Interferon-directed therapies for the treatment of systemic lupus erythematosus: a critical update

Interference of B lymphocyte tolerance by prolactin in rheumatic autoimmune diseases

Systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and systemic sclerosis (SSc) are the most common rheumatic autoimmune diseases/disorders (RADs) that affect autologous connective tissues as a result of the breakdown of the self-tolerance mechanisms of the immune system. Prolactin, a glycoprotein hormone, has been known for its crucial role in the pathogenesis of these rheumatic autoimmune diseases. In addition to regulating lymphocyte proliferation and antibody synthesis, prolactin is also responsible for regulating cytokine production. Moreover, it contributes to the breakdown of central and peripheral tolerance mechanisms of B lymphocytes. Given the crucial role of prolactin in the pathogenesis of the mentioned RADs, prolactin may contribute to their pathogenesis by the breakdown of tolerance. In the present study, the key role of prolactin to the breakdown of B lymphocyte tolerance and its possible implication for the pathogenesis of these diseases is discussed. Current literature supports prolactin's role in the breakdown of B lymphocyte central and peripheral tolerance mechanisms, such apoptosis, receptor editing, and also anergy. Therefore, prolactin may contribute to the pathogenesis of RADs by the breakdown of B lymphocyte tolerance. However, more investigations, particularly in RA and SSc animal models, are required to precisely address the pathologic role of prolactin.

Cannabinoids modulate the microbiota-gut-brain axis in HIV/SIV infection by reducing neuroinflammation and dysbiosis while concurrently elevating endocannabinoid and indole-3-propionate levels

BACKGROUND

Although the advent of combination anti-retroviral therapy (cART) has transformed HIV into a manageable chronic disease, an estimated 30-50% of people living with HIV (PLWH) exhibit cognitive and motor deficits collectively known as HIV-associated neurocognitive disorders (HAND). A key driver of HAND neuropathology is chronic neuroinflammation, where proinflammatory mediators produced by activated microglia and macrophages are thought to inflict neuronal injury and loss. Moreover, the dysregulation of the microbiota-gut-brain axis (MGBA) in PLWH, consequent to gastrointestinal dysfunction and dysbiosis, can lead to neuroinflammation and persistent cognitive impairment, which underscores the need for new interventions.

METHODS

We performed RNA-seq and microRNA profiling in basal ganglia (BG), metabolomics (plasma) and shotgun metagenomic sequencing (colon contents) in uninfected and SIV-infected rhesus macaques (RMs) administered vehicle (VEH/SIV) or delta-9-tetrahydrocannabinol (THC) (THC/SIV).

RESULTS

Long-term, low-dose THC reduced neuroinflammation and dysbiosis and significantly increased plasma endocannabinoid, endocannabinoid-like, glycerophospholipid and indole-3-propionate levels in chronically SIV-infected RMs. Chronic THC potently blocked the upregulation of genes associated with type-I interferon responses (NLRC5, CCL2, CXCL10, IRF1, IRF7, STAT2, BST2), excitotoxicity (SLC7A11), and enhanced protein expression of WFS1 (endoplasmic reticulum stress) and CRYM (oxidative stress) in BG. Additionally, THC successfully countered miR-142-3p-mediated suppression of WFS1 protein expression via a cannabinoid receptor-1-mediated mechanism in HCN2 neuronal cells. Most importantly, THC significantly increased the relative abundance of Firmicutes and Clostridia including indole-3-propionate (C. botulinum, C. paraputrificum, and C. cadaveris) and butyrate (C. butyricum, Faecalibacterium prausnitzii and Butyricicoccus pullicaecorum) producers in colonic contents.

CONCLUSION

This study demonstrates the potential of long-term, low-dose THC to positively modulate the MGBA by reducing neuroinflammation, enhancing endocannabinoid levels and promoting the growth of gut bacterial species that produce neuroprotective metabolites, like indole-3-propionate. The findings from this study may benefit not only PLWH on cART, but also those with no access to cART and more importantly, those who fail to suppress the virus under cART.