Serum PCSK9 in polycystic ovary syndrome: Relationship with body mass index and long-term cardiovascular risk

Increased sortilin and its independent effect on circulating proprotein convertase subtilisin/kexin type 9 (PCSK9) in statin-naive patients with coronary artery disease

Serum proprotein convertase subtilisin/kexin type 9 (PCSK9) levels are positively associated with serum cholesterol levels, which contribute to the growth of cancers. PCSK9 levels are low in patients with liver cirrhosis, with a high incidence of hepatocellular carcinoma (HCC). PCSK9 expression is increased in colorectal cancer (CRC), but serum levels in these patients have not been analyzed. Therefore, serum PCSK9 may serve as a diagnostic marker to differentiate between liver metastases from CRC and HCC. Serum PCSK9 was measured by ELISA in 36 patients with CRC metastases, 32 patients with HCC and 59 healthy controls. The serum PCSK9 levels of these three cohorts were similar. Serum PCSK9 levels were not associated with the tumor node metastasis (TNM) stage. Liver steatosis, inflammation and fibrosis scores did not correlate with serum PCSK9 levels. Cancer patients with hypercholesterolemia had elevated PCSK9 levels. These patients had higher TNM stages and Union for International Cancer Control scores in both cohorts. PCSK9 levels were also elevated in patients with viral hepatitis. When patients with hepatitis and hypercholesterolemia were excluded, serum PCSK9 levels were low in cancer patients compared to controls. Serum PCSK9 levels did not correlate with the tumor markers carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) in HCC and CRC patients. In the latter cohort, PCSK9 and alpha-fetoprotein were positively correlated. Serum PCSK9 is increased in patients with CRC metastases or HCC with hypercholesterolemia. This suggests that patients with high cholesterol levels may benefit most from PCSK9 blockage.

Proprotein convertase subtilisin/kexin type 9 (PCSK9) induces hepatic LDL receptor (LDLR) degradation and lowers the removal of LDL-cholesterol from circulation. Thus, PCSK9 has become an important therapeutic target for the treatment of hypercholesterolemia. The transcription of PCSK9 is prominently controlled by the HNF1 binding motif embedded in its proximal promoter region that binds to HNF1α or HNF1β as homodimers or heterodimers. Our previous in vivo studies showed that only HNF1α but not HNF1β regulates PCSK9 transcription in mouse liver. Statin has been shown to elevate circulating PCSK9 levels through stimulating PCSK9 gene transcription, which reduces the clinical efficacy of statin in LDL-cholesterol reduction. In this study, we utilized adenoviral shRNA expression vectors (Ad-shHNF1α and Ad-shHNF1β) to generate liver specific knockdown of HNF1α or HNF1β in hamsters to examine the impact of reduced expression of HNF1 transcription factors on statin-induced elevation of PCSK9. Administration of rosuvastatin (RSV) at a daily dose of 15 mg/kg to hamsters infected with a control adenovirus significantly increased liver PCSK9 mRNA levels by 94% and serum PCSK9 levels by 37%. However, injection of Ad-shHNF1α into hamsters largely abolished the RSV-induced elevation of PCSK9 serum levels and hepatic mRNA levels, which was accompanied by a significant increase in liver LDLR protein abundance by 64% as compared to hamsters injected with control virus. Surprisingly, injection of Ad-shHNF1β produced similar inhibitory effects on the RSV-induced PCSK9 expression as that of Ad-shHNF1α. This was different from the negative results of HNF1β knockdown conducted in mice. In addition to changes in PCSK9 levels, we observed a modest but significant reduction in serum non-HDL cholesterol level after knockdown of HNF1α (27%) or HNF1β (32%) in hamsters treated with RSV. Altogether, our study demonstrates that unlike mice, both HNF1α and HNF1β are positive regulators of hepatic PCSK9 transcription in hamster species and that transient, liver specific knockdown of either HNF1α or HNF1β could antagonize the RSV-induced elevation of serum PCSK9 and non-HDL cholesterol levels.

Systemic lupus erythematosus (SLE) patients have tendencies of accelerated atherosclerosis (AS) which can only partly be explained by traditional cardiovascular disease (CVD) risk factors. Imbalanced inflammation also plays a vital role. Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a new therapeutic target for AS for its dual mechanisms in lipids and inflammation. We aimed to assess serum PCSK9 concentrations in SLE patients and its possible role in atherogenesis of SLE. Ninety SLE patients and 50 healthy controls were included. SLE patients were further divided into SLE-AS and SLE-NonAS subgroups, according to the carotid intima-media thickness (cIMT). Traditional CVD risk factors, inflammatory biomarkers and PCSK9 concentrations were compared between: (I) SLE patients and controls; (II) SLE-AS subgroup and SLE-NonAS subgroup; (III) SLE patients with and without lupus nephritis (LN). Correlational analysis, univariate and multivariate linear regression analysis were applied to analyze the association between PCSK9 levels and disease parameter in SLE patients. Effects on PCSK9 concentrations by monotherapy with hydroxychloroquine (HCQ), which is thought having protective effects against AS in SLE, were investigated by follow-up analysis in 15 SLE patients. We found that SLE patients had significantly elevated serum PCSK9 levels than controls, especially in SLE-As subgroup or those with LN, accompanied with higher ratio of cIMT thickening. Correlational analysis showed PCSK9 concentrations correlated with C-reactive protein (CRP) levels, age and erythrocyte sedimentation rate (ESR). Univariate and multivariate linear regression revealed that only CRP, but not age or ESR was positive predictors of PCSK9. Interestingly, monotherapy with HCQ for three months significantly reduced PCSK9 and CRP levels in inactive SLE patients. Our results suggested that elevated PCSK9 levels in SLE are probably associated with atherogenic inflammation in SLE. HCQ, which is thought having protective effects against AS in SLE, can effectively reduce PCSK9 levels in SLE patients.

BackgroundSLE patients have a tendency of accelerated atherosclerosis(AS) which can only partly be explained by traditional risk factors for cardiovascular disease. Proprotein convertase subtilisin/kexin type 9 (PCSK9), which is a...

BackgroundPeriodontal disease is suggested to increase the risk of atherothrombotic disease by inducing dyslipidemia. Recently, we demonstrated that proprotein convertase subtilisin/kexin type 9 (PCSK9), which is known to play a critical role in the regulation of circulating low-density lipoprotein (LDL) cholesterol levels, is elevated in periodontitis patients. However, the underlying mechanisms of elevation of PCSK9 in periodontitis patients are largely unknown. Here, we explored whether Porphyromonas gingivalis, a representative periodontopathic bacterium, -induced inflammatory response regulates serum PCSK9 and cholesterol levels using animal models.MethodsWe infected C57BL/6 mice intraperitoneally with Porphyromonas gingivalis, a representative strain of periodontopathic bacteria, and evaluated serum PCSK9 levels and the serum lipid profile. PCSK9 and LDL receptor (LDLR) gene and protein expression, as well as liver X receptors (Lxrs), inducible degrader of the LDLR (Idol), and sterol regulatory element binding transcription factor (Srebf)2 gene expression, were examined in the liver.ResultsP. gingivalis infection induced a significant elevation of serum PCSK9 levels and a concomitant elevation of total and LDL cholesterol compared with sham-infected mice. The LDL cholesterol levels were significantly correlated with PCSK9 levels. Expression of the Pcsk9, Ldlr, and Srebf2 genes was upregulated in the livers of the P. gingivalis-infected mice compared with the sham-infected mice. Although Pcsk9 gene expression is known to be positively regulated by sterol regulatory element binding protein (SREBP)2 (human homologue of Srebf2), whereas Srebf2 is negatively regulated by cholesterol, the elevated expression of Srebf2 found in the infected mice is thought to be mediated by P. gingivalis infection.ConclusionsP. gingivalis infection upregulates PCSK9 production via upregulation of Srebf2, independent of cholesterol levels. Further studies are required to elucidate how infection regulates Srebf2 expression and subsequently influences lipid metabolism.

BackgroundGenetic and environment factors affect the occurrence and development of coronary artery disease (CAD). Proprotein convertase subtilisin/kexin type 9 (PCSK9), has been investigated extensively in the field of lipid metabolism and CAD. We performed this case-control study to investigate the relationship between serum PCSK9 levels and PCSK9 polymorphisms and lipid levels and CAD risk in a southern Chinese population.MethodsA hospital-based case-control study with 1, 096 subjects, including 626 CAD patients and 470 controls, were conducted. Genotyping of PCSK9 polymorphisms was performed using polymerase chain reaction-ligase detection reaction (PCR-LDR) method.ResultsThe frequencies of the AA, AG and GG genotypes of PCSK9 E670G polymorphism were 90.58, 9.27, and 0.16% in the CAD patients, compared with 88.72, 10.85 and 0.43% in the controls, respectively. No R46L variant was detected in this population. There were no significant differences in genotype and allele frequencies of PCSK9E670G polymorphism between the CAD group and the controls. Serum lipid levels were not significantly different in carriers with the G allele and those with the AA genotype. The median (QR) of PCSK9 concentration was 1205.00 ng/l (577.28–1694.13 ng/l) in cases and 565.87 ng/l (357.17–967.50 ng/l) in controls, respectively. Compared with controls, CAD patients had significantly higher PCSK9 levels (z = 4.559, P < 0.001). After adjusting for age, gender, essential hypertension, diabetic mellitus, smoking and lipid profiles, PCSK9 levels remain significantly associated with increased CAD susceptibility (OR = 1.002, 95% CI = 1.001–1.002, P < 0.001). The correlation analyses showed that serum PCSK9 levels were positively associated with triglyceride (TG), Apo B and atherogenic index of plasma (AIP) levels in controls. No significant association between the PCSK9 E670G polymorphism and serum PCSK9 levels was observed in the CAD group and the controls.ConclusionsThe present study shows that serum PCSK9 levels, but not PCSK9 polymorphisms, are associated with CAD risk in Southern Chinese Han population, and that serum PCSK9 levels are positively associated with AIP.

Analysis of the Association between PCSK9 Levels and Plasma Lipid Levels in Cameroonians with Type 2 Diabetes

Background/PurposeProprotein convertase subtilisin/kexin type 9 (PCSK9) is an enzyme that regulates cholesterol homeostasis by inducing posttranslational modification and lysosomal degradation of low‐density lipoprotein receptor (LDLR). However, the role of PCSK9 in dyslipidemia associated with rheumatoid arthritis (RA) is not well studied. The aim of this study was to examine how PCSK9 levels correlate with age [30–45; 46–60; and 61–80 years], sex, and RA disease, and with CD36, a major scavenger receptor targeted for proteasomal degradation by PCSK9.MethodsDe‐identified human RA serum samples (n=66; 33 female and 33 male) were obtained from patients diagnosed with RA according to the American College of Rheumatology 1987 classification criteria and healthy, age and gender‐matched serum samples were used for evaluation. Serum levels of human PCSK9 and CD36 were determined using commercially available ELISA kits.ResultsThe mean (SD) age of healthy group [55.6 (11.2) years] and RA group [57.2 (10.4) years] was observed. Results of the ELISA showed that the serum levels of PCSK9 in RA group is reduced by ~10% (mean ± SEM; 231 ± 11.6 ng/ml vs. 205 ± 11.1 ng/ml; p&lt;0.14). Interestingly, our gender‐based analysis showed that the basal serum PCSK9 levels were around 30% higher in the healthy female group compared to the healthy male group (260 ± 15.9 ng/ml vs. 202 ± 15.4 ng/ml; p=0.01). Furthermore, from a disease perspective, we observed approximately 15% lower serum PCSK9 levels in female RA group (260 ± 15.9 ng/ml vs. 219 ± 14.4 ng/ml; p=0.078) compared to only a modest 5% decline in male RA group (202 ± 15.4 ng/ml vs. 191 ± 16.8 ng/ml; p=0.62) when compared to their respective gender control groups. Analysis of PCSK9 data based on age showed that while PCSK9 levels gradually decreased in healthy female group [274.4 ± 38.9 ng/ml in 30–45y range vs. 241 ± 20.7 ng/ml in 61–80y], we observed an accelerated decrease in serum PCSK9 levels in RA female group [278.5 ± 62.4 ng/ml in 30–45y range vs. 220 ± 19.2 ng/ml in 46–60y; p=0.14]. This suggests that PCSK9 levels rapidly decline with RA progression in aging females. Interestingly, the serum PCSK9 levels in both healthy and RA male groups showed declines at a later stage of life [61–80y range; p&lt;0.001], implicating that PCSK9 levels deplete in male groups, independent of RA disease pathogenesis. Serum CD36 levels in healthy female group were modestly low when compared to the serum levels in healthy male group [mean ± SEM; 1121 ± 164 pg/ml vs. 1280 ± 216 pg/ml; p&lt;0.562]. Interestingly, while the CD36 levels were around 30% higher in RA males compared to the healthy male controls, we observed a modest decrease in serum CD36 by 15–20% in RA females when compared to the healthy female controls.ConclusionOur findings provide evidence of the gender differences in serum PCSK9 levels and its modulation with age. Furthermore, it is speculated that an early decline in serum PCSK9 in female RA patients may contribute towards the establishment of RA in females.Support or Funding InformationWashington State University, Spokane, WAThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

BackgroundPatients with systemic lupus erythematosus (SLE) have a tendency of accelerated atherosclerosis with controversial benefits from statin. This phenomenon can only partly be explained by traditional risk factors for cardiovascular...

Purpose The purpose of this study was to investigate the association between serum proprotein convertase subtilisin/kexin type 9 (PCSK9) levels and renal function impairment in type 2 diabetes mellitus (T2DM) patients. Methods PCSK9 levels were measured in T2DM patients, streptozotocin plus high-fat diet (STZ + HFD) mice, human proximal tubular epithelial (HK-2) cells treated with high glucose plus palmitic acid (HGPA) and the corresponding control groups. The T2DM patients were further divided into three groups according to serum PCSK9 levels. An analysis of clinical data was conducted, and a binary logistic regression model was used to test the relationship between potential predictors and urine albumin/urine creatinine ratio (UACR) and estimated glomerular filtration rate (eGFR). Results PCSK9 levels were higher in the DM group than in the control group in humans, mice and HK-2 cells. The systolic blood pressure (SBP), serum creatinine (Scr), blood urea nitrogen (BUN), triglyceride (TG), and urine α1-MG/urine creatinine ratio (UαCR) values in PCSK9 tertile 3 were significantly higher than those in PCSK9 tertile 1 (p < 0.05). The DBP and UACR values were significantly higher in PCSK9 tertile 3 than in PCSK9 tertile 1 and PCSK9 tertile 2 (both p < 0.05). In addition, URCR values were significantly higher in PCSK9 tertile 3 and PCSK9 tertile 2 than in PCSK9 tertile 1 (both p < 0.05). Serum PCSK9 levels were positively correlated with SBP, Scr, BUN, TG, URCR, UαCR and UACR but inversely correlated with eGFR. In STZ + HFD mice, serum PCSK9 levels were positively correlated with Scr, BUN and UACR, which was consistent with the findings in the patients. A logistic regression model revealed that serum PCSK9 is an independent risk factor for UACR ≥30 mg/g and eGFR <60 mL/min/1.73 m2. The ROC curve showed that 170.53 ng/mL and 337.26 ng/mL PCSK9 were the best cutoff values for UACR ≥30 mg/g and eGFR <60 mL/min/1.73 m2, respectively. Conclusion Serum PCSK9 levels are associated with renal function impairment in T2DM patients and in some patients lower PCSK9 may be helpful to decrease chronic kidney disease.

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is an important and major player in the pathophysiology of hypercholesterolemia and atherosclerosis. Recently, PCSK9 has been implicated in the pathogenesis of inflammatory diseases. Whether PCSK9 is involved in idiopathic pulmonary arterial hypertension (IPAH) remains unclear. This study aimed to investigate the relationship between PCSK9 and IPAH. Serum PCSK9, interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), interleukin-1 β (IL-1β), and monocyte chemotactic protein-1 (MCP-1) were measured by enzyme linked immunosorbent assay. Transthoracic echocardiography was performed among 40 IPAH patients and 20 control subjects. Hemodynamic data were collected via right heart catheterization in patients with IPAH. Serum PCSK9, TNF-α, IL-6, IL-1β, and MCP-1 levels were significantly higher in IPAH patients than in control subjects (p < 0.001). Among enrolled IPAH patients, PCSK9 levels were higher in WHO-FC III/IV patients compared with those in WHO-FC I/II (p < 0.05), and were positively correlated with TNF-α, IL-6, MCP-1, N-Terminal pro-brain natriuretic peptide, pulmonary arterial systolic pressure (r = 0.653, p < 0.001), pulmonary arterial diastolic pressure (r = 0.466, p = 0.002), mean pulmonary arterial pressure (mPAP, r = 0.730, <0.001), pulmonary vascular resistance (r = 0.488, p = 0.001), and right ventricle diameter (r = 0.563, p < 0.001). In multiple regression analysis, mPAP was strongly associated with serum PCSK9 (β = 0.694, p < 0.001), independent of other variables. Receiver operating characteristic curve analysis showed the optimal cutoff value of serum PCSK9 concentration for predicting IPAH was 90.67 ng/ml, with a sensitivity of 90.0% and a specificity of 85.0%. In conclusion, IPAH patients had elevated serum PCSK9 levels which correlated the presence and severity of pulmonary hypertension. PCSK9 may be a novel potential therapeutic target.

Introduction: Atorvastatin hinders cardiovascular disease by reducing cholesterol levels. Proprotein convertase subtilisin/kexin type 9 (PCSK9) enhances the secretion of insulin by binding to LDL receptor. Sortilin is committed in the transfer of intracellular proteins through the plasma membrane. Objectives: The purpose of this research was to determine the effect of atorvastatin consumption on alterations in the levels of 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMG-CoA-R), PCSK9 and sortilin in diabetic patients and pre-diabetics. Patients and Methods: This study was carried out on 80 individuals including normal subjects, diabetic patients and pre-diabetics. The participated individuals were divided as control group (i) (healthy individuals without diabetes mellitus), diabetic group receiving statin (ii), diabetic group not receiving statin (iii), pre-diabetic group receiving statin (iv) and pre-diabetic group not receiving statin (v). Levels of HMG-COA-R, PCSK9 and sortilin were determined by ELISA method. Results: In diabetics and pre-diabetics taking atorvastatin, the level of HMG-COA-R was not altered significantly compared to diabetics and pre-diabetics not taking atorvastatin, respectively (P&gt; 0.05). The serum PCSK9 level in diabetics and pre-diabetics was significantly higher than the healthy individuals (P= 0.001). Additionally, the serum PCSK9 level in diabetics and pre-diabetics receiving atorvastatin was significantly higher than diabetics and pre-diabetics not receiving atorvastatin, respectively (P=0.001). The serum sortilin level in diabetics and pre-diabetics was significantly higher than the healthy individuals (P=0.001). In addition, the serum sortilin level in pre-diabetics receiving atorvastatin was significantly higher than pre-diabetics not receiving atorvastatin (P=0.001). Conclusion: Atorvastatin improved insulin secretion and sensitivity by increasing serum sortilin and PCSK9 levels. Thereby, it prevented the development of diabetes in diabetics and the progression of pre-diabetes to diabetes in pre-diabetics.

Serum PCSK9 is associated with multiple metabolic factors in a large Han Chinese population

IL-22 and its interaction with amino acid and glycolipid metabolite in polycystic ovary syndrome (PCOS) patients