👤 Aishwarya Ravindran

Gout is an acute inflammatory arthritis triggered by monosodium urate (MSU) crystal deposition and activation of innate immune responses. In addition to inflammasome signaling, emerging evidence suggests that metabolic reprogramming of arachidonic acid (AA) pathways amplifies inflammatory responses during gout flares. However, the contribution of upstream fatty acid desaturation processes that regulate endogenous AA availability remains poorly defined. 1,2,3,4,6-Penta-O-galloyl-β-D-glucose (PGG) is a naturally occurring polyphenol with reported anti-inflammatory activity, but its effects on MSU-induced fatty acid metabolism and gouty inflammation have not been well established. Publicly available bulk and single-cell transcriptomic datasets from human and mouse gout studies were analyzed to assess dysregulation of AA-associated pathways. MSU-induced inflammatory responses were examined in mouse bone marrow-derived macrophages and in a murine MSU-induced gout model. Macrophages were treated with PGG prior to MSU stimulation, and inflammatory cytokine production, phagocytosis, and expression of fatty acid desaturases were assessed. Lipidomic analysis of macrophages and plasma was performed using gas chromatography-mass spectrometry (GC-MS) to quantify arachidonic acid and related fatty acids. In vivo disease severity, cytokine expression, and anti-inflammatory markers were evaluated following PGG treatment. Analysis of public datasets revealed consistent dysregulation of arachidonic acid-associated inflammatory pathways during gout flares. In macrophages, MSU stimulation increased expression of fatty acid desaturases FADS1 and FADS2 and promoted accumulation of arachidonic acid, concomitant with robust production of pro-inflammatory cytokines. PGG treatment significantly suppressed MSU-induced FADS1, FADS2 and arachidonic acid levels, and attenuated pro-inflammatory cytokine production. PGG also markedly impaired macrophage phagocytosis of MSU crystals. In vivo, PGG treatment significantly reduced clinical disease severity in an MSU-induced gout model, suppressed fatty acid desaturation and arachidonic acid accumulation in plasma, decreased pro-inflammatory cytokine expression, and enhanced anti-inflammatory markers. These findings identify fatty acid desaturation as an important metabolic contributor to gouty inflammation and demonstrate that PGG suppresses MSU-induced inflammation by limiting endogenous arachidonic acid availability, reducing inflammatory amplification, and impairing MSU crystal phagocytosis. Targeting upstream fatty acid metabolism represents a potential therapeutic strategy for modulating acute gout flares beyond conventional anti-inflammatory approaches. Show less

Genetic variation and lived experiences shape how our hearts respond to chronic stress and development of heart failure, manifested as compromised pumping function and abnormal hemodynamics. The hallmark of heart failure etiology is excessive stress signals followed by maladaptive structural, electrical, and functional changes to the heart muscle, also known as cardiac remodeling. The specific genetic mechanisms which underly such phenomenon, however, are still unclear, due in part to difficulties in accounting for environmental effects in human population studies. To overcome this challenge, we used the Collaborative Cross (CC) mouse population to investigate heritable susceptibility to cardiovascular stress by chronic β-adrenergic receptor stimulation with the β-agonist isoproterenol, which targets the common signaling gateway to heart failure, regardless of the particular upstream stressor. Across 8 founder and 63 CC lines, we measured non-failing and failing heart characteristics represented by cardiac structure and function, organ weights, and cell morphology. Genome-wide QTL mapping detected 49 genome-wide significant loci, collapsing to 20 unique intervals (nine significant for multiple traits and eleven trait-specific), averaging 12.83 Mb in size. To identify high-confidence candidate genes from these loci, we augmented our trait mapping with coding variants drawn from sequencing data, tractability in our in vitro rat cardiomyocyte model, and previously reported protein functions and mouse or human phenotypes. This approach recovered both known regulators, such as Hey2, and new candidates. Functional tests in in vitro models highlight three candidate genes that modulate hypertrophic growth: Abcb10, Mrps5 and Lmod3. Abcb10 knockdown increased cell size at baseline and further with isoproterenol, consistent with loss of a mitochondrial stress-buffering role. Mrps5 knockdown blunted stress-induced hypertrophy, possibly related to its previously known involvement in oxidative stress regulation. Lmod3 knockdown also attenuated hypertrophy, potentially via actin-assembly control under adrenergic stress. Together, these results reveal heritable pathways of β-adrenergic remodeling in mice and provide an interpretable, translational, and stepwise framework to prioritize candidate genes within broad loci for mechanistic studies of heart failure. Show less

BRAF and MEK inhibitors are standard treatments in histiocytic disorders, such as Erdheim-Chester disease (ECD). Some patients lack MAPK-pathway alterations, making these treatments less effective. We describe three patients with histiocytic disorders who have novel non-MAPK pathway alterations. These alterations were studied through genomic and in silico analyses when applicable, then treated with off-label medications rationally selected on the basis of genomic alterations. Patient 1 had rapidly progressive ECD involving the CNS. A CSF1R in-frame deletion (p.S560_P566del) was identified, and in silico modeling predicted a gain-of-function mutation. This alteration was targeted with pexidartinib, which led to a clinical complete response (CR) within 2 months, and a partial response (PR) on imaging after 3 months. After 15 months, the disease became resistant to pexidartinib and transformed to histiocytic sarcoma. Patient 2 has skin-only involvement of a xanthogranuloma disorder. A KIF5B-FGFR1 fusion was identified on RNA sequencing and targeted with pemigatinib. At 24 months of follow-up, she remains in a clinical PR. Patient 3 has ECD involving the bone marrow, gastrointestinal tract, and subcutaneous tissues. A MEF2C-FLT3 fusion was identified and targeted with sorafenib. He achieved a clinical CR and radiographic PR within 3 months, which has continued for 30 months. We report three patients with histiocytic disorders harboring novel alterations who had sustained responses to off-label kinase inhibitors specific to their histiocytic disorder. Pathogenic variants outside of the MAPK pathway, including variants of unknown significant, may be targeted with readily available small molecules. Show less

In conventional, the biologically treated tannery wastewaters are rich in dissolved organics and the application of reverse osmosis (RO) to biologically treated tannery wastewater was challenged with fouling and failure of RO membrane due to existence of lingering dissolved organic compounds. In present investigation the bacterial cell immobilized packed bed reactor (CIPBR) was operated to remove the dissolved organic compounds in biologically treated post-tanning wastewater to avoid membrane fouling in RO. The efficient microbial syndicate to eliminate dissolved organics in post-tanning wastewater was isolated and immobilized on to the carbon silica matrix (CSM) in the range of 2.98 ± 0.2 × 10 Show less

In patients with secondary (autoimmune) membranous nephropathy, two novel proteins, Exostosin 1 and Exostosin 2 (EXT1/EXT2), are potential disease antigens, biomarkers, or both. In this study, we validate the EXT1/EXT2 findings in a large cohort of membranous lupus nephritis. We conducted a retrospective cohort study of patients with membranous lupus nephritis, and performed immunohistochemistry studies on the kidney biopsy specimens against EXT1 and EXT2. Clinicopathologic features and outcomes of EXT1/EXT2-positive versus EXT1/EXT2-negative patients were compared. Our study cohort included 374 biopsy-proven membranous lupus nephritis cases, of which 122 (32.6%) were EXT1/EXT2-positive and 252 (67.4%) were EXT1/EXT2-negative. EXT1/EXT2-positive patients were significantly younger ( The prevalence of EXT1/EXT2 positivity was 32.6% in our cohort of membranous lupus nephritis. Compared with EXT1/EXT2-negative membranous lupus nephritis, EXT1/EXT2-positive disease appears to represent a subgroup with favorable kidney biopsy findings with respect to chronicity indices. Cases of membranous lupus nephritis that are EXT1/EXT2-negative are more likely to progress to ESKD compared with those that are EXT1/EXT2-positive. Show less

Membranous nephropathy (MN) is the most common cause of nephrotic syndrome in Caucasian adults. Phospholipase A2 receptor (PLA2R)- and exostosin 1 (EXT1)/exostosin 2 (EXT2)-associated MN represent the most common primary and secondary forms of MN. The complement profile using a proteomics approach has not been studied in these 2 common forms of MN. We used laser microdissection and mass spectrometry (MS/MS) to dissect glomeruli and identify glomerular complement proteins in PLA2R-associated ( MS/MS identified high total spectral counts for PLA2R and EXT1/EXT2 in corresponding cases of PLA2R- and EXT1/EXT2-positive MN. Both PLA2R- and EXT1/EXT2-associated MN had high spectral counts of complement proteins C3, C4, C5, C6, C7, C8, and C9. Complement protein C1 was present in low spectral counts in EXT1/EXT2-associated MN. Regulators of complement activation that were detected in MN included higher spectral counts of FH, FHR-1, FHR-5, clusterin, vitronectin and lower spectral counts of FHR-3, FHR-4, and CD59. Low spectral counts of FB and properdin, key components of the alternative pathway, also were detected. IgG4 and IgG1 were the most abundant IgG subclasses in PLA2R- and EXT1/EXT2-associated MN. Lower spectral counts for C3, C4, and C5 were detected in control cases when compared with MN. Significant complement activation is present in MN as evidenced by large spectral counts of complement proteins from C3- and C4-based pathways, including regulatory proteins of complement pathways. These data suggest that anticomplement drugs may be effective in treatment for MN. Show less

In membranous nephropathy (MN), which is characterized by deposition of immune complexes along the glomerular basement membrane (GBM), phospholipase A2 receptor (PLA2R) and thrombospondin type 1 domain-containing 7A are target antigens in approximately 70% and 1%-5% of cases of primary MN, respectively. In other cases of primary MN and in secondary MN, the target antigens are unknown. We studied 224 cases of biopsy-proven PLA2R-negative MN and 102 controls (including 47 cases of PLA2R-associated MN) in pilot and discovery cohorts. We also evaluated 48 cases of PLA2R-negative presumed primary MN and lupus MN in a validation cohort. We used laser microdissection and mass spectrometry to identify new antigens, which were localized by immunohistochemistry. Mass spectrometry detected exostosin 1 (EXT1) and exostosin 2 (EXT2) in 21 cases of PLA2R-negative MN, but not in PLA2R-associated MN and control cases. Immunohistochemistry staining revealed bright granular GBM staining for EXT1 and EXT2. Clinical and biopsy findings showed features of autoimmune disease, including lupus, in 80.7% of the 26 EXT1/EXT2-associated MN cases we identified. In the validation cohort, we confirmed that EXT1/EXT2 staining was detected in pure class 5 lupus nephritis (eight of 18 patients) and in presumed primary MN associated with signs of autoimmunity (three of 16 patients); only one of the 14 cases of mixed class 5 and 3/4 lupus nephritis was positive for EXT1/EXT2. Tests in seven patients with EXT1/EXT2-associated MN found no circulating anti-exostosin antibodies. A subset of MN is associated with accumulation of EXT1 and EXT2 in the GBM. Autoimmune disease is common in this group of patients. Show less