Systemic lupus erythematosus (SLE) is a complex autoimmune disorder characterized by the presence of various serum autoantibodies and multi-system effects, predominantly affecting young female patients. The pathogenesis of SLE involves a combination of genetic factors, environmental triggers, and pathogen invasions that disrupt immune cell activation, leading to the release of autoantibodies and chronic inflammation. Mitochondria, as the primary cellular powerhouses, play a crucial role in SLE development through their control of energy generation, reactive oxygen species (ROS) production, and cellular apoptotic pathways. Dysregulation of mitochondrial structure and function can contribute to the immune dysregulation, oxidative stress, and inflammation seen in SLE. Recent research has highlighted the impact of mitochondrial dysfunction on various immune cells involved in SLE pathogenesis, such as T-lymphocytes, B-lymphocytes, neutrophils, and plasmacytoid dendritic cells. Mitochondrial dysfunction in these immune cells leads to increased ROS production, disrupted mitophagy, and alterations in energy metabolism, contributing to immune dysregulation and inflammation. Moreover, genetic variations in mitochondrial DNA (mtDNA) and abnormalities in mitochondrial dynamics have been linked to the pathogenesis of SLE, exacerbating oxidative stress and immune abnormalities. Targeting mitochondrial function has emerged as a promising therapeutic approach for SLE. Drugs such as sirolimus, N-acetylcysteine, coenzyme Q10, and metformin have shown potential in restoring mitochondrial homeostasis, reducing oxidative stress, and modulating immune responses in SLE. These agents have demonstrated efficacy in preclinical models and clinical studies by improving disease activity, reducing autoantibody titers, and ameliorating organ damage in SLE patients. In conclusion, this review underscores the critical role of mitochondria in the pathogenesis of SLE and the potential of targeting mitochondrial dysfunction as a novel therapeutic strategy for improving outcomes in SLE patients. Further investigation into the mechanisms underlying mitochondrial involvement in SLE and the development of targeted mitochondrial therapies hold promise for advancing SLE treatment and enhancing patient care.

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by symmetrical joint inflammation, cartilage degradation, and bone erosion. This review explores the multifaceted aspects of RA pathogenesis, focusing on the dynamic interplay between innate and adaptive immune responses, genetic predisposition, and environmental triggers. The development of RA involves genetic susceptibility and trigger events such as infections, trauma, smoking, obesity, and microbiome alterations, fostering autoimmune reactions and tissue/organ destruction. The innate immune response, including toll-like receptor activation and synovial fibroblasts’ roles, contributes to the acceleration of inflammatory processes in joint tissues. Monocytes and macrophages organize and sustain chronic joint inflammation, leading to tissue damage and bone resorption, while highlighting the significance of CD14 and CD16 subsets in RA pathogenesis. In the adaptive immune response, aberrant activation and proliferation of CD4+ T cells and the role of regulatory T cells in maintaining immune tolerance are discussed. Target cytokines like TNF-α, IL-6, IL-1, IL-17, and BAFF, as well as chemokines such as CCL2, CXCL10, CCL5, and CXCL12, have emerged as critical components in managing chronic inflammation and joint damage in RA. This comprehensive overview provides insights into the pathophysiology of RA and potential therapeutic avenues, emphasizing the importance of understanding these complex immunological and genetic mechanisms for developing more effective treatment strategies.

Sjögren’s syndrome (SS) is a chronic autoimmune disorder characterised by lymphocytic infiltration of the exocrine glands, which leads to dryness of the eyes and mouth; systemic manifestations such as arthritis, vasculitis, and interstitial lung disease; and increased risks of lymphoma and cardiovascular diseases. SS predominantly affects women, with a strong genetic component linked to sex chromosomes. Genome-wide association studies (GWASs) have identified numerous single-nucleotide polymorphisms (SNPs) associated with primary SS (pSS), revealing insights into its pathogenesis. The adaptive and innate immune systems are crucial to SS’s development, with viral infections implicated as environmental triggers that exacerbate autoimmune responses in genetically susceptible individuals. Moreover, recent research has highlighted the role of vitamin D in modulating immune responses in pSS patients, suggesting its potential therapeutic implications. In this review, we focus on the recently identified SNPs in genes like OAS1, NUDT15, LINC00243, TNXB, and THBS1, which have been associated with increased risks of developing more severe symptoms and other diseases such as fatigue, lymphoma, neuromyelitis optica spectrum disorder (NMOSD), dry eye syndrome (DES), and adverse drug reactions. Future studies should focus on larger, multi-ethnic cohorts with standardised protocols to validate findings and identify new associations. Integrating genetic testing into clinical practise holds promise for improving SS management and treatment strategies, enabling personalised interventions based on comprehensive genetic profiles. By focusing on specific SNPs, vitamin D, and their implications, future research can lead to more effective and personalised approaches for managing pSS and its complications.

Activated neutrophils release neutrophil extracellular traps (NETs), complex structures composed of extracellular genetic material and proteins sourced from the nucleus, granules, and cytoplasm in response to pathogenic inflammatory conditions. These NETs play a crucial role in the hosts innate immune defense against invasive infections. Notably, in conditions like atherosclerosis, these extracellular formations can also be elicited by inflammatory stimuli such as lipids, prothrombotic factors, platelet aggregation, or proinflammatory cytokines. NETs have been identified on the inner arterial walls in cardiovascular disease states. By promoting inflammation through NETosis-mediated cell adhesion processes and exerting cytotoxic effects leading to cellular dysfunction and tissue damage, NETs contribute to the pathogenesis of inflammatory conditions.

Cathelicidins (human LL-37 and rat CRAMP) are multifunctional peptides involved in various cardiovascular conditions. This review integrates the recent findings about the functional involvement of LL-37/CRAMP across atherosclerosis, acute coronary syndrome, myocardial infarction, heart failure, diabetic cardiomyopathy, and platelet aggregation/thrombosis. In atherosclerosis, LL-37 interacts with scavenger receptors to modulate lipid metabolism and binds with mitochondrial DNA and lipoproteins. In acute coronary syndrome, LL-37 influences T cell responses and mitigates calcification within atherosclerotic plaques. During myocardial infarction and ischaemia/reperfusion injury, LL-37/CRAMP exhibits dual roles: protecting against myocardial damage through the AKT and ERK1/2 signalling pathways, while exacerbating inflammation via TLR4 and NLRP3 inflammasome activation. In heart failure, LL-37/CRAMP attenuates hypertrophy and fibrosis via NF-κB inhibition and the activation of the IGFR1/PI3K/AKT and TLR9/AMPK pathways. Moreover, in diabetic cardiomyopathy, these peptides alleviate oxidative stress and fibrosis by inhibiting TGFβ/Smad and AMPK/mTOR signalling and provide anti-inflammatory effects by reducing NF-κB nuclear translocation and NLRP3 inflammasome formation. LL-37/CRAMP also modulates platelet aggregation and thrombosis through the FPR2 and GPVI receptors, impacting apoptosis, autophagy, and other critical cellular processes. This comprehensive overview underscores LL-37/CRAMP as a promising therapeutic target in cardiovascular diseases, necessitating further elucidation of its intricate signalling networks and biological effects for clinical translation.