Supplementation with carnosine, a food-derived bioactive dipeptide, alleviates dexamethasone-induced oxidative stress and bone impairment via the NRF2 signaling pathway.

BACKGROUND: Carnosine, a natural bioactive dipeptide derived from meat muscle, possesses strong antioxidant properties. Dexamethasone, widely employed for treating various inflammatory diseases, raises concerns regarding its detrimental effects on bone health. This study aimed to investigate the protective effects of carnosine against dexamethasone-induced oxidative stress and bone impairment, along with its underlying mechanisms, utilizing chick embryos and a zebrafish model in vivo, as well as MC3T3-E1 cells in vitro. RESULTS: Our findings revealed that carnosine effectively mitigated bone injury in dexamethasone-exposed chick embryos, accompanied by reduced oxidative stress. Further investigation demonstrated that carnosine alleviated impaired osteoblastic differentiation in MC3T3-E1 cells and zebrafish by suppressing the excessive production of reactive oxygen species (ROS) and enhancing the activity of antioxidant enzymes such as superoxide dismutase (SOD) and glutathione peroxidase (GPX). Moreover, mechanistic studies elucidated that carnosine promoted the expression and nuclear translocation of nuclear factor erythroid 2-related factor 2 (NRF2), thereby facilitating the transcription of its downstream antioxidant response elements, including heme oxyense-1 (HO-1), glutamate cysteine ligase modifier (GCLM), and glutamate cysteine ligase catalytic (GCLC) to counteract dexamethasone-induced oxidative stress. CONCLUSION: Overall, this study underscores the potential therapeutic efficacy of carnosine in mitigating oxidative stress and bone damage induced by dexamethasone exposure, shedding light on its underlying mechanism of action by activating the NRF2 signaling pathway. © 2024 Society of Chemical Industry.

Cetuximab versus bevacizumab following prior FOLFOXIRI and bevacizumab in postmenopausal women with advanced KRAS and BRAF wild-type colorectal cancer: a retrospective study.

BACKGROUND: An upgraded understanding of factors (sex/estrogen) associated with survival benefit in advanced colorectal carcinoma (CRC) could improve personalised management and provide innovative insights into anti-tumour mechanisms. The aim of this study was to assess the efficacy and safety of cetuximab (CET) versus bevacizumab (BEV) following prior 12 cycles of fluorouracil, leucovorin, oxaliplatin, and irinotecan (FOLFOXIRI) plus BEV in postmenopausal women with advanced KRAS and BRAF wild-type (wt) CRC. METHODS: Prospectively maintained databases were reviewed from 2013 to 2017 to assess postmenopausal women with advanced KRAS and BRAF wt CRC who received up to 12 cycles of FOLFOXIRI plus BEV inductive treatment, followed by CET or BEV maintenance treatment. The primary endpoints were overall survival (OS), progression-free survival (PFS), response rate. The secondary endpoint was the rate of adverse events (AEs). RESULTS: At a median follow-up of 27.0 months (IQR 25.1-29.2), significant difference was detected in median OS (17.7 months [95% confidence interval [CI], 16.2-18.6] for CET vs. 11.7 months [95% CI, 10.4-12.8] for BEV; hazard ratio [HR], 0.63; 95% CI, 0.44-0.89; p=0.007); Median PFS was 10.7 months (95% CI, 9.8-11.3) for CET vs. 8.4 months (95% CI, 7.2-9.6) for BEV (HR, 0.67; 95% CI 0.47-0.94; p=0.02). Dose reduction due to intolerable AEs occurred in 29 cases (24 [24.0%] for CET vs. 5 [4.8%] for BEV; p< 0.001). CONCLUSIONS: CET tends to be superior survival benefit when compared with BEV, with tolerated AEs.

Predicting Value of ALCAM as a Target Gene of microRNA-483-5p in Patients with Early Recurrence in Hepatocellular Carcinoma.

The long-term survival rate of hepatocellular carcinoma (HCC) is poor. One of the reasons for the poor rate of survival is the high rate of recurrence caused by intrahepatic metastas is that adversely affects long-term outcome. Many studies have indicated that microRNAs play an important role in HCC, but there has been no research of clonal origins on recurrent HCC (RHCC) by analzing microRNAs. In the present study, we found that miR-483-5p was significantly upregulated in RHCC tissues of short-term recurrence (≤ 2 years) by miRNA microarray screening, and can significantly promote migration and invasion of HCC cells in vitro and increase intrahepatic metastasis in nude mice in vivo. Furthermore, we demonstrated that activated leukocyte cell adhesion molecule (ALCAM), which significantly suppressed migration and invasion of HCC cells, was a direct target of miR-483-5p, and the re-introduction of ALCAM expression could antagonize the promoting effects of miR-483-5p on the capacity of HCC cells for migration and invasion. In addition, expression level of ALCAM was negatively correlated with microvascular invasion and tumor size recognized as prognostic factors. The cases which were negative for ALCAM expression had shorter time to recurrence than positive cases, and univariate and multivariate survival analyses showed that ALCAM was an independent risk factor of HCC recurrence. qRT-PCR and Western blotting showed that the expression of EMT related genes (MMP-2, MMP-9, E-caherin and vimentin) significantly changed as a result of interfering or overexpression of ALCAM, and ALCAM was significantly associated with EMT in HCC. These results suggest that the miR-483-5p/ALCAM axis is an important regulator in invasion and metastasis and biomarker for recurrence risk assessment of HCC.

Proteomic analysis of human articular cartilage: identification of differentially expressed proteins in knee osteoarthritis.

OBJECTIVES: The mechanisms underlying the development of age related osteoarthritis (OA) remain unclear. To better understand the pathogenesis of OA and the molecular basis of progressive destruction of articular cartilage in OA, we compared the proteome of OA cartilage with that of normal cartilage. METHODS: After removal of proteoglycans and collagens, proteins extracted from either normal or OA knee joint cartilage were separated by two-dimensional gel electrophoresis (2-DE). The differentially expressed proteins in OA cartilage were chosen to be further identified by linear ion trap-Fourier transform ion cyclotron resonance mass spectrometry (LTQ-FT/MS). RESULTS: A total of 1436+/-49 or 1472+/-7 protein spots were resolved by 2-DE of normal or OA cartilage extractions, respectively. Sixteen spots from OA cartilage samples were found to have statistically significant changes in the amount of protein compared with normal samples. Of 16 spots, the identities of 14 proteins were unambiguously determined by LTQ-FT/MS. These OA associated proteins fell into five groups, including glycolysis and energy production (ADH, ADK, ENOA, KPYM and FR), signaling (ANNX-I, PEBP and TUB), Redox (PRDX3 and SODM), and cartilage matrix (COLL-I and COLL-VI). Interestingly, two novel RING (Really Interesting New Gene) domain-containing proteins, RF, Zn-RF, were identified, suggesting novel pathways of cartilage protein regulation. CONCLUSIONS: This study shows that 2-DE followed by LTQ-FT/MS can be successfully used to characterize the proteome of cartilage without in vitro culturing which could obfuscate physiological differences. The definition of unique OA-associated proteins described here provides significant mechanistic insights into OA by corroborating previously suggested mechanisms and by defining unique players with roles yet to be defined in disease pathogenesis.