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Reddi, R.

Publications and source records attributed to Reddi, R..

3 recordsLinked to original sources

Yin Yang Interactomes Drive the Metabolic Dysfunction-Associated Liver Disease Continuum to Hepatocellular Carcinoma

The risk for hepatocellular carcinoma (HCC) arising from metabolic dysfunction- associated steatotic liver disease (MASLD)-related cirrhosis exceeds the risk for cancer developing in the kidney, heart, or lung as a consequence of end-stage disease in those organs. Both experimental and clinical studies support the existence of circulating biomarkers whose elevated expression is associated with, and supports the diagnosis of, HCC. We posit the existence of oncogenic HCC biomarkers under regulation by tumor-suppressive microRNAs (miRs), and that reduced tumor-suppressive miR expression leads to increased oncogenic biomarker expression. By interrogating the MASLD-HCC miR interactome and miRs known to regulate HCC biomarkers, we identified hsa-miR-577, hsa-miR-9500, hsa-miR-101-3p, miR-206, hsa- miR-219a-1-3p, and hsa-miR-613 as tumor-suppressive miRs whose expression is reduced across multiple cancers. Their target genes, osteopontin, Golgi protein-73, and Dickkopf-related protein 1, exhibit increased expression in HCC and display oncogenic activity. Collectively, dysregulated expression of these miRs and their downstream gene products may contribute to progression along the MASLD continuum toward HCC. HighlightsWe identified tumor suppressive miRs, hsa-miR-577, hsa-miR-9500, hsa-miR-101-3p, miR-206, hsa-miR-219a-1-3p, and hsa-miR-613 with potentially reduced expression levels in HCC. Their gene products, osteopontin, Golgi protein-73, and Dickkopf-related protein 1, exhibit oncogenic properties and increased expression levels in HCC. These miR-gene product interactions may drive the MASLD continuum to HCC. Mechanistic insights should illuminate therapies. Identification of therapeutics that interrupt these interactions may represent a therapeutic pillar for patients with MASLD. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=159 SRC="FIGDIR/small/698028v1_ufig1.gif" ALT="Figure 1"> View larger version (29K): org.highwire.dtl.DTLVardef@1892140org.highwire.dtl.DTLVardef@1e61677org.highwire.dtl.DTLVardef@cd0488org.highwire.dtl.DTLVardef@1e48d8a_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOFigureC_FLOATNO MASLD-related HCC. The intersection set between the MASLD-HCC miR interactome and the set of miRs regulating biomarkers diagnostic for HCC was interrogated and tumor suppressive miRs regulating HCC biomarkers with oncogenic activity were identified. Increased risk for HCC in patients with MASLD and MASLD-cirrhosis may arise from interactions between these dysregulated miRs and their downstream gene products. C_FIG PrologueMetabolic Dysfunction-Associated Liver Disease (MASLD), the leading cause of hepatocellular carcinoma (HCC) in Sweden, is now taking epidemic proportions in South Asia. In India, there is a relatively high prevalence of pre-diabetes, diabetes and insulin resistance; body mass indices > 35 are being observed. Each of these and/or their combinations represent risk factors for MASLD. Nevertheless, both patients and providers are largely oblivious to this disease, both from a lack of general awareness and the asymptomatic nature of MASLD, at least early within its continuum. Diagnosis is often made late, and by exclusion, when presentation may include fatigue, drowsiness, mild encephalopathy (MASLD-pituitary feedback loop), prominent hepatomegaly and asciites, and with liver-specific test demonstrating stiffness, scarring and even HCC. Societal awareness and effective management of this disease are urgent needs. A strategy akin to the 4 pillars for treatment of type 2 diabetes and chronic kidney disease (CKD) needs to be implemented for treatment of patients with MASLD. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=30 SRC="FIGDIR/small/698028v1_ufig2.gif" ALT="Figure 2"> View larger version (11K): org.highwire.dtl.DTLVardef@89a77org.highwire.dtl.DTLVardef@d50c15org.highwire.dtl.DTLVardef@10c6964org.highwire.dtl.DTLVardef@1db2cfa_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOFigureC_FLOATNO Four-pillar Strategy for MASLD. A strategy akin to the one in place for treatment of type 2 diabetes and CKD needs to be implemented for treatment of patients with MASLD. Aspects of this strategy, viz. SGLT2i and GLP-1{+/-}GIP agonists, are already approved in MASLD. C_FIG

bioinformatics↗

Structural basis for C-type inactivation in a Shaker family voltage gated K+ channel

C-type inactivation is a process by which ion flux through a voltage-gated K+ (Kv) channel is regulated at the selectivity filter. While prior studies have indicated that C-type inactivation involves structural changes at the selectivity filter, the nature of the changes have not been resolved. Here we report the crystal structure of the Kv1.2 channel in a C-type inactivated state. The structure shows that C-type inactivation involves changes in the selectivity filter that disrupt the outer two ion binding sites in the filter. The changes at the selectivity filter propagate to the extracellular mouth and the turret regions of the channel pore. The structural changes observed are consistent with the functional hallmarks of C-type inactivation. This study highlights the intricate interplay between K+ occupancy at the ion binding sites and the interactions of the selectivity filter in determining the balance between the conductive and the inactivated conformations of the filter.

biochemistry↗

Crystallographic and electrophilic fragment screening of the SARS-CoV-2 main protease

COVID-19, caused by SARS-CoV-2, lacks effective therapeutics. Additionally, no antiviral drugs or vaccines were developed against the closely related coronavirus, SARS-CoV-1 or MERS-CoV, despite previous zoonotic outbreaks. To identify starting points for such therapeutics, we performed a large-scale screen of electrophile and non-covalent fragments through a combined mass spectrometry and X-ray approach against the SARS-CoV-2 main protease, one of two cysteine viral proteases essential for viral replication. Our crystallographic screen identified 71 hits that span the entire active site, as well as 3 hits at the dimer interface. These structures reveal routes to rapidly develop more potent inhibitors through merging of covalent and non-covalent fragment hits; one series of low-reactivity, tractable covalent fragments was progressed to discover improved binders. These combined hits offer unprecedented structural and reactivity information for on-going structure-based drug design against SARS-CoV-2 main protease.

biophysics↗