👤 Asmita Thapa

Pancreatic ductal adenocarcinoma (PDAC) is characterized by dense stromal fibrosis that promotes immune exclusion and treatment resistance, yet the upstream drivers of this pro-fibrotic cascade remain poorly defined. Here, we identify phosphoinositide 3-kinase δ (PI3Kδ) as a previously unrecognized driver of fibrosis in PDAC. Pharmacological inhibition of PI3Kδ reduces collagen deposition while enhancing the infiltration of activated CD8 Show less

Angiopoietin-like 3 (ANGPTL3) is a major regulator of lipoprotein metabolism. ANGPTL3 deficiency results in lower levels of triglycerides, LDL-cholesterol (LDL-C), and HDL-cholesterol (HDL-C), and may protect from cardiovascular disease. ANGPTL3 oligomerizes with ANGPTL8 to inhibit lipoprotein lipase (LPL), the enzyme responsible for plasma triglyceride hydrolysis. Independently of ANGPTL8, oligomers of ANGPTL3 can inhibit endothelial lipase (EL), which regulates circulating HDL-C and LDL-C levels through the hydrolysis of lipoprotein phospholipids. The N-terminal region of ANGPTL3 is necessary for both oligomerization and lipase inhibition. However, our understanding of the specific residues that contribute to these functions is incomplete. In this study, we performed mutagenesis of the N-terminal region to identify residues important for EL inhibition and oligomerization. We also assessed the presence of different ANGPTL3 species in human plasma. We identified a motif important for lipase inhibition, and protein structure prediction suggested that this region interacted directly with EL. We also found that recombinant ANGPTL3 formed a homotrimer and was unable to inhibit EL activity when trimerization was disrupted. Surprisingly, we observed that human plasma contained more monomeric ANGPTL3 than trimeric ANGPTL3. An important implication of these findings is that previous correlations between circulating ANGPTL3 and circulating triglyceride-rich lipoproteins need to be revisited. Show less

Venetoclax showed promising activity in a small phase II trial in relapsed/refractory Waldenström macroglobulinemia (WM). To report the clinical activity of venetoclax and prognostic factors associated with outcomes in a larger cohort, we retrospectively identified 76 patients with relapsed/refractory lymphoplasmacytic lymphoma (LPL)/WM treated with venetoclax monotherapy at nine US medical centers. The median age at venetoclax treatment initiation was 66 years. MYD88, CXCR4, and TP53 mutations were detected in 65 (94%), 23 (40%), and 10 (22%) patients, respectively. The median number of prior lines of treatment was 3, including covalent BTK inhibitor in 82% and alkylating agent in 71% of patients. The overall and major response rates to venetoclax were 70% and 63%, respectively. The median and 2-year progression-free survival (PFS) were 28.5 months and 57%, respectively. The median and 2-year overall survival were not reached and 82%, respectively. Prior treatment with BTK inhibitor was the only factor associated with PFS in multivariate analysis (hazard ratio 2.97, p = 0.012). Venetoclax dose interruptions and/or reductions occurred in 27 patients (41%). Five patients (7%) developed laboratory tumor lysis syndrome (TLS), including 3 (4%) with clinical TLS. Venetoclax resulted in a high response rate and a prolonged PFS in patients with heavily pretreated LPL/WM. Show less

Hepatic proteomes are intricately controlled through biosynthesis, extracellular secretion, and intrahepatic degradation. Autophagy governs lysosome-mediated intrahepatic degradation and the hepatic proteome. When autophagy is impaired, it leads to the accumulation of intrahepatic proteins, causing proteinopathy. This study investigates whether autophagy can modulate the hepatic proteome non-degradatively. Utilizing conditional, inducible, and hepatotoxin models of hepatic autophagy impairment, we assessed the overall hepatic proteome expression using Coomassie brilliant blue (CBB) staining and liquid chromatography-tandem mass spectrometry (LC/MS). We pinpointed and confirmed four specific hepatic proteins-Cps1, Ahcy, Ca3, and Gstm1-that were selectively modified in autophagy-deficient livers. Expression of Cps1, Ahcy, and Ca3 were significantly reduced, while Gstm1 expression increased in livers with autophagy impairment. Interestingly, these changes in hepatic protein levels were not due to defective autophagic degradation but were associated with alterations in mRNA transcript levels. Moreover, as a result of autophagic dysfunction, sustained activation of the nuclear erythroid-derived 2-like 2 (Nrf2) transcription factor, transcriptionally regulated the mRNA levels of these proteins. Our findings indicate that autophagy can influence hepatic proteins not solely via traditional degradative routes but also through non-degradative transcriptional processes by modulating Nrf2. Show less

The purpose of this study was to examine whether myeloid dendritic cells (mDCs) from patients with multiple sclerosis (MS) and healthy controls (HCs) become similarly tolerogenic when exposed to IL-27 as this may represent a potential mechanism of autoimmune dysregulation. Our study focused on natural mDCs that were isolated from HCs and MS patient peripheral blood mononuclear cells (PBMCs). After a 24-h treatment with IL-27 ± lipopolysaccharide (LPS), the mDCs were either harvested to identify IL-27-regulated gene expression or co-cultured with naive T-cells to measure how the treated DC affected T-cell proliferation and cytokine secretion. mDCs isolated from HCs but not untreated MS patients became functionally tolerogenic after IL-27 treatment. Although IL-27 induced both HC and untreated MS mDCs to produce similar amounts of IL-10, the tolerogenic HC mDCs expressed PD-L2, IDO1, and SOCS1, while the non-tolerogenic untreated MS mDCs expressed IDO1 and IL-6R. Cytokine and RNA analyses identified two signature blocks: the first identified genes associated with mDC tolerizing responses to IL-27, while the second was associated with the presence of MS. In contrast to mDCs from untreated MS patients, mDCs from HCs and IFNb-treated MS patients became tolerogenic in response to IL-27. The genes differentially expressed in the different donor IL-27-treated mDCs may contain targets that regulate mDC tolerogenic responses. Show less

CKD-519, a potent cholesteryl ester transfer protein (CETP) inhibitor, is a clinical candidate being developed for the treatment of dyslipidemia. It is considered a Biopharmaceutical Classification System II compound with low solubility and high permeability. The objective of this study was to develop early formulations focusing on the dissolution rate of the compound to achieve dose-dependent exposure. High performance formulation strategies including solid dispersion (SD) and a self-microemulsifying drug delivery system (SMEDDS) were investigated and their in vivo and in vitro correlations were also evaluated in monkeys along with dose optimization in human volunteers. The SD granules were prepared in a fluid bed granulator using microcrystalline cellulose and mannitol as carriers. Poloxamer 407 and Eudragit E PO were each found to be a suitable solubilizing agent and polymer for the improvement of the CKD-519 dissolution rate. Pharmacokinetic studies in monkeys showed that the SD tablets exhibited better absorption than the SMEDDS in a dose-dependent manner from 1.5 mg to 100 mg. The mannitol-based SD tablet formulations were bioequivalent. However, pharmacokinetics studies in humans showed that the dose was saturable above 100 mg of CKD-519. This study was performed to determine how to develop early formulations for clinical studies and to identify rational formulation development strategies for CKD-519 to establish the pharmaceutical proof-of-concept in humans. Show less