Helium-neon laser (He-Ne Laser, 632.8 nm) is a low-energy laser that has therapeutic efficacy on various clinical conditions. Our previous study has demonstrated efficacy of He-Ne laser on vitiligo, a disease characterized by skin depigmentation. To regain skin tone on vitiligo lesions, the process began by the migration of the immature melanoblasts (MBs) to the epidermis, which was followed by their functional development to produce melanin. In this study, we investigated the physiologic effects of He-Ne laser irradiation on two MB cell lines: the immature NCCmelb4 and the more differentiated NCCmelan5. The intricate interactions between MBs with their innate extracelluar matrix, fibronectin, were also addressed. Our results showed that He-Ne laser irradiation enhanced NCCmelb4 mobility via enhanced phosphorylated focal adhesion kinase expression and promoted melanogenesis in NCCmelan5. In addition, He-Ne laser decreased the affinity between NCCmelb4 and fibronectin, whereas the attachment of NCCmelan5 to fibronectin increased. The alpha5beta1 integrin expression on NCCmelb4 cells was enhanced by He-Ne laser. In conclusion, we have demonstrated that He-Ne laser induced different physiologic changes on MBs at different maturation stages and recapitulated the early events during vitiligo repigmentation process brought upon by He-Ne laser in vitro.
In recent years, probiotics of human origin have shown superior results and performance compared to probiotics from plant or dairy sources, in both in vitro and animal studies. Towards this end, the current study was conducted to explore the ergogenic properties of Bifidobacterium longum subsp. longum OLP-01 isolated from the intestinal microbiome of the gold medalist from the 2008 Beijing Olympics women’s 48 kg weightlifting competition. Male Institute of Cancer Research (ICR) mice were divided into four groups (n = 10 per group) and orally administered OLP-01 for 4 weeks at 0 (vehicle), 2.05 × 109 (OLP-01-1X), 4.10 × 109 (OLP-01-2X), and 1.03 × 1010 (OLP-01-5X) CFU/kg/day. Physical performance tests including grip strength and endurance time were measured, with OLP-01 supplementation dose-dependently elevating grip strength and endurance. The anti-fatigue activity levels of serum lactate, ammonia, glucose, blood urea nitrogen (BUN), and creatine kinase (CK) were measured after an acute exercise challenge, and OLP-01 was found to significantly decrease lactate, ammonia, and CK levels. OLP-01 treatment was also found to significantly increase the resting levels of both hepatic and muscular glycogen, an indicator of energy storage. Supplementation by OLP-01 showed no subchronic toxic effects while supporting many health-promoting, performance-improving, and fatigue-ameliorating functions.
Although several reports have failed to observe adverse subchronic renal effects following relatively high melamine exposure, the safety of low and continuous melamine exposure is still debatable. Recent studies suggest that long-term, low-dose melamine exposure is associated with an increased risk of urolithiasis, which has been linked to chronic kidney disease (CKD). CKD is a consequence of nephron loss and is associated with the interaction of inflammation, oxidative stress, and transforming growth factor-β (TGF-β), which increases extracellular matrix genes and cell apoptosis with progression to fibrosis and end-stage renal disease. Thus far, information is still lacking regarding the influence of melamine at the gene and protein levels, which are activated at a much earlier phase than the occurrence of the renal morphological change. In this study, we stimulated human renal proximal tubular HK-2 cells with melamine (0, 125, 250, 500, or 1000 µg/ml) for different time intervals and observed its effects on several well-documented molecular mechanisms of CKD. Here, we demonstrate that melamine can activate mitogen-activated protein kinases, NFκB, and reactive oxygen species, which results in the upregulation of interleukin-6, monocyte chemoattractant protein-1, vascular cell adhesion molecule-1, and TGF-β1 in HK-2 cells. The melamine-stimulated overexpression of TGF-β1 not only promotes fibronectin production but also leads to decreased antiapoptotic (bcl-2, bcl-xl)/proapoptotic (bad, bax) protein ratio, increased caspase-3 and caspase-9 activities, and eventually HK-2 cell apoptosis. Our study suggests that melamine exposure may be a risk factor for the chronic loss of tubular cells and may ultimately lead to tubulointerstitial damage.
O-linked N-acetylglucosamine (O-GlcNAc) protein modification has been implicated in the regulation of signaling pathways, cell function, and gene expression. Glutamine:fructose-6-phosphate amidotransferase-1 (GFAT-1) is the rate-limiting enzyme in the hexosamine biosynthetic pathway (HBP), which generates the sugar nucleotide UDP-GlcNAc, where this nucleotide acts as the donor for O-GlcNAc modification. In this study, we determined whether GFAT-1 regulates adipogenesis in adipocytes. 3T3-L1 preadipocytes were differentiated using medium containing high glucose, insulin, dexamethasone, and isobutylmethylxanthine. Cells were harvested 4, 8, and 12 h and 1, 2, 3, 4, 6, and 8 days after the initiation of differentiation. Global level of O-GlcNAc modification increased 4 h after induction and persisted for 8 days of observation. GFAT-1 mRNA and protein expression was also upregulated beginning 4 h after induction. Pharmacological inhibition of GFAT-1 or GFAT-1 siRNA treatment blocked the increase in O-GlcNAcylation and the formation of lipid droplets in adipocytes. GFAT-1 may regulate the expression of C/EBPβ, PPARγ, SREBP-1, fatty acid synthase, S3-12, perilipin, or adipophilin during adipogenesis. Our results suggest that GFAT-1 plays a critical role in modulating adipogenesis via the regulation of protein O-GlcNAcylation in adipocytes.
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