Ischemia‐reperfusion (I‐R) injury is damage caused by restoring blood flow into ischemic tissues or organs. This complex and characteristic lesion accelerates cell death induced by signaling pathways such as apoptosis, necrosis, and even ferroptosis. In addition to the direct association between I‐R and the release of reactive oxygen species and reactive nitrogen species, it is involved in developing mitochondrial oxidative damage. Thus, its mechanism plays a critical role via reactive species scavenging, calcium overload modulation, electron transport chain blocking, mitochondrial permeability transition pore activation, or noncoding RNA transcription. Other receptors and molecules reduce tissue and organ damage caused by this pathology and other related diseases. These molecular targets have been gradually discovered and have essential roles in I‐R resolution. Therefore, the current study is aimed at highlighting the importance of these discoveries. In this review, we inquire about the oxidative damage receptors that are relevant to reducing the damage induced by oxidative stress associated with I‐R. Several complications on surgical techniques and pathology interventions do not mitigate the damage caused by I‐R. Nevertheless, these therapies developed using alternative targets could work as coadjuvants in tissue transplants or I‐R‐related pathologies

Obesity affects the adaptability of adipose tissue (AT), impairing its ability to regulate energy and metabolism. Obesity is associated with many metabolic disorders, including dyslipidemia, hypertension, sleep disorders, non-alcoholic liver disease, and some types of cancer. Toll-like receptors (TLRs) are important in obesity and related metabolic disorders. TLRs are pattern-recognizing receptors (PRRs) involved in the innate immune system and recognize pathogen-associated molecular patterns (PAMPs) and endogenous ligands. TLRs, especially TLR2 and TLR4, are activated by fatty acids, endotoxins, and other ligands. TLR2 and TLR4 activation triggers inflammatory responses. Chronic inflammation driven by TLR activation is a hallmark of obesity and metabolic diseases. The inflammatory response triggered by TLR activation alters insulin signaling, contributing to insulin resistance, a key feature of metabolic syndrome and type 2 diabetes. Modulation of TLR activity through lifestyle changes (diet and exercise), obesity surgery, and pharmacological agents is under study as a possible therapeutic approach to controlling obesity and its complications.

Background . Neuropeptide Y (NPY) is a sympathetic neurotransmitter with effects on the regulation of inflammatory cells. The role of NPY on autoimmune inflammatory diseases such as rheumatoid arthritis (RA) is not completely understood. Therefore, we evaluate if NPY levels are markers of disease activity in RA and if there is a correlation between NPY levels and tumor necrosis factor‐alpha (TNF‐ α ), leptin, and interleukin 6 (IL‐6) levels. Methods . Cross‐sectional design, including 108 women with RA. We assessed disease activity by DAS28‐ESR (considering active disease a score of ≥2.6). Serum NPY levels and anti‐CCP2 antibody, TNF‐ α , IL‐6, and leptin levels were quantified (ELISA). Results . Sixty‐eight RA had an active disease (RA‐active), and 40 were in remission (RA‐remission). RA‐active patients had higher NPY levels vs. RA‐remission (22.8 ± 13.6 vs. 17.8 ± 10.3; p = 0.04). NPY levels correlated with increased TNF‐ α levels ( r = 0.32, p = 0.001). Leptin or IL‐6 did not correlate with NPY levels. In the logistic regression analysis, NPY increased the risk of disease activity (OR: 1.04, 95% CI 1.006‐1.09, and p = 0.03). Conclusion . Higher NPY levels are an independent marker of disease activity in RA. This study encourages the quantification of NPY levels as a surrogate marker for RA‐active. Future studies evaluating the role of NPY levels interacting with other proinflammatory cytokines are required.

Background. Myostatin is a regulator of muscle size. To date, there have been no published studies focusing on the relation between myostin levels and myopenia in rheumatoid arthritis (RA). Objective. Evaluate the value of serum myostatin as a biomarker of cachexia and low skeletal muscle mass (LSMM) in RA patients, along with whether high serum myostatin is associated to these conditions after adjusting for potential confounders. Methods. This cross-sectional study included 161 female RA patients and 72 female controls. In the RA group, we assessed several potential risk factors for LSMM and rheumatoid cachexia. Dual-energy X-ray absorptiometry was used to quantify the skeletal muscle mass index (SMMI) (considering kg/m²) and the presence of rheumatoid cachexia (a fat-free mass percentile and fat mass percentile of the reference population). Serum myostatin concentrations were determined by ELISA. To identify a cut-off for high serum myostatin levels, we performed ROC curve analysis. Multivariable logistic regression analysis was used to identify the risk factors for LSMM and rheumatoid cachexia. The risk was expressed as odds ratios (ORs) and their 95% confidence intervals (95% CIs). Results. Compared to the controls, the RA group had a higher proportion of LSMM and exhibited high serum myostatin levels ( ). ROC curve analysis showed that a myostatin ng/mL was the most efficient cut-off for identifying rheumatoid cachexia (sensitivity: 53%, specificity: 71%) and LSMM (sensitivity: 43%, specificity: 77%). In the multivariable logistic regression, RA with high myostatin levels (≥17 ng/mL) was found to increase the risk of cachexia ( , 95% CI: 1.24-6.29; ) and LSMM ( , 95% CI: 1.17-7.89; ). Conclusions. High serum myostatin levels increase the risk of LSMM and rheumatoid cachexia. We propose that high myostatin levels are useful biomarkers for the identification of patients in risk of rheumatoid cachexia and myopenia.

There is a significant rate of therapeutic failure in rheumatoid arthritis (RA) patients treated with leflunomide (LEF). This study investigates the utility values of teriflunomide levels (A77 1726) in identifying RA patients who remained with moderate or severe disease activity after the treatment with LEF. In this cross-sectional study, we compared: (a) RA patients who achieved a DAS28-ESR ≤ 3.2, and (b) RA patients who maintained a DAS28-ESR > 3.2 after treatment. ROC curves determined the cut-off of A77 1726 with the better performance to identify patients achieving a DAS28-ESR ≤ 3.2. Of the 115 patients treated with LEF, 69 (60%) remained with moderate/severe disease activity and 46 (40%) achieved low disease activity/remission. Higher A77 1726 levels showed a negative correlation with DAS28-ESR (r = − 0.42, p < 0.001) and other parameters of disease activity. We obtained the following utility values with the cut-off of A77 1726 > 10 µg/mL to identify RA patients who achieved a DAS28-ESR ≤ 3.2: sensitivity of 91.31%; specificity of 73.91%; positive predictive value of 70.00%; and negative predictive value of 92.73%. Serum A77 1726 discriminated between RA patients who remained with moderate/severe disease activity despite the treatment with LEF both as monotherapy and LEF as combo therapy.

Background: Muscle wasting, also known as myopenia, is frequent in rheumatoid arthritis (RA). To date, it is still unknown if the failure of pharmacologic therapies increases the risk of myopenia in RA. Objective: To identify if treatment failure with conventional synthetic DMARDs (csDMARDs) constitutes an independent risk factor of muscle wasting in women with RA. Methods: This was a cross-sectional study. We included 277 women with RA. Assessments in RA patients included: clinical, epidemiological, and therapeutic variables. The skeletal muscle index (SMI) was estimated by DXA, and myopenia was diagnosed if they had an SMI < 5.45 kg/m². Multivariable logistic regression models identified risk factors of myopenia. Results: Muscle wasting was observed in 28.2% of patients with RA. The risk factors of myopenia in RA were menopausal (OR: 4.45, 95% CI: 1.86 to 10.64) and failure of combined therapy with csDMARDs (OR: 2.42, 95% CI: 1.15 to 5.07). The increased body mass index was protective (OR:0.81, 95% CI: 0.75 to 0.87). Conclusions: Around one of four patients with RA presented muscle wasting. Muscle wasting is related to treatment failure of combined csDMARDs; other factors influencing the presence of muscle wasting is being postmenopausal, whereas, the body mass index was a protective factor.