Primary Human Chondrocytes Affected by Cigarette Smoke-Therapeutic Challenges

In vitro assessment of ferroptosis of cells exposed to cigarette smoke aerosol using a self-designed on-chip evaluation system based on gas-liquid dual-dimensional exposure

Aerosol pollutants significantly cause health concerns. Herein, we established an original real-time aerosol exposure system that used a self-designed bionic-lung microfluidic chip. The chip features a 4 × 4 intersecting array within gas and liquid layers, creating 16 distinct microenvironments. A membrane situated between the layers offers attachment for cells and establishes a gas-liquid interface. This design provides a reliable screening capacity for investigating the biological effects of aerosol exposure in vitro by manipulating the gas and/or liquid conditions. Using this system, we validated that cigarette smoke (CS) aerosol triggered a concentration- and time-dependent reduction in cell viability and intracellular glutathione levels, accompanied by an increase in intracellular reactive oxygen species and Fe2+. Furthermore, CS aerosol significantly downregulated the expression of GPX4, SLC7A11, and FTL mRNA while inducing a notable increase in that of ACSL4 mRNA. Additionally, CS aerosol markedly stimulated the release of proinflammatory cytokines. Crucially, the ferroptosis inhibitor deferoxamine mesylate reversed these biological indicators. These results demonstrate that our novel bionic-lung chip presents a suitably achievable approach to investigate the biological effects induced by aerosol exposure.

Cigarette smoke extract exacerbates progression of osteoarthritic-like changes in cartilage explant cultures

Established risk factors for osteoarthritis (OA) include obesity, joint injury, age, race, and genetics. However, the relationship between cigarette smoking and OA has yet to be established. In the present study, we have employed the use of cigarette smoke extract (CSE), the water-soluble vapor phase of cigarette smoke, with porcine cartilage explants to investigate the effects of cigarette smoking on cartilage catabolism at the tissue level. Articular cartilage explants were first exposed to 2.5%, 5%, and 10% CSE to assess its effects on cartilage homeostasis. Following, the effects of CSE on OA-like inflammation was observed by culturing explants with a combined treatment of IL-1β and TNF-α and 10% CSE (CSE + OA). Cartilage explants were assessed for changes in viability, biochemical composition, extracellular matrix (ECM) integrity, and equilibrium mechanical properties (aggregate modulus and hydraulic permeability). CSE alone leads to both a time- and dose-dependent decrease in chondrocyte viability but does not significantly affect sGAG content, percent sGAG loss, or the ECM integrity of cartilage explants. When IL-1β and TNF-α were combined with 10% CSE, this led to a synergistic effect with more significant losses in viability, significantly more sGAG loss, and significantly higher production of ROS than OA-like inflammation only. Cartilage explant equilibrium mechanical properties were unaffected. Within the timeframe of this study, CSE alone does not cause OA but when combined with OA-like inflammation leads to worsened articular cartilage degeneration as measured by chondrocyte viability, sGAG loss, proteoglycan staining, and ROS production.

Smoking and osteoimmunology: Understanding the interplay between bone metabolism and immune homeostasis

Smoking continues to pose a global threat to morbidity and mortality in populations. The detrimental impact of smoking on health and disease includes bone destruction and immune disruption in various diseases. Osteoimmunology, which explores the communication between bone metabolism and immune homeostasis, aims to reveal the interaction between the osteoimmune systems in disease development. Smoking impairs the differentiation of mesenchymal stem cells and osteoblasts in bone formation while promoting osteoclast differentiation in bone resorption. Furthermore, smoking stimulates the Th17 response to increase inflammatory and osteoclastogenic cytokines that promote the receptor activator of NF-κB ligand (RANKL) signaling in osteoclasts, thus exacerbating bone destruction in periodontitis and rheumatoid arthritis. The pro-inflammatory role of smoking is also evident in delayed bone fracture healing and osteoarthritis development. The osteoimmunological therapies are promising in treating periodontitis and rheumatoid arthritis, but further research is still required to block the smoking-induced aggravation in these diseases.

Translational potential

This review summarizes the adverse effect of smoking on mesenchymal stem cells, osteoblasts, and osteoclasts and elucidates the smoking-induced exacerbation of periodontitis, rheumatoid arthritis, bone fracture healing, and osteoarthritis from an osteoimmune perspective. We also propose the therapeutic potential of osteoimmunological therapies for bone destruction aggravated by smoking.

Association between sarcopenia and osteoarthritis among the US adults: a cross-sectional study

The association between sarcopenia and OA still presents many uncertainties. We aimed to assess whether sarcopenia is associated with occurrence of OA in US adults. We conducted a cross-sectional study consisting of 11,456 participants from National Health and Nutrition Examination Survey 1999-2006. Sarcopenia was defined by a low muscle mass. The skeletal muscle index (SMI) was calculated as the appendicular skeletal muscle mass divided by body mass indexes (BMI) or body weight. OA status was assessed by using self-reported questionnaire. We evaluated the association between sarcopenia and OA using multivariate regression models. In addition, subgroup and interaction analysis were performed. Sarcopenia was associated with OA when it was defined by the BMI-adjusted SMI (OR = 1.23 [95% CI, 1.01, 1.51]; P = 0.038) and defined by the weight-adjusted SMI (OR = 1.30 [95% CI, 1.10, 1.55]; P = 0.003). Subgroup and interaction analysis found that the strongest positive association mainly exists in smoker (OR = 1.54 [95% CI, 1.21, 1.95], Pint = 0.006), and this association is not significant in other groups. In conclusion, we found that sarcopenia was associated with occurrence of OA. Subgroup analysis revealed that the association between sarcopenia and OA was more pronounced in smoker. Further well-designed prospective cohort studies are needed to assess our results.

The Causal Association between Alcohol, Smoking, Coffee Consumption, and the Risk of Arthritis: A Meta-Analysis of Mendelian Randomization Studies

Objective: To evaluate the genetic causality between alcohol intake, smoking, coffee consumption, and arthritis. Methods: Mendelian randomization (MR) studies with alcohol, smoking, and coffee consumption behaviors as exposures, and osteoarthritis (OA) and rheumatoid arthritis (RA) as outcomes were retrieved from up to July 2023. Two researchers with relevant professional backgrounds independently assessed the quality and extracted data from the included studies. Meanwhile, we applied MR analyses of four lifestyle exposures and five arthritis outcomes (two for OA and three for RA) with gene-wide association study (GWAS) data that were different from the included studies, and the results were also included in the meta-analysis. Statistical analyses were performed using Stata 16.0 and R software version 4.3.1. Results: A total of 84 studies were assessed. Of these, 11 were selected for meta-analysis. As a whole, the included studies were considered to be at a low risk of bias and were of high quality. Results of the meta-analysis showed no significant genetic causality between alcohol intake and arthritis (odds ratio (OR): 1.02 (0.94-1.11)). Smoking and arthritis had a positive genetic causal association (OR: 1.44 (1.27-1.64)) with both OA (1.44 (1.22-1.71)) and RA (1.37 (1.26-1.50)). Coffee consumption and arthritis also had a positive genetic causal association (OR: 1.02 (1.01-1.03)). Results from the subgroup analysis showed a positive genetic causality between coffee consumption and both OA (OR: 1.02 (1.00-1.03)) and RA (OR: 1.56 (1.19-2.05)). Conclusion: There is positive genetic causality between smoking and coffee consumption and arthritis (OA and RA), while there is insufficient evidence for genetic causality between alcohol intake and arthritis.

Effect of smoking on the redox status of knee osteoarthritis: A preliminary study

Even though smoking has been scarcely studied in osteoarthritis (OA) etiology, it is considered a controversial risk factor for the disease. Exposure to tobacco smoke has been reported to promote oxidative stress (OS) as part of the damage mechanism. The aim of this study was to assess whether smoking increases cartilage damage through the generation of OS. Peripheral blood (PB) and synovial fluid (SF) samples from patients with OA were analyzed. The samples were stratified according to smoking habit, Kellgren-Lawrence score, pain, and cotinine concentrations in PB. Malondialdehyde (MDA), methylglyoxal (MGO), advanced protein oxidation products (APOPs), and myeloperoxidase (MPO) were assessed; the activity of antioxidant enzymes such as gamma-glutamyl transferase (GGT), glutathione S-transferase (GST) and catalase (CAT), as well as the activity of arginase, which favors the destruction of cartilage, was determined. When stratified by age, for individuals <60 years, the levels of MDA and APOPs and the activity of MPO and GST were higher, as well as antioxidant system activity in the smoking group (OA-S). A greater degree of pain in the OA-S group increased the concentrations of APOPs and arginase activity (P < 0.01 and P < 0.05, respectively). Arginase activity increased significantly with a higher degree of pain (P < 0.01). Active smoking can be an important risk factor for the development of OA by inducing systemic OS in young adults, in addition to reducing antioxidant enzymes in older adults and enhancing the degree of pain and loss of cartilage.

Update on Novel Non-Operative Treatment for Osteoarthritis: Current Status and Future Trends

Osteoarthritis (OA) is a leading cause of pain and disability which results in a reduced quality of life. Due to the avascular nature of cartilage, damaged cartilage has a finite capacity for healing or regeneration. To date, conservative management, including physical measures and pharmacological therapy are still the principal choices offered for OA patients. Joint arthroplasties or total replacement surgeries are served as the ultimate therapeutic option to rehabilitate the joint function of patients who withstand severe OA. However, these approaches are mainly to relieve the symptoms of OA, instead of decelerating or reversing the progress of cartilage damage. Disease-modifying osteoarthritis drugs (DMOADs) aiming to modify key structures within the OA joints are in development. Tissue engineering is a promising strategy for repairing cartilage, in which cells, genes, and biomaterials are encompassed. Here, we review the current status of preclinical investigations and clinical translations of tissue engineering in the non-operative treatment of OA. Furthermore, this review provides our perspective on the challenges and future directions of tissue engineering in cartilage regeneration.

Smoking and the patient with a complex lower limb injury

Smoking is known to increase the risk of peri-operative complications in Orthoplastic surgery by impairing bone and wound healing. The effects of nicotine replacement therapies (NRTs) and electronic cigarettes (e-cigarettes) has been less well established. Previous reviews have examined the relationship between smoking and bone and wound healing separately. This review provides surgeons with a comprehensive and contemporaneous account of how smoking in all forms interacts with all aspects of complex lower limb trauma. We provide a guide for surgeons to refer to during the consent process to enable them to tailor information towards smokers in such a way that the patient may understand the risks involved with their surgical treatment. We update the literature with recently discovered methods of monitoring and treating the troublesome complications that occur more commonly in smokers effected by trauma.

Adverse impact of smoking on the spine and spinal surgery

Background

Tobacco smokers and companies are well aware that smoking increases the risks for cancers, vascular morbidity, and early mortality. This is a review of the plethora of adverse effects chronic smoking has on spinal tissues and spinal surgery.

Methods

Medline (PubMed) and Google Scholar databases were searched for pertinent literature through keywords related to smoking, spondylosis, and spinal surgery.

Results

Smoking accelerates spondylosis by impairing spinal tissue vascular supply through atherosclerosis and thrombosis, while inducing local hypoxia, inflammation, proteolysis, and cell loss. It, thus, compromises disc, cartilage, synovium, bone, and blood vessels. It can lead to early surgery, delayed wound healing, increased surgical site infection, failed fusion, more re-operations, and chronic spinal pain.

Conclusion

There is ample evidence to support surgeons' declining to operate on chronic smokers. The need for immediate and permanent smoking cessation and its potential benefits should be emphasized for the patient considering or who has undergone spinal surgery.

Maqui berry extract prevents cigarette smoke induced oxidative stress in human osteoblasts in vitro

Oxidative stress which can be induced by cigarette smoke (CS) is associated with an altered osteoblast differentiation, and an inhibition of the mineralization process. Therefore, treatments focusing on reducing oxidative stress in osteoblasts could be a potential therapy supporting bone formation. Maqui berry extract (MBE) is the richest natural source of delphinidins with high antioxidant activity. In the present study, we pre-/ co-/ post-incubated MBE in cigarette smoke extract (CSE)-affected human osteoblasts (hOBs), to investigate the effects of MBE as an antioxidant on hOBs. Our results clearly showed that high concentrations of MBE are toxic for hOBs, while physiological concentrations of MBE have no negative effects in vitro. Physiological concentrations of MBE can reduce oxidative stress caused by CSE in hOBs by activating the antioxidative regulator Nrf2 and its regulated antioxidative enzymes. Moreover, the physiological concentration of MBE prevents the detrimental effects of CSE-induced oxidative damage on hOBs by increasing cell viability, differentiation capability and matrix mineralization. Pre-incubation with MBE showed a positive effect on the activation of the cellular antioxidant system in hOBs. Thus, we conclude that MBE at physiological concentrations can effectively protect osteoblasts from oxidative stress-induced damage by activating the cells' antioxidative defense system.