Three-dimensional printing has come into the spotlight in the realm of tissue engineering. We intended to evaluate the plausibility of 3D-printed (3DP) scaffold coated with mesenchymal stem cells (MSCs) seeded in fibrin for the repair of partial tracheal defects. MSCs from rabbit bone marrow were expanded and cultured. A halfpipe-shaped 3DP polycaprolactone scaffold was coated with the MSCs seeded in fibrin. The half-pipe tracheal graft was implanted on a 10 × 10-mm artificial tracheal defect in four rabbits. Four and eight weeks after the operation, the reconstructed sites were evaluated bronchoscopically, radiologically, histologically, and functionally. None of the four rabbits showed any sign of respiratory distress. Endoscopic examination and computed tomography showed successful reconstruction of trachea without any collapse or blockage. The replaced tracheas were completely covered with regenerated respiratory mucosa. Histologic analysis showed that the implanted 3DP tracheal grafts were successfully integrated with the adjacent trachea without disruption or granulation tissue formation. Neocartilage formation inside the implanted graft was sufficient to maintain the patency of the reconstructed trachea. Scanning electron microscope examination confirmed the regeneration of the cilia, and beating frequency of regenerated cilia was not different from those of the normal adjacent mucosa. The shape and function of reconstructed trachea using 3DP scaffold coated with MSCs seeded in fibrin were restored successfully without any graft rejection.
Osteogenesis Imperfecta (OI) is a human syndrome characterized by exquisitely fragile bones due to osteoporosis. The majority of autosomal dominant OI cases result from point or splice site mutations in the type I collagen genes, which are thought to lead to aberrant osteoid within developing bones. OI also occurs in humans with homozygous mutations in Prolyl-3-Hydroxylase-1 (LEPRE1). Although P3H1 is known to hydroxylate a single residue (pro-986) in type I collagen chains, it is unclear how this modification acts to facilitate collagen fibril formation. P3H1 exists in a complex with CRTAP and the peptidyl-prolyl isomerase cyclophilin B (CypB), encoded by the Ppib gene. Mutations in CRTAP cause OI in mice and humans, through an unknown mechanism, while the role of CypB in this complex has been a complete mystery. To study the role of mammalian CypB, we generated mice lacking this protein. Early in life, Ppib-/- mice developed kyphosis and severe osteoporosis. Collagen fibrils in Ppib-/- mice had abnormal morphology, further consistent with an OI phenotype. In vitro studies revealed that in CypB–deficient fibroblasts, procollagen did not localize properly to the golgi. We found that levels of P3H1 were substantially reduced in Ppib-/- cells, while CRTAP was unaffected by loss of CypB. Conversely, knockdown of either P3H1 or CRTAP did not affect cellular levels of CypB, but prevented its interaction with collagen in vitro. Furthermore, knockdown of CRTAP also caused depletion of cellular P3H1. Consistent with these changes, post translational prolyl-3-hydroxylation of type I collagen by P3H1 was essentially absent in CypB–deficient cells and tissues from CypB–knockout mice. These data provide significant new mechanistic insight into the pathophysiology of OI and reveal how the members of the P3H1/CRTAP/CypB complex interact to direct proper formation of collagen and bone.
Gallic acid [3,4,5-trihydroxybenzoic acid (GA)], a natural phytochemical, is known to have a variety of cellular functions including beneficial effects on metabolic syndromes. However, the molecular mechanism by which GA exerts its beneficial effects is not known. Here we report that GA plays its role through the activation of AMP-activated protein kinase (AMPK) and by regulating mitochondrial function via the activation of peroxisome proliferator-activated receptor-γ coactivator1α (PGC1α). Sirtuin 1 (Sirt1) knockdown significantly blunted GA's effect on PGC1α activation and downstream genes, suggesting a critical role of the AMPK/Sirt1/PGC1α pathway in GA's action. Moreover, diet-induced obese mice treated with GA showed significantly improved glucose and insulin homeostasis. In addition, the administration of GA protected diet-induced body weight gain without a change in food intake. Biochemical analyses revealed a marked activation of AMPK in the liver, muscle, and interscapular brown adipose tissue of the GA-treated mice. Moreover, uncoupling protein 1 together with other genes related to energy expenditure was significantly elevated in the interscapular brown adipose tissue. Taken together, these results indicate that GA plays its beneficial metabolic roles by activating the AMPK/Sirt1/PGC1α pathway and by changing the interscapular brown adipose tissue genes related to thermogenesis. Our study points out that targeting the activation of the AMPK/Sirt1/PGC1α pathway by GA or its derivatives might be a potential therapeutic intervention for insulin resistance in metabolic diseases.
Combined aerobic and anaerobic exercise training during dialysis was found to be effective on physical health status, intradialytic hypotension, and depression in terms of mental health. Therefore, the findings of the current study may provide an appropriate guidance for encouraging exercise by nephrologists.
Glioblastoma multiforme (GBM) is an aggressive, treatment-refractory type of brain tumor for which effective therapeutic targets remain important to identify. Here we report that cyclophilin B (CypB), a prolyl isomerase residing in the endoplasmic reticulum (ER), provides an essential survival signal in GBM cells. Analysis of gene expression databases revealed that CypB is upregulated in many cases of malignant glioma. We found that suppression of CypB reduced cell proliferation and survival in human GBM cells in vitro and in vivo. We also found that treatment with small molecule inhibitors of cyclophilins, including the approved drug cyclosporine, greatly reduced the viability of GBM cells. Mechanistically, depletion or pharmacologic inhibition of CypB caused hyperactivation of the oncogenic RAS-MAPK pathway, induction of cellular senescence signals, and death resulting from loss of MYC, mutant p53, Chk1 and JAK/STAT3 signaling. Elevated reactive oxygen species, ER expansion and abnormal unfolded protein responses in CypB-depleted GBM cells indicated that CypB alleviates oxidative and ER stresses and coordinates stress adaptation responses. Enhanced cell survival and sustained expression of multiple oncogenic proteins downstream of CypB may thus contribute to the poor outcome of GBM tumors. Our findings link chaperone-mediated protein folding in the ER to mechanisms underlying oncogenic transformation, and they make CypB an attractive and immediately targetable molecule for GBM therapy.
Advances in physics and biology have made it possible to apply non-thermal atmospheric pressure plasma (NTP) in the biomedical field. Although accumulating evidence suggests that NTP has various medicinal effects, such as facilitating skin wound healing on exposed tissue while minimizing undesirable tissue damage, the underlying molecular mechanisms are not fully understood. In this study, NTP generated from N optimized wound healing in the scratch wound healing assay. In addition, matrix metalloproteinase (MMP)-9 expression and enzyme activity increased and the urokinase-type plasminogen activator (uPA) system was activated after NTP treatment. We also showed that NTP treatment increased Slug and TCF8/ZEB1 expression and decreased that of E-cadherin, suggesting induction of the epithelial-to-mesenchymal transition (EMT). The effect of N NTP was verified on rat wound model. Taken together, these results suggest that N NTP promotes wound healing by inducing the EMT and activating the MMP-9/uPA system. These findings show the therapeutic potential of NTP for skin wound healing.
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