AIM:To explore the effect of leptin on the expression of degeneration-related genes in rat nucleus pulposus ( NP) cells and to detect the possible mechanism .METHODS:The normal NP cells isolated from SD rats were analyzed by immunochemistry and immunofluorescence for the collagen II and cytokeratin 19 expression.The NP cells were treated with leptin and/or interleukin-1β( IL-β).The mRNA expression of MMP-1, MMP-3, MMP-9, MMP-13, ADAMTS-4, ADAMTS-5, aggrecan and COL2A1 in the cells was detected by real-time PCR.Alcian blue staining and im-munochemistry were used to examine the expression of proteoglycan and collagen II .Activation of involved pathways was studied by Western blot .The inhibitors of the pathways were used to reveal the effect of these pathways on NP cells .RE-SULTS:The results of real-time PCR revealed that leptin alone up-regulated the mRNA expression of MMP-1, MMP-13, ADAMTS-4, ADAMTS-5 and COL2A1.The synergy of leptin and IL-βwas found in the increased expression of MMP-1, MMP-3 and ADAMTS-5.The NP cells treated with leptin showed less expression of collagen II .Both PI3K/Akt and JAK2/SATA3 pathways were activated by leptin , whereas only inhibitor of JAK 2/SATA3 pathway reversed the expression of MMP-1 and MMP-13.CONCLUSION:Leptin may promote catabolism in rat NP cells via JAK2/SATA3 pathways, which may be the mechanism mediating the association between obesity and intervertebral disc degeneration .

AIM:Toexploretheeffectofglucocorticoidonautophagyandsenescenceinthechondrocytes. METHODS:The collagen II in the normal chondrocytes isolated from the SD rats was checked.After stimulation with glu-cocorticoid, LysoTracker Red staining, MDC staining and Western blot were used to detect the level of autophagy in the chondrocytes.The mTOR pathway related molecules were investigated by Western blot.Cell senescence was analyzed by SA-β-gal staining.RESULTS:A dose-dependent increase in the number of autophagic vacuoles was observed in the dexa-methasone-treated chondrocytes, which was demonstrated by the LysoTracker Red and MDC staining.The expression of LC3-II and beclin-1 was increased by dexamethasone, especially in the cells treated with dexamethasone for 4 d.However, P62 expression was decreased.SA-β-gal staining showed that the percentage of cell senescence was increased by dexam-ethasone.Surprisingly, the cell senescence induced by dexamethasone was exacerbated by the autophagic inhibitor 3-MA. CONCLUSION:Autophagy induced by dexamethasone protects chondrocyte from senescence.The mTOR pathway may be involved in the autophagy activation.

Objective:To explore the feasibility and clinical effectiveness of preoperative positioning grid combined with CTA assisted design of anterolateral thigh perforator flap (ALTPF) in reconstruction of soft tissue defects around foot and ankle.Methods:From May 2018 to December 2021, a total of 18 cases with soft tissue defects around foot and ankle were admitted to the Department of Plastic and Reconstructive Surgery, First Affiliated Hospital of Ningbo University. The patients were 11 males and 7 females, aged from 32 to 78 years old, with an average age of 57.5 years old. Among them, 10 had chronic ulcer wounds, 6 had traumatic wounds, and 2 had postoperative wounds after malignant tumor resection. The sizes of soft tissue defect ranged from 6.0 cm×8.0 cm to 9.0 cm×13.0 cm, and the flap sizes ranged from 8.0 cm×10.0 cm to 11.0 cm×15.0 cm. Preoperative positioning grid combined with CTA three-dimensional reconstruction were used to mark the exit point of the perforator vessels in digital format, in order to restore the course of vessels and calculate the length of the vascular pedicles. ALTPFs were accurately designed based on the digitally reconstructed images, and then the ALTPFs were used to repair the soft tissue defects around the ankle. The flap donor sites were directly closed in stage Ⅰ. After the operation, all the patients were included in scheduled follow-ups at the outpatient department to observe the appearance of the recipient flaps and donor sites. The functional evaluation of the affected feet were assessed according to the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score.Results:All 18 flaps survived, and the wounds in both the recipient and donor sites healed in stageⅠ. Postoperative follow-up for the 18 patients were 5 to 36 months, with an average of 13 months. At the last follow-up, the appearances of the flaps were good without swelling, the donor sites had good recovery, and there was no obvious scar hypertrophy. The function evaluation of the affected feet were found at excellent in 10 cases, good in 6 cases, and fair in 2 cases.Conclusion:Preoperative position grid combined with CTA three-dimensional reconstruction can digitally mark the exit points and running courses of the perforator vessels. It is an effective method for accurate position of perforator vessels before surgery. It can effectively reduce the operation time, lower the surgical risks, and achieve a high survival rate of the flap, thus holding considerable clinical value.