👤 Joseph M Miano

BACKGROUNDMetabolic dysfunction-associated steatotic liver disease (MASLD) has a substantial inherited component. Rare variants in apolipoprotein B gene (APOB) have been implicated in susceptibility to liver steatosis, but their role in disease progression and outcomes is unclear.METHODSWe investigated APOB rare variants in a case-control cohort of people with advanced MASLD versus healthy controls (n = 510 and 261, respectively), a family-based study (n = 43 and literature meta-analysis), the Million Veteran Program (MVP) cohort (n = 94,885), and the UK Biobank (UKBB) (n = 417,657).RESULTSIn the clinical cohort, APOB variants were enriched in people with advanced MASLD (OR 13.8, 95% CI: 2.7-70.7, P = 0.002) and associated with lower circulating lipids, but higher MASLD activity and fibrosis (P < 0.05). In the family study, APOB variants segregated with hepatic steatosis and fibrosis (P < 0.05). Cross-ancestry meta-analysis of the study cohorts yielded pooled ORs for cirrhosis and hepatocellular carcinoma (HCC) of 1.82, 95% CI: 1.33-2.49 and 3.53, 95% CI: 2.09-5.98, respectively. Variants affecting specifically ApoB100 had a 3-fold greater effect on hepatic lipid metabolism compared with those impairing also ApoB48 and were specifically protective against coronary artery disease (P < 0.05). The variants affected cirrhosis risk similarly, but ApoB48/100 had a larger effect on HCC (P < 0.05).CONCLUSIONSRare APOB variants predispose individuals to advanced MASLD and HCC, with distinct contributions from disrupted VLDL and chylomicrons secretion. These findings highlight the interplay between hepatic and intestinal lipid handling, suggesting that APOB genotyping may enhance MASLD risk stratification and patient identification.FUNDINGEuropean Union, Italian Ministry of Health, Swedish Research Council, Veterans Health Administration, NIH. Show less

Cholestatic liver diseases are a heterogeneous group of conditions that can remain unexplained despite a comprehensive diagnostic assessment. Genetic disorders may underlie many of these unexplained adult-onset cholestasis cases. However, genetic testing in adults has been focused on genes linked to progressive familial intrahepatic cholestasis (PFIC). This study evaluated the diagnostic utility of whole exome sequencing (WES) by targeting a broader set of genes beyond PFIC genes. Adults with unexplained cholestatic liver disease from one tertiary center underwent WES. Pathogenic and rare damaging variants in candidate cholestatic and liver disease genes were prioritized, and genotype-phenotype correlations were conducted. Twenty-one patients with three distinct cholestatic phenotypes (recurrent lithiasis, intrahepatic cholestasis, and primary sclerosing cholangitis with unusual features) were included. WES yielded a genetic diagnosis of inherited cholestatic or liver disorder mimicking the cholestatic phenotype in 5 cases (23.8%). ABCB4 was the causative gene in 2 cases (40.0%), whereas genes outside the PFIC spectrum (ABCC2, PPOX, APOB) accounted for the other 3 (60.0%). This study highlights the value of WES in the diagnostic workup of adult-onset cholestatic liver disease and expands our understanding of its genetic landscape, paving the way for larger-scale studies. Show less

Cirrhosis and hepatocellular carcinoma (HCC) are long-term complications of chronic liver disease (CLD). In this large multi-ancestry genome-wide association study of all-cause cirrhosis (35,481 cases, 2.36M controls) and HCC (6,680 cases, 1.76M controls), we identified 27 loci associated with cirrhosis (10 novel) and 11 with HCC (three novel). Three novel cirrhosis loci were replicated in independent cohorts (e.g. Show less

Familial hypercholesterolemia (FH) is characterized by elevated LDL-C and an increased risk of premature cardiovascular events. Inclisiran is a small interfering RNA that inhibits hepatic PCSK9 synthesis and promotes LDL-C clearance by enhancing LDLR expression on hepatocytes. This study aimed to evaluate the efficacy of six-months add-on inclisiran on lipid profile and PWV in FH; furthermore, we investigated the association between LDL-C reduction and PWV variation. This prospective observational study involved 78 genetically confirmed FH subjects with an LDL-C off-target despite high-intensity statins plus ezetimibe. All subjects obtained biochemical analysis and PWV evaluation at baseline and after six months add-on inclisiran. After six months add-on inclisiran, 41 % of subjects achieved LDL-C targets. Significant reductions of LDL-C (-41.5 %, p < 0.001), ApoB (-33.7 %, p < 0.01), Non-HDL-C (-35.9 %, p < 0.001), and Lp(a) (-18 %, p < 0.01) were observed, while PWV improved by 14.4 % (p < 0.001). In a secondary analysis, the Primary prevention group showed a higher prevalence of subjects on LDL-C target than the Secondary prevention group (59 % vs 23.1 %, p < 0.001). Both groups exhibited significant improvements of lipid profile and PWV (Δ - 14.1 %, p < 0.01 and Δ - 14.6 %, p < 0.001, respectively). Linear regression showed a significant association between ΔPWV and ΔLDL-C in the whole study population as well as in the Primary and Secondary prevention groups (p for all <0.001). Inclisiran significantly improved lipid profile and PWV in FH subjects. ΔPWV was significantly associated with ΔLDL-C. Show less

Familial hypercholesterolemia (FH) is characterized by lifelong elevated LDL-C levels and increased cardiovascular risk. PCSK9 inhibitors (PCSK9i) reduce LDL-C and Lp(a), however, the effect of dual lipid reduction on mechanical vascular function remains unclear. The aim of this study was to evaluate the efficacy of PCSK9i in reducing LDL-C and Lp(a) and to assess the relationship between the dual lipid reduction and the mechanical vascular profile improvement in FH subjects. This prospective observational study included 301 genetically confirmed FH subjects treated with PCSK9i added to high-intensity statins and ezetimibe. Biochemical and PWV measurements were performed at baseline and after six months. Subjects were stratified into four groups based on median values of ΔLDL-C and ΔLp(a). After six months of add-on PCSK9i, 44.9% of FH subjects achieved their LDL-C targets. Reductions were observed in LDL-C (− 49.8%, Dual lipid reduction with PCSK9i was associated with a pronounced mechanical vascular profile improvement in FH subjects; however, an intensive Lp(a) reduction may be needed to achieve a greater mechanical vascular benefit. Show less

Epidemiological studies suggest that individuals in the Mediterranean region with deficiency of glucose-6-phosphate dehydrogenase (G6PD) are less susceptible to cardiovascular diseases. However, our knowledge regarding the effects of G6PD deficiency on pathogenesis of vascular diseases caused by factors, like angiotensin II (Ang-II), which stimulate synthesis of inflammatory cytokines and vascular inflammation, is lacking. Furthermore, to-date the effect of G6PD deficiency on vascular health has been controversial and difficult to experimentally prove due to a lack of good animal model. To determine the effect of Ang-II-induced hypertension (HTN) and stiffness in a rat model of the Mediterranean G6PD (G6PD Our findings revealed that infusion of Ang-II (490 ng/kg/min) elicited less HTN and medial hypertrophy of carotid artery in G6PD The G6PD Show less

Megacystis microcolon intestinal hypoperistalsis syndrome (MMIHS) is a congenital visceral myopathy characterized by severe dilation of the urinary bladder and defective intestinal motility. The genetic basis of MMIHS has been ascribed to spontaneous and autosomal dominant mutations in actin gamma 2 ( Show less

Prostatic smooth muscle cells (pSMCs) differentiation is a key factor for prostatic homeostasis, with androgens exerting multiple effects on these cells. Here, we demonstrated that the myodifferentiator complex Srf/Myocd is up-regulated by testosterone in a dose-dependent manner in primary cultures of rat pSMCs, which was associated to the increase in Acta2, Cnn1, and Lmod1 expressions. Blocking Srf or Myocd by siRNAs inhibited the myodifferentiator effect of testosterone. While LPS led to a dedifferentiated phenotype in pSMCs, characterized by down-regulation of Srf/Myocd and smooth muscle cell (SMC)-restricted genes, endotoxin treatment on Myocd-overexpressing cells did not result in phenotypic alterations. Testosterone at a physiological dose was able to restore the muscular phenotype by normalizing Srf/Myocd expression in inflammation-induced dedifferentiated pSMCs. Moreover, the androgen reestablished the proliferation rate and IL-6 secretion increased by LPS. These results provide novel evidence regarding the myodifferentiating role of testosterone on SMCs by modulating Srf/Myocd. Thus, androgens preserve prostatic SMC phenotype, which is essential to maintain the normal structure and function of the prostate. J. Cell. Physiol. 232: 2806-2817, 2017. © 2016 Wiley Periodicals, Inc. Show less

Several studies have shown through chemical inhibitors that p38 mitogen-activated protein kinase (MAPK) promotes vascular smooth muscle cell (VSMC) differentiation. Here, we evaluate the effects of knocking down a dominant p38MAPK isoform on VSMC differentiation. Knockdown of p38MAPKα (MAPK14) in human coronary artery SMCs unexpectedly increases VSMC differentiation genes, such as miR145, ACTA2, CNN1, LMOD1, and TAGLN, with little change in the expression of serum response factor (SRF) and 2 SRF cofactors, myocardin (MYOCD) and myocardin-related transcription factor A (MKL1). A variety of chemical and biological inhibitors demonstrate a critical role for a RhoA-MKL1-SRF-dependent pathway in mediating these effects. MAPK14 knockdown promotes MKL1 nuclear localization and VSMC marker expression, an effect partially reversed with Y27632; in contrast, MAP2K6 (MKK6) blocks MKL1 nuclear import and VSMC marker expression. Immunostaining and Western blotting of injured mouse carotid arteries reveal elevated MAPK14 (both total and phosphorylated) and reduced VSMC marker expression. Reduced MAPK14 expression evokes unanticipated increases in VSMC contractile genes, suggesting an unrecognized negative regulatory role for MAPK14 signaling in VSMC differentiation. Show less

Smooth muscle cell (SMC) differentiation is defined largely by a number of cell-restricted genes governed directly by the serum response factor (SRF)/myocardin (MYOCD) transcriptional switch. Here, we describe a new SRF/MYOCD-dependent, SMC-restricted gene known as Leiomodin 1 (Lmod1). Conventional and quantitative RT-PCRs indicate that Lmod1 mRNA expression is enriched in SMC-containing tissues of the mouse, whereas its two paralogs, Lmod2 and Lmod3, exhibit abundant expression in skeletal and cardiac muscle with very low levels in SMC-containing tissues. Western blotting and immunostaining of various adult and embryonic mouse tissues further confirm SMC-specific expression of the LMOD1 protein. Comparative genomic analysis of the human LMOD1 and LMOD2 genes with their respective mouse and rat orthologs shows high conservation between the three exons and several noncoding sequences, including the immediate 5' promoter region. Two conserved CArG boxes are present in both the LMOD1 and LMOD2 promoter regions, although LMOD1 displays much higher promoter activity and is more responsive to SRF/MYOCD stimulation. Gel shift assays demonstrate clear binding between SRF and the two CArG boxes in human LMOD1. Although the CArG boxes in LMOD1 and LMOD2 are similar, only LMOD1 displays SRF or MYOCD-dependent activation. Transgenic mouse studies reveal wild type LMOD1 promoter activity in cardiac and vascular SMC. Such activity is abolished upon mutation of both CArG boxes. Collectively, these data demonstrate that Lmod1 is a new SMC-restricted SRF/MYOCD target gene. Show less