Biomechanics of a novel artificial cervical vertebra from an in vivo caprine cervical spine non-fusion model.

Objective: Anterior cervical corpectomy and fusion (ACCF) has been widely used in the treatment of cervical spondylotic myelopathy (CSM) but is accompanied by unavoidable motion loss and destruction of vertebra. We aim to evaluate the range of motion (ROM) of caprine cervical spine constructs implanted with cervical artificial disc and vertebra system (ADVS). The purpose of this study was to investigate the biomechanical properties of the ADVS from an in vivo caprine cervical spine non-fusion model. Methods: Twelve goats were randomly divided into ADVS or control group, with 6 animals in each group. The animals in the ADVS group were implanted with ADVS at the C4 level. The cervical spine constructs were harvested 6 months after the operation. The ROM of cervical spine specimens in the ADVS group was recorded. Biomechanical testing of the specimens in the control group were conducted to evaluate the ROM of the cervical spine specimens under intact and fixed condition (C3-C5) by an anterior plate, respectively. Results: The biomechanical outcomes showed that the ROM of the levels (C3-C5) implanted with ADVS was maintained. The ROM in the adjacent level (C2-3) did not increase significantly comparing with intact group. Conclusions: In general, ADVS could preserve the ROM of operative levels and could reconstruct the height of the vertebra. ADVS did not increase the ROM of upper adjacent level. This device provides a non-fusion method for the treatment of patients suffering from CSM. However, improvements on the design of ADVS are still needed. Translational potential statement: This study introduced a novel cervical spinal implant, which was designed to have the ability of motion preservation and vertebra construction. Our study provided a non-fusion procedure in the treatment of CSM after ACCF.

Ellagic Acid Alleviates Rheumatoid Arthritis in Rats through Inhibiting MTA1/HDAC1-Mediated Nur77 Deacetylation.

Ellagic acid (EA) was reported to play protective roles in rheumatoid arthritis (RA). It was found that the level of metastasis-associated gene 1 (MTA1)/histone deacetylase 1 (HDAC1) protein complex was downregulated by polyphenols in several human disorders. Notably, inhibition of MTA1 or HDAC1 has anti-inflammatory effects on RA. Therefore, our study is aimed at investigating whether EA prevents RA progression through regulating the MTA1/HDAC1 complex. Herein, the human fibroblast-like synoviocyte (FLS) cell line MH7A was treated with TNF-α to induce an inflammation model in vitro and then incubated with different concentrations of EA. Western blot analysis showed that EA reduced MTA1 expression in a dose-dependent manner in MH7A cells. Then, TNF-α-treated MH7A cells were incubated with EA alone or together with MTA1 overexpression plasmid (pcDNA-MTA1), and we found that EA inhibited proliferation, inflammation cytokine levels, and oxidative stress marker protein levels and promoted apoptosis in MH7A cells, while MTA1 overexpression abolished these effects. Moreover, coimmunoprecipitation assay verified the interaction between MTA1 and HDAC1. EA downregulated the MTA1/HDAC1 complex in MH7A cells. MTA1 knockdown inhibited proliferation, inflammation, and oxidative stress and promoted apoptosis in MH7A cells, while HDAC1 overexpression reversed these effects. Moreover, chromatin immunoprecipitation assay indicated that EA inhibited HDAC1-mediated Nur77 deacetylation. Rescue experiments demonstrated that Nur77 knockdown reversed the effects of EA on MH7A cell biological behaviors. Additionally, EA treatment attenuated arthritis index, paw swelling, synovial hyperplasia, and inflammation in collagen-induced arthritis (CIA) rats. In conclusion, EA inhibited proliferation, inflammation, and oxidative stress and promoted apoptosis in MH7A cells and alleviated the severity of RA in CIA rats though downregulating MTA1/HDAC1 complex and promoting HDAC1 deacetylation-mediated Nur77 expression.

Knockdown of TRIM8 Attenuates IL-1ß-induced Inflammatory Response in Osteoarthritis Chondrocytes Through the Inactivation of NF-κB Pathway.

Osteoarthritis (OA) is a degenerative joint disease associated with inflammatory response. Tripartite motif 8 (TRIM8) is a member of TRIM family that has been found to regulate inflammation. The present study was aimed to evaluate the role of TRIM8 in OA chondrocytes. Our results showed that TRIM8 expression was significantly increased in interleukin 1 beta (IL-1ß)-stimulated OA chondrocytes. To knock down the TRIM8 expression in chondrocytes, the chondrocytes were transfected with si-TRIM8. Knockdown of TRIM8 attenuated IL-1ß-induced production of inflammatory mediators including nitric oxide and prostaglandin E2. The increased expression levels of inducible nitric oxide synthase and cyclooxygenase-2 in IL-1ß-induced chondrocytes were suppressed by TRIM8 knockdown. The IL-1ß-induced production of proinflammatory cytokines including TNF-α and IL-6 was significantly decreased after transfection with si-TRIM8. Besides, knockdown of TRIM8 mitigated the IL-1ß-induced decrease in aggrecan and collagen-II proteins expression and increase in matrix-degrading enzymes in chondrocytes. Furthermore, TRIM8 knockdown prevented IL-1ß-induced nuclear factor kappa B (NF-κB) activation in chondrocytes. Taken together, these findings indicated that knockdown of TRIM8 attenuates IL-1ß-induced inflammatory response in OA chondrocytes through the inactivation of NF-κB pathway. Thus, targeting TRIM8 might provide therapeutic treatment for OA.

A new scaffold containing small intestinal submucosa and mesenchymal stem cells improves pancreatic islet function and survival in vitro and in vivo.

It is unknown whether a scaffold containing both small intestinal submucosa (SIS) and mesenchymal stem cells (MSCs) for transplantation may improve pancreatic islet function and survival. In this study, we examined the effects of a SIS-MSC scaffold on islet function and survival in vitro and in vivo. MSCs and pancreatic islets were isolated from Sprague-Dawley rats, and SIS was isolated from Bamei pigs. The islets were apportioned among 3 experimental groups as follows: SIS-islets, SIS-MSC-islets and control-islets. In vitro, islet function was measured by a glucose-stimulated insulin secretion test; cytokines in cultured supernatants were assessed by enzyme-linked immunosorbent assay; and gene expression was analyzed by reverse transcription-quantitative PCR. In vivo, islet transplantation was performed in rats, and graft function and survival were monitored by measuring the blood glucose levels. In vitro, the SIS-MSC scaffold was associated with improved islet viability and enhanced insulin secretion compared with the controls, as well as with the increased the expression of insulin 1 (Ins1), pancreatic and duodenal homeobox 1 (Pdx1), platelet endothelial cell adhesion molecule 1 [Pecam1; also known as cluster of differentiation 31 (CD31)] and vascular endothelial growth factor A (Vegfa) in the islets, increased growth factor secretion, and decreased tumor necrosis factor (TNF) secretion. In vivo, the SIS-MSC scaffold was associated with improved islet function and graft survival compared with the SIS and control groups. On the whole, our findings demonstrate that the SIS-MSC scaffold significantly improved pancreatic islet function and survival in vitro and in vivo. This improvement may be associated with the upregulation of insulin expression, the improvement of islet microcirculation and the secretion of cytokines.

Effect of bone mesenchymal stem cells transplantation on the micro-environment of early osteonecrosis of the femoral head.

Autologous implantation of bone mesenchymal stem cells (BMSCs) has achieved promising clinical efficacy for the treatment of early-stage osteonecrosis of the femoral head (ONFH). However, the underlying mechanisms are not completely elucidated. Here, we investigated the effect of BMSCs on the early ONFH in vitro and in vivo. In co-cultured system, primary BMSCs enhanced the activity and inhibited the apoptosis of primary OB. The concentrations of VEGF and BMP-2 in the co-cultured medium were significantly higher than those without co-culture. Importantly, BMSCs implantation increased OB, capillaries and VEGF and BMP-2 expressions of the necrotic areas of femoral head in the ONFH rabbits. In conclusion, our results indicated that BMSCs treated the early ONFH possibly through increasing OB and capillaries, as well as VEGF and BMP-2 expression in the femoral head. These results provided possible mechanisms for the treatment of early-stage ONFH with BMSCs transplantation.

Dickkopf-1 is a key regulator of myeloma bone disease: opportunities and challenges for therapeutic intervention.

Myeloma bone disease (MBD) is the most visible aspect of plasma cell myeloma (PCM), which is characterized by the displacement of hematopoiesis and the formation of osteolytic bone lesions. The secreted glycoprotein Dickkopf-1 (DKK1), an inhibitor of the Wnt signaling pathway, is broadly expressed in myeloma cells but highly restricted in normal tissues. DKK1 plays a critical role in several aspects of bone biology and actively participates in regulating MBD by inhibiting osteoblasts and by activating osteoclasts. Based on these findings, ongoing research has been targeting DKK1 to find novel therapeutic strategies for MBD, such as DKK1-neutralizing antibodies, proteasome inhibitors, and vaccines. All these strategies have produced encouraging clinical results and consequently, revealed the significance of DKK1 in MBD. This review discusses the recent advances in our understanding of the DKK1 pathway signaling and how DKK1 can be exploited in the therapeutic intervention of MBD.

Study on systemic immune tolerance induction in rat islet transplantation by intravenous infusion of Sertoli cells.

BACKGROUND: Sertoli cells are usually co-transplanted with pancreatic islets to induce local immune tolerance. In this report, we used infusion with Sertoli cells in islet transplantation to induce systemic immune tolerance and studied the mechanism of the tolerance induction. METHODS: Streptozotocin-induced diabetic rats were divided into four groups before islet transplantation: group A as control; group B with intravenous infusion of Sertoli cells; group C with Sertoli cell infusion and Fas ligand antibody treatment; and group D with Sertoli cell infusion and transforming growth factor-beta1 antibody treatment. The mean survival time (MST) and insulin expression of islet grafts were measured. The number of lymphocytes and the levels of cytokines in peripheral blood were also measured. RESULTS: Group B had the longest MST of islet allografts (41.6+/-4.20 days) followed by groups C, D, and A (P<0.05). Immunohistochemistry showed similar results with MST. The rats in group B had the least CD4 T cells (only 15.6%+/-6.4%) compared with other groups (P<0.05). The numbers of CD8 T cells in rats of groups B (11.2%+/-4.3%) and D (14.5%+/-5.6%) were significantly lower than those of groups A and C (P<0.05). After transplantation, group B's interleukin (IL)-2 level (1.92+/-0.68 ng/mL) was found to be significantly lower than that of other groups (P<0.05). Interferon-gamma showed similar pattern of change as IL-2 (P<0.05). Groups A and D had significantly lower levels of IL-4 (4.31+/-1.97 pg/mL 4.69+/-1.33 pg/mL, respectively) than groups B and C (P<0.05). CONCLUSION: Infusion of Sertoli cells could effectively prolong the survival of islet grafts and reduce peripheral blood lymphocyte and cytokine levels. In this process, transforming growth factor-beta1 played a major role and Fas ligand played a smaller additional role.

[Comparison of different isolation methods on adult Sertoli cells co-transplanted with islets].

AIM: To establish a more convenient and effective method for isolating adult Sertoli cells and apply the method to islet transplantation. METHODS: Trypsin, DNase, collagenase and hyaluronidase were used for a one-step digestion in group A. A two-step digestion was used in group B, in which testis tissues were first digested by trypsin and DNase and then were digested by collagenase and hyaluronidase. In group C, trypsin and DNase were used in the first step of digestion, hyaluronidase was used in the second step and collagenase was used in the third step. Sertoli cells were identified by morphology and immunohistochemistry and the viability and purity of Sertoli cells were detected by MTT and flow cytometry (FCM). Expression of Fas-L was detected by Western blot and the effects of the co-transplantation of islets and Sertoli cells were compared between the three groups. RESULTS: Typical Sertoli cells were seen after isolation using the three different methods. Sertoli cells isolated by method A and method B were large in number while those isolated by method B and method C were pure. The results of MTT showed that the viability of Sertoli cells in group B was significantly higher than that in group A and group C (P<0.05) and Western blot results showed that expression of Fas-L on Sertoli cells in group B was significantly stronger than that in group A and group C (P<0.05). The purity of Sertoli cells detected by FCM in group B and group C were significantly higher than that in group A (P<0.05). The survival of islets co-transplanted with Sertoli cells to renal capsule of diabetic mice was significantly longer in group B compared with that in control group as well as in group A and group C (P<0.05). CONCLUSION: Sertoli cells obtained by the two-step digestion method are of higher purity and viability, which significantly prolong the survival of islet graft by co-transplantation.

Application of kushenin on patients with chronic hepatitis C after renal transplantation.

OBJECTIVE: To evaluate the efficacy of kushenin in treating patients with chronic hepatitis C after renal transplantation. METHODS: Fifty-five patients were randomly assigned by lottery to the treatment group (29 cases) and control group (26 cases). The same immunosuppression therapy was given to all patients in both groups. Patients in the treatment group were treated with kushenin 0.6 g once a day, while those in the control group were treated with conventional liver protective agents such as vitamins. The treatment duration of both groups was 3 months. The incidences of serious hepatitis and acute rejection reaction, serum biochemistry parameters including indicators of liver and kidney functions, hepatic fibrosis index, and serum HCV-RNA were compared between the two groups. RESULTS: (1) The incidence of serious hepatitis in the treatment group and the control group was 3.45% (1/29 cases) and 11.54% (3/26 cases), respectively, which was insignificantly different between the two groups (P=0.335). (2) The incidence of acute rejection in the treatment group was 6.90% (2/29 cases) and that in the control group was 7.69% (2/26 cases), showing insignificant difference (P=0.335). (3) The differences in serum alanine aminotransferase (ALT), direct bilirubin (DBIL), hyaluronic acid (HA), propeptide collagen type III (PC III), laminin (LN), collagen type IV (Col IV) levels between the two groups were insignificant before transplantation (P>0.05), while the above-mentioned parameters in the treatment group were significantly lower than those in the control group after transplantation (P<0.05). The difference in serum creatinine (SCr) and endogenous creatinine clearance rate (CCr) between the two groups was insignificant before and after transplantation (P>0.05). (4) The negative conversion rate of HCV-RNA in the treatment group was 31.03% (9/29 cases), significantly higher than the value of 11.54% (3/26 cases) in the control group after transplantation (P<0.05). (5) The levels of serum ALT and DBIL in patients with HCV-RNA converted to negative were significantly lower than those with still-positive HCV-RNA (P<0.05). CONCLUSIONS: Kushenin has a certain effect on inhibiting the proliferation of HCV, protecting liver cells, and anti-liver fibrosis. On the other hand, it has no obvious influence on renal allograft function. Thus, the drug is clinically safe and effective for use in treating patients with chronic hepatitis C after renal transplantation.

[Expression of Bax and Caspase-3 and apoptosis in human lumbar intervertebral disc degeneration].

OBJECTIVE: To detect the cell density, apoptotic incidence and the expressions of Bax and Caspase-3 in human lumbar intervertebral discs, so as to further understand the mechanism of human lumbar intervertebral disc degeneration and provide a new idea for biologic treatment of it in future. METHODS: From May to December in 2006, 30 human lumbar intervertebral discs in experimental group (L2 to S1) were surgically collected from 27 patients undergoing posterior lumbar intervertebral discoidectomy and fusion. All the cases were affirmed by MRI and they never experienced discography, collagenolysis of nucleus pulposus and percutaneous laser disc decompression. The control group consisted of 20 human lumbar intervertebral discs (L2 to S1) harvested from 5 young men without spine-related condition immediately after their accidental death. Apoptotic disc cells were detected by TUNEL and histomorphology, and immunohistochemical staining with SP method was performed to examine the expressions of Bax and Caspase-3 in all specimens. RESULTS: HE staining disclosed that the average cell density in control group (17.16 +/- 1.22)/HP was higher than that in experimental group (12.41 +/- 0.95)/HP (P < 0.01). However, TUNEL staining observed that the average TUNEL positive incidence in control group (6.97% +/- 0.92%) was lower than that in experimental group (12.59% +/- 0.95%), (P < 0.01). Immunohistochemical staining with SP method showed that the Bax and Caspase-3 positive incidence of nucleus pulposus in control group (11.02% +/- 1.18%, 9.01% +/- 1.00%) were lower than those in experimental group (19.29% +/- 1.18%, 15.07% +/- 0.97%), (P < 0.01). The results of the average gray scale value of nucleus pulposus in control group were 187.33 +/- 7.88 and 185.68 +/- 3.26, respectively, with 124.98 +/- 6.69 and 160.13 +/- 4.37 in experimental group. There was significant difference between the two groups (P < 0.01). When the total 50 specimens in the two groups were analyzed, TUNEL positive incidence showed significant inverse correlations with their respectively corresponding cell densities (r = - 0.88, r = - 0.93, P < 0.01). The Bax and Caspase-3 positive incidence of nucleus pulposus showed significant positive correlation with the TUNEL positive incidence of nucleus pulposus (r = 0.83, r = 0.91, P < 0.01). CONCLUSION: The decrease of cell density is involved in the development of human lumbar intervertebral disc degeneration. Bax and Caspase-3 might play a role in disc cell apoptosis in nucleus pulposus of human lumbar intervertebral disc.