Some chemoattractants and leukocytes such as M1 and M2 macrophages are known to be involved in the development of glomerulosclerosis during diabetic nephropathy (DN). In the course of diabetes, an altered and defective cellular metabolism leads to the increase in adenosine levels, and thus to changes in the polarity (M1/M2) of macrophages. MRS1754, a selective antagonist of the A2B adenosine receptor (A2BAR), attenuated glomerulosclerosis and decreased macrophage-myofibroblast transition in DN rats. Therefore, we aimed to investigate the effect of MRS1754 on the glomerular expression/secretion of chemoattractants, the intraglomerular infiltration of leukocytes, and macrophage polarity in DN rats. Kidneys/glomeruli of non-diabetic, DN, and MRS1754-treated DN rats were processed for transcriptomic analysis, immunohistopathology, ELISA, and in vitro macrophage migration assays. The transcriptomic analysis identified an upregulation of transcripts and pathways related to the immune system in the glomeruli of DN rats, which was attenuated using MRS1754. The antagonism of the A2BAR decreased glomerular expression/secretion of chemoattractants (CCL2, CCL3, CCL6, and CCL21), the infiltration of macrophages, and their polarization to M2 in DN rats. The in vitro macrophages migration induced by conditioned-medium of DN glomeruli was significantly decreased using neutralizing antibodies against CCL2, CCL3, and CCL21. We concluded that the pharmacological blockade of the A2BAR decreases the transcriptional expression of genes/pathways related to the immune response, protein expression/secretion of chemoattractants, as well as the infiltration of macrophages and their polarization toward the M2 phenotype in the glomeruli of DN rats, suggesting a new mechanism implicated in the antifibrotic effect of MRS1754.

Although a lack of diversity in genetic studies is an acknowledged obstacle for personalized medicine and precision public health, Latin American populations remain particularly understudied despite their heterogeneity and mixed ancestry. This gap extends to COVID-19 despite its variability in susceptibility and clinical course, where ethnic background appears to influence disease severity, with non-Europeans facing higher hospitalization rates. In addition, access to high-quality samples and data is a critical issue for personalized and precision medicine, and it has become clear that the solution lies in biobanks. The creation of the Chilean COVID-19 Biorepository reported here addresses these gaps, representing the first nationwide multicentric Chilean initiative. It operates under rigorous biobanking standards and serves as one of South America’s largest COVID cohorts. A centralized harmonization strategy was chosen and included unified standard operating procedures, a sampling coding system, and biobanking staff training. Adults with confirmed SARS-CoV-2 infection provided broad informed consent. Samples were collected to preserve blood, plasma, buffy coat, and DNA. Quality controls included adherence to the standard preanalytical code, incident reporting, and DNA concentration and absorbance ratio 260/280 assessments. Detailed sociodemographic, health, medication, and preexisting condition data were gathered. In five months, 2262 participants were enrolled, pseudonymized, and sorted by disease severity. The average Amerindian ancestry considering all participant was 44.0% [SD 15.5%], and this value increased to 61.2% [SD 19.5%] among those who self-identified as Native South Americans. Notably, 279 participants self-identified with one of 12 ethnic groups. High compliance (>90%) in all assessed quality controls was achieved. Looking ahead, our team founded the COVID-19 Genomics Network (C19-GenoNet) focused on identifying genetic factors influencing SARS-CoV-2 outcomes. In conclusion, this bottom-up collaborative effort aims to promote the integration of Latin American populations into global genetic research and welcomes collaborations supporting this endeavor. Interested parties are invited to explore collaboration opportunities through our catalog, accessible online.

The pathophysiological mechanisms underlying diabetic lung disease (DLD) remain poorly understood. Beyond hyperglycemia, dysregulated molecules such as adenosine may contribute to pulmonary inflammation and fibrosis. MRS1754, a selective antagonist of the A2B adenosine receptor (A2BAR), has demonstrated anti-inflammatory and antifibrotic effects, including reductions in macrophage (MΦ) infiltration in animal models of diabetes-associated complications; however, its effects on DLD remain unexplored. Here, diabetic Sprague-Dawley rats were treated with MRS1754, and pulmonary inflammation, fibrosis, MΦ infiltration, and polarization were assessed in bronchoalveolar lavage fluid (BALF) and lung tissue using immunohistopathological and molecular approaches. According to data normality, one-way ANOVA/Tukey’s test or Kruskal–Wallis/Dunn’s test were employed, as appropriate; ordinal data were analyzed using the Mann–Whitney test with Bonferroni correction. Compared with controls, diabetic rats exhibited pulmonary inflammation and fibrosis, increased MΦ infiltration, and an M1/M2 polarization imbalance. MRS1754 attenuated these alterations, reducing Tumor necrosis factor-alpha (TNF-α) and Transforming growth factor-beta 1 (TGF-β1) levels, decreasing MΦ accumulation in BALF and lung tissue, and fully restoring the M1/M2 balance to control levels. BALF MΦ populations, particularly the M2 (Cluster of differentiation 163-positive; CD163⁺) subset, correlated strongly with TGF-β1 and fibronectin (FN1) levels. Reanalysis of human fibrotic lung single-cell transcriptomic data further identified MΦ as a major TGF-β1-expressing cell population. Collectively, these findings suggest that A2BAR antagonism partially mitigates inflammation, fibrosis, and MΦ infiltration while fully restoring MΦ polarization balance in DLD, supporting its potential as a therapeutic strategy.