Hari Krishna Yalamanchili

Astrocytes are key regulators of lipid metabolism, and dysregulated astrocytic lipid processing is implicated in Parkinson’s disease (PD) pathogenesis. Our prior genome-wide screens identified ACSBG1, an astrocyte-enriched acyl-CoA synthetase, as a candidate regulator of α-synuclein (α-Syn) levels. However, how ACSBG1 links lipid reprogramming to inflammatory astrocyte activation and α-Syn pathology remains unknown. We compared the transcriptomic, cytokine, and lipid secretomes of TNF-α and IL-1α stimulated primary astrocytes from wild-type (WT) and Acsbg1 knockout (KO) mice. In vivo, we crossed Acsbg1 KO mice with a Thy1-α-Syn PD model to assess behavior, neuroinflammation, synaptic integrity, and α-Syn levels. Following cytokine exposure, Acsbg1 KO astrocytes mounted an attenuated inflammatory transcriptional response, secreting significantly fewer inflammatory mediators (e.g., IL-6, RANTES, MIP-3α) and less long-chain Sphingosine 20:1 than WT astrocytes. Importantly, exogenous Sphingosine 20:1 or cytokines from WT reactive astrocytes induced neuronal α-Syn phosphorylation (pS129). In vivo, Acsbg1 deletion in Thy1-α-Syn mice reduced astrogliosis, rescued synaptic and behavioral deficits, and decreased total and pS129-α-Syn. These findings establish ACSBG1 as a key regulator of inflammatory astrocyte signaling that contributes to α-Syn phosphorylation via specific cytokine and lipid mediators, identifying ACSBG1 as a novel therapeutic target for modulating astrocyte-neuron communication in PD. Graphical

Endometriosis is a chronic gynecological disorder marked by the growth of endometrial-like tissue outside the uterus, often leading to pelvic pain, inflammation, and infertility. Despite its global prevalence, diagnosis remains delayed, and effective non-surgical treatments are lacking. While recent transcriptomic studies have identified mRNA transcript changes in ectopic lesions, the contribution of alternative pre-mRNA splicing, a key posttranscriptional regulatory layer, remains largely unknown. In this study, we performed a comprehensive analysis of alternative splicing (AS) events in endometriotic lesions using transcriptomic data. We uncovered distinct alterations in alternative splicing events are associated with endometriosis, highlighting a previously underappreciated layer of gene regulation. Specifically, we discovered that AS events, including exon skipping (SE) and intron retention (IR), were more prevalent than other events, and altered AS events correlated with transcriptomic variation in lesions. We identified two genes, GALNT7 and ZNF28 , with significantly reduced exon inclusion in epithelial cells of lesions, potentially resulting in decreased levels of mature transcripts. Functional assays showed that knockdown of GALNT7 and ZNF28 , or of critical exons within these genes, increased cellular proliferation, supporting their potential roles as growth‑suppressive genes in endometriotic cells. Together, this study broadens our understanding of transcriptomic dysregulation and highlights misregulated alternative splicing as a potential contributor to endometriotic cell growth and disease progression.

Increased pulmonary vascular pressures due to vascular remodeling, elevated vascular resistance, and vasoconstriction characterize Pulmonary Arterial Hypertension (PAH). The narrowing of the pulmonary arteries and obstruction of blood flow increase the Right Ventricular (RV) afterload, forcing the RV to undergo structural and functional changes. While adaptive remodeling leads to RV compensation by maintaining function, maladaptive remodeling leads to RV decompensation, characterized by worsening function and eventual failure. At present, there is no effective treatment for these patients as therapies for left ventricular failure are ineffectual, and there are no therapies specifically targeting the RV. Therefore, there is a clear need to understand the pathophysiology of RV failure and to identify the differences between adaptive and maladaptive RV remodeling. This study analyzes changes in polyadenylation site usage, a process known as alternative polyadenylation (APA), in RV failure. APA is a mechanism used to regulate mRNA maturation that can result in either shortening or elongation of the mRNA 3’UTR. By analyzing APA patterns in RV tissue from donor controls and patients with compensated and decompensated RV failure, we demonstrate a pattern of 3’UTR elongation that is present in decompensated RV failure and not in compensated or control RVs. Further, altered APA was also detected in 3 distinct rat models of PH, where 15 transcripts had shared APA alterations across both rat models and human disease. Our study provides an unbiased approach to identifying the molecular changes leading to RV dysfunction while pinpointing novel therapeutic targets that can be leveraged for intervention. These APA signatures may serve as biomarkers to distinguish adaptive from maladaptive RV remodeling. In addition, the RNA-processing machinery that regulates APA, such as NUDT21 and CPSF6, represents potential therapeutic targets for RNA-based interventions. Together, our findings link RNA processing to diagnostic and therapeutic opportunities in right heart failure.

Rich HE, et al. Immune Netw. 2026 Apr;26(2):e4. https://doi.org/10.4110/in.2026.26.e4

The senescent cell (SC) fate is linked to aging, multiple disorders and diseases, and physical dysfunction. Senolytics, agents that selectively eliminate 30%–70% of SCs, act by transiently disabling the senescent cell antiapoptotic pathways (SCAPs), which defend those SCs that are proapoptotic and pro‐inflammatory from their own senescence‐associated secretory phenotype (SASP). Consistent with this, a JAK/STAT inhibitor, Ruxolitinib, which attenuates the pro‐inflammatory SASP of senescent human preadipocytes, caused them to become “senolytic‐resistant”. Administering senolytics to obese mice selectively decreased the abundance of the subset of SCs that is pro‐inflammatory. In cell cultures, the 30%–70% of human senescent preadipocytes or human umbilical vein endothelial cells (HUVECs) that are senolytic‐resistant (to Dasatinib or Quercetin, respectively) had increased p16 ^INK4a , p21 ^CIP1 , senescence‐associated β‐galactosidase (SAβgal), γH2AX, and proliferative arrest similarly to the total SC population (comprising senolytic‐sensitive plus‐resistant SCs). However, the SASP of senolytic‐resistant SCs entailed less pro‐inflammatory/apoptotic factor production, induced less inflammation in non‐senescent cells, and was equivalent or richer in growth/fibrotic factors. Senolytic‐resistant SCs released less mitochondrial DNA (mtDNA) and more highly expressed the anti‐inflammatory immune evasion signal, glycoprotein non‐melanoma‐B (GPNMB). Transplanting senolytic‐resistant SCs intraperitoneally into younger mice caused less physical dysfunction than transplanting the total SC population. Because Ruxolitinib attenuates SC release of proapoptotic SASP factors, while pathogen‐associated molecular pattern factors (PAMPs) can amplify the release of these factors rapidly (acting as “senosensitizers”), senolytic‐resistant and senolytic‐sensitive SCs appear to be interconvertible.

Acute respiratory distress syndrome (ARDS) is a life-threatening condition driven by uncontrolled inflammation and immune dysregulation. The post-transcriptional mechanisms that fine-tune macrophage activation in ARDS remain poorly understood. Here, we identify Nudix hydrolase 21 (NUDT21) as a critical regulator of macrophage-mediated inflammation through alternative polyadenylation (APA). NUDT21 was downregulated in macrophages from human and mouse ARDS lungs. Functional studies using macrophage-specific Nudt21 knockout mice (Nudt21 ^f/f LysmCre, Nudt21 ^f/f Cxcr1Cre, or mice with bone marrow transplantation) revealed that Nudt21 loss amplifies cytokine production, neutrophil infiltration, and lung injury in lipopolysaccharide or bleomycin-induced lung injury models. Notably, neutrophil depletion did not alleviate the exaggerated inflammation in Nudt21 ^f/f LysmCre mice, confirming a macrophage-specific mechanism. In contrast, Nudt21 ^f/f CD68 rtTA/tetOCre mice did not exhibit increased injury, likely because alveolar macrophages—but not recruited macrophages—play a major role in the LPS model. Transcriptome profiling revealed widespread 3’UTR shortening of inflammatory genes and elevated protein expression in NUDT21-deficient macrophages, indicating APA-mediated translational activation. Furthermore, we identified hypoxia-induced microRNA-181a as an upstream repressor of NUDT21, linking oxygen stress to APA remodeling. Collectively, these findings uncover a previously unrecognized hypoxia–miR-181a–NUDT21–APA axis that amplifies macrophage inflammation and lung injury.

The senescent cell (SC) fate is linked to aging, multiple disorders and diseases, and physical dysfunction. Senolytics, agents that selectively eliminate 30-70% of SCs, act by transiently disabling the senescent cell anti-apoptotic pathways (SCAPs), which defend those SCs that are pro-apoptotic and pro-inflammatory from their own senescence-associated secretory phenotype (SASP). Consistent with this, a JAK/STAT inhibitor, Ruxolitinib, which attenuates the pro-inflammatory SASP of senescent human preadipocytes, caused them to become “senolytic-resistant”. Administering senolytics to obese mice selectively decreased abundance of the subset of SCs that is pro-inflammatory. In cell cultures, the 30-70% of human senescent preadipocytes or human umbilical vein endothelial cells (HUVECs) that are senolytic-resistant (to Dasatinib or Quercetin, respectively) had increased p16 ^INK4a , p21 ^CIP1 , senescence-associated β-galactosidase (SAβgal), γH2AX, and proliferative arrest similarly to the total SC population (comprising senolytic-sensitive plus -resistant SCs). However, the SASP of senolytic-resistant SCs entailed less pro-inflammatory/ apoptotic factor production, induced less inflammation in non-senescent cells, and was equivalent or richer in growth/ fibrotic factors. Senolytic-resistant SCs released less mitochondrial DNA (mtDNA) and more highly expressed the anti-inflammatory immune evasion signal, glycoprotein non-melanoma-B (GPNMB). Transplanting senolytic-resistant SCs intraperitoneally into younger mice caused less physical dysfunction than transplanting the total SC population. Because Ruxolitinib attenuates SC release of pro-apoptotic SASP factors, while pathogen-associated molecular pattern factors (PAMPs) can amplify the release of these factors rapidly (acting as “senosensitizers”), senolytic-resistant and senolytic-sensitive SCs appear to be interconvertible.