A structured biomimetic nanoparticle as inflammatory factor sponge and autophagy-regulatory agent against intervertebral disc degeneration and discogenic pain.

Lower back pain (LBP) is a common condition closely associated with intervertebral disc degeneration (IDD), causing a significant socioeconomic burden. Inflammatory activation in degenerated discs involves pro-inflammatory cytokines, dysregulated regulatory cytokines, and increased levels of nerve growth factor (NGF), leading to further intervertebral disc destruction and pain sensitization. Macrophage polarization is closely related to autophagy. Based on these pathological features, a structured biomimetic nanoparticle coated with TrkA-overexpressing macrophage membranes (TMNP@SR) with a rapamycin-loaded mesoporous silica core is developed. TMNP@SR acted like sponges to adsorbe inflammatory cytokines and NGF and delivers the autophagy regulator rapamycin (RAPA) into macrophages through homologous targeting effects of the outer engineered cell membrane. By regulating autophagy activation, TMNP@SR promoted the M1-to-M2 switch of macrophages to avoid continuous activation of inflammation within the degenerated disc, which prevented the apoptosis of nucleus pulposus cells. In addition, TMNP@SR relieved mechanical and thermal hyperalgesia, reduced calcitonin gene-related peptide (CGRP) and substance P (SP) expression in the dorsal root ganglion, and downregulated GFAP and c-FOS signaling in the spinal cord in the rat IDD model. In summary, TMNP@SR spontaneously inhibits the aggravation of disc inflammation to alleviate disc degeneration and reduce the ingress of sensory nerves, presenting a promising treatment strategy for LBP induced by disc degeneration.

Bizarre parosteal osteochondromatous proliferation (Nora lesion) involving the spine: a case report and systematic review.

Bizarre parosteal osteochondromatous proliferation (BPOP), also termed Nora lesion, is a rare, benign tumor most often located in the hands and feet. We herein present the second reported case of BPOP affecting the spine, an uncommon location. One year after surgical excision, the patient was pain-free and showed no evidence of recurrence. We reviewed a total of 323 cases of BPOP among 101 articles, providing the first systematic update on the latest knowledge of BPOP. The age of patients with BPOP ranges from 3 months to 87 years, peaking in the second and third decades of life. The hands are the most common location of BPOP (58.39%), followed by the feet (20.81%). Imaging features play a key role in the diagnosis of BPOP, but histopathologic diagnosis remains the gold standard. Differential diagnosis of BPOP should be based on the epidemiologic and clinical features as well as clinical examination findings. Surgical resection is the most extensively used treatment for BPOP. Recurrence is common (37.44%) and can be treated with re-excision. This article can deepen our understanding of BPOP and will be helpful for the diagnosis and treatment of BPOP in clinical practice.

POLE2 promotes osteosarcoma progression by enhancing the stability of CD44.

Osteosarcoma (OS) is the most prevalent primary malignancy of bone in children and adolescents. It is extremely urgent to develop a new therapy for OS. In this study, the GSE14359 chip from the GEO database was used to screen differentially expressed genes in OS. DNA polymerase epsilon 2 (POLE2) was confirmed to overexpress in OS tissues and cell lines by immunohistochemical staining, qPCR and Western blot. Knockdown of POLE2 inhibited the proliferation and migration of OS cells in vitro, as well as the growth of tumors in vivo, while the apoptosis rate was increased. Bioinformatics analysis revealed that CD44 and Rac signaling pathway were the downstream molecule and pathway of POLE2, which were inhibited by knockdown of POLE2. POLE2 reduced the ubiquitination degradation of CD44 by acting on MDM2. Moreover, knockdown of CD44 inhibited the tumor-promoting effects of POLE2 overexpression on OS cells. In conclusion, POLE2 augmented the expression of CD44 via inhibiting MDM2-mediated ubiquitination, and then activated Rac signaling pathway to influence the progression of OS, indicating that POLE2/CD44 might be potential targets for OS treatment.

SP1/CTR1-mediated oxidative stress-induced cuproptosis in intervertebral disc degeneration.

Intervertebral disc degeneration (IDD) is an age-related disease and is responsible for low back pain. Oxidative stress-induced cell death plays a fundamental role in IDD pathogenesis. Cuproptosis is a recently discovered form of programmed cell death dependent on copper availability. Whether cuproptosis is involved in IDD progression remains unknown. Herein, we established in vitro and in vivo models to investigate cuproptosis in IDD and the mechanisms by which oxidative stress interacts with copper sensitivity in nucleus pulposus cells (NPCs). We found that ferredoxin-1 (FDX1) content increased in both rat and human degenerated discs. Sublethal oxidative stress on NPCs led to increased FDX1 expression, tricarboxylic acid (TCA) cycle-related proteins lipoylation and aggregation, and cell death in the presence of Cu2+ at physiological concentrations, while FDX1 knockdown inhibited cell death. Since copper homeostasis is involved in copper-induced cytotoxicity, we investigated the role of copper transport-related proteins, including importer (CTR1) and efflux pumps (ATPase transporter, ATP7A, and ATP7B). CTR1 and ATP7A content increased under oxidative stress, and blocking CTR1 reduced oxidative stress/copper-induced TCA-related protein aggregation and cell death. Moreover, oxidative stress promoted the expression of specific protein 1 (SP1) and SP1-mediated CTR1 transcription. SP1 inhibition decreased cell death rates, preserved disc hydration, and alleviated tissue degeneration. This suggests that oxidative stress upregulates FDX1 expression and copper flux through promoting SP1-mediated CTR1 transcription, leading to increased TCA cycle-related protein aggregation and cuproptosis. This study highlights the importance of cuproptosis in IDD progression and provides a promising therapeutic target for IDD treatment.

Roles of organokines in intervertebral disc homeostasis and degeneration.

The intervertebral disc is not isolated from other tissues. Recently, abundant research has linked intervertebral disc homeostasis and degeneration to various systemic diseases, including obesity, metabolic syndrome, and diabetes. Organokines are a group of diverse factors named for the tissue of origin, including adipokines, osteokines, myokines, cardiokines, gastrointestinal hormones, and hepatokines. Through endocrine, paracrine, and autocrine mechanisms, organokines modulate energy homeostasis, oxidative stress, and metabolic balance in various tissues to mediate cross-organ communication. These molecules are involved in the regulation of cellular behavior, inflammation, and matrix metabolism under physiological and pathological conditions. In this review, we aimed to summarize the impact of organokines on disc homeostasis and degeneration and the underlying signaling mechanism. We focused on the regulatory mechanisms of organokines to provide a basis for the development of early diagnostic and therapeutic strategies for disc degeneration.

PGC1α-Inducing Senomorphic Nanotherapeutics Functionalized with NKG2D-Overexpressing Cell Membranes for Intervertebral Disc Degeneration.

Cellular senescence is a significant contributor to intervertebral disc aging and degeneration. However, the application of senotherapies, such as senomorphics targeting senescence markers and the senescence-associated secretory phenotype (SASP), remains limited due to challenges in precise delivery. Given that the natural killer group 2D (NKG2D) ligands are increased on the surface of senescent nucleus pulposus (NP) cells, the NKG2D-overexpressing NP cell membranes (NNPm) are constructed, which is expected to achieve a dual targeting effect toward senescent NP cells based on homologous membrane fusion and the NKG2D-mediated immunosurveillance mechanism. Then, mesoporous silica nanoparticles carrying a peroxisome proliferator-activated receptor-É£ coactivator 1α (PGC1α)inducer (SP) are coated with NNPm (SP@NNPm) and it is found that SP@NNPm selectively targets senescent NP cells, and the SP cores exhibit pH-responsive drug release. Moreover, SP@NNPm effectively induces PGC1α-mediated mitochondrial biogenesis and mitigates senescence-associated markers induced by oxidative stress and the SASP, thereby alleviating puncture-induced senescence and disc degeneration. This dual-targeting nanotherapeutic system represents a novel approach to delivery senomorphics for disc degeneration treatment.

Nucleus pulposus cells regulate macrophages in degenerated intervertebral discs via the integrated stress response-mediated CCL2/7-CCR2 signaling pathway.

Lower back pain (LBP), which is a primary cause of disability, is largely attributed to intervertebral disc degeneration (IDD). Macrophages (MΦs) in degenerated intervertebral discs (IVDs) form a chronic inflammatory microenvironment, but how MΦs are recruited to degenerative segments and transform into a proinflammatory phenotype remains unclear. We evaluated chemokine expression in degenerated nucleus pulposus cells (NPCs) to clarify the role of NPCs in the establishment of an inflammatory microenvironment in IDD and explored the mechanisms. We found that the production of C-C motif chemokine ligand 2 (CCL2) and C-C motif chemokine ligand 7 (CCL7) was significantly increased in NPCs under inflammatory conditions, and blocking CCL2/7 and their receptor, C-C chemokine receptor type 2(CCR2), inhibited the inductive effects of NPCs on MΦ infiltration and proinflammatory polarization. Moreover, activation of the integrated stress response (ISR) was obvious in IDD, and ISR inhibition reduced the production of CCL2/7 in NPCs. Further investigation revealed that activating Transcription Factor 3 (ATF3) responded to ISR activation, and ChIP-qPCR verified the DNA-binding activity of ATF3 on CCL2/7 promoters. In addition, we found that Toll-like receptor 4 (TLR4) inhibition modulated ISR activation, and TLR4 regulated the accumulation of mitochondrial reactive oxygen species (mtROS) and double-stranded RNA (dsRNA). Downregulating the level of mtROS reduced the amount of dsRNA and ISR activation. Deactivating the ISR or blocking CCL2/7 release alleviated inflammation and the progression of IDD in vivo. Moreover, MΦ infiltration and IDD were inhibited in CCR2-knockout mice. In conclusion, this study highlights the critical role of TLR4/mtROS/dsRNA axis-mediated ISR activation in the production of CCL2/7 and the progression of IDD, which provides promising therapeutic strategies for discogenic LBP.

Kongensin a attenuates intervertebral disc degeneration by inhibiting TAK1-mediated PANoptosis of nucleus pulposus cells.

Low back pain (LBP) is most commonly caused by intervertebral disc degeneration (IVDD). Pyroptosis, apoptosis, and necroptosis are crucial in IVDD pathogenesis; however, possible simultaneous occurrence in IVDD and co-regulation between the pathways and the regulatory mechanisms have not been investigated. PANoptosis is a regulated cell death (RCD) pathway with the key characteristics of pyroptosis, apoptosis, and necroptosis. This study revealed that tert-butyl hydroperoxide (TBHP) altered the expression of key proteins involved in PANoptosis in nucleus pulposus cells (NPCs). Furthermore, the natural product Kongensin A (KA), which has potential anti-necrotic and anti-inflammatory properties, inhibited PANoptosis. TAK1, often referred to as mitogen-activated protein kinase kinase kinase 7 (Map3k7), is a key regulator of innate immunity, cell death, inflammation, and cellular homeostasis; however, the physiological roles and regulatory mechanisms underlying IVDD remain unclear. In this study, we discovered that KA can upregulate TAK1 expression in NPCs, -which inhibits PANoptosis by suppressing oxidative stress. In conclusion, our results suggest that KA inhibits PANoptosis and delays IVDD progression in NPCs by upregulating TAK1 expression to maintain mitochondrial redox balance. Consequently, targeting TAK1 may be a promising therapeutic approach for IVDD therapy.

An Engineered Bionic Nanoparticle Sponge as a Cytokine Trap and Reactive Oxygen Species Scavenger to Relieve Disc Degeneration and Discogenic Pain.

The progressive worsening of disc degeneration and related nonspecific back pain are prominent clinical issues that cause a tremendous economic burden. Activation of reactive oxygen species (ROS) related inflammation is a primary pathophysiologic change in degenerative disc lesions. This pathological state is associated with M1 macrophages, apoptosis of nucleus pulposus cells (NPC), and the ingrowth of pain-related sensory nerves. To address the pathological issues of disc degeneration and discogenic pain, we developed MnO2@TMNP, a nanomaterial that encapsulated MnO2 nanoparticles with a TrkA-overexpressed macrophage cell membrane (TMNP). Consequently, this engineered nanomaterial showed high efficiency in binding various inflammatory factors and nerve growth factors, which inhibited inflammation-induced NPC apoptosis, matrix degradation, and nerve ingrowth. Furthermore, the macrophage cell membrane provided specific targeting to macrophages for the delivery of MnO2 nanoparticles. MnO2 nanoparticles in macrophages effectively scavenged intracellular ROS and prevented M1 polarization. Supportively, we found that MnO2@TMNP prevented disc inflammation and promoted matrix regeneration, leading to downregulated disc degenerative grades in the rat injured disc model. Both mechanical and thermal hyperalgesia were alleviated by MnO2@TMNP, which was attributed to the reduced calcitonin gene-related peptide (CGRP) and substance P expression in the dorsal root ganglion and the downregulated Glial Fibrillary Acidic Protein (GFAP) and Fos Proto-Oncogene (c-FOS) signaling in the spinal cord. We confirmed that the MnO2@TMNP nanomaterial alleviated the inflammatory immune microenvironment of intervertebral discs and the progression of disc degeneration, resulting in relieved discogenic pain.

Corrigendum to "Cellular senescence-driven transcriptional reprogramming of the MAFB/NOTCH3 axis activates the PI3K/AKT pathway and promotes osteosarcoma progression" [Genes & Diseases 11 (2024) 952-963].

[This corrects the article DOI: 10.1016/j.gendis.2023.02.028.].

Enzymatically Bioactive Nucleus Pulposus Matrix Hydrogel Microspheres for Exogenous Stem Cells Therapy and Endogenous Repair Strategy to Achieve Disc Regeneration.

Exogenous stem cell therapy and endogenous repair has shown great potential in intervertebral disc regeneration. However, limited nutrients and accumulation of lactate largely impair the survival and regenerative capacity of implanted stem cells and endogenous nucleus pulposus cells (NPCs). Herein, an injectable hydrogel microsphere (LMGDNPs) have been developed by immersing lactate oxidase (LOX)-manganese dioxide (MnO2 ) nanozyme (LM) into glucose-enriched decellularized nucleus pulposus hydrogel microspheres (GDNPs) through a microfluidic system. LMGDNPs showed a delayed release profile of LOX and satisfactory enzymatic capacity in consuming lactate. Mesenchymal stem cells (MSCs) plated on LMGDNPs exhibited better cell viability than cells on GelMA and decellularized nucleus pulposus microspheres (DNP) and showed a obviously increased NPCs phenotype. LMGDNPs prevented MSCs and NPCs death and promoted extracellular matrix synthesis by exhausting lactate. It is determined that LMGDNPs promoted NPCs autophagy by activating transforming growth factor ß2 overlapping transcript 1 (TGFB2-OT1), relying on the nanozyme. MSCs-loaded LMGDNPs largely preserved disc hydration and alleviated matrix degradation in vivo. Summarily, LMGDNPs promoted cell survival and matrix regeneration by providing a nutrient supply, exhausting lactate, and activating autophagy via TGFB2-OT1 and its downstream pathway and may serve as an ideal delivery system for exogenous stem cell therapy and endogenous repair.

Bardoxolone methyl breaks the vicious cycle between M1 macrophages and senescent nucleus pulposus cells through the Nrf2/STING/NF-κB pathway.

Intervertebral disc (IVD) degeneration (IDD), an age-related degenerative disease, is accompanied by the accumulation of senescent nucleus pulposus (NP) cells and extracellular matrix (ECM) degradation. The current study aims to clarify the role of M1 macrophages in the senescence of NP cells, and further explores whether bardoxolone methyl (CDDO-Me) can alleviate the pathological changes induced by M1 macrophages and relieve IDD. On the one hand, conditioned medium (CM) of M1 macrophages (M1CM) triggered senescence of NP cells and ECM degradation in a time-dependent manner. On the other hand, CM of senescent NP cells (S-NPCM) was collected to treat macrophages and we found that S-NPCM promoted the migration and M1-polarization of macrophages. However, both of the above effects can be partially blocked by CDDO-Me. We further explored the mechanism and found that M1CM promoted the expression level of STING and nuclear translocation of P65 in NP cells, while being restrained by CDDO-Me and STING inhibitor H151. In addition, the employment of Nrf2 inhibitor ML385 facilitated the expression level of STING and nuclear translocation of P65, thereby blocking the effects of CDDO-Me on suppressing senescence of NP cells and ECM degradation. In vivo, the injection of CDDO-Me into the disc decreased the infiltration of M1 macrophages and ameliorated degenerative manifestations in the puncture-induced rat IDD model. In conclusion, CDDO-Me was proved to break the vicious cycle between M1 macrophages and senescent NP cells through the Nrf2/STING/NF-κB pathway, thereby attenuating the progression of IDD.

Cellular senescence-driven transcriptional reprogramming of the MAFB/NOTCH3 axis activates the PI3K/AKT pathway and promotes osteosarcoma progression.

Osteosarcoma is the most common primary malignancy of bones and primarily occurs in adolescents and young adults. However, a second smaller peak of osteosarcoma incidence was reported in the elderly aged more than 60. Elderly patients with osteosarcoma exhibit different characteristics compared to young patients, which usually results in a poor prognosis. The mechanism underlying osteosarcoma development in elderly patients is intriguing and of significant value in clinical applications. Senescent cells can accelerate tumor progression by metabolic reprogramming. Recent research has shown that methylmalonic acid (MMA) was significantly up-regulated in the serum of older individuals and played a central role in the development of aggressive characteristics. We found that the significant accumulation of MMA in elderly patients imparted proliferative potential to osteosarcoma cells. The expression of MAFB was excessively up-regulated in osteosarcoma specimens and was further enhanced in response to MMA accumulation as the patient aged. Specifically, we first confirmed a novel molecular mechanism between cellular senescence and cancer, in which the MMA-driven transcriptional reprogramming of the MAFB-NOTCH3 axis accelerated osteosarcoma progression via the activation of PI3K-AKT pathways. Moreover, the down-regulation of the MAFB-NOTCH3 axis increased the sensitivity and effect of AKT inhibitors in osteosarcoma through significant inhibition of AKT phosphorylation. In conclusion, we confirmed that MAFB is a novel age-dependent biomarker for osteosarcoma, and targeting the MAFB-NOTCH3 axis in combination with AKT inhibition can serve as a novel therapeutic strategy for elderly patients with osteosarcoma in experimental and clinical trials.

Arthroscopic In Situ Fixation of Osteochondral Fragments on the Weightbearing Area of the Knee Joint With a Single Anchor.

Osteochondral fracture of knee joint occurring in the femur is a serious clinical trauma. The presence of osteochondral fragments in the knee joint often necessitates surgery. Arthroscopic repair is a minimally invasive treatment, and there are many methods, among which suture anchor is often adopted by clinicians because of its obvious advantages such as simplicity. In the past, there were many methods for fixing osteochondral fragments, but using suture anchors to fix free osteochondral fragments has become a common approach. Moreover, the local mechanical environment will also be affected because of the increase in the number of bone channels. In this report, we describe a method for fixing 1 or 2 osteochondral fragments using a single suture anchor based on the mechanical characteristics of the femoral weightbearing region of the knee joint. We use relevant case reports to introduce our technology. Through the application of our improved technique, the arthroscopic repair of osteochondral fractures in the weightbearing area of femur can be more convenient and more economical, and the rehabilitation of patients will not be affected.

Targeted Silencing of Heparanase Gene by Small Interfering RNA Inhibits Invasiveness and Metastasis of Osteosarcoma Cells / 华中科技大学学报（医学）（英德文版）

The effects of targeted silencing of heparanase gene by small interfering RNA (siRNA) on invasiveness and metastasis of osteosarcoma cells (MG63 cells) were investigated in the present study.Two complementary oligonucleotide strands were synthesized and inserted into pGenesil-1 vector based on the mRNA sequence of heparanase gene.The expression vector containing short hairpin RNA (pGenesil-shRNA) was constructed successfully.MG63 cells were randomly allocated into 3 groups:blank group,empty vector (pGenesil) transfected group and expression vector (pGenesil-shRNA) transfected group.Under the induction of Lipofectamine 2000,the recombinants were transfected into MG63cells.Heparanase gene expression level was detected by RT-PCR and Western blotting.Cell proliferation was measured by MTT assay.Cell invasiveness and metastasis were examined by cell adhesion and Transwell-ECM assays.HUVECs migration assay was applied for the detection of angiogenesis.As compared with negative controls,the mRNA and protein expression levels ofheparanase were down-regulated by 76.1％ (P＜0.01) and 75.3％ (P＜0.01) respectively in the pGenesil-shRNA transfected group.Meanwhile,the proliferation,adhesiveness,invasiveness and angiogenesis properties of MG63 cells were all significantly inhibited.It was suggested that targeted silencing of heparanase gene by siRNA could dramatically inhibit the invasiveness and metastasis of osteosarcoma cells.

Mobilization Efficiency of Granulocyte Colony-stimulating Factor and Stem Cell Factor to Bone Marrow Mononuclear Cells and Mechanisms / 华中科技大学学报（医学）（英德文版）

The mobilization efficiency of granulocyte colony-stimulating factor (G-CSF) and stem cell factor (SCF) to bone marrow mononuclear cells (MNCs) in mice was observed,and the changes of CXCL12/CXCR4 signal were detected in order to find out the mobilization mechanism of stem cells.Kunming mice were randomly divided into two groups.The mice in treatment group were subjected to subcutaneous injection of G-CSF at a dose of 100 μg/kg and SCF at a dose of 25 μg/kg every day for 5 days,and those in control group were given isodose physiological saline.The MNCs were separated,counted and cultured,and the colony-forming unit-fibroblast (CFU-F) was evaluated.CD34+CXCR4+ MNCs were sorted by flow cytometry.The expression of CXCL12 protein in bone marrow extracellular fluid was detected by ELISA,and that of CXCL12 mRNA in bone marrow was measured by RT-PCR.The results showed that the counts of MNCs in peripheral blood and bone marrow were increased after administration of G-CSF/SCF (P＜0.01).The factors had a dramatic effect on the expansion capability of CFU-F (P＜0.05).Flow cytometric of bone marrow MNCs surface markers revealed that CD34+CXCR4+ cells accounted for 44.6%±8.7% of the total CD34+ MNCs.Moreover,G-CSF/SCF treatment induced a decrease in bone marrowCXCL12 mRNA that closely mirrored the fall in CXCL12 protein.In this study,it is evidenced that G-CSF/SCF can effectively induce MNCs mobilization by disrupting the balance of CXCL12/CXCR4 signaling pathway in the bone marrow and down-regulating the interaction of CXCL12/CXCR4.

Expression of Beclinl in Osteosarcoma and the Effects of Down-regulation of Autophagy on the Chemotherapeutic Sensitivity / 华中科技大学学报（医学）（英德文版）

To explore the expression of Beclin1 in osteosarcoma and investigate the effects of down-regulation of autophagy on the chemotherapeutic sensitivity to cisplatin (DDP),the expression of Beclin1 in 28 specimens of osteosarcoma (group A) and 19 specimens of normal bone tissues (group B) were immunohistochemically detected. The expression of Beclin1 mRNA in MG63 cells treated with different concentrations of DDP was examined with RT-PCR. After down-regulation of autophagy in MG63 cells by an autophagy inhibitor,3-methyladenine (3-MA),the cell proliferation inhibition rate of MG63 cells treated with DDP was evaluated by using the MTT assay. The positive rates of Beclinl were 67.85% in group A and 94.73% in group B. Its expression was lower in osteosarcoma than in normal bone tissues,with a significant difference found between them (P＜0.05).RT-PCR showed that the expression of Bcclin1 mRNA in the cells treated with high-dose DDP were higher than that in the non-treated cells,and no significant difference in the expression of Beclin1 mRNA was found between the cells treated with low-dose DDP and the non-treated cells. There was a positive correlation between the level of Beclin1 mRNA expression and the concentration of DDP.MTT assay showed that the proliferation inhibition rates of the cell treated with 3-MA and DDP combined were substantially increased when compared with those treated with DDP alone (P＜0.01).This study demonstrated that autophagy may be implicated in the carcinogenesis of osteosarcoma,and DDP may induce autophagy in the MG63 cells. It also suggests that the down-regulated autophagy could increase chemotherapeutic sensitivity of DDP to osteosarcoma.

Effect of RGD-modified Silk Material on the Adhesion and Proliferation of Bone Marrow-derived Mesenchymal Stem Cells / 华中科技大学学报（医学）（英德文版）

In order to investigate the effect ofArg-Gly-Asp (RGD) peptide-modified silk biomaterial on the adhesion and proliferation of bone marrow-derived mesenchymal stem cells (MSCs),MSCs of third generation were seeded onto the surface of RGD-decorated silk (silk-RGD group),silk alone (silk group) or tissue culture plate (TCP group).After incubation for 4 or 12 h,MSCs were examined quantitatively by using precipitation method for cell attachment.The cell proliferation,which was de-fined as cell density,was compared among the three groups after culture for 1,2,3,and 4 days.Cell skeleton,which was labeled fluorescently,was observed under laser confocal microscope after 24 h of culture.The results showed that cell adhesion rate in silk-RGD group was higher than in silk group (P<0.05),but similar to that in TCP group after incubation for 4 or 12 h (P>0.05).There were no sig-nificant differences in the cell proliferation among the three groups at different time points (P>0.05 for all).Laser confocal microscopy revealed that in silk-RGD group,MSCs,strongly fluorescently stained,spread fully,with stress fibers clearly seen,while in silk group,actin filaments were sparsely aligned and less stress fibers were found.It was concluded that RGD peptide could improve the ad-hesion of MSCs to the silk scaffold,but had no impact on the proliferation of the cells.

Experimental Study on Inhibitory Effect of Niacinamide on Tumor Necrosis Factor-alpha-induced Matrix Degradation of Annulus Fibrous Tissue in vitro / 华中科技大学学报（医学）（英德文版）

Summary: The inhibitory effect of niacinamide on tumor necrosis factor-α (TNF-α) induced annulus fibrous (AF) degradation was assessed, and the mechanism of the inhibition was investigated. Chiba's intervertebral disc (IVD) culture model was established. Forty-eight IVDs from 12 adult Japanese white rabbits were randomly divided into 4 groups (12 IVDs in each group), and various concentrations of niacinamide and TNF-α were added to the medium for intervention: negative control group, niacinamide control group (0.5 mg/mL niacinamide), degeneration group (10 ng/mL TNF-α), and treatment group (0.5 mg/mL niacinamide and 10 ng/mL TNF-α). After one week's culture, AFs were collected for glycosaminoglycan (GS) content measurement, safranin O-fast green staining, and immunohistochemical staining for typeⅠ,Ⅱ collagen and cysteine containing aspartate specific protease-3 (Caspase-3). It was found that the GS content in treatment group was increased by about 48% as compared with degeneration group (t=16.93, P<0.001), and close to that in niacinamide control group (r=0.71, P=0.667). Safranine O-fast green staining exhibited higher staining density and better histological structure of AF in the treatment group as compared with the degeneration group. Immunohistochemical staining for both Type Ⅰ and Ⅱ collagen demonstrated that lameilar structure and continuity of collagen in treatment group were better reserved than in degeneration group. Positive staining rate of Caspase-3 in AFs of negative control group, niacinamide control group, degeneration group and treatment group was 3.4%, 4.3%, 17.9% and 10.3% respectively. The positive rate in treatment group was significantly lower than in degeneration group (P<0.01). It was concluded that niacinamide could effectively alleviate TNF-α induced destruction and synthesis inhibition of matrix ingredients in AFs. The inhibition may be related with reduction of expression of Caspase-3. Thus, niacinamide is of potential for IVD degeneration clinical treatment.

Treatment of Severe Gluteal Muscle Contracture in Children / 华中科技大学学报（医学）（英德文版）

To investigate the efficacy of a combination therapy on gluteal muscle contracture, 286 definitely diagnosed patients were subjected to surgical treatment, and then functional exercises and physical therapy. The patients with severe symptoms were asked to have a set of specially-designed functional exercises. All the patients were followed up for 3 to 24 months by hospital visit, correspondenee or telephone interview. The effective rate was 100%, and the curative rate was up to 94.6%. Few patients developed complications and relapse was rare. It is concluded that the combination therapy, including surgical removal of diseased tissues, functional exercises and physical therapy, is an effective approach for the treatment of severe juvenile gluteal muscle contracture.