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Sayed, N.

Publications and source records attributed to Sayed, N..

7 recordsLinked to original sources

Immuno-Proteomic Age of Cardiovascular Etiology (iPACE) Signature Predicts Cardiovascular Risk in Elderly Patients

Despite advances in clinical care, cardiovascular disease (CVD) remains the leading cause of disability and mortality worldwide. While age alone is a primary risk factor for CVD, accumulating evidence suggests the immune system influences the initiation and progression of CVD pathophysiology, particularly in heart failure with preserved ejection fraction (HFpEF) and atherosclerotic CVD (ASCVD). Here, using two independent cohorts of older adults, we develop a thirty-protein signature of age based on serum immune proteomics, which correlates with HFpEF and ASCVD risk and mortality (Immuno-Proteomic Age of Cardiovascular Etiology, iPACE). We find aging-related circulating immune proteins associated with ASCVD and HFpEF-specific resilience and susceptibility that may be used as potential prognostic, diagnostic, or therapeutic targets.

immunology↗

Restoring Klf9 Expression with Pressure Overload Leads to Metabolic Maladaptation and Early Onset of Heart Failure

Klf9 is a cardiac-enriched transcription factor of the Kruppel-like factor (Klf) family. Klf9 levels decrease during cardiac hypertrophy; however, no studies have examined its transcriptional targets or role in the progression of hypertrophy. Here, we report genome-wide differential Klf9 occupancy during cardiac hypertrophy, with a predominant enrichment at the metabolic gene promoters. Further, using conditional Klf9 knock-in mice subjected to pressure overload for 1 or 2 weeks, we show that restoring Klf9 expression initially inhibits hypertrophy but later leads to early-onset heart failure. We conclude that a decrease in Klf9 is required for metabolic adaptations that support the development of compensatory hypertrophy.

cell biology↗

Constitutive expression of cardiomyocyte Klf9 precipitates metabolic dysfunction and spontaneous heart failure.

Metabolic adaptations and flexibility during development and disease play an essential in cardiomyocyte function and survival. We recently reported Glucocorticoid receptor (GR)-Kruppel-like factor 9 (Klf9) axis in mediating metabolic adaptations in cardiomyocytes stimulated with Dexamethasone. Klf9 expression decreases in hypertrophic and failing hearts, suggesting its importance in cardiac homeostasis and its potential contribution to dysfunction under pressure overload. Genome wide Klf9 occupancy in adult hearts revealed 2,242 genes directly associated with Klf9, with enrichment in metabolic pathways, autophagy, ubiquitin-mediated proteolysis, and cellular senescence. We generated and characterized a conditional cardiac specific Klf9 knock-In (Klf9KI) mice, which developed progressive cardiac hypertrophy, cardiac dysfunction and cardiac failure by 8wks of age, with mortality by 12-14wks. RNA-seq analysis at 1wk, 4wks, and 8wks showed stage-specific transcriptional changes. At 1 week, 64.81% of differentially expressed genes were downregulated, aligning with Klf9s predicted role as a transcriptional repressor. At 4wks and 8wks, more genes were upregulated, suggesting more of secondary targets in response to cardiac phenotype. KEGG pathway analysis showed dysregulation in lipid, carbohydrate and glutathione metabolism, transcriptional regulation, apoptosis, and innate immunity. Untargeted Metabolomics at 4wks identified significant alterations in tissue metabolite levels, particularly in pathways involving fatty acid metabolism, amino acids, and glucose, correlating with transcriptome data. Mitochondrial function assays revealed progressive dysregulation. At 2 weeks, complex I activity was significantly reduced, while complex II and IV activities were partially preserved. By 4 weeks, all measured respiratory complexes showed significant declines, consistent with decline in mitochondrial function. These mitochondrial deficits preceded overt cardiac dysfunction and likely contributed to the development of hypertrophy and failure. In conclusion, constitutive Klf9 overexpression disrupts transcriptional and metabolic homeostasis, driving progressive hypertrophy, cardiac dysfunction, and failure.

cell biology↗

A murine model of cardiovascular-kidney-metabolic syndrome demonstrates compromised limb function in the ischemic hind limb

AbstractsO_ST_ABSBackgroundC_ST_ABSCardiovascular-Kidney-metabolic (CKM) syndrome is a public health problem involving > 90% of the US and results in premature CVD at a relatively preserved GFR. The molecular mediators of CKM are poorly understood, partly due to the lack of a reliable animal model. We set out to generate an animal model with renal and metabolic dysfunctions, using PAD as a CKM manifestation. MethodsA group of C57BL/6 mice was randomized into four groups-a normal diet (ND), a 0.2% adenine diet (AD, a CKD model), a high-fat diet (HFD, a metabolic model), and a combination of HFD+AD (a potential CKM model). Mice underwent a hind limb ischemia surgery. An array of structural (capillary density, soleus muscle evaluation), and functional assays were performed. ResultsCompared to ND mice, AD mice showed loss of weight (40%) and GFR (90%) (P<0.001). The HFD+AD mice had 23-50% higher weight and GFR than the AD group (P = 0.003). The kidneys of HFD+AD showed tubular atrophy, tubulointerstitial fibrosis, immune infiltration, glomerulomegaly, consistent with glomerular hyperperfusion, hypercholesterolemia, impaired glucose tolerance, and adipophilin in the liver, an early marker of hepatic steatosis, and myocardial fibrosis. Compared to ND mice, the AD and HFD+AD mice showed similar reductions in the hind limb perfusion ratios, microcapillary density, Type II muscle fibers, and increased muscle fibrosis, immune infiltration, and lowest cross-sectional muscle area. Compared to AD, HFD+AD mice showed a lower flux ratio and grip strength, all at a GFR double that of the AD group. ConclusionA combination of HFD+AD in mice displays features of CKD (loss of GFR, renal fibrosis), dysfunctional obesity (dyslipidemia, impaired glucose tolerance, hepatic steatosis and glomerulomegaly), and cardiovascular disease (myocardial fibrosis and PAD) at a higher GFR, consistent with the features of CKM. This model can be explored to probe the mechanisms of CKM syndrome.

pathology↗

Immunosuppression Drugs Exhibit Differential Effects on Endothelial Cell Function

Immunosuppressive medications are widely used to treat patients with neoplasms, autoimmune conditions, and solid organ transplants. Prior studies indicate that immunosuppression drugs can cause adverse vascular remodeling. Given the systemic effects of the drugs, elucidating cell-type specific drug-effects has been challenging. We utilized induced pluripotent stem-cell derived endothelial cells to investigate the role of widely used immunosuppression drugs on endothelial function. We found that among immunosuppression agents, sirolimus reduced basic endothelial cell functions including cell migration, proliferation, acetylated LDL uptake, and angiogenesis properties; while tacrolimus only reduced nitric oxide release. This model allows for investigation of differential effect of immunosuppression drugs on endothelial function that can elucidate mechanisms contributing to adverse vascular profiles observed clinically.

cell biology↗

An Inflammatory Clock Predicts Multi-morbidity, Immunosenescence and Cardiovascular Aging in Humans

While many diseases of aging have been linked to the immunological system, immune metrics with which to identify the most at-risk individuals are lacking. Here, we studied the blood immunome of 1001 individuals age 8-96 and derived an inflammatory clock of aging (iAge), which tracked with multi-morbidity and immunosenescence. In centenarians, iAge was on average, 40 years lower than their corresponding chronological age. The strongest contributor to this metric was the chemokine CXCL9, which was involved in cardiac aging, affected vascular function, and down-regulated Sirtuin-3, a longevity-associated molecule. Thus, our results identify an important link between inflammatory molecules and pathways known to govern lifespan.

immunology↗

Toxicogenomic identification of repositioned therapy for a monogenic disease

The cost of drug development from initial concept to FDA approval has been estimated to be about 2.6 billion USD.1 This cost precludes development of targeted therapies for rare diseases such as monogenetic cardiomyopathies. As part of the Library of Integrated Network-based Cellular Signatures (LINCS) program funded by the NIH, the Broad Institute of MIT has publicly released transcriptional profiles quantifying the effects of more than 25,000 perturbagens on the expression of 978 genes in up to 77 cell lines.2 Transcriptomics has been shown to be a powerful tool in repurposing drugs3,4 and this dataset affords us the unique opportunity to systematically identify small molecule mimics or inhibitors of specific genes, thereby identifying novel treatments for genetic disorders. In this report, we take this approach to identify a novel drug therapy for a monogenic form of familial dilated cardiomyopathy with the transcriptional profile of FDA approved drugs. This approach could potentially be replicated for a wide range of monogenic diseases.

genomics↗