Could the Propionic Acid Treatment in Combination with Metformin be Safe for the Small Intestine of Diabetic Rats?

BACKGROUND: Effects of propionic acid (PA) on the cellular and molecular processes in the small intestine under type 2 diabetes mellitus (T2DM)-induced endoplasmic reticulum (ER) stress remain incompletely studied. OBJECTIVES: The aim of the study was to assess the state of unfolded protein response (UPR) system in the small intestine of diabetic rats and to explore PA's influence on metformin treatment. METHODS: Male Wistar rats were divided into 1) control and 2) T2DM groups, and groups receiving (14 days, orally) 3) metformin (60 mg/kg), 4) PA (60 mg/kg), and 5) PA+metformin. Western blotting, RT-PCR, and transmission electron microscopy were performed. RESULTS: We found that T2DM induced elevation of ER intermembrane space and UPR overactivation based on increased GRP78, ATF6 and PERK levels in small intestine. Metformin treatment led to a further UPR activation. PA supplementation partially restored enterocytes functioning via normalization of ATF6 and PERK content, while IRE1 level reached the maximum value, compared to all groups. The most pronounced effect of adaptation to the T2DMinduced ER stress was observed after combined metformin and PA action. In particular, decreased ER intermembrane space in enterocytes was detected compared to separate metformin and PA administration, which was accompanied by restored GRP78, PERK and IRE1 levels. CONCLUSION: Our study proves the safety of additional therapy with propionic acid in combination with metformin for the functional state of small intestine. Due to its ability to modulate UPR signaling, PA may be considered a safe and perspective candidate for supportive therapy in T2DM, especially for neuroprotection.

Regulation of the apoptosis/autophagy switch by propionic acid in ventromedial hypothalamus of rats with type 2 diabetes mellitus.

Background: Hypothalamic dysregulation may cause abnormal glucose metabolism and type 2 diabetes mellitus (T2DM). The balance between autophagy and apoptosis is important for maintaining cellular/tissue homeostasis and may be disrupted in T2DM. Objectives: Since propionic acid (PA) exerts neuroprotective effects, the aim was to investigate its effects on apoptosis/autophagy switch in the ventromedial hypothalamus (VMH) of T2DM rats. Materials and methods: Male Wistar rats were divided: 1) control; 2) T2DM; groups that received (14 days, orally): 3) metformin (60 mg/kg); 4) sodium salt of PA (60 mg/kg); 5) PA + metformin. Western blotting (Bax, Bcl-xl, LC3, Beclin-1, caspase-3), RT-PCR (Bax, Bcl-xl, LC3, Beclin-1), transmission electron microscopy and immunohistochemical staining (Bax, Bcl-xl) were performed on the VMH samples. Results: T2DM-induced apoptosis and mitoptosis, enlarged endoplasmic reticulum (ER) tubules/cisterns were observed in VMH, and accompanied by an imbalance of pro- and anti-apoptotic factors: elevation of pro-apoptotic markers Bax and caspase-3, decrease in autophagy protein LC3 and anti-apoptotic Bcl-xl. Metformin and PA administration partially improved VMH ultrastructural changes by reducing mitochondrial swelling and diminishing the number of apoptotic neurons. Metformin inhibited neuronal apoptosis, however, caused reactive astrogliosis and accumulation of lipofuscin granules. Elevated number of autophagosomes was associated with the LC3, Beclin-1 and Bcl-xl increase and decrease in Bax and caspase-3 vs. T2DM. PA switched cell fate from apoptosis to autophagy by elevating LC3 and Beclin-1 levels, increasing Bcl-xl content that altogether may represent adaptive response to T2DM-induced apoptosis. PA + metformin administration lowered relative area of ER membranes/cisterns vs. control, T2DM and metformin, and was optimal considering ratio between the pro-apoptotic, anti-apoptotic and autophagy markers. Conclusion: T2DM was associated with apoptosis activation leading to impairments in VMH. PA in combination with metformin may be effective against diabetes-induced cell death by switching apoptosis to autophagy in VMH.

Plasma-derived exosomes implement miR-126-associated regulation of cytokines secretion in PBMCs of CHF patients in vitro.

Background The investigation of regulatory effects of intra-exosomal compounds, especially microRNAs, has promising therapeutic prospects in the treatment of numerous diseases, including cardiovascular disorders. In this study, we investigated the effect of healthy donors` plasma exosomes (HDPE) on the production of cytokines by PBMC cells of patients with congestive heart failure (CHF) and showed the integral role of miRNA-126 in CHF-mediated changes of mononuclear paracrine secretion. Methods Peripheral blood mononuclear cells (PBMСs) were isolated from a peripheral blood of fifteen patients with CHF (age, 66,8±9,8 years; left ventricular ejection fraction, 44±19%). The concentration of cytokines (IL-10, ICAM-1, VEGF-A, TNF-α and MCP-1) in culture medium and PBMCs was measured by ELISA. The level of miRNA-126 expression in PBMCs was performed by real-time PCR. Results Dramatic increase of ICAM-1 level in activated PBMCs of CHF patients, as well as an increase of the IL-10, ICAM-1 and TNF-α levels in the culture medium was observed. It was accompanied by CHF-related miRNA-126 overexpression in PBMCs. HDPE treatment distinguished by a tendency to reduction in miRNA-126 expression by CHF PBMCs and correlated with upregulation of IL-10, ICAM-1, TNF-α and MCP-1 with normalization of cytokines secretion. Conclusions The altered paracrine secretion of cytokines by CHF PBMCs and miRNA-126 overexpression in vitro was found. HDPE treatment modulated production and secretion of most of studied cytokines by CHF PBMCs in vitro. The experimental application of exosomes for the modulation of paracrine secretion and PBMCs cellular functions may be promising for CVD therapy, including endothelial dysfunction and CHF.

THE EFFECTIVENESS OF THERAPY BY CRYOPRESERVED HUMAN PLASMA IN PATIENTS WITH DEFICIENCY OF MANNOSE BINDING LECTIN SUFFERING FROM HERPES VIRUS INFECTION.

OBJECTIVE: The aim: To research the ef f ectiveness of cryopreserved blood plasma replacement therapy in patients with primary mannose binding lectin (MBL) def i ciency, suf f ering from chronic active herpes virus infections. PATIENTS AND METHODS: Materials and methods: Patients of the study group (SG) n= 36 additionally received cryopreserved blood plasma therapy Octaplas (Octapharma, Switzerland). Patients of the control group (CG) n=36 received only chemotherapy with Valganciclovir 450 mg 2/day per os for 1-3 months. The diagnosis of active herpes virus infection was established by PCR of blood leukocytes. Statistical analysis of the obtained information was processed by the calculation of the chi-square (χ2) Pearson criterion, the odds ratio and the associated 95% conf i dence interval (95% CI). RESULTS: Results: The adding cryopreserved blood plasma substitute to standard therapy with valganciclovir for the treatment of chronic active herpes virus infection in patients with total serum MBL def i ciency below 50 ng/ml, allowed to get more negative PCR results. The ef f ectiveness of combination therapy was 50% higher in carrier of HHV-6 (χ2=8,533 and р=0,004; Yeats correction 6,533 and signif i cance 0,011; OR=11,667 and 95% CI=1,939-70,180) and 43% in carrier of HHV-7 (χ2=8,846 and р=0,003; Yeats correction 7,165 and signif i cance 0,008; OR=6,375 and 95% CI=1,711-23,758), compared with monotherapy. The close association between def i cit MBL compensation and the results of antiviral treatment is also reported. The ef f ect of such treatment in patients with chronic EBV infection was less (27%). CONCLUSION: Conclusions: We assumed, that virostatic ef f ect of valganciclovir is increased by MBL-mediated clearance of blood serum from viral particles.