Vitamin D delays intervertebral disc degeneration and improves bone quality in ovariectomized rats.

Known to be involved in bone-cartilage metabolism, Vitamin D (VD) may play a role in human's disc pathophysiology. Given that postmenopausal women are prone to suffer VD deficiency and intervertebral disc degeneration (IDD), this study is intended to investigate whether VD can delay IDD in ovariectomized rats by improving bone microstructure and antioxidant stress. Female Sprague-Dawley rats were randomly allocated into four groups: sham, oophorectomy (OVX)+VD deficiency (VDD), OVX, and OVX+VD supplementation (VDS). In vivo, after a 6-month intervention, imaging and pathology slice examinations showed that IDD induced by OVX was significantly alleviated in VDS and deteriorated by VDD. The expressions of aggrecan and Collagen II in intervertebral disc were reduced by OVX and VDD, and elevated by VDS. Compared with the OVX+VDD and OVX group vertebrae, OVX+VDS group vertebrae showed significantly improved endplate porosity and lumbar bone mineral density with increased percent bone volume and trabecular thickness. Furthermore, 1α,25(OH)2D3 restored the redox balance (total antioxidant capacity, ratio of oxidized glutathione/glutathione) in the disc. The cocultivation of 1α,25(OH)2D3 and nucleus pulposus cells (NPCs) was conducted to observe its potential ability to resist excessive oxidative stress damage induced by H2O2. In vitro experiments revealed that 1α,25(OH)2D3 reduced the senescence, apoptosis, and extracellular matrix degradation induced by H2O2 in NPCs. In conclusion, VDS exhibits protective effects in OVX-induced IDD, partly by regulating the redox balance and preserving the microstructure of endplate. This finding provides a new idea for the prevention and treatment of IDD.

α-Ketoglutaric acid ameliorates intervertebral disk degeneration by blocking the IL-6/JAK2/STAT3 pathway.

Intervertebral disk degeneration (IVDD) is the major cause of low back pain. Alpha-ketoglutaric acid (α-KG), an important intermediate in energy metabolism, has various functions, including epigenetic regulation, maintenance of redox homeostasis, and antiaging, but whether it can ameliorate IVDD has not been reported. Here, we examined the impacts of long-term administration of α-KG on aging-associated IVDD in adult rats. In vivo and in vitro experiments showed that α-KG supplementation effectively ameliorated IVDD in rats and the senescence of nucleus pulposus cells (NPCs). α-KG supplementation significantly attenuated senescence, apoptosis, and matrix metalloproteinase-13 (MMP-13) protein expression, and it increased the synthesis of aggrecan and collagen II in IL-1ß-treated NPCs. In addition, α-KG supplementation reduced the levels of IL-6, phosphorylated JAK2 and STAT3, and the nuclear translocation of p-STAT3 in IL-1ß-induced degenerating NPCs. The effects of α-KG were enhanced by AG490 in NPCs. The underlying mechanism may involve the inhibition of JAK2/STAT3 phosphorylation and the reduction of IL-6 expression. Our findings may help in the development of new therapeutic strategies for IVDD.NEW & NOTEWORTHY Alpha-ketoglutaric acid (α-KG) exerted its protective effect on nucleus pulposus cells' (NPCs) degeneration by inhibiting the senescence-associated secretory phenotype and extracellular matrix degradation. The possible mechanism may be associated with negatively regulating the JAK2/STAT3 phosphorylation and the decreased IL-6 expression, which could be explained by a blockage of the positive feedback control loop between IL-6 and JAK2/STAT3 pathway.

Association Between Poor Nutritional Status and Increased Risk for Subsequent Vertebral Fracture in Elderly People with Percutaneous Vertebroplasty.

Background: The relationship between a poor nutritional state and the risk of fractures has not been investigated. This study aimed to investigate the ability of the Controlling Nutritional Status (CONUT) and Geriatric Nutritional Risk Index (GNRI) to predict the incidence of subsequent vertebral fracture (SVF) after percutaneous vertebroplasty (PVP). Methods: A total of 307 women and 138 men over 50 years old who underwent PVP for osteoporotic vertebral compression fracture (OVCF) were included. Blood biochemical indexes, body mass index (BMI), bone mineral density (BMD), physical function, and muscle strength were measured at baseline. Cox regression analysis was used to determine whether nutritional state was an independent predictor for SVF. Results: During follow-up, 35 (25.4%) men and 85 (27.7%) women suffered SVF. Patients with SVF had lower BMI, serum albumin levels, GNRI scores, grip strength, lumbar BMD, and Short-Physical Performance Battery (SPPB) scores and higher fall rates and CONUT scores (P < 0.05). Compared with normal nutrition, mild malnutrition was associated with higher risk for SVF (women: HR 2.37, p=0.001, men: HR 2.97, p=0.021 by GNRI; women: HR 2.36, p=0.005, men: HR 3.62, p=0.002 by CONUT) after adjusting for confounding factors. Those with moderate-severe malnutrition also had a higher risk of SVF. Kaplan-Meier analysis showed that poor nutrition state was significantly associated with lower SVF-free survival (P<0.05). The area under curve (AUC) for predicting SVF was 0.65 and 0.73 for the GNRI and 0.67 and 0.66 for the CONUT in men and women, respectively. Conclusion: GNRI and CONUT are simple and effective tools for predicting SVF in patients undergoing PVP. Health management and nutrition supplement after PVP is a potentially effective prevention strategy against SVF.