. In obesity and type 2 diabetes mellitus, both insulin and PST level are elevated, but it is not clearly understood how anti-insulin effect of PST get regulated in hyperinsulinemic state. Simultaneously we have explored pancreastatin inhibitor PSTi8 against the native PST in the same hyperinsulinemic state. In in-vitro studies, we found that PST treatment increases lipid droplets and reactive oxygen species production in 3T3L1 adipocyte cells and theses effects of PST was found synergistic with chronic-insulin treatment. Treatment of PSTi8 in 3T3L1 adipocytes attenuates PST effect on lipid droplet formation and reactive oxygen species production. We further validated these findings in epididymal white adipose tissue of C57BL/6 mice, implanted with mini-osmotic insulin pump with and without PSTi8 for 4 weeks. We found that chronic hyperinsulinemia enhanced PST levels in circulation which in turn induces expression of various pro-inflammatory cytokines and oxidative stress. In addition, it also stimulated the expression of lipogenic genes, fat mass and body weight gain through the regulation of circulating adiponectin level. The change in PST mediated inflammatory and lipogenic parameters were attenuated by PSTi8 treatment, leading to enhanced insulin sensitivity and improved glucose homeostasis. PSTi8 rescue from PST mediated insulin resistance in adipose via inhibition of MAPK and NOX3-JNK stress signalling pathway which stimulates GLUT4 expression through activation of AKT-AS160 pathway. Thus PSTi8 may be a novel therapeutic agent for the treatment of hyperinsulinemia induced obesity and inflammation mediated insulin resistance.


Asunto(s)
Cromogranina A/antagonistas & inhibidores , Hiperinsulinismo/complicaciones , Resistencia a la Insulina , Proteínas Quinasas JNK Activadas por Mitógenos/metabolismo , Proteínas Quinasas Activadas por Mitógenos/metabolismo , NADPH Oxidasas/metabolismo , Obesidad/tratamiento farmacológico , Células 3T3-L1 , Animales , Homeostasis/efectos de los fármacos , Inflamación/tratamiento farmacológico , Inflamación/etiología , Inflamación/patología , Lípidos/sangre , Lipogénesis/efectos de los fármacos , Masculino , Ratones , Obesidad/etiología , Obesidad/metabolismo , Obesidad/patología , Estrés Oxidativo/efectos de los fármacos , Transducción de Señal/efectos de los fármacos
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