Urolithin B reduces cartilage degeneration and alleviates osteoarthritis by inhibiting inflammation.

Osteoarthritis is the most prevalent degenerative joint disease reported worldwide. Conventional treatment strategies mainly focus on medication and involve surgical joint replacement. The use of these therapies is limited by gastrointestinal complications and the lifespan of joint prostheses. Hence, safe and efficacious drugs are urgently needed to impede the osteoarthritis progression. Urolithin B, a metabolite of ellagic acid in the gut, exhibits anti-inflammatory and antioxidant properties; however, its role in osteoarthritis remains unclear. In this study, we demonstrated that urolithin B efficiently inhibits the inflammatory factor-induced production of matrix metalloproteinases (MMP3 and MMP13) in vitro and upregulates the expression of type II collagen and aggrecan. Urolithin B alleviates cartilage erosion and osteophyte formation induced by anterior cruciate ligament transections. Moreover, urolithin B inhibits the activation of the NF-κB pathway by reducing the phosphorylation of Iκb-α and the nuclear translocation of P65. In summary, urolithin B significantly inhibits inflammation and alleviates osteoarthritis. Hence, urolithin B can be considered a potential agent suitable for the effective treatment of osteoarthritis in the future.

Restrained Mitf-associated autophagy by Mulberroside A ameliorates osteoclastogenesis and counteracts OVX-Induced osteoporosis in mice.

Bone and mineral metabolism homeostasis accounts for the maintenance of normal skeletal remodeling. However, with aging and changes in hormone levels, over-activated osteoclasts disrupt homeostasis, induce osteoporosis, and even cause osteoporotic fractures, leading to an enormous economic burden. Despite the rapid development of pharmacological therapy for osteoporosis, safer and more effective treatments remain to be explored. Here, we demonstrate that Mulberroside A (Mul-A), a natural component extracted from mulberry bark and branches, effectively suppresses osteoclastogenesis in vitro and counteracts bone loss caused by ovariectomy (OVX). The mechanism underlying this effect involves the repression of autophagic flux during osteoclastogenesis by Mul-A, which can be attributed to the restrained expression of microphthalmia-related transcription factor (Mitf) and its nuclear translocation. Importantly, Mitf overexpression partially reverses the inhibitory effects of Mul-A on autophagy and osteoclastogenesis. Moreover, applying two autophagy agonizts, rapamycin and Torin 1, attenuates the osteoclastogenic regulatory role of Mul-A. Collectively, our study demonstrates that Mul-A damages osteoclast differentiation and ameliorates osteoporosis caused by estrogen deficiency by modulation of Mitf-associated autophagy, indicating its therapeutic potential against osteoporosis.

Risk factors for surgical site infection after closed proximal humerus fractures.

Proximal humerus fractures are common in clinical practice, and there are relatively a few studies on postoperative incision infections of such fractures. The purpose of this study was to explore the risk factors for surgical site infection (SSI) after internal fixation in patients with closed proximal humerus fractures. Patients with closed proximal humerus fractures who underwent surgery from January 2016 to January 2022 were retrospectively analysed. Cases with superficial or deep infections within 3 months after surgery were in the infection group and the remaining cases were in the non-infection group. The types of pathogenic bacteria in the infection group were analysed. The potential risk factors for SSI in all patients were recorded: (1) patient-related factors: gender, age, body mass index (BMI), smoking, comorbidities; (2) trauma-related factors: mechanism of injury, Injury Severity Score, visual analogue scale, fracture type, soft tissue condition and combined dislocation; (3) laboratory-related indexes: haemoglobin, albumin; (4) surgery-related factors: time from injury to surgery, American Society of Anesthesiologists anaesthesia classification, surgical time, fixation mode, intraoperative blood loss, suture method, bone graft and postoperative drainage. The risk factors for the occurrence of SSI were analysed using univariate analysis and multivariate logistic regression. The incidence of SSI was 15.7%. The most common bacterium in the infection group was Staphylococcus aureus. High BMI (p = 0.033), smoking (p = 0.030), an increase in mean time from injury to definitive surgery (p = 0.013), and prolonged surgical time (p = 0.044) were independent risk factors for the development of SSI after closed proximal humeral fractures. In patients with closed proximal humerus fractures, weight loss, perioperative smoking cessation, avoidance of delayed surgery, and shorter surgical time may be beneficial in reducing the incidence of SSI.

[Long-term outcomes of lateral femoral notch after early anterior cruciate ligament reconstruction].

OBJECTIVE: To investigate the outcome of lateral femoral notch (LFN) after early anterior cruciate ligament (ACL) reconstruction and evaluate the recovery of knee joint function after the operation. METHODS: The clinical data of 32 patients who underwent early ACL reconstruction from December 2015 to December 2019 were retrospectively analyzed. The study included 18 males and 14 females, aged 16 to 54 years old, with an average age of (25.39±2.82) years. The body mass index (BMI) of the patients ranged from 20 to 30 kg/cm2, with an average of (26.15±3.09) kg/cm2. Among them, 6 cases were caused by traffic accidents, 19 by exercise, and 7 by the crush of heavy objects. MRI of all patients showed LFN depth was more than 1.5 mm after injury, and no intervention for LFN was performed during surgery. Preoperative and postoperative depth, area, and volume of LFN defects were observed by MRI data. International Cartilage Repair Society (ICRS) score, Lysholm score, Tegner activity levels, and knee injury and osteoarthritis outcome score (KOOS) were analyzed before and after the operation. RESULTS: All patients were followed up from 2 to 6 years with an average of (3.28±1.12) years. There was no significant difference in the defect depth of LFN from (2.31±0.67) mm before the operation to (2.53±0.50) mm at follow-up (P=0.136). The defect area of LFN was decreased from (207.55±81.01)mm2 to (171.36±52.69)mm2 (P=0.038), and the defect volume of LFN was decreased from (426.32±176.54) mm3 to (340.86±151.54)mm3 (P=0.042). The ICRS score increased from (1.51±0.34) to (2.92±0.33) (P<0.001), the Lysholm score increased from (35.37±10.54) to (94.46±8.45) (P<0.001), and the Tegner motor score increased from (3.45±0.94) to (7.56±1.28), which was significantly higher than that of the preoperative data (P<0.001). The KOOS score of the final follow-up was 90.42±16.35. CONCLUSION: With the increase of recovery time after anterior cruciate ligament reconstruction, the defect area and volume of LFN decreased gradually, but the defect depth remained unchanged. The knee joint function of the patients significantly improved. The cartilage of the LFN defect improved, but the repair effect was not good.