Publications by authors named "Jianjun Geng"

Article Synopsis
  • The study investigates how exosomes and miRNAs, particularly miR-330-5p, regulate pigmentation in skin cells by examining the interactions between keratinocytes (skin cells) and melanocytes (pigment-producing cells).
  • Keratinocytes were found to secrete exosomes containing miR-330-5p, which then influenced melanocyte behavior by decreasing melanin production and the expression of the TYR gene, responsible for pigmentation.
  • The research highlights a novel mechanism of crosstalk between skin cells that may provide new insights into the regulation of skin pigmentation and potential therapeutic targets.
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In order to investigate the effects of the keratin 2 (KRT2) on alpaca melanocyte in vivo and vitro, the immunohistochemistry (IHC), quantitative real-time PCR (qPCR), Western blot, and alpaca melanocytes transfection methods were used. The results showed that mRNA and protein expression of KRT2 was highly expressed in brown skin in comparison with that in white skin. Moreover, we found that KRT2 was expressed in alpaca melanocytes in vitro by immunocytochemistry.

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The aims of the study were to establish a culture system for sheep skin melanocytes and uncover the effects of endothelin-1 on melanin synthesis in cultured melanocytes in order to provide an optimal cell system and a theoretical basis for studying the regulatory mechanism of coat color in sheep. In this study, skin punch biopsies were harvested from the dorsal region of 1-3-yr-old sheep, and skin melanocytes were then obtained by the two-step digestion using dispase II and trypsin/ethylene diamine tetraacetic acid (EDTA). The primary cultures of the melanocytes were established and characterized by dopa-staining, immunocytochemical localization of melanocyte markers, and RT-polymerase chain reaction (PCR) analysis of coat color genes.

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Hepatocyte growth factor (HGF)/c-Met signaling has been considered as a key pathway in both melanocyte development and melanogenesis. To understand better the expression patterns and tissue distribution characterization of HGF and its receptor c-Met in skin of white versus brown alpaca (Vicugna pacos), we detected the tissue distribution of HGF and c-Met using immunohistochemistry and analyzed the expression patterns by using Western blot and quantitative real time PCR (qPCR). Immunohistochemistry analysis demonstrated that HGF staining robustly increased in the dermal papilla and mesenchymal cells of white alpaca skin compared with that of brown.

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Unlabelled: AB BACKGROUND: MicroRNAs (miRNAs) are small, non-coding 21-25 nt RNA molecules that play an important role in regulating gene expression. Little is known about the expression profiles and functions of miRNAs in skin and their role in pigmentation. Alpacas have more than 22 natural coat colors, more than any other fiber producing species.

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Blood samples from 23 Huacaya alpacas, 3 males and 20 females, were used to study chromosomes and karyotypes, so as to provide some effective cytogenetic bases for the selection, improvement by crossing, disease diagnosis of alpacas, and genetic mechanisms of sex determination. Peripheral blood lymphocyte culture was used to prepare chromosome. A method of trypase-EDTA was used for G-banding.

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