Effects of rumen-protected betaine supplementation on meat quality and the composition of fatty and amino acids in growing lambs.

Rumen-protected betaine (RPB) can enhance betaine absorption in the small intestine of ruminants, while betaine can alter fat distribution and has the potential to affect the meat quality of livestock. Hence, we hypothesized that RPB might also affect the meat quality of lambs. Sixty male Hu sheep of similar weight (30.47 ± 2.04 kg) were selected and randomly subjected to five different treatments. The sheep were fed a control diet (control treatment, CTL); 1.1 g/day unprotected-betaine supplemented diet (UPB); or doses of 1.1 g/day (low RPB treatment; L-PB), 2.2 g/day (middle RPB treatment; M-PB) or 3.3 g/day (high RPB treatment; H-PB) RPB-supplemented diet for 70 days. Slaughter performance, meat quality, fatty acid and amino acid content in the longissimus dorsi (LD) muscle, shoulder muscle (SM) and gluteus muscle (GM) were measured. Compared with CTL, betaine (including UPB and RPB) supplementation increased the average daily weight gain (ADG) (P < 0.05) and average daily feed intake (P < 0.01) of lambs. Rumen-protected betaine increased ADG (P < 0.05) compared with UPB. With increasing RPB doses, the eye muscle area of the lambs linearly increased (P < 0.05). Compared with CTL, betaine supplementation decreased water loss (P < 0.05) in SM and increased pH24 in the SM (P < 0.05) and GM (P < 0.05). Compared with UPB, RPB decreased water loss in the GM (P < 0.01), decreased shear force (P < 0.05) in the LD and SM and increased the pH of the meat 24 h after slaughter (pH24). With increasing RPB doses, the shear force and b* value in the LD linearly decreased (P < 0.05), and the pH24 of the meat quadratically increased (P < 0.05). Compared with CTL, betaine supplementation increased the polyunsaturated fatty acid in the GM (P < 0.05). Compared with UPB, RPB supplementation decreased the saturated fatty acid (SFA) content in the LD (P < 0.05) and increased the unsaturated fatty acids (UFA), mono-unsaturated fatty acids and UFA/SFA ratio in the LD (P < 0.05). Compared with CTL, the content of histidine in the LD increased with betaine supplementation. Compared with UPB, RPB supplementation increased the content of total free amino acids and flavor amino acids in the LD of lambs (P < 0.05). With increasing RPB, the isoleucine and phenylalanine contents in the LD linearly increased (P < 0.05). Overall, the data collected indicated that the meat quality of lambs (especially in the LD) improved as a result of betaine supplementation, and RPB showed better effects than those of UPB.

HOTAIR promotes myocardial fibrosis through regulating URI1 expression via Wnt pathway.

OBJECTIVE: To investigate whether HOX transcript antisense RNA (HOTAIR) regulates myocardial fibrosis via promoting proliferation of cardiac fibroblasts (CFs) and upregulating the expression levels of fibrotic proteins through activating Wnt signaling pathway. MATERIALS AND METHODS: The expression level of HOTAIR in Ang II-induced cardiac fibroblasts was detected by quantitative Real-time-polymerase chain reaction (qRT-PCR). Overexpression or knockdown of HOTAIR expression was achieved by lentivirus transfection. The effects of HOTAIR on regulating cell proliferation, migration and apoptosis were measured by cell counting kit-8 (CCK-8) test, transwell assay and flow cytometry, respectively. Western blot and qRT-PCR experiments were performed to detect expressions of fibrosis-related genes and Wnt pathway-related genes. Target gene of HOTAIR was predicted by bioinformatics analysis. Rescue assays were conducted to assess whether HOTAIR could regulate cell proliferation and fibrosis by activating Wnt signaling pathway via URI1. RESULTS: QRT-PCR results showed that HOTAIR expression in Ang II-induced CF cells was significantly higher than that in control. HOTAIR overexpression in CF cells can promote cell proliferation and migration, inhibit apoptosis, and promote the expressions of fibrosis-related genes. Western blot results indicated that HOTAIR could upregulate URI1 expression and activate Wnt signaling pathway. In addition, rescue assay demonstrated that overexpression of URI1 reversed the inhibitory effect of HOTAIR knockdown on Wnt pathway. CONCLUSIONS: Highly expressed HOTAIR promoted proliferation and migration of cardiac fibroblasts. HOTAIR remarkably upregulated fibrosis-related genes in CF cells. The mechanism of HOTAIR in regulating myocardial fibrosis might be related to the activation of Wnt signaling pathway through targeting URI1 expression.

Study of Hgp44 from Porphyromonas gingivalis on inducing HUVECs to secrete IL-6 and IL-8.

The aim of this study was to clone, express the gene of Hgp44 in adhesin domains of gingipains from Porphyromonas gingivalis and purify the protein. Furthermore, the effect of Hgp44 from P. gingivalis on inducing HUVECs to secrete IL-6 and IL-8 was evaluated. The Hgp44 gene fragment was amplified by polymerase chain reaction, and then inserted into the cloning vector pMD18-T and linked with a prokaryotic expression vector pET22b to construct the recombinant expression plasmid pET22b-Hgp44. Fusion protein expression was induced by IPTG, and it was purified by immobilized metal-chelating affinity chromatography (IMAC) using an Ni(2+) matrix column. HUVECs were cultured in vitro and different concentrations of Hgp44 were added to confluent HUVEC monolayers and incubated for 2, 8 and 24 h. We extracted the supernatants and then used ELISA kits to test the changes in IL-6 and IL-8 levels. Finally, a 1100-bp fragment was successfully amplified, and the expression of the fusion protein was examined by SDS-PAGE and Western blot analysis, and the data showed that the protein was 44 kDa in size and expressed mostly in the form of inclusion bodies. The purification of the fusion protein was achieved using Ni(2+) affinity chromatography. About 3.5 mg/L fusion protein was obtained. Hgp44 could induce HUVECs to secrete IL-6 and IL-8 levels, which were remarkably increased. In a word, Hgp44 was successfully expressed in a prokaryotic expression system and purified by IMAC using the Ni(2+) matrix column. The effect of Hgp44 in inducing HUVECs to secrete IL-6 and IL-8 was demonstrated.