We explore the interaction between estrogen and PCSK9 and their collective impact on lipid metabolism, especially concerning the regulation of low-density lipoprotein receptor levels. Utilizing both animal and cellular models, including ovariectomized mice and HepG2 cell lines, we demonstrate that estrogen deficiency leads to a disruption in lipid metabolism, characterized by elevated levels of total cholesterol and LDL-C. The study commences with mice undergoing ovariectomy, followed by a diet regimen comprising either high-fat diet or normal feed for a four-week duration. Key assessments include analyzing lipid metabolism, measuring PCSK9 levels in the bloodstream, and evaluating hepatic low-density lipoprotein receptor expression. We will also conduct correlation analyses to understand the relationship between PCSK9 and various lipid profiles. Further, a subset of ovariectomized mice on high-fat diet will undergo treatment with either estrogen or PCSK9 inhibitor for two weeks, with a subsequent re-evaluation of the earlier mentioned parameters. Our findings reveal that estrogen inhibits PCSK9-mediated degradation of low-density lipoprotein receptor, a process crucial for maintaining lipid homeostasis. Through a series of experiments, including immunohistochemistry and western blot analysis, we establish that PCSK9 is involved in lipid metabolism disorders caused by estrogen deficiency and that estrogen regulates PCSK9 and low-density lipoprotein receptor at post-transcriptional level. The study provides a mechanism for the involvement of PCSK9 in elucidating the disorders of lipid metabolism caused by estrogen deficiency due to perimenopause and ovarian decline.

BACKGROUND: Familial hypercholesterolemia (FH) is a common inherited metabolic disease that causes premature atherosclerosis, cardiovascular disease, and even death at a young age. Approximately 95% of FH-causing genetic variants that have been identified are in the LDLR gene. However, only 10% of the FH population worldwide has been diagnosed and adequately treated, due to the existence of numerous unidentified variants, uncertainties in the pathogenicity scoring of many variants, and a substantial number of individuals lacking access to genetic testing.
OBJECTIVE: The aim of this study was to identify a novel variant in the LDLR gene that causes FH in a Chinese family, thereby expanding the spectrum of FH-causing variants.
METHODS: Patients were recruited from Beijing Anzhen Hospital, Capital Medical University. FH diagnosis was made according to the Dutch Lipid Clinical Network (DLCN) criteria. Whole-exome sequencing (WES) was conducted to identify the FH-causing variant in the proband, and amplicon sequencing was used to verify the variant in his family members.
RESULTS: A three-generation Chinese family was recruited, and two FH patients were clinically diagnosed, both without known FH-causing variants. These two FH patients and another possible patient carried a novel variant, NC_000019.9(NM_000527.5):c.89_92dup (NP_000518.1:p.Phe32Argfs*21), in the ligand-binding domain of the low-density lipoprotein (LDL) receptor that led to a frameshift. The FH adults in the family showed severe clinical symptoms and statin therapy resistance.
CONCLUSIONS: This study identified a novel pathogenic LDLR variant, c.89_92dup, associated with severe FH clinical manifestations and statin therapy resistance.

BACKGROUND: Familial hypercholesterolemia (FH) is a prevalent hereditary disease that can cause aberrant cholesterol metabolism. In this study, we confirmed that c.415G > A in low-density lipoprotein receptor (LDLR), an FH-related gene, is a pathogenic variant in FH by in silico analysis and functional experiments.
METHODS: The proband and his family were evaluated using the diagnostic criteria of the Dutch Lipid Clinic Network. Whole-exome and Sanger sequencing were used to explore and validate FH-related variants. In silico analyses were used to evaluate the pathogenicity of the candidate variant and its impact on protein stability. Molecular and biochemical methods were performed to examine the effects of the LDLR c.415G > A variant in vitro.
RESULTS: Four of six participants had a diagnosis of FH. It was estimated that the LDLR c.415G > A variant in this family was likely pathogenic. Western blotting and qPCR suggested that LDLR c.415G > A does not affect protein expression. Functional studies showed that this variant may lead to dyslipidemia by impairing the binding and absorption of LDLR to low-density lipoprotein ( LDL).
CONCLUSIONS: LDLR c.415G > A is a pathogenic variant in FH; it causes a significant reduction in LDLR\'s capacity to bind LDL, resulting in impaired LDL uptake. These findings expand the spectrum of variants associated with FH.

This study aimed to develop an innovative dosage form for 10-hydroxycamptothecin (HCPT), a chemotherapeutic agent with limited aqueous solubility and stability, to enhance its parenteral delivery and targeting to hepatic cancer. We formulated HCPT into a nanoemulsion using tributyrin, a dietary component with histone deacetylase inhibitor activity. The resulting HCPT-loaded tributyrin nanoemulsion (Tri-HCPT-E) underwent extensive evaluations. Tri-HCPT-E significantly improved the aqueous solubility, stability, and anti-cancer activities in HepG2 cells. Pharmacokinetic studies confirmed the increased stability and hepatic targeting, with Tri-HCPT-E leading to a 120-fold increase in plasma exposure of intact HCPT and a 10-fold increase in hepatic exposure compared to the commercial free solution. Co-administration of 17α-ethynylestradiol, an up-regulator of low-density lipoprotein (LDL) receptor, further enhanced the distribution and metabolism of HCPT, demonstrating an association between the LDL receptor pathway and hepatic targeting. Most importantly, Tri-HCPT-E exhibited superior in vivo anti-cancer efficacy in a mouse xenograft model compared to the commercial formulation, without causing escalated hepatic or renal toxicity. In conclusion, formulating HCPT into a nanoemulsion with tributyrin has proven to be an innovative and effective strategy for targeted hepatic cancer chemotherapy while tributyrin, a pharmacologically active dietary component, has emerged as a promising functional excipient for drug delivery.

UNASSIGNED: Low-density lipoprotein receptor (LDL-R) gene polymorphisms have been indicated to be correlated with ischemic cerebrovascular disease including ischemic stroke susceptibility. However, the results from each published study are inconsistent.
UNASSIGNED: All eligible case-control studies that met the search terms were retrieved in PubMed, Embase, Wanfang Med Online and Chinese National Knowledge Infrastructure (CNKI) databases. We identified seven independent case-control studies with a total of 10,355 subjects from Chinese population up to May 2023. Summary odds ratios (ORs) and 95% confidence intervals (CIs) were used to evaluate the susceptibility of ischemic stroke.
UNASSIGNED: Meta-analysis results indicated that rs1122608 polymorphism of LDL-R gene significantly decreased ischemic stroke risk under dominant model (OR = 0.69, 95% CI = 0.54-0.87), heterozygote comparison (OR = 0.69, 95% CI = 0.53-0.92) and allele comparison (OR = 0.74, 95% CI = 0.65-0.84) in overall analysis. Furthermore, pooled analysis showed that significant associations were observed between rs688 polymorphism and ischemic stroke risk in heterozygote carriers (OR = 1.71, 95% CI = 1.07-2.71) and dominant model (OR = 1.67, 95% CI = 1.04-2.68) in Chinese population.
UNASSIGNED: Our comprehensive meta-analysis on the role of LDL-R gene rs1122608 and rs688 polymorphisms in the risk of ischemic stroke revealed that the rs1122608 polymorphism was associated with a decreased risk, while the rs688 polymorphism was associated with an increased risk of ischemic stroke in Chinese population. Further multicenter studies were needed to confirm the effect on the susceptibility of ischemic stroke.

BACKGROUND: Curcumin nicotinate (Curtn), derived from curcumin and niacin, reduces serum LDL-C levels, partly due to its influence on PCSK9. This study investigates IDOL\'s role in Curtn\'s lipid-lowering effects.
OBJECTIVE: To elucidate Curtn\'s regulation of the IDOL/LDLR pathway and potential molecular mechanisms in hepatocytes.
METHODS: Differential metabolites in Curtn-treated HepG2 cells were identified via LC-MS. Molecular docking assessed Curtn\'s affinity with IDOL. Cholesterol content and LDLR expression effects were studied in high-fat diet Wistar rats. In vitro evaluations determined Curtn\'s influence on IDOL overexpression\'s LDL-C uptake and LDLR expression in hepatocytes.
RESULTS: Lipids were the main differential metabolites in Curtn-treated HepG2 cells. Docking showed Curtn\'s higher affinity to IDOL\'s FERM domain compared to curcumin, suggesting potential competitive inhibition of IDOL\'s binding to LDLR. Curtn decreased liver cholesterol in Wistar rats and elevated LDLR expression. During in vitro experiments, Curtn significantly enhanced the effects of IDOL overexpression in HepG2 cells, leading to increased LDL-C uptake and elevated expression of LDL receptors.
CONCLUSIONS: Curtn modulates the IDOL/LDLR pathway, enhancing LDL cholesterol uptake in hepatocytes. Combined with its PCSK9 influence, Curtn emerges as a potential hyperlipidemia therapy.

BACKGROUND: Familial hypercholesterolemia (FH) is an autosomal dominant disease of lipid metabolism mainly caused by mutations in the low-density lipoprotein receptor (LDLR) gene. Genetic detection of patients with FH help with precise diagnosis and treatment, thus reducing the risk of coronary heart disease (CHD) and other related diseases. The study aimed to identify the causative gene mutations in a Chinese FH family and reveal the pathogenicity and the mechanism of these mutations.
RESULTS: Whole exome sequencing was performed in a patient with severe lipid metabolism dysfunction seeking fertility guidance from a Chinese FH family. Two LDLR variants c.1875 C > G (p.N625K; novel variant) and c.1448G > A (p.W483*) were identified in the family. Wildtype and mutant LDLR constructs were established by the site-direct mutagenesis technique. Functional studies were carried out by cell transfection to evaluate the impact of detected variants on LDLR activity. The two variants were proven to affect LDL uptake and binding, resulting in cholesterol clearance reduction to different degrees. According to The American College of Medical Genetics and Genomics (ACMG) Standards and Guidelines, the W483* variant was classified as \"Pathogenic\", while the N625K variant as \"VUS\".
CONCLUSIONS: Our results provide novel experimental evidence of functional alteration by LDLR variants identified in our study and expand the mutational spectrum of LDLR mutation induced FH.

BACKGROUND: Cerebral venous sinus thrombosis (CVST) is typically associated with a prothrombotic state of the blood, with its causative factors varying widely. Prior research has not reported the simultaneous occurrence of CVST and dural arteriovenous fistulas (DAVFs) as potentially resulting from genetic mutations. In this case report, we introduce a unique occurrence wherein a patient with a heterozygous mutation of the low-density lipoprotein receptor (LDLR) gene presented with CVST in conjunction with DAVFs.
METHODS: Presentation: A male patient, aged 51, sought treatment at our facility due to a consistent decline in cognitive functions accompanied by recurrent headaches. Comprehensive evaluations were administered, including neurological examinations, laboratory tests, magnetic resonance imaging, digital subtraction angiography, and whole exome sequencing. Digital subtraction angiography identified DAVFs in the patient\'s right sigmoid sinus and an occlusion within the left transverse sinus. The whole exome sequencing of blood samples pinpointed a heterozygous mutation in the LDLR gene (NM_000527:exon12:c.C1747T:p.H583Y). Following the confirmed diagnosis of CVST and DAVFs, the patient underwent anticoagulant therapy combined with endovascular procedures - these comprised embolization of the arteriovenous fistula in the right sigmoid sinus and balloon dilation with stent implantation in the left transverse sinus. A six-month follow-up indicated a significant abatement in the patient\'s symptoms.
CONCLUSIONS: This report marks the first documented case of an LDLR gene mutation that could be associated with the onset of CVST and DAVFs. The mutation in the LDLR gene might foster a prothrombotic environment, facilitating the gradual emergence of CVST and the subsequent genesis of DAVFs.

Carbon nanodots present resistance to photobleaching, bright photoluminescence, and superior biocompatibility, making them highly promising for bioimaging applications. Herein, nanoprobes were caged with four-armed oligomers and subsequently modified with a novel DBCO-PEG-modified retro-enantio peptide ligand reL57, enhancing cellular uptake into U87MG glioma cells highly expressing low-density lipoprotein receptor-related protein 1 (LRP1). A key point in the development of the oligomers was the incorporation of ε-amino-linked lysines instead of standard α-amino-linked lysines, which considerably extended the contour length per monomer. The four-armed oligomer 1696 was identified as the best performer, spanning a contour length of ~8.42 nm for each arm, and was based on an altering motive of two cationic ε-amidated lysine tripeptides and two tyrosine tripeptides for electrostatic and aromatic stabilization of the resulting formulations, cysteines for disulfide-based caging, and N-terminal azidolysines for click-modification. This work highlights that well-designed four-armed oligomers can be used for noncovalent coating and covalent caging of nanoprobes, and click modification using a novel LRP1-directed peptide ligand facilitates delivery into receptor-expressing target cells.

BACKGROUND: Anlotinib has demonstrated encouraging clinical outcomes in the treatment of lung cancer, soft tissue sarcoma and thyroid carcinoma. Several clinical studies have shown a relationship between anlotinib treatment and the occurrence of hyperlipidemia. The fundamental mechanisms, however, are still largely unclear. Here, the effect of anlotinib on lipid metabolism in an animal model and human cancer cells was evaluated and the role of lipid metabolism in the antitumor efficacy of anlotinib was investigated.
METHODS: The C57BL/6 J mouse model as well as A549 and H460 human lung cancer cell lines were used to examine the impact of anlotinib on lipid metabolism both in vivo and in vitro. Levels of triglycerides, high-density lipoprotein, low-density lipoprotein (LDL), and total cholesterol in serum or cell samples were determined using assay kits. The expression levels of crucial genes and proteins involved in lipid metabolism were measured by quantitative RT-PCR and Western blotting. Furthermore, exogenous LDL and knockdown of low-density lipoprotein receptor (LDLR) were used in H460 cells to investigate the relevance of lipid metabolism in the anticancer efficacy of anlotinib.
RESULTS: Anlotinib caused hyperlipidemia in C57BL/6 J mice, possibly by downregulating hepatic LDLR-mediated uptake of LDL cholesterol. AMP-activated protein kinase and mammalian target of rapamycin inhibition may also be involved. Additionally, anlotinib enhanced sterol response element binding protein 1/2 nuclear accumulation as well as upregulated LDLR expression in A549 and H460 cells, which may be attributable to intracellular lipid accumulation. Knockdown of LDLR reduced intracellular cholesterol content, but interestingly, anlotinib significantly improved intracellular cholesterol accumulation in LDLR-knockdown cells. Both exogenous LDL and LDLR knockdown decreased the sensitivity of cells to anlotinib.
CONCLUSIONS: Anlotinib modulates host lipid metabolism through multiple pathways. Anlotinib also exerts a significant impact on lipid metabolism in cancer cells by regulating key transcription factors and metabolic enzymes. In addition, these findings suggest lipid metabolism is implicated in anlotinib sensitivity.