Jun Fan

XAV939, a tankyrase 1 inhibitior, promotes cell apoptosis in neuroblastoma cell lines by inhibiting Wnt/β-catenin signaling pathway

BackgroundNeuroblastoma (NB) is the most common extracranial solid tumor in childhood. The present treatment including surgery, chemotherapy and radiation, which have only 40% long-term cure rates, and usually cause tumor recurrence. Thus, looking for new effective and less toxic therapies has important significance. XAV939 is a small molecule inhibitor of tankyrase 1(TNKS1). The objective of this study is to investigate the effect of XAV939 on the proliferation and apoptosis of NB cell lines, and the related mechanism.MethodsIn the present study, we used both XAV939 treatment and RNAi method to demonstrate that TNKS1 inhibition may be a potential mechanism to cure NB. MTT method was used for determining the cell viability and the appropriate concerntration for follow-up assays. The colony formation assay, Annexin V staining and cell cycle analysis were used for detecting colony forming ability, cell apoptosis and the percentage of different cell cycle. The Western blot was used for detecting the expression of key proteins of Wnt/ beta-catenin (Wnt/β-catenin) signaling pathway.ResultsThe results showed that TNKS1 inhibition decreased the viability of SH-SY5Y, SK-N-SH and IMR-32 cells, induced apoptosis in SH-SY5Y as well as SK-N-SH cells, and led to the accumulation of NB cells in the S and G2/M phase of the cell cycle. Moreover, we demonstrated TNKS1 inhibition may in part blocked Wnt/β-catenin signaling and reduced the expression of anti-apoptosis protein. Finally, we also demonstrated that TNKS1 inhibition decreased colony formation in vitro.ConclusionsThese findings suggested that TNKS1 may be a potential molecule target for the treatment of NB.

Autologous transplantation of adipose-derived mesenchymal stem cells ameliorates streptozotocin-induced diabetic nephropathy in rats by inhibiting oxidative stress, pro-inflammatory cytokines and the p38 MAPK signaling pathway

Diabetic nephropathy is the leading cause of end-stage renal disease. The aim of this study was to investigate the renoprotective effects of autologous transplantation of adipose-derived mesenchymal stem cells (ADMSCs) and to delineate its underlying mechanisms of action in diabetic nephropathy. Diabetes was induced in adult male Sprague-Dawley rats by streptozotocin (STZ) injection. ADMSCs were administered intravenously 4 weeks after STZ injection and metabolic indices and renal structure were assessed (12 weeks). Markers of diabetes including blood glucose, cholesterol, triglycerides, urea nitrogen and creatinine were measured. Renal pathology, levels of oxidative stress and the expression of pro-inflammatory cytokines and the MAPK signaling pathway members were also determined. Autologous transplantation of ADMSCs significantly attenuated common metabolic disorder symptoms associated with diabetes. Furthermore, ADMSC administration minimized pathological alterations, reduced oxidative damage and suppressed the expression of pro-inflammatory cytokines in the renal tissues of diabetic rats. ADMSC transplantation also decreased the expression of p-p38, p-ERK and p-JNK, which are all important molecules of the MAPK signaling pathway. In conclusion, we provide experimental evidence demonstrating that autologous transplantation of ADMSCs can be used therapeutically to improve metabolic disorder and relieve renal damage induced by diabetes, and that the key mechanisms underlying the positive therapeutic impact of ADMSC treatment in kidneys could be due to the suppression of inflammatory response and oxidative stress.

3D Bioprinting Technologies for Hard Tissue and Organ Engineering

Hard tissues and organs, including the bones, teeth and cartilage, are the most extensively exploited and rapidly developed areas in regenerative medicine field. One prominent character of hard tissues and organs is that their extracellular matrices mineralize to withstand weight and pressure. Over the last two decades, a wide variety of 3D printing technologies have been adapted to hard tissue and organ engineering. These 3D printing technologies have been defined as 3D bioprinting. Especially for hard organ regeneration, a series of new theories, strategies and protocols have been proposed. Some of the technologies have been applied in medical therapies with some successes. Each of the technologies has pros and cons in hard tissue and organ engineering. In this review, we summarize the advantages and disadvantages of the historical available innovative 3D bioprinting technologies for used as special tools for hard tissue and organ engineering.

Curcumin attenuates rat thoracic aortic aneurysm formation by inhibition of the c-Jun N-terminal kinase pathway and apoptosis

OBJECTIVE Recent studies have suggested that c-Jun N-terminal kinase (JNK) plays an important role in the formation of abdominal aortic aneurysms, and that direct blockade of JNK by specific inhibitors can effectively prevent the progression of aortic aneurysms. A study has demonstrated that curcumin can suppress the development of experimental abdominal aortic aneurysms by inhibiting inflammation. We sought to investigate whether curcumin could inhibit JNK pathways and apoptosis in thoracic aortic aneurysms. METHODS We used a rat model of a CaCl₂-induced thoracic aortic aneurysm followed by daily oral gavage with curcumin 100 mg/kg or vehicle alone. After treatment for 4 wk, tissue specimens were obtained for histologic assessments, and tissue composition was evaluated using immunohistochemistry, western blotting, and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling. RESULTS Curcumin significantly suppressed the CaCl₂-induced expansion of the thoracic aortic diameter and the structural preservation of medial elastin fibers. Most importantly, curcumin treatment significantly inhibited the phosphorylation of JNK and c-Jun, accompanied by less cell apoptosis in thoracic aortic aneurysm tissues. Furthermore, the expression levels of caspase-3 and the Bax/Bcl-2 ratio were significantly decreased in the aortic walls of curcumin-treated rats. CONCLUSION The present study indicates that the beneficial effect of curcumin on degenerative aortic aneurysms is related to the inhibition of JNK and apoptosis in the walls of thoracic aortic aneurysms.

Adipose stem cells promote smooth muscle cells to secrete elastin in rat abdominal aortic aneurysm.

Background Abdominal aortic aneurysm (AAA) is a life-threatening disease and its prevalence rate increases with social aging. The degradation of elastic is an important factor in the formation of AAA. Methods Adipose derived stem cells (ADSCs) and bone marrow mesenchymal stem cells (BMSCs) were isolated from rats, and identified by Oil red O and alizarin red staining after adipogenesis and osteogenesis induction. In addition, ADSCs were also identified by flow cytometry with CD markers. AAA model in rats was established, and smooth muscle cells (SMCs) were isolated from AAA aortic wall and identified by immunohistochemistry. ADSCs or BMSCs were co-cultured with AAA aortic wall for in vitro experiment, and ADSCs were injected into AAA model for in vivo test. Then orcein staining was used for observing the morphology of elastic fiber, Western blot and real-time PCR were used respectively to detect the protein and gene expression of elastin, gelatinases spectrum analysis was used to detect the activity of matrix metalloproteinase-2 (MMP-2) and MMP-9. Results Lots of red lipid droplets were visible by Oil red O staining after adipogenesis induction, and black calcium nodules appeared by alizarin red staining after osteogenesis induction. The results of flow cytometry showed that ADSCs expressed CD44 and CD105, but exhibited negligible expression of CD31 and CD45. SMCs exhibited spindle-like morphology and α-actin protein was positive in cytoplasm. After co-cultured with ADSCs or BMSCs, the elastic fiber recovered normal winding shape, both the gene and protein expression of elastin increased, and the activity of MMP-2 decreased. The in vivo result was similar to that of in vitro. Conclusions ADSCs promote the expression of elastin in SMCs and contribute to the reconstruction of elastic fiber, which may provide new ideas for treating AAA.

Zinc Prevents Abdominal Aortic Aneurysm Formation by Induction of A20-Mediated Suppression of NF-κB Pathway

Chronic inflammation and degradation of elastin are the main processes in the development of abdominal aortic aneurysm (AAA). Recent studies show that zinc has an anti-inflammatory effect. Based on these, zinc may render effective therapy for the treatment of the AAA. Currently, we want to investigate the effects of zinc on AAA progression and its related molecular mechanism. Rat AAA models were induced by periaortic application of CaCl2. AAA rats were treated by daily intraperitoneal injection of ZnSO4 or vehicle alone. The aorta segments were collected at 4 weeks after surgery. The primary rat aortic vascular smooth muscle cells (VSMCs) were stimulated with TNF-α alone or with ZnSO4 for 3 weeks. The results showed that zinc supplementation significantly suppressed the CaCl2-induced expansion of the abdominal aortic diameter, as well as a preservation of medial elastin fibers in the aortas. Zinc supplementation also obviously attenuated infiltration of the macrophages and lymphocytes in the aortas. In addition, zinc reduced MMP-2 and MMP-9 production in the aortas. Most importantly, zinc treatment significantly induced A20 expression, along with inhibition of the NF-κB canonical signaling pathway in vitro in VSMCs and in vivo in rat AAA. This study demonstrated, for the first time, that zinc supplementation could prevent the development of rat experimental AAA by induction of A20-mediated inhibition of the NF-κB canonical signaling pathway.

MCP-1, ICAM-1 and VCAM-1 are present in early aneurysmal dilatation in experimental rats.

Recent studies have suggested that inflammation actively participates in ascending aortic aneurysm formation. The aim of the present study was to evaluate the expression changes of adhesion molecules and MMPs in an experimental model of ascending aortic aneurysm induced by ascending aorta banding in Wistar rats. Twelve rats developed aortic dilation after ascending aorta banding treatment, while nine normal animals underwent surgery without banding were used as controls. Light microscope and scanning electron microscope showed that the wall of the ascending aorta became disorganized as well as infiltration by inflammatory cells in aneurysmal rats. By using immunohistochemical techniques, a significant increase in the immunostaining of MCP-1 was observed in the aneurysmal wall as compared to the normal aortic wall. Under similar experimental conditions, we also found that the immunostaining of ICAM-1 and VCAM-1 was markedly increased in the aneurysmal wall. In addition, gelatin zymographic analysis showed that the expression and activities of MMP-2 and MMP-9 were remarkably enhanced in the ascending aorta of ascending aortic aneurysmal rats as compared to normal rats. These results demonstrate that MCP-1, ICAM-1 and VCAM-1 are involved in the pathogenesis of ascending aortic aneurysm and an increase in the immunostaining and activity of MMP-2 and MMP-9 may promote the progression of ascending aortic aneurysm.

Gelatin-Based Hydrogels for Organ 3D Bioprinting

Three-dimensional (3D) bioprinting is a family of enabling technologies that can be used to manufacture human organs with predefined hierarchical structures, material constituents and physiological functions. The main objective of these technologies is to produce high-throughput and/or customized organ substitutes (or bioartificial organs) with heterogeneous cell types or stem cells along with other biomaterials that are able to repair, replace or restore the defect/failure counterparts. Gelatin-based hydrogels, such as gelatin/fibrinogen, gelatin/hyaluronan and gelatin/alginate/fibrinogen, have unique features in organ 3D bioprinting technologies. This article is an overview of the intrinsic/extrinsic properties of the gelatin-based hydrogels in organ 3D bioprinting areas with advanced technologies, theories and principles. The state of the art of the physical/chemical crosslinking methods of the gelatin-based hydrogels being used to overcome the weak mechanical properties is highlighted. A multicellular model made from adipose-derived stem cell proliferation and differentiation in the predefined 3D constructs is emphasized. Multi-nozzle extrusion-based organ 3D bioprinting technologies have the distinguished potential to eventually manufacture implantable bioartificial organs for purposes such as customized organ restoration, high-throughput drug screening and metabolic syndrome model establishment.

XAV939 inhibits the stemness and migration of neuroblastoma cancer stem cells via repression of tankyrase 1.

Neuroblastoma (NB) is the most common extracranial solid tumor in childhood. One fundamental issue regarding NB recurrence and metastasis is the maintenance of cancer stem cells (CSCs) stemness. Tankyrase 1 (TNKS1) is overexpressed in several types of cancers and in NB cell lines. XAV939 is a small molecule inhibitor of TNKS1 and can induce apoptosis of NB cells. In this study, we showed that the surface marker CD133 method was more suitable for isolating NB CSCs than the side-population method, and 60 µM etoposide was optimal for enriching NB CSCs. The NB CSCs were demonstrated in juvenescence or stemness state by electron microscopy, which was in line with the characteristics of CSCs. Furthermore, we demonstrated that the expression of the CSCs marker CD133 and migration ability of CSCs decreased after XAV939 treatment or by RNAi‑mediated knockdown of the TNKS1 gene. These findings suggest that XAV939 treatment or RNAi-TNKS1 inhibits the stemness and migration of NB CSCs via the repression of TNKS1, and TNKS1 may be a potential molecular target for eliminating NB CSCs by small molecule drugs.

Sodium orthovanadate induces the apoptosis of SH-SY5Y cells by inhibiting PIWIL2

PIWIs have been shown to be abnormally expressed in a variety of cancers and may be important in the maintenance and invasion of cancer cells. The high expression of PIWIL2 contributed to the resistance effect of cisplatin in colon cancer cells, and the knockout of the PIWIL2 gene reduced the aggressive nature and malignant degree of colon cancer cells. Sodium orthovanadate (SOV) is a vanadium compound, and exhibited antineoplastic activity in certain types of human cancer cells, including lung, kidney and prostate cancer cells. However, its effects in human neuroblastoma (NB) cells have not yet been reported. The objective of this study was to investigate the effect of SOV on the apoptosis of NB cells and to explore how PIWIL2 is involved in the mechanism underlying this effect. In the present study, SH‑SY5Y cells were treated with SOV and the optimal concentration was determined for further assays. Cell apoptosis, cell count, viability, the cell cycle, and the expression of PIWIL2 mRNA and protein were then determined. The results showed that SOV could induce cell apoptosis, reduce the percentage of viable cells, induce accumulation of SH‑SY5Y cells at the G2/M and S phase of the cell cycle, and inhibit the expression of PIWIL2 and Bcl‑2 mRNA and protein. The results suggested that the underlying mechanisms may be, at least in part, due to SOV inhibiting the expression of PIWIL2. These findings demonstrated the effect of SOV and supported its further evaluation as a treatment for human NB.