Leptin (Mouse /rat) ELISA Kit

The study presents the results obtained in DNA testing of allelic polymorphism by PCR-RFLP based methods for the leptin and stearoyl-coenzyme A desaturase genes and the interaction of their complex genotypes on the milk productivity indicators of Holstein heifers of Tatarstan population. The study was carried out among 471 Holstein cow-heifers by Integrated Agricultural Production Centre "Stud farm named after Lenin" of Atninsky district of the Republic of Tatarstan in 2016-2018. All complex LEP/SCD1 genotypes were identified through the study. The maximum frequency was observed in the combination of heterozygous genotypes LEPTCSCD1TC - 149 animals (31.5 %). Milk productivity test, based on the complex genotypes LEP and SCD1, showed that a significantly high level of productivity for 305 days of lactation was 7314.4 kg, and in heifers with a complex genotype LEPTTSCD1CC was minimal (6337.4 kg) in comparison with indicators of milk yield of heifers with other complex genotypes. According to the content of the mass fraction of fat, reliably the best indicators were established in a subpopulation of animals with a complex TT/TC genotype - 3.87 %. The content of the mass fraction of protein was maximal for animals with a complex CC/CC genotype.

Leptin, the first discovered adipokine, has been connected to various physiological and pathophysiological processes, including cancerogenesis. Increasing evidence confirms its influence on prostate cancer cells. However, studies on the effects of leptin on the proliferation and apoptosis of the androgen-sensitive LNCaP line of prostate cancer cells brought conflicting results. Therefore, we performed studies on the effects of high LEP concentration (1 x 10(-6) M) on gene expression profile, change of selected signaling pathways, proliferation and apoptosis of LNCaP cells. RTCA (real-time cell analyzer) revealed inhibitory effect of LEP on cell proliferation, but lower LEP concentrations (10(-8) and 10(-10) M) did not affect cell division. Moreover, flow cytometry with a specific antibody for Cleaved PARP-1, an apoptosis marker, confirmed the activation of apoptosis in leptin-exposed LNCaP line of prostate cancer cells. Within 24 h LEP (10(-6) M) increases expression of 297 genes and decreases expression of 119 genes. Differentially expressed genes (DEGs) were subjected to functional annotation and clusterization using the DAVID bioinformatics tools. Most ontological groups are associated with proliferation and apoptosis (seven groups), immune response (six) and extracellular matrix (two). These results were confirmed by the Gene Set Enrichment Analysis (GSEA). The leptin's effect on apoptosis stimulation was also confirmed using Pathview library. These results were also confirmed by qPCR method. The results of Western Blot analysis (exposure to LEP 10 min, 1, 2, 4 and 24 h) suggest (after 24 h) decrease of p38 MAPK, p44-42 mitogen-activated protein kinase and Bcl-2 phosphorylated at threonine 56. Moreover, exposure of LNCaP cells to LEP significantly stimulates the secretion of matrix metallopeptidase 7 (MMP7). Obtained results suggest activation of apoptotic processes in LNCaP cells cultured at high LEP concentration. At the same time, this activation is accompanied by inhibition of proliferation of the tested cells.