Wound-induced hair follicle neogenesis: a new perspective on hair follicles regeneration in adult mammals / 中国修复重建外科杂志

Objective: To explore the research progress of the cell sources and related signaling pathways of the wound-induced hair follicle neogenesis (WIHN) in recent years. Methods: The literature related to WIHN in recent years was reviewed, and the cell sources and molecular mechanism were summarized and discussed. Results: Current research shows that WIHN is a rare regeneration phenomenon in the skin of adult mammals, with multiple cell origins, both hair follicle stem cells and epithelial stem cells around the wound. Its molecular mechanism is complicated, which is regulated by many signaling pathways. Besides, the process is closely related to the immune response, the immunocytes and their related cytokines provide suitable conditions for this process. Conclusion: There are still many unsolved problems on the cellular origins and molecular mechanisms of the WIHN. Further study on the mechanisms will enhance the understanding of adult mammals' hair follicle regeneration and may provide new strategy for functional healing of the human skin.

The Pancreatic Tissue Regeneration and Molecular Regulators / 대한해부학회지

Pancreas is a unique organ that produces and secretes digestive enzymes to alimentary tube and supplies endocrine hormones regulating metabolic homeostasis. In the postnatal stage, pancreatic tissue is maintained by a simple proliferation of the preexisting cells. It has been known that tissue regeneration rarely occurs in the normal adult pancreas, particularly in the human pancreas. However regeneration of pancreatic tissue can be induced experimentally following pancreatic injuries in animal models. Regeneration occurs at the site of tissue injury by forming new lobules, so called 'neogenic lobule', that consist of the immature pancreatic tissues of both exocrine and endocrine components. We postulate that regeneration is instigated from the small tubular structures with elongated epithelial cells (neogenic ductules) which grow to ducts and acini for exocrine neogenesis, as well as to islet cells for endocrine tissue formation. As a sequential process of neogenic regeneration, the regenerating tissue becomes heterogeneous in tissue composition. Neogenic lobules in earlier regenerating stage were mainly composed of neogenic ductules which are substituted with developing acini in later stages. The endocrine cells, including insulin secreting beta cells, are also derived from the stem/precursor cells in neogenic ductules. After budding off from the neogenic ductules, the primitive endocrine cells continue to proliferate and differentiate, forming a large cell cluster or primitive islet. Such neogenic regeneration differs, but not completely, from pancreas development during fetal organogenesis. We found that the pancreatic regeneration is regulated by the several biological factors including nestin, clusterin and INGAP which are not involved in embryonic pancreas development. We suggest that the stem/precursor cells are recapitulated and regenerated to functional cells, and stem cell-derived pancreatic regeneration could provide a source of the pancreatic cells, particularly insulin secreting beta cells for cell replacement therapy of diabetes.

Cloning and expression of islet neogenesis associated protein in Pichia yeast / 中华胰腺病杂志

Objective To clone the human Islet neogenesis associated protein(rhINGAP)gene,express the gene extraeellulary in Pichia yeast for.further study on biological function and animal test on INGAP.Methods INGAP gene Was amplified with PCR and inserted into the recombinant plasmidα/pUC18.Then,the fusion gene of α and INGAP was digested and inserted into the expression plasmid pPIC9K.The positive recombinant plasmid which integrated INGAP Was confirmed by restriction enzyme digestion and sequencing,and it Was linearized with Sal Ⅰ digestion and transfered into the yeast host strain GS115 through electroporation.The yeast transformants that harbor the desired gene INGAP with high copy were selected by the auxotroph mediam G418,and verified by PCR.The condition of hake-flask culture was optimized,and the recombinant human INGAP Was induced expression with methanol as the only Carbone source.The antigen activity of the desired protein Was detected by Western blotting and ELISA method.Results Recombinant plasmid αINGAP/pPIC9K were successfully constructed and three positive Pichia yeast transformants were obtained.The expressed protein had satisfactory antigen activity,which Was confirmed by the Western blotting and ELISA method.Conclusions Pichia yeast expressing human Islet neogenesis associated protein (rhINGAP)gene was successfully constructed.

Effects of Yiqi Huoxue Huayu Chinese medicine on expression of bFGF and neogenesis of blood vessels in BPH rats / 中华中医药杂志

Objective:To study the effects of Yiqi Huoxue Huayu Chinese medicine on neogenesis of blood vessels and basic fibroblast growth factor(bFGF)expression in benign prostatic hyperplasia(BPH)rats.Methods:7 days after being castrated,fifty SD rats were injected with testosterone(5 mg?kg-1?d-1),the decoction of Yiqi Huoxue Huayu and Zerguilongshuang were orally administrated respectively,after 30 days'treatment,the rats were sacrificed,the prostate volume were measured,and the prostate index(PI)were analyzed,the micro-vessels density(MVD)and level of bFGF were measured.Results:The prostate volume and index of rats in model group was obviously higher than those in normal group(P

Stem Cell In Adult Pancreas: Its Activation and Induction of Beta Cell Differentiation / 대한해부학회지

Stem cells in adult pancreas and their specific marker are poorly characterized. We hypothesized that pancreatic stem cells could evolve from the duct system in response to neogenic stimulation. Following partial pancreatectomy (Px), we found extensive formation of ductules consisting of nestin-positive epithelial cells with higher replicating ability in the neogenic foci after Px. The neogenic ductules were isolated for the culture of nestin-positive duct cells. These nestinpositive duct cells were numerous and displayed extensive self-replication in the duct cell explants, thus depicted as nestin-positive duct stem (NPDS) cells. Endocrine cells, mostly insulin cells were present in the explants at day 2 as single cells or as small clusters adjacent to the NPDS cells, and formed islet-like masses at day 3 of culture, implying islet cell differentiation from NPDS cells. We found transient up-regulation of PDX-1 expression by RT-PCR at day 3 after Px in pancreatic tissue. We investigated the effect of clusterin overexpression on differentiation of insulin beta cells from duct cells We found that the number of insulin producing cells increased 11.5 fold when clusterin was overexpressed. Insulin expression, both insulin mRNA and peptide levels, was increased in clusterin cDNA transfected cells. In conclusion, we suggest that NPDS cells could be generated from adult pancreas by neogenic motivations and they may differentiate into insulin-secreting-cells, and clusterin could stimulate not only differentiation of precursor cells in the pancreatic duct, but also proliferation of predifferentiated beta cells. Those differentiated beta cells are functional cells secreting insulin in response to glucose stimulation.

A Verification of Neogenesis of Vascular Cells by BrdU Immunohistochemistry During Callotasis of the Tibiae in Sprague-Dawley Rats

The callotasis is widely used in lengthening of bones without bone graft. We thought that the accompanying vessels is critical in the viability of distal tissue to the lengthened area and has an important effect on the bone-lenthening itself. So we made an assumption that the accompanying vessels is adapted to the lengthening via neogenesis more than simple physical stretching. At this, we placed a pair of small external fixator in the left tibiae of ten Spraugue-Dawley rats and made an osteotomies. At two weeks after 25% lengthening, vessels of both lengthened and unlengthened side was harvested and five sections from each vessels were stained with BrdU immunohistochemical staining. We investigated the DNA synthesis counting the number of BrdU labeled cells. The number of BrdU labeled cells is significantly increased in the lenthened side arteries(p<0.0001). The synthesis of DNA was significantly increased in the center rather than the ends (p<0.0001). And there was no difference between the number of the BrdU labeled cells of proximal part and that of distal parts(p=0.316). It means that the accompanying vessles in the distraction-lengthening are adapted to the lengthening not only by just physical stretching but also by neogenesis of vascular cells.

Stimualtion of Beta Cell Neogenesis by SBTI (Soybean Trypsin Inhibitor) or Soybean Diet in the Subtotal Pancreatectomy Models / 대한해부학회지

The present study was performed to corroborate our hypothesis that soybean diet or SBTI treatment could stimulate neogenic regeneration of pancreatic beta cells, but also increase insulin synthesis and secretion from the beta cells for correction of hyperglycemia and diabetic symptoms. We, thus, monitored the beta cell regeneration in the neogenic pancreas as well as the changes of the blood glucose and insulin levels after subtotal pancreatectomy. The diabetic animals with hyperglycemia induced by the subtotal pancreatectomy showed recovery of blood glucose level toward the normal range (<150 mg/dl) by giving raw soybean for 3~4 weeks. Most animals treated with SBTI remained in euglycemic condition in spite of diabetic induction by subtotal pancreatectomy. Their serum insulin level was also recovered to the level of normal control, indicating the increased insulin synthesis and secretion from the neogenic beta cells. Neogenic area was enlarged at least 2 times in the pancreatectomized rats with dietary soybean or SBTI treatment, when compared with their pancreatectomized controls without any dietary treatment. In neogenic tissue, few endocrine cells were detected as a single cell or cell cluster at 3 days, and they formed primitive islet at 7 days after pancreatectomy in non-treated controls. The numbers of beta cells as well as alpha cells were considerably increased in the SBTI treated rats, and early formation of primitive islets were found in the neogenic tissue of those animals at 3 days after pancreatectomy. Those beta cells demonstrated a strong immunoreactivity for insulin, indicating their bioactive insulin secretion. Clusterin, a marker protein for pancreatic neogenesis, was expressed in the wider pancreatic area and at earlier stage after pancreatectomy when compared with non-treated control rats, indicating acceleration and stimulation of neogenesis of pancreas by stimulating proliferation and differentiation of the functional pancreatic cells. Taken together, we concluded that dietary soybean and SBTI could stimulate beta cell neogenesis and induce activation of insulin synthesis and secretion from the neogenic beta cells for correction of glucose homeostasis in diabetic subjects.

Islet β-cell mass and clinical progression of diabetes mellitus / 中华内分泌代谢杂志

Normally, pancreatic islet?-cell mass is regulated by?-cell replication, neogenesis, apoptosis and cell size.?-cell mass in diabetic patients is conspicuously less than that in normal persons. Decline of?-cell mass is mainly caused by increased?-cell apoptosis. The change of?-cell mass is clinically becoming more and more important in regard to the progression of diabetes mellitus.