Background Diagnosing rheumatoid arthritis (RA) remains challenging, particularly in resource-constrained settings. Circulating microRNAs (miRNAs) have emerged as candidate non-invasive biomarkers; however, their expression in African populations has not been systematically evaluated. Methods This hospital-based study drew on a parent cohort of 170 participants (85 patients with rheumatoid arthritis and 85 healthy controls) recruited at Kenyatta National Hospital, Kenya. Circulating miRNAs were quantified in a subsample of 40 participants (20 RA, 20 controls). Two miRNAs (miR-21-5p and miR-223-3p) were measured in plasma using stem-loop RT-qPCR with miR-16-5p as the endogenous control. Relative expression was assessed using the comparative cycle threshold (ΔΔCt) method. Diagnostic performance was evaluated by receiver operating characteristic analysis with bootstrap confidence intervals and bootstrap internal validation, and all comparisons were additionally adjusted for age and sex. Results Both miRNAs were significantly downregulated in RA patients relative to controls (miR-21-5p fold change 0.21; miR-223-3p fold change 0.35; both P < 0.001), and both differences persisted after adjustment for age and sex (miR-21-5p adjusted P = 0.006; miR-223-3p adjusted P = 0.019). miR-21-5p showed the stronger individual discrimination (AUC 0.900, 95% CI 0.772–0.990) compared with miR-223-3p (AUC 0.857, 95% CI 0.717–0.960). A two-miRNA logistic model achieved an apparent AUC of 0.925 (95% CI 0.820–0.997), corresponding to an optimism-corrected AUC of 0.911 after bootstrap internal validation; this did not significantly exceed miR-21-5p alone (ΔAUC 0.025, P = 0.299). No statistically significant difference was detected between the two-miRNA model and CRP, ACPA or RF, although the study was not powered for equivalence testing. Within RA patients, no correlation between miRNA expression and clinical variables survived correction for multiple testing. Conclusion Circulating miR-21-5p and miR-223-3p are markedly downregulated in Kenyan patients with rheumatoid arthritis, and miR-21-5p discriminated patients from healthy controls with an apparent AUC of 0.900 (95% CI 0.772–0.990); the two-miRNA logistic model had an apparent AUC of 0.925 and an optimism-corrected AUC of 0.911. Within-group analyses suggest that age alone is unlikely to account for the between-group difference in miR-21-5p (age explained approximately 1% of the observed difference), although age and disease status are strongly collinear and the age distributions overlap very little. These findings identify circulating miR-21-5p as a credible candidate diagnostic biomarker in a sub-Saharan African population, in which no such evaluation has previously been reported. Consistent with the accepted sequence of biomarker development, establishing clinical diagnostic accuracy now requires validation against early disease and clinically relevant disease controls.
Concurrent chemoradiation therapy (CCRT) is the standard treatment for locally advanced cervical cancer (LACC); however, approximately 30% of patients respond poorly, and alternative therapeutic options remain limited. We aimed to identify peripheral immune biomarkers associated with treatment response and characterize the immune mechanisms underlying clinical outcomes. Thirty patients with LACC undergoing CCRT were enrolled and classified three months after treatment as responders (n = 15) or non-responders (n = 15) according to Response Evaluation Criteria in Solid Tumors. Peripheral blood mononuclear cells were collected at baseline and at one and three months after treatment. Flow cytometry was used to analyze CD4+ and CD8+ T cells, CD4+ forkhead box P3 (FOXP3)+ regulatory T cells, interferon gamma (IFN-γ)- and interleukin-10 (IL-10)-producing T cells, and programmed cell death protein 1 (PD-1)-expressing exhausted T cells. Responders showed elevated baseline levels of CD4+ T cells, FOXP3+ regulatory T cells, and IL-10-producing CD4+ T cells, together with increased IFN-γ-producing CD8+ T cells during treatment. Non-responders exhibited elevated PD-1-expressing CD8+ T cells and reduced regulatory and effector T-cell activity. Ratios incorporating FOXP3+ regulatory T cells and PD-1 expression demonstrated strong predictive performance, with area under the curve values up to 0.98. These findings indicate that a balanced regulatory-to-effector T-cell profile is associated with favorable response to CCRT, whereas increased T-cell exhaustion is linked to treatment failure. Peripheral immune profiling may provide a minimally invasive approach for early prediction of treatment outcomes in LACC.
Putrescine, a core polyamine, is closely linked to intestinal immune homeostasis and the pathogenesis of intestinal disease, yet its role in shaping dendritic cell (DC) subset differentiation in the intestinal lamina propria and the mechanism behind it remains undefined. Here, we first performed integrated analysis of seven public human single-cell RNA sequencing datasets to profile dendritic cell subsets across colorectal cancer tissues with varied MMR phenotypes. We fed mice a 1% (w/v) putrescine diet to raise intestinal putrescine levels and examined the effects on lamina propria DC subsets using flow cytometry, single-cell RNA sequencing, transcriptomics, and O2K-based metabolic assays. Elevated putrescine expanded the cDC1 subset (CD103+CD11b−CD172a−), contracted the cDC2 subsets (CD103−CD11b+CD172a+ and CD103+CD11b+CD172a+), and reduced surface expression of CD11b and CD172a on lamina propria DCs. Single-cell and transcriptomic profiling showed that putrescine reshaped the transcriptional landscape of DC subsets, with marked downregulation of reactive oxygen species (ROS) and oxidative phosphorylation (OXPHOS) pathways. O2K metabolic analysis confirmed that putrescine lowered ROS output and oxygen consumption rate across several mitochondrial respiratory states, including basal and ATP-coupled respiration, while western blotting showed reduced Cybb expression in lamina propria DCs. Together, these findings indicate that putrescine reshapes intestinal lamina propria DC subset composition by suppressing Cybb, thereby limiting ROS production and OXPHOS activity. This work offers new mechanistic insight into how polyamine metabolism governs intestinal immune homeostasis and points to potential therapeutic targets for intestinal disorders such as colorectal cancer and inflammatory bowel disease.
Aging is associated with chronic low-grade inflammation and cellular senescence, and macrophages are thought to contribute to these changes in the kidney. This study examined whether pharmacological inhibition of colony-stimulating factor 1 receptor (CSF1R) with PLX5622 modulates age-associated inflammatory and senescence-related changes in murine kidneys. Young and aged wild-type mice were treated with low-dose or high-dose PLX5622, and kidneys were analyzed for macrophage abundance, inflammatory markers, senescence-associated markers, and kidney injury markers. Aged kidneys showed increased expression of p16, IL-6, CX3CR1, and LCN2, together with higher numbers of F4/80-positive macrophages. Additional immunohistochemical analyses demonstrated increased CSF1R and p16 expression in F4/80-positive cells and increased senescence-associated β-galactosidase activity in aged kidneys. High-dose PLX5622 significantly reduced macrophage numbers in young and aged kidneys and lowered CX3CR1 expression, but was associated with increased blood urea nitrogen levels. In contrast, low-dose PLX5622 partially reduced macrophage abundance and significantly decreased IL-6, TNF-α, CX3CR1, p16, and senescence-associated β-galactosidase activity in aged kidneys without increasing blood urea nitrogen, while TIM1 remained unchanged. These findings indicate that CSF1R-sensitive macrophage populations contribute to age-associated inflammatory and senescence-related changes in the kidney and suggest that partial macrophage depletion may attenuate these processes without overt evidence of renal toxicity.
m 6 A methylation modification participates in the regulation of inflammatory responses, whereas the specific role and related mechanism of its cofactor RBM15 in asthma remain poorly defined. This study aimed to explore the function of RBM15 in allergic asthma and further elucidate its molecular mechanism regulating the NF-κB pathway through the m 6 A-YTHDF2-TNFAIP3 axis. In this research, an OVA-induced mouse allergic asthma model was established to detect RBM15 expression and assess the influences of RBM15 knockdown on airway inflammation, airway hyperresponsiveness and Th2 immune response. Besides, TNF-α was applied to construct an in vitro inflammatory model of airway epithelial cells. Western blot, mRNA stability detection, m 6 A-MeRIP-qPCR and RIP-qPCR were adopted to explore the mechanism by which RBM15 modulates TNFAIP3, and YTHDF2 complementation experiment was performed to confirm the function of this regulatory axis. The results revealed that RBM15 was highly expressed in lung tissues of asthmatic mice. Silencing RBM15 could alleviate airway inflammation, decrease serum IgE and Th2 cytokine levels, and ameliorate airway hyperresponsiveness. In vitro assays verified that RBM15 elevated the m 6 A modification level of TNFAIP3 mRNA, thereby facilitating YTHDF2-dependent degradation of TNFAIP3 mRNA, suppressing TNFAIP3 expression and triggering NF-κB pathway activation. RBM15 knockdown recovered TNFAIP3 expression and blocked NF-κB signaling, and such changes could be rescued by YTHDF2 overexpression. Collectively, inhibition of RBM15 relieves airway inflammation and airway hyperresponsiveness in allergic asthma via the m 6 A-YTHDF2-TNFAIP3 axis.
