Objective: To investigate the relationship between hypoxia inducible factor-1α (HIF-1α) and the autophagic response in osteoarthritic chondrocytes (OA), under inflammatory insult as represented by OA model.

Methods: Human chondrocyte cell line C28/I2 was cultured in both normoxic and hypoxic conditions and treated with interleukin-1β (IL1β) to emulate OA inflammatory insult . Cellular HIF-1α expression was silenced using siRNA transfection and cellular autophagic (P62/LC3II) response and OA chondrocyte damage (COL2A1/MMP13) related proteins were examined using western blotting. Cellular mitophagic (BNIP3/PINK1/Parkin) and apoptotic (Caspase/Cleaved Caspase 3) were also evaluated to assess mitophagy-mediated cell death due to HIF-1α silencing.

Results: Chondrocyte basal autophagy levels were higher in a HIF-1α elevated environment and was more resistant to IL1β-induced inflammatory insult. Increase in autophagic proteins showed better chondrocyte repair, which resulted a lower level of reactive oxygen species production, and lesser damage to chondrocyte integrity. Silencing HIF-1α activates cellular PINK1/Parkin and BNIP3 mitophagic proteins, which leads to the activation of Caspase/Cleaved Caspase 3 apoptotic cascade.

Conclusion: Our results show that chondrocyte autophagy is dependent on HIF-1α expression, showing the importance of HIF-1α in hypoxic chondrocyte function in OA. Dysregulation of HIF-1α expression results in the activation of mitophagy-mediated apoptosis.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8804738PMC
http://dx.doi.org/10.1177/19476035211035434DOI Listing

Publication Analysis

Top Keywords

inflammatory insult
12
hif-1α expression
12
hypoxia inducible
8
inducible factor-1α
8
osteoarthritic chondrocytes
8
hif-1α
8
caspase/cleaved caspase
8
chondrocyte
7
factor-1α regulator
4
regulator autophagy
4

Similar Publications

Patients with a traumatic brain injury (TBI) are susceptible to hospital-acquired infections, presenting a significant challenge to an already-compromised immune system. The consequences and mechanisms by which this dual insult worsens outcomes are poorly understood. This study aimed to explore how a systemic immune stimulus (lipopolysaccharide, LPS) influences outcomes following experimental TBI in young adult mice.

View Article and Find Full Text PDF

Carbon tetrachloride does not promote hepatic fibrosis in ob/ob mice via downregulation of lipocalin-2 protein.

Redox Biol

January 2025

Department of Anatomy and Convergence Medical Science, College of Medicine, Metabolic Dysfunction Liver Disease Research Center, Institute of Medical Science, Gyeongsang National University, Jinju, 52727, Republic of Korea. Electronic address:

Although leptin-deficient ob/ob mice have been investigated to determine whether hepatic steatosis promotes susceptibility to hepatotoxic insults, carbon tetrachloride (CCl)-induced hepatic fibrosis in ob/ob mice remains largely unknown. In this study, we evaluate the pathogenic mechanisms of hepatic fibrosis in CCl-treated wild-type (WT) and ob/ob mice and analyze some parameters related to lipogenesis, inflammation, fibrosis, oxidative stress, apoptosis, and autophagy. CCl treatment attenuated liver weight and lipogenesis in ob/ob mice.

View Article and Find Full Text PDF

Cerebral Global Ischemia (CGI) is a devastating neurological condition affecting millions globally each year, leading to significant inflammatory responses and long-term consequences, including delayed neuronal death and neurocognitive impairment. Following brain injury, resident microglial cells are activated, triggering pro-inflammatory cytokine expression and altering neuroimmune processes in a sex-dependent manner, particularly within the hippocampus. Coumestrol, a plant estrogen, is promoted as an alternative to post-menopausal hormone therapy due to its various mechanisms that enhance brain health, including its anti-inflammatory effects.

View Article and Find Full Text PDF

Objectives: There have been conflicting reports about the frequency of neural autoantibodies in epilepsy cohorts, which is confounded by the lack of clear distinction of epilepsy from acute symptomatic seizures due to encephalitis. The aim of this study was to determine the frequency of neural autoantibodies in a well characterised population of refractory focal epilepsy of known and unknown cause.

Methods: Cases were recruited from epilepsy outpatient clinics at the Princess Alexandra, Mater, Royal Brisbane and Women's and Cairns Base Hospitals from 2021 - 2023.

View Article and Find Full Text PDF

Background: Patients with transfusion-dependent thalassemia experience iron dysregulation, which affects the immune response. Surface proteins such as FcγRIII (CD16), lipopolysaccharide receptor (CD14), and human leukocyte antigen (HLA-DR) on monocytes are crucial for innate and adaptive responses. Blood monocytes, identified by their CD14 and CD16 expression, show functional diversity during injury or inflammation.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!