Publications by authors named "Li Pik Shan"

Congenital scoliosis (CS), affecting approximately 0.5 to 1 in 1,000 live births, is commonly caused by congenital vertebral malformations (CVMs) arising from aberrant somitogenesis or somite differentiation. While Wnt/ß-catenin signaling has been implicated in somite development, the function of Wnt/planar cell polarity (Wnt/PCP) signaling in this process remains unclear.

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SULT2A8 is a male-predominant and liver-specific mouse cytosolic sulfotransferase (SULT) that sulfonates 7α-hydroxyl (7α-OH) bile acids in vitro. Sulfonation regulates bile acid homeostasis, which in turn regulates cholesterol and energy metabolism. Using the Sult2a8-heterozygous (HT) mouse model created earlier in our laboratory, we aimed to investigate the physiological role of SULT2A8 in sulfonating 7α-OH bile acids and its impact on energy metabolism in vivo under both fed and energy-deprivation conditions.

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Bag1 transcribes a multifunctional protein that participates in many important biological processes such as cell apoptosis, proliferation, differentiation and embryo development. Despite numerous published studies, the role of Bag1 in the context of embryonic stem (ES) cells, has not been explored. To investigate the function of Bag1 in ES cells, we generated mutant Bag1 ES cells using the CRISPR/Cas9 system.

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Article Synopsis
  • Super-enhancers are clusters of Mediator-bound enhancer elements that play a crucial role in regulating gene identity, especially in erythroid cells during development and disease.
  • By creating mouse models to delete individual regulatory elements of the α-globin super-enhancer, researchers found that each enhancer operates independently and adds to the overall gene expression and chromatin structure without synergistic effects.
  • This study emphasizes the need for thorough functional genetic analyses to uncover new insights into transcriptional regulation.
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Article Synopsis
  • The study investigates how hepatitis B virus (HBV) integration contributes to the risk of hepatocellular carcinoma (HCC) by analyzing HBV-positive HCC cell lines through transcriptome sequencing.
  • Researchers identified a chimeric fusion transcript called HBx-LINE1 that has tumor-promoting effects and is present in about 23.3% of HBV-associated HCC tumors, linking it to poorer patient outcomes.
  • The findings suggest that HBx-LINE1 enhances β-catenin activity and activates Wnt signaling, which may increase susceptibility to cancer and indicate a new target for understanding HCC mechanisms.
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The transcription factor Runx1 is a pivotal regulator of definitive hematopoiesis in mouse ontogeny. Vertebrate Runx1 is transcribed from 2 promoters, the distal P1 and proximal P2, which provide a paradigm of the complex transcriptional and translational control of Runx1 function. However, very little is known about the biologic relevance of alternative Runx1 promoter usage in definitive hematopoietic cell emergence.

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The transcription factor Runx1 plays a pivotal role in hematopoietic stem cell (HSC) emergence, and studies into its transcriptional regulation should give insight into the critical steps of HSC specification. Recently, we identified the Runx1 +23 enhancer that targets reporter gene expression to the first emerging HSCs of the mouse embryo when linked to the heterologous hsp68 promoter. Endogenous Runx1 is transcribed from 2 alternative promoters, P1 and P2.

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The transcription factor Runx1/AML1 is an important regulator of hematopoiesis and is critically required for the generation of the first definitive hematopoietic stem cells (HSCs) in the major vasculature of the mouse embryo. As a pivotal factor in HSC ontogeny, its transcriptional regulation is of high interest but is largely undefined. In this study, we used a combination of comparative genomics and chromatin analysis to identify a highly conserved 531-bp enhancer located at position + 23.

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This study investigated the effect of fosinopril (Fos), valsartan (Val), and combination of both drugs (Fos + Val) on the cardiac and renal expression of aquaporin-1 (AQP1) and aquaporin-2 (AQP2) in congestive heart failure (CHF). A rat model of CHF was created by ligating the left anterior descending coronary artery to induce acute myocardial infarction (AMI). Rats were treated by Fos, Val, or Fos + Val for 4 weeks.

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