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1.
PLoS One ; 15(9): e0238163, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32881885

RESUMO

OBJECTIVE: We evaluated the effects of grape juice (Vitis labrusca L.) on dyslipidemia, resistance to insulin, and left ventricular hypertrophy (LVH) in mice homozygous for the absence of the LDL receptor gene (LDLr -/-) under a hyperlipidemic diet. METHODOLOGY: We divided 30 male mice (3 months old) into three groups (n = 10); the HL group was fed a high-fat diet, the HLU group received a high-fat diet and 2 g/kg/day of grape juice, and the HLS group was fed a high-fat diet and simvastatin (20 mg/kg/day). We assessed the blood pressure profile of the mice. We also determined the levels of C-reactive protein (CRP) and lipid profile, glycemic and insulinemic profiles, and calculated the HOMA-IR. Cardiomyocyte hypertrophy, interstitial collagen deposit, and the expression of CD40 ligand (CD40L) and metalloproteinases 2 and 9 were assessed immunohistologically. RESULTS: After 60 days, the mice treated with grape juice showed similar results as those of the group treated with simvastatin. The use of grape fruit attenuated dyslipidemia and insulin resistance and significantly increased the levels of high cholesterol density lipoproteins (HDLc). The antioxidant potential of phenolic compounds associated with the increase in HDLc levels in the mice of the HLU group prevented the development of LVH and arterial hypertension since it inhibited the inflammatory response induced by the CD40 pathway and its ligand CD40L. Consequently, there was a lower expression of MMP-2 and MMP-9 and lower serum levels of CRP. CONCLUSION: Grape juice has a hypolipidemic and cardiac protective potential, presenting a similar effect as that of simvastatin through a direct antioxidant action of phenolic compounds, or indirectly, via antioxidant action and anti-inflammatory activity of the HDLc. These results suggest that grape juice is a functional food possessing a high potential to prevent cardiovascular diseases.


Assuntos
Dislipidemias/patologia , Sucos de Frutas e Vegetais , Hipertrofia Ventricular Esquerda/prevenção & controle , Vitis/química , Animais , Pressão Sanguínea/efeitos dos fármacos , Proteína C-Reativa/análise , Ligante de CD40/genética , Ligante de CD40/metabolismo , Colágeno/metabolismo , Dieta Hiperlipídica , Dislipidemias/tratamento farmacológico , Sucos de Frutas e Vegetais/análise , Ventrículos do Coração/patologia , Hipertrofia Ventricular Esquerda/patologia , Masculino , Metaloproteinase 2 da Matriz/genética , Metaloproteinase 2 da Matriz/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Substâncias Protetoras/química , Substâncias Protetoras/uso terapêutico , Receptores de LDL/deficiência , Receptores de LDL/genética , Sinvastatina/uso terapêutico , Vitis/metabolismo
3.
Nat Commun ; 11(1): 4084, 2020 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-32796843

RESUMO

Lipid peroxidation generates reactive dicarbonyls including isolevuglandins (IsoLGs) and malondialdehyde (MDA) that covalently modify proteins. Humans with familial hypercholesterolemia (FH) have increased lipoprotein dicarbonyl adducts and dysfunctional HDL. We investigate the impact of the dicarbonyl scavenger, 2-hydroxybenzylamine (2-HOBA) on HDL function and atherosclerosis in Ldlr-/- mice, a model of FH. Compared to hypercholesterolemic Ldlr-/- mice treated with vehicle or 4-HOBA, a nonreactive analogue, 2-HOBA decreases atherosclerosis by 60% in en face aortas, without changing plasma cholesterol. Ldlr-/- mice treated with 2-HOBA have reduced MDA-LDL and MDA-HDL levels, and their HDL display increased capacity to reduce macrophage cholesterol. Importantly, 2-HOBA reduces the MDA- and IsoLG-lysyl content in atherosclerotic aortas versus 4-HOBA. Furthermore, 2-HOBA reduces inflammation and plaque apoptotic cells and promotes efferocytosis and features of stable plaques. Dicarbonyl scavenging with 2-HOBA has multiple atheroprotective effects in a murine FH model, supporting its potential as a therapeutic approach for atherosclerotic cardiovascular disease.


Assuntos
Aterosclerose/metabolismo , Benzilaminas/metabolismo , Benzilaminas/farmacologia , Benzilaminas/uso terapêutico , Hiperlipoproteinemia Tipo II/metabolismo , Receptores de LDL/genética , Animais , Aorta , Apolipoproteínas E , Aterosclerose/tratamento farmacológico , Colesterol/sangue , Colesterol/metabolismo , Feminino , Humanos , Hiperlipoproteinemia Tipo II/tratamento farmacológico , Hiperlipoproteinemia Tipo II/patologia , Inflamação/tratamento farmacológico , Peroxidação de Lipídeos , Lipoproteínas HDL/metabolismo , Lipoproteínas IDL/sangue , Lipoproteínas IDL/metabolismo , Masculino , Malondialdeído/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fragmentos de Peptídeos
4.
Life Sci ; 258: 118030, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32739470

RESUMO

The risk of atherosclerosis (AS) ascends among post-menopausal women, while current hormone replacement therapy exerts several adverse effects. Alisol B 23-acetate (AB23A), a tetracyclic triterpenoid isolated from the rhizome of Alisma orientale, was reported to show multiple physiological activities, including regulating lipid metabolism. According to molecular docking analysis, it was predicted to bind with estrogen receptor α (ERα). In this study, we aimed to observe the effect of AB23A on preventing post-menopausal AS and explore whether the mechanism was mediated by ERα. In vitro, free fatty acid (FFA) was applied to induce the abnormal lipid metabolism of L02 cells. In vivo, the ApoE-/- mice were ovariectomized to mimic the cessation of estrogen. The high-fat diet was also given to induce post-menopausal AS. We demonstrated AB23A attenuated the accumulation of total cholesterol and triglyceride induced by free fatty acids in hepatocytes. In high-fat diet-ovariectomy-treated ApoE-/- mice, AB23A eliminated lipids in blood and liver. AB23A not only reduced the synthesis of proprotein convertase subtilisin/kexin type 9 (PCSK9) through sterol-regulatory element binding proteins (SREBPs) but also suppressed the secretion of PCSK9 through silent information regulator 1 (SIRT1). Notably, AB23A promoted the expression of ERα in vivo and in vitro. The both ERα inhibitor and ERα siRNA were also applied in confirming whether the hepatic protective effect of AB23A was mediated by ERα. We found that AB23A significantly promoted the expression of ERα. AB23A could inhibit the synthesis and secretion of PCSK9 through ERα, lower the accumulation of triglyceride and cholesterol, and prevent post-menopausal AS.


Assuntos
Aterosclerose/patologia , Colestenonas/farmacologia , Receptor alfa de Estrogênio/metabolismo , Metabolismo dos Lipídeos/efeitos dos fármacos , Pós-Menopausa/efeitos dos fármacos , Animais , Aterosclerose/genética , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Colestenonas/química , Dieta Hiperlipídica , Ácidos Graxos/metabolismo , Feminino , Lipoproteínas LDL/metabolismo , Camundongos , Ovariectomia , Regiões Promotoras Genéticas/genética , Pró-Proteína Convertase 9/genética , Pró-Proteína Convertase 9/metabolismo , Receptores de LDL/genética , Receptores de LDL/metabolismo , Sirtuína 1/metabolismo , Proteínas de Ligação a Elemento Regulador de Esterol/genética , Proteínas de Ligação a Elemento Regulador de Esterol/metabolismo , Regulação para Cima/efeitos dos fármacos
5.
Proc Natl Acad Sci U S A ; 117(28): 16401-16408, 2020 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-32601215

RESUMO

Proteins have evolved by incorporating several structural units within a single polypeptide. As a result, multidomain proteins constitute a large fraction of all proteomes. Their domains often fold to their native structures individually and vectorially as each domain emerges from the ribosome or the protein translocation channel, leading to the decreased risk of interdomain misfolding. However, some multidomain proteins fold in the endoplasmic reticulum (ER) nonvectorially via intermediates with nonnative disulfide bonds, which were believed to be shuffled to native ones slowly after synthesis. Yet, the mechanism by which they fold nonvectorially remains unclear. Using two-dimensional (2D) gel electrophoresis and a conformation-specific antibody that recognizes a correctly folded domain, we show here that shuffling of nonnative disulfide bonds to native ones in the most N-terminal region of LDL receptor (LDLR) started at a specific timing during synthesis. Deletion analysis identified a region on LDLR that assisted with disulfide shuffling in the upstream domain, thereby promoting its cotranslational folding. Thus, a plasma membrane-bound multidomain protein has evolved a sequence that promotes the nonvectorial folding of its upstream domains. These findings demonstrate that nonvectorial folding of a multidomain protein in the ER of mammalian cells is more coordinated and elaborated than previously thought. Thus, our findings alter our current view of how a multidomain protein folds nonvectorially in the ER of living cells.


Assuntos
Retículo Endoplasmático/metabolismo , Receptores de LDL/química , Receptores de LDL/genética , Retículo Endoplasmático/química , Retículo Endoplasmático/genética , Células HeLa , Humanos , Biossíntese de Proteínas , Conformação Proteica , Domínios Proteicos , Dobramento de Proteína , Receptores de LDL/metabolismo
6.
Arterioscler Thromb Vasc Biol ; 40(9): 2108-2113, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32640904

RESUMO

OBJECTIVE: Renin cleavage of angiotensinogen has species specificity. As the residues at positions 11 and 12 are different between human angiotensinogen and mouse angiotensinogen, we determined whether these 2 residues in angiotensinogen affect renin cleavage and angiotensin II-mediated blood pressure regulation and atherosclerosis using an adenoassociated viral approach for manipulating angiotensinogen in vivo. Approach and Results: Hepatocyte-specific angiotensinogen deficient (hepAGT-/-) mice in an LDL receptor-deficient background were infected with adenoassociated virals containing a null insert, human angiotensinogen, or mouse angiotensinogen expressing the same residues of the human protein at positions 11 and 12 (mouse angiotensinogen [L11V;Y12I]). Expression of human angiotensinogen in hepAGT-/- mice led to high plasma human angiotensinogen concentrations without changes in plasma endogenous mouse angiotensinogen, plasma renin concentrations, blood pressure, or atherosclerosis. This is consistent with human angiotensinogen not being cleaved by mouse renin. To determine whether the residues at positions 11 and 12 in human angiotensinogen lead to the inability of mouse renin to cleave human angiotensinogen, hepAGT-/- mice were injected with adenoassociated viral vector encoding mouse angiotensinogen (L11V;Y12I). Expression of mouse angiotensinogen (L11V;Y12I) in hepAGT-/- mice resulted in increased plasma mouse angiotensinogen concentrations, reduced renin concentrations, and increased renal AngII concentrations that were comparable to their concentrations in hepAGT+/+ mice. This mouse angiotensinogen variant increased blood pressure and atherosclerosis in hepAGT-/- mice to the magnitude of hepAGT+/+ mice. CONCLUSIONS: Replacement of L11 and Y12 to V11 and I12, respectively, in mouse angiotensinogen does not affect renin cleavage, blood pressure, and atherosclerosis in LDL receptor-deficient mice.


Assuntos
Angiotensina II/metabolismo , Angiotensinogênio/metabolismo , Aterosclerose/metabolismo , Pressão Sanguínea , Hepatócitos/metabolismo , Hipertensão/metabolismo , Renina/metabolismo , Substituição de Aminoácidos , Angiotensinogênio/deficiência , Angiotensinogênio/genética , Animais , Aterosclerose/genética , Aterosclerose/patologia , Modelos Animais de Doenças , Feminino , Humanos , Hipertensão/genética , Hipertensão/fisiopatologia , Masculino , Camundongos Knockout , Placa Aterosclerótica , Receptores de LDL/genética , Receptores de LDL/metabolismo , Especificidade da Espécie
7.
Arterioscler Thromb Vasc Biol ; 40(9): 2084-2094, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32673528

RESUMO

OBJECTIVE: Increased postprandial lipemia (PPL) is an independent risk factor for atherosclerotic cardiovascular diseases. PCSK9 (Proprotein convertase subtilisin kexin type 9) is an endogenous inhibitor of the LDLR (low-density lipoprotein receptor) pathway. We previously showed that PCSK9 inhibition in mice reduces PPL. However, the relative contribution of intracellular intestinal PCSK9 or liver-derived circulating PCSK9 to this effect is still unclear. Approach and Results: To address this issue, we generated the first intestine-specific Pcsk9-deficient (i-Pcsk9-/-) mouse model. PPL was measured in i-Pcsk9-/- as well as in wild-type and streptozotocin-induced diabetic mice following treatment with a PCSK9 monoclonal antibody (alirocumab). Blocking the circulating form of PCSK9 with alirocumab significantly reduced PPL, while overexpressing human PCSK9 in the liver of full Pcsk9-/- mice had the opposite effect. Alirocumab regulated PPL in a LDLR-dependent manner as this effect was abolished in Ldlr-/- mice. In contrast, i-Pcsk9-/- mice did not exhibit alterations in plasma lipid parameters nor in PPL. Finally, PPL was highly exacerbated by streptozotocin-induced diabetes mellitus in Pcsk9+/+ but not in Pcsk9-/- mice, an effect that was mimicked by the use of alirocumab in streptozotocin-treated Pcsk9+/+ mice. CONCLUSIONS: Taken together, our data demonstrate that PPL is significantly altered by full but not intestinal PCSK9 deficiency. Treatment with a PCSK9 monoclonal antibody mimics the effect of PCSK9 deficiency on PPL suggesting that circulating PCSK9 rather than intestinal PCSK9 is a critical regulator of PPL. These data validate the clinical relevance of PCSK9 inhibitors to reduce PPL, especially in patients with type 2 diabetes mellitus.


Assuntos
Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Tipo 2/sangue , Hiperlipidemias/sangue , Intestinos/enzimologia , Lipídeos/sangue , Pró-Proteína Convertase 9/sangue , Animais , Anticorpos Monoclonais Humanizados/farmacologia , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Experimental/enzimologia , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/enzimologia , Hiperlipidemias/enzimologia , Hiperlipidemias/genética , Hiperlipidemias/prevenção & controle , Hipolipemiantes/farmacologia , Intestinos/efeitos dos fármacos , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Período Pós-Prandial , Pró-Proteína Convertase 9/antagonistas & inibidores , Pró-Proteína Convertase 9/deficiência , Pró-Proteína Convertase 9/genética , Receptores de LDL/genética , Receptores de LDL/metabolismo
8.
Am J Physiol Heart Circ Physiol ; 319(1): H32-H41, 2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32412785

RESUMO

Disruption of the normal gut microbiome (dysbiosis) is implicated in the progression and severity of myriad disorders, including hypercholesterolemia and cardiovascular disease. Probiotics attenuate and reverse gut dysbiosis to improve cardiovascular risk factors like hypertension and hypercholesterolemia. Lactobacillus reuteri is a well-studied lactic acid-producing probiotic with known cholesterol-lowering properties and anti-inflammatory effects. In the present study, we hypothesized that L. reuteri delivered to hypercholesterolemic low-density lipoprotein receptor knockout (LDLr KO) mice will reduce cholesterol levels and minimize cardiac injury from an ischemic insult. L. reuteri [1 × 109 or 50 × 106 colony-forming units (CFU)/day] was administered by oral gavage to wild-type mice and LDLr KO for up to 6 wk followed by an ischemia-reperfusion (I/R) protocol. After 4 wk of gavage, total serum cholesterol in wild-type mice receiving saline was 113.5 ± 5.6 mg/dL compared with 113.3 ± 6.8 and 101.9 ± 7.5 mg/dL in mice receiving 1 × 109 or 50 × 106 CFU/day, respectively. Over the same time frame, administration of L. reuteri at 1 × 109 or 50 × 106 CFU/day did not lower total serum cholesterol (283.0 ± 11.1, 263.3 ± 5.0, and 253.1 ± 7.0 mg/dL; saline, 1 × 109 or 50 × 106 CFU/day, respectively) in LDLr KO mice. Despite no impact on total serum cholesterol, L. reuteri administration significantly attenuated cardiac injury following I/R, as evidenced by smaller infarct sizes compared with controls in both wild-type and LDLr KO groups. In conclusion, daily L. reuteri significantly protected against cardiac injury without lowering cholesterol levels, suggesting anti-inflammatory properties of L. reuteri uncoupled from improvements in serum cholesterol.NEW & NOTEWORTHY We demonstrated that daily delivery of Lactobacillus reuteri to wild-type and hypercholesterolemic lipoprotein receptor knockout mice attenuated cardiac injury following ischemia-reperfusion without lowering total serum cholesterol in the short term. In addition, we validated protection against cardiac injury using histology and immunohistochemistry techniques. L. reuteri offers promise as a probiotic to mitigate ischemic cardiac injury.


Assuntos
Colesterol/sangue , Traumatismo por Reperfusão Miocárdica/microbiologia , Probióticos/uso terapêutico , Animais , Microbioma Gastrointestinal , Lactobacillus reuteri/patogenicidade , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Traumatismo por Reperfusão Miocárdica/sangue , Traumatismo por Reperfusão Miocárdica/genética , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Probióticos/administração & dosagem , Receptores de LDL/deficiência , Receptores de LDL/genética
9.
Arterioscler Thromb Vasc Biol ; 40(6): 1523-1532, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32321308

RESUMO

OBJECTIVE: Although the molecular components of circadian rhythms oscillate in discrete cellular components of the vasculature and many aspects of vascular function display diurnal variation, the cellular connections between the molecular clock and inflammatory cardiovascular diseases remain to be elucidated. Previously we have shown that pre- versus postnatal deletion of Bmal1 (brain and muscle aryl hydrocarbon receptor nuclear translocator-like 1), the nonredundant core clock gene has contrasting effects on atherogenesis. Here we investigated the effect of myeloid cell Bmal1 deletion on atherogenesis and abdominal aortic aneurysm formation in mice. Approach and Results: Mice lacking Bmal1 in myeloid cells were generated by crossing Bmal1 flox/flox mice with lysozyme 2 promoter-driven Cre recombinase mice on a hyperlipidemic low-density lipoprotein receptor-deficient background and were fed on a high-fat diet to induce atherosclerosis. Atherogenesis was restrained, concomitant with a reduction of aortic proinflammatory gene expression in myeloid cell Bmal1 knockout mice. Body weight, blood pressure, blood glucose, triglycerides, and cholesterol were unaltered. Similarly, myeloid cell depletion of Bmal1 also restrained Ang II (angiotensin II) induced formation of abdominal aortic aneurysm in hyperlipidemic mice. In vitro, RNA-Seq analysis demonstrated a proinflammatory response in cultured macrophages in which there was overexpression of Bmal1. CONCLUSIONS: Myeloid cell Bmal1 deletion retards atherogenesis and restrains the formation of abdominal aortic aneurysm and may represent a potential therapeutic target for inflammatory cardiovascular diseases.


Assuntos
Fatores de Transcrição ARNTL/deficiência , Fatores de Transcrição ARNTL/fisiologia , Aneurisma da Aorta Abdominal/prevenção & controle , Aterosclerose/prevenção & controle , Hiperlipidemias/complicações , Células Mieloides/química , Fatores de Transcrição ARNTL/genética , Angiotensina II/farmacologia , Animais , Aneurisma da Aorta Abdominal/induzido quimicamente , Aterosclerose/etiologia , Aterosclerose/patologia , Células Cultivadas , Cruzamentos Genéticos , Dieta Hiperlipídica , Deleção de Genes , Expressão Gênica , Hiperlipidemias/etiologia , Inflamação , Integrases/genética , Macrófagos Peritoneais/química , Macrófagos Peritoneais/fisiologia , Camundongos , Camundongos Knockout , Muramidase/genética , Regiões Promotoras Genéticas/genética , Receptores de LDL/deficiência , Receptores de LDL/genética
10.
Invest Ophthalmol Vis Sci ; 61(4): 15, 2020 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-32298438

RESUMO

Purpose: Pathological neovascularization and fibrosis are common pathological changes of many retinal diseases, such as proliferative retinopathy (PR) and age-related macular degeneration (AMD). Treatment modalities for these pathological changes are limited. The purpose of the present study was to test the effects of palmitoylethanolamide (PEA), an endocannabinoid mimetic amide, on retinal neovascularization and fibrosis and to determine its molecular mechanism of action. Methods: A rat Müller cell line (rMC-1), a mouse model of oxygen-induced retinopathy (OIR), and the very-low-density lipoprotein receptor (VLDLR) knockout mouse model were used. PEA was intraperitoneally injected or orally administrated in animal models. Inflammation and profibrotic changes were evaluated by western blot analysis. Glial fibrillary acidic protein (GFAP) and peroxisome proliferator-activated receptor alpha (PPARα) were measured by RT-PCR and western blot analysis. Results: Profibrotic changes were present in OIR and Vldlr-/- retinas. PEA significantly alleviated inflammation and inhibited neovascularization in OIR and Vldlr-/- retinas and suppressed profibrotic changes in OIR and Vldlr-/- retinas. Moreover, PEA potently suppressed Müller gliosis in these retinas. In rMC-1 cells, PEA suppressed Müller gliosis, reduced inflammatory cytokines, and attenuated profibrotic changes. Further, both mRNA and protein levels of PPARα were elevated in the retina under PEA treatment, and the effects of PEA were abolished in Pparα-/- OIR mice. Conclusions: PEA reduced retinal neovascularization and fibrotic changes and suppressed Müller gliosis in experimental PR and neovascular AMD by activating PPARα. PEA may be a potential treatment for retinopathies with pathological neovascularization and fibrosis.


Assuntos
Agonistas de Receptores de Canabinoides/uso terapêutico , Etanolaminas/uso terapêutico , Gliose/tratamento farmacológico , PPAR alfa/metabolismo , Ácidos Palmíticos/uso terapêutico , Retina/patologia , Neovascularização Retiniana/tratamento farmacológico , Administração Oral , Animais , Western Blotting , Linhagem Celular , Modelos Animais de Doenças , Células Ependimogliais/efeitos dos fármacos , Fibrose/tratamento farmacológico , Fibrose/metabolismo , Fibrose/patologia , Proteína Glial Fibrilar Ácida/genética , Proteína Glial Fibrilar Ácida/metabolismo , Gliose/metabolismo , Gliose/patologia , Marcação In Situ das Extremidades Cortadas , Injeções Intraperitoneais , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Oxigênio/toxicidade , PPAR alfa/genética , Ratos , Reação em Cadeia da Polimerase em Tempo Real , Receptores de LDL/genética , Retina/metabolismo , Neovascularização Retiniana/induzido quimicamente , Neovascularização Retiniana/metabolismo , Neovascularização Retiniana/patologia
11.
Toxicol Appl Pharmacol ; 395: 114979, 2020 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-32234517

RESUMO

Epidemiology suggests that adverse environmental exposure during pregnancy may predispose children to hypercholesterolemia in adulthood. This study aimed to demonstrate hypercholesterolemia induced by prenatal dexamethasone exposure (PDE) in adult male offspring rats and explore the intrauterine programming mechanisms. Pregnant Wistar rats were injected subcutaneously with dexamethasone (0, 0.1, 0.2, and 0.4 mg/kg∙d) from gestational days (GD) 9 to 21, and the serum and liver of the male offsprings were collected at GD21, postnatal week (PW) 12 and 28. Furthermore, the effects of dexamethasone on the expression of low-density lipoprotein receptor (LDLR) and its epigenetic mechanism was confirmed in the bone marrow mesenchymal stem cells (BMSCs) hepatoid differentiated cells and continuous hepatocyte line. PDE could reduce the birth weight of male offsprings, increase the serum total cholesterol (TCH) level in adult rats, and decrease the liver low-density lipoprotein receptor (LDLR) expression. Serum TCH level and liver LDLR expression were decreased in PDE male fetuses in utero (GD21). Moreover, PDE increased the translocation of the glucocorticoid receptor (GR) in the fetal liver, the expression of DiGeorge syndrome critical region 8 gene (DGCR8), the pre- and post-natal expression of miR-148a. The results of PDE offspring in vivo and in vitro exhibited similar changes. These changes could be reversed by overexpressing LDLR, inhibiting miR-148a or GR. PDE caused hypercholesterolemia in male adult offspring rats, which was mediated via dexamethasone activated intrauterine hepatic GR, enhanced the expression of DGCR8 and miR-148a, thereby reducing the expression of LDLR, leading to impaired liver cholesterol reverse transport function, and finally causing hypercholesterolemia in adult rats.


Assuntos
Dexametasona/efeitos adversos , Hipercolesterolemia/etiologia , Hipercolesterolemia/metabolismo , MicroRNAs/fisiologia , Efeitos Tardios da Exposição Pré-Natal , Receptores de LDL/fisiologia , Animais , Dexametasona/administração & dosagem , Epigênese Genética/efeitos dos fármacos , Feminino , Expressão Gênica/efeitos dos fármacos , Idade Gestacional , Fígado/química , Fígado/embriologia , Fígado/metabolismo , Masculino , MicroRNAs/genética , Gravidez , Ratos , Ratos Wistar , Receptores de Glucocorticoides/efeitos dos fármacos , Receptores de Glucocorticoides/fisiologia , Receptores de LDL/genética
12.
Biochim Biophys Acta Biomembr ; 1862(7): 183296, 2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32268133

RESUMO

The hepatitis C virus (HCV) is a major cause of liver diseases ranging from liver inflammation to advanced liver diseases like cirrhosis and hepatocellular carcinoma (HCC). HCV infection is restricted to the liver, and more specifically to hepatocytes, which represent around 80% of liver cells. The mechanism of HCV entry in human hepatocytes has been extensively investigated since the discovery of the virus 30 years ago. The entry mechanism is a multi-step process relying on several host factors including heparan sulfate proteoglycan (HSPG), low density lipoprotein receptor (LDLR), tetraspanin CD81, Scavenger Receptor class B type I (SR-BI), Epidermal Growth Factor Receptor (EGFR) and Niemann-Pick C1-like 1 (NPC1L1). Moreover, in order to establish a persistent infection, HCV entry is dependent on the presence of tight junction (TJ) proteins Claudin-1 (CLDN1) and Occludin (OCLN). In the liver, tight junction proteins play a role in architecture and homeostasis including sealing the apical pole of adjacent cells to form bile canaliculi and separating the basolateral domain drained by sinusoidal blood flow. In this review, we will highlight the role of liver tight junction proteins in HCV infection, and we will discuss the potential targeted therapeutic approaches to improve virus eradication.


Assuntos
Hepatite C/genética , Interações Hospedeiro-Patógeno/genética , Junções Íntimas/genética , Internalização do Vírus , Hepacivirus/genética , Hepacivirus/patogenicidade , Hepatite C/virologia , Hepatócitos/virologia , Humanos , Fígado/patologia , Fígado/virologia , Proteínas de Membrana Transportadoras/genética , Ocludina/genética , Receptores de LDL/genética , Tetraspanina 28/genética , Junções Íntimas/virologia
13.
Arterioscler Thromb Vasc Biol ; 40(6): 1479-1490, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32268785

RESUMO

OBJECTIVE: Enhanced expression of PAI-1 (plasminogen activator inhibitor-1) has been implicated in atherosclerosis formation in humans with obesity and metabolic syndrome. However, little is known about the effects of pharmacological targeting of PAI-1 on atherogenesis. This study examined the effects of pharmacological PAI-1 inhibition on atherosclerosis formation in a murine model of obesity and metabolic syndrome. Approach and Results: LDL receptor-deficient (ldlr-/-) mice were fed a Western diet high in cholesterol, fat, and sucrose to induce obesity, metabolic dysfunction, and atherosclerosis. Western diet triggered significant upregulation of PAI-1 expression compared with normal diet controls. Addition of a pharmacological PAI-1 inhibitor (either PAI-039 or MDI-2268) to Western diet significantly inhibited obesity and atherosclerosis formation for up to 24 weeks without attenuating food consumption. Pharmacological PAI-1 inhibition significantly decreased macrophage accumulation and cell senescence in atherosclerotic plaques. Recombinant PAI-1 stimulated smooth muscle cell senescence, whereas a PAI-1 mutant defective in LRP1 (LDL receptor-related protein 1) binding did not. The prosenescent effect of PAI-1 was blocked by PAI-039 and R2629, a specific anti-LRP1 antibody. PAI-039 significantly decreased visceral adipose tissue inflammation, hyperglycemia, and hepatic triglyceride content without altering plasma lipid profiles. CONCLUSIONS: Pharmacological targeting of PAI-1 inhibits atherosclerosis in mice with obesity and metabolic syndrome, while inhibiting macrophage accumulation and cell senescence in atherosclerotic plaques, as well as obesity-associated metabolic dysfunction. PAI-1 induces senescence of smooth muscle cells in an LRP1-dependent manner. These results help to define the role of PAI-1 in atherosclerosis formation and suggest a new plasma-lipid-independent strategy for inhibiting atherogenesis.


Assuntos
Aterosclerose/prevenção & controle , Síndrome Metabólica/tratamento farmacológico , Inibidor 1 de Ativador de Plasminogênio/efeitos dos fármacos , Animais , Senescência Celular/efeitos dos fármacos , Dieta Ocidental , Modelos Animais de Doenças , Ácidos Indolacéticos/administração & dosagem , Macrófagos/efeitos dos fármacos , Macrófagos/patologia , Síndrome Metabólica/patologia , Síndrome Metabólica/prevenção & controle , Camundongos , Camundongos Knockout , Obesidade/etiologia , Obesidade/prevenção & controle , Placa Aterosclerótica/patologia , Inibidor 1 de Ativador de Plasminogênio/fisiologia , Receptores de LDL/deficiência , Receptores de LDL/genética
14.
Arterioscler Thromb Vasc Biol ; 40(5): 1311-1324, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32188273

RESUMO

OBJECTIVE: TMEM55B (transmembrane protein 55B) is a phosphatidylinositol-(4,5)-bisphosphate (PI[4,5]P2) phosphatase that regulates cellular cholesterol, modulates LDLR (low-density lipoprotein receptor) decay, and lysosome function. We tested the effects of Tmem55b knockdown on plasma lipids in mice and assessed the roles of LDLR lysosomal degradation and change in (PI[4,5]P2) in mediating these effects. Approach and Results: Western diet-fed C57BL/6J mice were treated with antisense oligonucleotides against Tmem55b or a nontargeting control for 3 to 4 weeks. Hepatic Tmem55b transcript and protein levels were reduced by ≈70%, and plasma non-HDL (high-density lipoprotein) cholesterol was increased ≈1.8-fold (P<0.0001). Immunoblot analysis of fast protein liquid chromatography (FPLC) fractions revealed enrichment of ApoE-containing particles in the LDL size range. In contrast, Tmem55b knockdown had no effect on plasma cholesterol in Ldlr-/- mice. In primary hepatocytes and liver tissues from Tmem55b knockdown mice, there was decreased LDLR protein. In the hepatocytes, there was increased lysosome staining and increased LDLR-lysosome colocalization. Impairment of lysosome function (incubation with NH4Cl or knockdown of the lysosomal proteins LAMP1 or RAB7) abolished the effect of TMEM55B knockdown on LDLR in HepG2 (human hepatoma) cells. Colocalization of the recycling endosome marker RAB11 (Ras-related protein 11) with LDLR in HepG2 cells was reduced by 50% upon TMEM55B knockdown. Finally, knockdown increased hepatic PI(4,5)P2 levels in vivo and in HepG2 cells, while TMEM55B overexpression in vitro decreased PI(4,5)P2. TMEM55B knockdown decreased, whereas overexpression increased, LDL uptake in HepG2 cells. Notably, the TMEM55B overexpression effect was reversed by incubation with PI(4,5)P2. Conclusions: These findings indicate a role for TMEM55B in regulating plasma cholesterol levels by affecting PI(4,5)P2-mediated LDLR lysosomal degradation.


Assuntos
Colesterol/sangue , Hepatócitos/metabolismo , Fígado/metabolismo , Lisossomos/metabolismo , Fosfatidilinositol 4,5-Difosfato/metabolismo , Fosfatases de Fosfoinositídeos/metabolismo , Receptores de LDL/metabolismo , Animais , Dieta Hiperlipídica , Regulação para Baixo , Feminino , Células Hep G2 , Humanos , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fosfatases de Fosfoinositídeos/genética , Transporte Proteico , Proteólise , Receptores de LDL/genética , Proteínas de Transporte Vesicular/genética , Proteínas de Transporte Vesicular/metabolismo
15.
Arch Med Res ; 51(2): 153-159, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32113782

RESUMO

BACKGROUND: Familial hypercholesterolemia (FH) is an autosomal dominant disease characterized by an increased LDL-cholesterol (LDLc) serum concentration and premature cardiovascular disease. Screening of small populations where at least one homozygous (HoFH) patient has been identified may be a proper approach for detecting FH patients. Previously, we reported an HoFH patient carrying the mutation p.Asp360His LDLR, who was born in the Mexican community El Triunfo (Quimixtlan, Puebla). AIM OF THE STUDY: To identify patients with familial hypercholesterolemia in the community El Triunfo and to describe their clinical and biochemical characteristics. METHODS: We studied 308 individuals by quantifying lipid levels and by DNA sequencing. RESULTS: Sixteen of 308 individuals presented an LDLc level >170 mg/dL and all of them turned out to be heterozygous for the LDLR p.Asp360His variant. Subsequently, 34 of their first-degree relatives (mainly siblings and parents) were genotyped rendering six additional HeFH patients, which resulted in 22 carriers of the mutated allele. The study of six LDLR polymorphisms in four unrelated individuals from the community (one HoFH and three HeFH) showed the same haplotype combination, suggesting a unique ancestral origin of the mutation. CONCLUSIONS: The community El Triunfo, has the highest worldwide frequency ever reported of HeFH, with 7.14% (22/308, equivalent to 1/14 inhabitants). Since the HeFH patients showed variable biochemical expression, we suggest looking for factors with the potential to modify the phenotype. Finally, we stress the importance of establishing accurate LDLc cut-off points applicable to Mexican population for the diagnosis of FH.


Assuntos
LDL-Colesterol/sangue , Hiperlipoproteinemia Tipo II/genética , Receptores de LDL/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Humanos , Masculino , México , Pessoa de Meia-Idade , Mutação , Adulto Jovem
16.
Lipids Health Dis ; 19(1): 24, 2020 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-32035489

RESUMO

BACKGROUND: The LDL-C lowering effect of ezetimibe has been attributed primarily to increased catabolism of LDL-C via up-regulation of LDL receptor (LDLR) and decreased cholesterol absorption. Recently, ezetimibe has been demonstrated to have reverse cholesterol transport (RCT) promoting effects in mice, hamsters and humans. However, the underlying mechanisms are still not clear. The aim of this study is to investigate whether ezetimibe improves RCT-related protein expression in LDLR-/- hamsters. METHODS: A high-fat diet was used to induce a human-like hyperlipidemia in LDLR-/- hamsters. Lipid profiles were assayed by commercially available kits, and the effects of ezetimibe on lipid metabolism-related protein expression were carried out via western blot. RESULTS: Our data demonstrated that ezetimibe administration significantly reduced plasma total cholesterol (~ 51.6% reduction, P < 0.01) and triglyceride (from ~ 884.1 mg/dL to ~ 277.3 mg/dL) levels in LDLR-/- hamsters fed a high-fat diet. Ezetimibe administration (25 mg/kg/d) significantly promoted the protein expression of cholesterol 7 alpha-hydroxylase A1 (CYP7A1), LXRß and peroxisome proliferator-activated receptor (PPAR) γ; and down-regulated the protein expression of PPARα and PPARß. However, it showed no significant effect on sterol regulatory element-binding protein (SREBP)-1c, SREBP-2, proprotein convertase subtilisin/kexin type 9 (PCSK9), Niemann-Pick C1-like 1 (NPC1L1), and ATP-biding cassette (ABC) G5/G8. CONCLUSION: Ezetimibe may accelerate the transformation from cholesterol to bile acid via promoting CYP7A1 and thereby enhance RCT. As a compensatory mechanism of TG lowering, ezetimibe promoted the protein expression of PPARγ and decreased PPARα and ß. These results are helpful in explaining the lipid-lowering effects of ezetimibe and the potential compensatory mechanisms.


Assuntos
Colesterol 7-alfa-Hidroxilase/metabolismo , Ezetimiba/farmacologia , Receptores Ativados por Proliferador de Peroxissomo/metabolismo , Receptores de LDL/metabolismo , Animais , Transporte Biológico/efeitos dos fármacos , Western Blotting , Colesterol/metabolismo , Cricetinae , Dieta Hiperlipídica , Metabolismo dos Lipídeos/efeitos dos fármacos , Receptores de LDL/deficiência , Receptores de LDL/genética
17.
Sci Rep ; 10(1): 1727, 2020 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-32015373

RESUMO

The primary genetic cause of familial hypercholesterolemia (FH) is related to mutations in the LDLR gene encoding the Low-density Lipoprotein Receptor. LDLR structure is organized in 5 different domains, including an EGF-precursor homology domain that plays a pivotal role in lipoprotein release and receptor recycling. Mutations in this domain constitute 51.7% of the total missense variants described in LDLR. The aim of the present work was to analyse how clinically significant variants in the EGF-precursor homology domain impact LDLR. The activity of sixteen LDLR variants was functionally characterized by determining LDLR expression by Western blot and LDLR expression, LDL binding capacity and uptake, and LDLR recycling activity by flow cytometry in transfected CHO-ldlA7 cells. Of the analysed variants, we found six non-pathogenic LDLR variants and ten pathogenic variants distributed as follow: three class 3 variants; four class 2 variants; and three class 5 variants. These results can be incorporated into clinical management of patients by helping guide the appropriate level of treatment intensity depending on the extent of loss of LDLR activity. This data can also contribute to cascade-screening for pathogenic FH variants.


Assuntos
Hiperlipoproteinemia Tipo II/genética , Mutação de Sentido Incorreto/genética , Receptores de LDL/genética , Animais , Células CHO , Cricetulus , Fator de Crescimento Epidérmico/genética , Humanos , Lipoproteínas LDL/metabolismo , Fenótipo , Polimorfismo Genético , Domínios Proteicos/genética , Receptores de LDL/metabolismo
18.
Sci Rep ; 10(1): 1725, 2020 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-32015418

RESUMO

Recent evidence suggests that enhanced protease-mediated inflammation may promote insulin resistance and result in diabetes. This study tested the hypothesis that serine protease plays a pivotal role in type 2 diabetes, and inhibition of serine protease activity prevents hyperglycemia in diabetic animals by modulating insulin signaling pathway. We conducted a single-center, cross-sectional study with 30 healthy controls and 57 patients with type 2 diabetes to compare plasma protease activities and inflammation marker between groups. Correlations of plasma total and serine protease activities with variables were calculated. In an in-vivo study, LDLR-/- mice were divided into normal chow diet, high-fat diet (HFD), and HFD with selective serine protease inhibition groups to examine the differences of obesity, blood glucose level, insulin resistance and serine protease activity among groups. Compared with controls, diabetic patients had significantly increased plasma total protease, serine protease activities, and also elevated inflammatory cytokines. Plasma serine protease activity was positively correlated with body mass index, hemoglobin A1c, homeostasis model assessment-insulin resistance index (HOMA-IR), tumor necrosis factor-α, and negatively with adiponectin concentration. In the animal study, administration of HFD progressively increased body weight, fasting glucose level, HOMA-IR, and upregulated serine protease activity. Furthermore, in-vivo serine protease inhibition significantly suppressed systemic inflammation, reduced fasting glucose level, and improved insulin resistance, and these effects probably mediated by modulating insulin receptor and cytokine expression in visceral adipose tissue. Our findings support the serine protease may play an important role in type 2 diabetes and suggest a rationale for a therapeutic strategy targeting serine protease for clinical prevention of type 2 diabetes.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Serina Proteases/metabolismo , Inibidores de Serino Proteinase/uso terapêutico , Adulto , Idoso , Animais , Estudos Transversais , Citocinas/sangue , Dieta Hiperlipídica , Modelos Animais de Doenças , Feminino , Humanos , Inflamação , Mediadores da Inflamação/sangue , Resistência à Insulina , Masculino , Camundongos , Camundongos Knockout , Pessoa de Meia-Idade , Receptores de LDL/genética
19.
Cleve Clin J Med ; 87(2): 109-120, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32015064

RESUMO

Familial hypercholesterolemia is an autosomal dominant disorder that affects the metabolism of low-density lipo-protein cholesterol (LDL-C) through mutations in the gene for LDL receptor (LDLR), and less commonly in those for apolipoprotein B (APOB), proprotein convertase subtili-sin-kexin type 9 (PCSK9), and others. Patients with these mutations have elevated plasma levels of LDL-C and, as a result, an increased risk of atherosclerotic cardiovascular disease beginning in childhood, leading to significant risk of illness and death.


Assuntos
Anticolesterolemiantes/uso terapêutico , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Hiperlipoproteinemia Tipo II/diagnóstico , Hiperlipoproteinemia Tipo II/tratamento farmacológico , Pró-Proteína Convertase 9/antagonistas & inibidores , Anticorpos Monoclonais Humanizados/uso terapêutico , Testes Genéticos , Humanos , Hiperlipoproteinemia Tipo II/genética , Anamnese , Guias de Prática Clínica como Assunto , Receptores de LDL/genética , Medição de Risco
20.
Arterioscler Thromb Vasc Biol ; 40(3): 819-829, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32078365

RESUMO

OBJECTIVE: To clarify the association between PCSK9 (proprotein convertase subtilisin/kexin type 9) and Lp(a) (lipoprotein [a]), we studied Lp(a) kinetics in patients with loss-of-function and gain-of-function PCSK9 mutations and in patients in whom extended-release niacin reduced Lp(a) and PCSK9 concentrations. Approach and Results: Six healthy controls, 9 heterozygous patients with familial hypercholesterolemia (5 with low-density lipoprotein receptor [LDLR] mutations and 4 with PCSK9 gain-of-function mutations) and 3 patients with heterozygous dominant-negative PCSK9 loss-of-function mutations were included in the preliminary study. Eight patients were enrolled in a second study assessing the effects of 2 g/day extended-release niacin. Apolipoprotein kinetics in VLDL (very-low-density lipoprotein), LDL (low-density lipoprotein), and Lp(a) were studied using stable isotope techniques. Plasma Lp(a) concentrations were increased in PCSK9-gain-of-function and familial hypercholesterolemia-LDLR groups compared with controls and PCSK9-loss-of-function groups (14±12 versus 5±4 mg/dL; P=0.04), but no change was observed in Lp(a) fractional catabolic rate. Subjects with PCSK9-loss-of-function mutations displayed reduced apoE (apolipoprotein E) concentrations associated with a VLDL-apoE absolute production rate reduction. Lp(a) and VLDL-apoE absolute production rates were correlated (r=0.50; P<0.05). ApoE-to-apolipoprotein (a) molar ratios in Lp(a) increased with plasma Lp(a) (r=0.96; P<0.001) but not with PCSK9 levels. Extended-release niacin-induced reductions in Lp(a) and VLDL-apoE absolute production rate were correlated (r=0.83; P=0.015). In contrast, PCSK9 reduction (-35%; P=0.008) was only correlated with that of VLDL-apoE absolute production rate (r=0.79; P=0.028). CONCLUSIONS: VLDL-apoE production could determine Lp(a) production and/or assembly. As PCSK9 inhibitors reduce plasma apoE and Lp(a) concentrations, apoE could be the link between PCSK9 and Lp(a).


Assuntos
Apolipoproteínas E/sangue , Hiperlipoproteinemia Tipo II/sangue , Lipoproteína(a)/sangue , Lipoproteínas VLDL/sangue , Adolescente , Adulto , Anticolesterolemiantes/uso terapêutico , Biomarcadores/sangue , Estudos de Casos e Controles , Preparações de Ação Retardada , Feminino , Predisposição Genética para Doença , Heterozigoto , Humanos , Hiperlipoproteinemia Tipo II/diagnóstico , Hiperlipoproteinemia Tipo II/tratamento farmacológico , Hiperlipoproteinemia Tipo II/genética , Cinética , Lipoproteína(a)/biossíntese , Masculino , Pessoa de Meia-Idade , Mutação , Niacina/uso terapêutico , Fenótipo , Pró-Proteína Convertase 9/genética , Ensaios Clínicos Controlados Aleatórios como Assunto , Receptores de LDL/genética , Resultado do Tratamento , Adulto Jovem
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