PCSK9 promotes the lysosomal degradation of cell surface LDL receptor (LDLR). We analyzed how excess LDLR generated by PCSK9 deficiency is differently handled in male and female mice to possibly unveil the mechanism leading to the lower efficacy of PCSK9 mAb on LDL-cholesterol levels in women. Analysis of intact or ovariectomized PCSK9 knockout (KO) mice supplemented with placebo or 17β-estradiol (E2) demonstrated that female, but not male mice massively shed the soluble ectodomain of the LDLR in the plasma. Liver-specific PCSK9 KO or alirocumab-treated WT mice exhibit the same pattern. This shedding is distinct from the basal one and is inhibited by ZLDI-8, a metalloprotease inhibitor pointing at ADAM10/ADAM17. In PCSK9 KO female mice, ZLDI-8 raises by 80 % the LDLR liver content in a few hours. This specific shedding is likely cholesterol-dependent: it is prevented in PCSK9 KO male mice that exhibit low intra-hepatic cholesterol levels without activating SREBP-2, and enhanced by mevalonate or high cholesterol feeding, or by E2 known to stimulate cholesterol synthesis via the estrogen receptor-α. Liver transcriptomics demonstrates that critically low liver cholesterol in ovariectomized female or knockout male mice also hampers the cholesterol-dependent G2/M transition of the cell cycle. Finally, higher levels of shed LDLR were measured in the plasma of women treated with PCSK9 mAb. PCSK9 knockout female mice hormonally sustain cholesterol synthesis and shed excess LDLR, seemingly like women. In contrast, male mice rely on high surface LDLR to replenish their stocks, despite 80 % lower circulating LDL.
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http://dx.doi.org/10.1016/j.bbalip.2022.159217 | DOI Listing |
Stargardt disease is a currently untreatable, inherited neurodegenerative disease that leads to macular degeneration and blindness due to loss-of-function mutations in the ABCA4 gene. We have designed a dual adeno-associated viral vector encoding a split-intein adenine base editor to correct the most common mutation in ABCA4 (c.5882G>A, p.
View Article and Find Full Text PDFTransl Psychiatry
January 2025
Ear Institute, University College London, London, UK.
The 22q11.2 deletion is a risk factor for multiple psychiatric disorders including schizophrenia and also increases vulnerability to middle-ear problems that can cause hearing impairment. Up to 60% of deletion carriers experience hearing impairment and ~30% develop schizophrenia in adulthood.
View Article and Find Full Text PDFNat Commun
January 2025
Ruminant Diseases Research Center, College of Life Sciences, Shandong Normal University, Jinan, Shandong, China.
Phenazine biosynthesis-like domain-containing protein (PBLD) and Cedrelone have been identified as tumor suppressors. However, their roles in virus infection remain unclear. Here, we demonstrate that PBLD upregulates the type I interferon (IFN-I) response through activating NF-kappaB (NF-κB) signaling pathway to resist viral infection in cells and mice.
View Article and Find Full Text PDFJ Mol Histol
January 2025
Department of Laboratory Medicine, Xiamen Key Laboratory of Genetic Testing, the First Affiliated Hospital of Xiamen University, School of Medicine, Xiamen University, 55 Zhenhai Road, Siming District, Xiamen, 361003, Fujian, China.
Objective: This study aimed to elucidate the role of pyruvate dehydrogenase kinase-1 (PDK1) in cervical cancer (CC) by investigating its impact on cell proliferation, migration, and epithelial-mesenchymal transition (EMT) under hypoxic conditions.
Methods: PDK1-silenced CC cell lines were established using lentiviral shRNA technology. Cell migration and invasion were assessed through scratch and Transwell assays, respectively.
J Neurosci
January 2025
Bowles Center for Alcohol Studies, University of North Carolina School of Medicine, Chapel Hill, NC, USA; Department of Pharmacology, University of North Carolina School of Medicine, Chapel Hill, NC, USA, 27599.
Blunted sensitivity to ethanol's aversive effects can increase motivation to consume ethanol; yet, the neurobiological circuits responsible for encoding these aversive properties are not fully understood. Plasticity in cells projecting from the anterior insular cortex (aIC) to the basolateral amygdala (BLA) is critical for taste aversion learning and retrieval, suggesting this circuit's potential involvement in modulating the aversive properties of ethanol. Here, we tested the hypothesis that GABAergic currents onto aIC-BLA projections would be facilitated as a consequence of retrieval of an ethanol-conditioned taste aversion (CTA).
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