Ononitol monohydrate enhances PRDM16 & UCP-1 expression, mitochondrial biogenesis and insulin sensitivity via STAT6 and LTB4R in maturing adipocytes
BIOMEDICINE & PHARMACOTHERAPY
Authors: Subash-Babu, P.; Alshatwi, Ali A.
Abstract
Ononitol monohydrate (OMH), a glycoside was originally isolated from Cassia tora (Linn.). Glycosides regulate lipid metabolism but scientific validation desired. Hence, we aimed to evaluate the effect of OMH on enhancing mitochondrial potential, mitochondrial biogenesis, upregulate the expression of brown adipogenesis specific genes in maturing adipocytes. In addition, we observed the inter-relation between adipocyte and T-lymphocyte; whether, OMH treated adipocyte-condition medium stimulate T-cell chemokine linked with insulin resistance. In a dose dependent manner OMH treated to preadipocyte significantly inhibited maturation and enhanced mitochondrial biogenesis, it was confirmed by Oil red 'O and Nile red stain without inducing cytotoxicity. The mRNA levels of adipocyte browning related genes such as, PR domain containing 16 (PRDM16), peroxisome proliferator activated receptor gamma coactivator 1 alpha (PPAR gamma C1 alpha) and uncoupling protein-1 (UCP-1) have been significantly upregulated. In addition, adipogenic transcription factors [such as proliferator activated receptor gamma (PPAR gamma), CCAAT/enhancer binding protein (C/EBP alpha) and sterol regulatory element binding protein-1c (SREBP-1c)] and adipogenic genes were significantly down-regulated by treatment with OMH when compared to control cells. Protein expression levels of adiponectin have been increased; leptin, C/EBP alpha and leukotriene B4 receptor (LTB4R) were down regulated by OMH in mature adipocytes. In addition, adipocyte condition medium and OMH treated T-lymphocyte, significantly increased insulin signaling pathway related mRNAs, such as interlukin-4 (IL-4), signal transducer and activator of transcription 6 (STAT(6)) and decreased leukotriene B4 (LTB4). The present findings suggest that OMH increased browning factors in differentiating and maturing preadipocyte also decreased adipose tissue inflammation as well as the enhanced insulin signaling.
Leukotriene Pathway Activation Associates with Poor Glycemic Control and with Cardiovascular Autonomic Neuropathy in Type 1 Diabetes
MEDIATORS OF INFLAMMATION
Authors: Santos-Bezerra, Daniele P.; Filgueiras, Luciano R.; Monteiro, Maria Beatriz; Admoni, Sharon N.; Perez, Ricardo, V; Cavaleiro, Ana M.; Machado, Cleide G.; Machado, Ubiratan F.; Passarelli, Marisa; Jancar, Sonia; Correa-Giannella, Maria Lucia
Abstract
Background and Aims. Since hyperglycemia promotes inflammation by different pathways and inflammation participates in the development of chronic diabetes complications, we investigated the association between the leukotriene (LT) pathway and microvascular diabetes complications. Methods and Results. Quantitative polymerase chain reaction was employed to quantify the expression of ALOX5 (encodes 5-lipoxygenase), LTB4R (encodes one of the LTB4 receptors), and MYD88 in peripheral blood mononuclear cells from 164 type 1 diabetes (T1D) individuals presenting or not diabetes kidney disease, retinopathy, peripheral neuropathy, and cardiovascular autonomic neuropathy (CAN); 26 nondiabetic subjects were included as controls. LTB4 plasmatic concentrations were also evaluated. The expression of LTB4R was significantly higher in T1D individuals than in controls. T1D individuals with microvascular complications presented lower MYD88 mRNA expression when compared to those without microvascular complications. Higher LTB4 concentrations were found in individuals with CAN versus without CAN. The observation of two distinct subgroups of T1D individuals in the correlation analyses motivated us to evaluate the characteristics of each one of these groups separately. The group presenting higher expression of ALOX5 and of LTB4R also presented higher values of HbA(1)C, of fructosamine, and of plasmatic LTB4. Conclusion. In the diabetes setting, the LT pathway is not only activated by hyperglycemia but is also modulated by the status of the autonomic nervous system.