Hypertension and clinical outcomes in patients with familial hypercholesterolemia.

BACKGROUND: Hypertension is a known risk factor for cardiovascular disease; however, its impact on clinical outcomes in patients with heterozygous familial hypercholesterolemia (HeFH) is unclear. Hence, we aimed to investigate the effects of hypertension on severity of coronary artery atherosclerosis and cardiovascular outcomes in patients with HeFH. METHODS: A total of 480 patients with clinical or molecular diagnosis of definite or probable familial hypercholesterolemia according to Dutch Lipid Clinic Network criteria (DLCN score ≥6) were included in the study. They were divided into the two groups according to their blood pressure status: hypertension group and normotension group. The severity of coronary stenosis was assessed by a number of diseased vessels, Gensini, Syntax, and Jeopardy scores. All individuals were followed up for cardiovascular events (CVEs) and cox proportion hazard models were used to evaluate the association of hypertension with cardiovascular outcomes. RESULTS: Patients with hypertension had more severe coronary stenosis and a higher incidence of CVEs compared with the ones with normotension (log-rank P < 0.001). After multivariable adjustment, there was a 2.1-fold increased risk of CVEs among patients with hypertension compared with patients with normotension (adjusted hazard ratio 2.06, 95% confidential interval 1.17-3.65, P < 0.01). Hypertension control status was also associated with CVEs even after adjustment of multiple variables. However, no combined effect on increased cardiovascular risks was detected in this HeFH cohort. CONCLUSION: In patients with HeFH, hypertension is an independent risk factor for cardiovascular events. Moreover, blood pressure control status in patients with hypertension is associated with the worse outcomes.

SORBS2 as a molecular target for atherosclerosis in patients with familial hypercholesterolemia.

BACKGROUND: Familial hypercholesterolemia (FH) is a metabolic disease in which patients are prone to develop premature atherosclerosis (AS). Sorbin and SH3 Domain Containing 2 (SORBS2) is known to play a role in coronary heart disease (CHD). However, the mechanism underlying SORBS2 involvement in the development of hypercholesterolemia remains unknown. Here, we investigated the effects of SORBS2 on inflammation and foam cell formation and its underlying mechanisms. METHODS: Using Bioinformatics analysis, we established that SORBS2 is upregulated in patients with FH. Circulating concentrations of SORBS2 were measured using ELISA kit (n = 30). The association between circulating SORBS2 levels and inflammatory factors or lipid indexes were conducted using Spearman correlation analysis. We further conducted in vitro experiments that the expression of SORBS2 were analyzed, and SORBS2 siRNA were transfected into oxidized LDL (OxLDL)-induced macrophages, followed by western blot and immunofluorescence. RESULTS: Circulating SORBS2 levels were positively associated with inflammatory factors and lipid indexes. We also observed that high in vitro expression of SORBS2 in OxLDL-induced macrophages. After SORBS2 silencing, Nod like receptor family pyrin domain-containing 3 protein(NLRP3)-Caspase1 activation and NF-κB activation were attenuated, and secretion of pro-inflammatory cytokines (IL-1ß and IL-18) was decreased. Moreover, SORBS2 silencing blocked reactive oxygen species (ROS) production and lipid accumulation, and promoted cholesterol efflux through ABCG1-PPARγ pathway. CONCLUSIONS: SORBS2 regulates lipid-induced inflammation and foam cell formation, and is a potential therapeutic target for hypercholesterolemia.

Impact of diabetes on coronary severity and cardiovascular outcomes in patients with heterozygous familial hypercholesterolaemia.

AIMS: Type 2 diabetes mellitus (T2DM) is an independent risk factor for cardiovascular disease. However, the association between T2DM and coronary artery disease (CAD) in patients with heterozygous familial hypercholesterolaemia (HeFH) has not been thoroughly evaluated. Our study aimed to assess the effect of T2DM on CAD severity and hard cardiovascular endpoints in a HeFH cohort. METHODS AND RESULTS: A total of 432 patients with HeFH with a molecular and/or clinical Dutch Lipid Clinic Network score ≥6 (definite and probable) were enrolled. Patients were divided into a T2DM group (n = 99) and a non-T2DM group (n = 333). The severity of coronary stenosis was assessed by the number of diseased vessels and Gensini, SYNTAX, and Jeopardy scores. Hard endpoints included a composite of non-fatal myocardial infarction, non-fatal stroke, and cardiac death. Cox regression and Kaplan-Meier analyses were used to evaluate the effect of T2DM on hard cardiovascular endpoints. The prevalence of CAD was higher in patients with T2DM compared with those without (96.0% vs. 77.5%, respectively; P < 0.001). Patients with T2DM demonstrated a greater number of diseased vessels (P = 0.029) and more severe coronary lesions with high Gensini, SYNTAX, and Jeopardy score tertiles (P = 0.031, P = 0.001, and P = 0.024, respectively). During a median of 3.75 years up to a maximum of 9 years of follow-up, hard endpoints occurred in 13 of 99 patients with T2DM and 16 of 333 without T2DM at baseline. Compared with patients without T2DM, patients with T2DM were at a significantly greater risk of hard endpoints [multivariate adjusted hazard ratio (HR) 2.32, 95% confidence interval (CI) 1.02-4.84; P = 0.025]. Additionally, patients with T2DM and good glucose control (HbA1c < 7.0%) were at a lower risk of hard endpoints compared with those with poor glucose control (HbA1c ≥ 7.0%, HR 0.08, 95% CI 0.01-0.56; P = 0.011). CONCLUSION: We conclude that T2DM is an independent predictor of CAD severity when assessed by number of diseased vessels, Gensini, SYNTAX, Jeopardy scores, and hard cardiovascular endpoints, suggesting that T2DM could be further used for risk stratification of patients with HeFH.

Relations of physical signs to genotype, lipid and inflammatory markers, coronary stenosis or calcification, and outcomes in patients with heterozygous familial hypercholesterolemia.

BACKGROUND: Although the presence of physical signs [tendon xanthomas and/or corneal arcus (TX/CA)], are associated with the risk of coronary artery disease in patients with heterozygous familial hypercholesterolemia (HeFH), their relationship with genotypes and clinical characteristics has not been fully determined. This study aimed to examine the association of TX/CA with genetic mutation, lipid- and inflammation-related markers, the severity of coronary stenosis or calcification, and cardiovascular events (CVEs) in patients with HeFH. METHODS: LDLR, APOB, and PCSK9 genes were screened in 523 HeFH patients, and patients with TX/CA (n = 50) were 1:4 propensity score-matched to patients without TX/CA (n = 200) to adjust for age and sex. Laboratory markers (proprotein convertase subtilisin/kexin type 9 [PCSK9], lipoprotein(a) and high-sensitivity C-reactive protein [hsCRP]), computed tomography angiography, coronary angiography, and follow-up for CVEs were performed. RESULTS: Patients with physical signs had significantly higher low-density lipoprotein cholesterol levels; higher PCSK9 or hsCRP concentrations; more LDLR positive mutations; and higher prevalence of high tertiles of Gensini, SYNTAX and Jeopardy scores as well as coronary artery calcium scores than did those without. Over an average follow-up of 3.7 years, the incidence of CVEs was significantly higher in patients with TX/CA (log-rank p < 0.001). Patients with physical signs and mutation positivity had threefold higher risks of CVEs (adjusted hazard ratio 3.34, 95% confidence interval 1.04-10.72, p = 0.024). CONCLUSIONS: Physical signs were associated with genotypes and phenotypes, and worse outcomes in patients with HeFH, suggesting that these signs may help in risk stratification in these patients.

Plasma proprotein convertase subtilisin/kexin type 9 concentration and recurrent cardiovascular events in patients with familial hypercholesterolemia.

AIMS: Familial hypercholesterolemia patients are characterized by early onset of coronary artery calcification and atherosclerosis, and high incidence of cardiovascular events. Plasma proprotein convertase subtilisin/kexin type 9 was reported to be a predictor for cardiovascular risk in the general population. However, its prognostic value for predicting recurrent cardiovascular events in familial hypercholesterolemia patients remains undetermined. METHODS: A total of 249 patients with molecularly and/or clinically (Dutch Lipid Clinic Network score > 6) defined familial hypercholesterolemia who had experienced a first cardiovascular event were consecutively included and plasma proprotein convertase subtilisin/kexin type 9 concentrations were measured by enzyme-linked immunosorbent assay. Coronary artery calcification was measured using Agatston method and coronary severity was assessed by Gensini score, respectively. All patients received standard lipid-lowering therapy and were followed-up for recurrent cardiovascular events. Univariate and multivariate regression and Cox analyses was used to calculate hazard ratios with 95% confidence interval. RESULTS: Circulating proprotein convertase subtilisin/kexin type 9 concentrations were positively associated with coronary artery calcification scores and Gensini score by both univariate and multivariate analyses. During a mean follow-up of 43 ± 19 months, 29 (11.51%) recurrent cardiovascular events occurred. Kaplan-Meier analysis showed that patients with the highest proprotein convertase subtilisin/kexin type 9 levels had the lowest event-free survival time. Multivariable Cox regression analysis revealed that proprotein convertase subtilisin/kexin type 9 was independently associated with recurrent cardiovascular events (hazard ratio: 1.45, 95% confidence interval: 1.11-1.88). The combination of proprotein convertase subtilisin/kexin type 9 to Cox prediction model led to an enhanced predictive value for recurrent cardiovascular events. CONCLUSIONS: Increased level of proprotein convertase subtilisin/kexin type 9 was a significant risk factor of atherosclerosis and independently predicted future recurrent cardiovascular events in familial hypercholesterolemia patients receiving standard lipid-lowering treatment.

Differential leukocyte counts and cardiovascular mortality in very old patients with acute myocardial infarction: a Chinese cohort study.

BACKGROUND: Total leukocyte and differential Leukocyte counts are prognostic indictors in patients with coronary artery disease (CAD). However, there is no data available regarding their prognostic utility in very old patients with acute myocardial infarction (AMI). The aim of this study is to investigate the potential role of different leukocyte parameters in predicting the mortality among very old patients with AMI. METHODS: A total of 523 patients aged over 80 years with AMI were consecutively enrolled into this study. Leukocyte and its subtypes were obtained at admission in each patient. The primary study endpoint was cardiovascular mortality. Patients were followed up for an average of 2.2 years and 153 patients died. The associations of leukocyte parameters with mortality were assessed using Cox regression analyses. The concordance index was calculated to test the model efficiency. RESULTS: In multivariable regression analysis, neutrophils-plus-monocytes-to-lymphocytes ratio (NMLR) and neutrophils-to-lymphocytes ratio (NLR) were two most significant predictors of mortality among all the leukocyte parameters (HR = 3.21, 95% CI 1.75-5.35; HR = 2.79, 95% CI 1.59-4.88, respectively, all p < 0.001, adjusted for age, male gender, body mass index, family history of CAD, smoking, hypertension, diabetes mellitus, high-density lipoprotein cholesterol (HDL-C), non-HDL-C, high sensitivity C-reactive protein, creatinine, left ventricular ejection fraction, troponin I, use of statin, angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, and percutaneous coronary intervention). Furthermore, adding NMLR and NLR into the Cox model increased the C-statistic by 0.038 and 0.037 respectively, which were more significant than that of other leukocyte parameters. Besides, addition of NMLR and NLR to the Canada Acute Coronary Syndrome Risk Score model also increased the C-statistic by 0.079 and 0.077 respectively. CONCLUSION: Our data firstly indicated that most leukocyte subtypes were independent markers for the mortality in very old patients with AMI, while NMLR and NLR appeared to be more effective.

Long-term prognostic utility of low-density lipoprotein (LDL) triglyceride in real-world patients with coronary artery disease and diabetes or prediabetes.

BACKGROUND: Recent guidelines highlighted the association between atherosclerosis and triglyceride-enriched lipoproteins in patients with impaired glucose metabolism. However, evidence from prospective studies for long-term prognostic utility of low-density lipoprotein triglyceride (LDL-TG) in real-world patients with prediabetes (Pre-DM) or diabetes mellitus (DM) and coronary artery disease (CAD) is currently not available. The aim of the present study was to evaluate the impact of LDL-TG on major adverse cardiovascular events (MACEs) in patients with stable CAD under different glucose metabolism status. METHODS: A total of 4381 patients with CAD were consecutively enrolled and plasma LDL-TG level was measured by an automated homogeneous assay. They were categorized according to both status of glucose metabolism [DM, Pre-DM, normal glycaemia regulation (NGR)] and tertiles of LDL-TG. All subjects were followed up for the occurrence of MACEs. RESULTS: During a median of 5.1 (interquartile range 3.9 to 5.9) years' follow-up, 507 (11.6%) MACEs occurred. Cubic spline models showed a significant association between LDL-TG and MACEs in DM and Pre-DM but not in NGR. When the combined effect of elevated LDL-TG and glucose disorders was considered for risk stratification, the medium tertile of LDL-TG plus DM, and the highest tertile of LDL-TG plus Pre-DM or plus DM subgroups were associated with significantly higher risk of MACEs after adjustment of confounders including triglyceride [hazard ratios (95% confidence intervals): 1.843 (1.149-2.955), 1.828 (1.165-2.867), 2.212 (1.396-3.507), all p < 0.05]. Moreover, adding LDL-TG into the original model increased the C-statistic from 0.687 to 0.704 (∆C-statistic = 0.016, p = 0.028) and from 0.734 to 0.749 (∆C-statistic = 0.014, p = 0.002) in Pre-DM and DM, respectively. CONCLUSIONS: In this longitudinal cohort study on real-world practice, higher LDL-TG was associated with worse outcomes among Pre-DM and DM patients with stable CAD.

Developing protein arginine methyltransferase 1 (PRMT1) inhibitor TC-E-5003 as an antitumor drug using INEI drug delivery systems.

Injectable implants with the ability to form in situ are one of the most promising carriers for the delivery of chemotherapeutic drugs to tumor sites. We have reported a novel injectable in situ-forming implant system composed of n-butyl-2-cyanoacrylate (NBCA), ethyl oleate, along with the sol-gel phase transition. The chemotherapeutic drug-loaded injectable NBCA ethyl oleate implant (INEI) exhibited excellent therapeutic efficacy for local chemotherapy. Herein, we utilize this INEI to carry N, N'-(Sulfonyldi-4,1-phenylene)bis(2-chloroacetamide) (TE-C-5003), which is a selective protein arginine methyltransferase 1 (PRMT1) inhibitor, to treat the lung cancer mice model. The in vitro experiment shows that TE-C-5003 has a good anti-tumor effect on lung cancer (IC50 = 0.7022 µM for A549; IC50 = 0.6844 µM for NCL-H1299) and breast cancer (IC50 = 0.4128 µM for MCF-7; IC50 = 0.5965 µM for MDA-MB-231). Anti-tumor experiments in animal models showed that the average growth inhibition rate of xenografted human lung cancer cells by the TE-C-5003-loaded INEI (40% NBCA) was 68.23%, which is far more than TC-E-5003 alone (31.76%). Our study further confirms that INEI is an effective technique to improve the anti-tumor effect. The druggability of small molecule compounds can be improved with the help of the mentioned technology. Also, TC-E-5003 may be developed as a broad spectrum anti-tumor drug.

Baseline and on-statin treatment lipoprotein(a) levels for predicting cardiovascular events in patients with familial hypercholesterolemia.

BACKGROUND AND AIMS: Lipoprotein(a) [Lp(a)] has been considered as a causal risk factor for cardiovascular disease (CVD) in the general population and levels vary in different ethnicities. However, no systemic analysis is currently available regarding the relation of plasma Lp(a) levels to cardiovascular events (CVEs) in Chinese patients with heterozygous familial hypercholesterolemia (HeFH). METHODS: Three hundred and ninety-three patients with HeFH undergoing Lp(a) measurement at baseline were consecutively enrolled and followed prospectively for an average of 36.5 months. Lp(a) levels were determined using an immunoturbidimetry assay. Cox regression analysis with adjusted hazard ratios (HRs) and Kaplan-Meier analysis were used to evaluate the prognostic value of Lp(a) on CVEs. RESULTS: Thirty-five events occurred during follow-up. Lp(a) was significantly higher in patients with CVEs (53.3 mg/dL versus 31.7 mg/dL, p < 0.001). In Kaplan-Meier analysis, patients with upper tertile of Lp(a) had a significant lower event-free survival (p = 0.004). After adjusting for confounding risk factors, per log unit increase in baseline Lp(a) was independently associated with CVEs [HR: 2.03(1.28-3.21), p = 0.002]. HRs remained unchanged after accounting for hard endpoints and did not vary too much in several relevant subgroups. Adding Lp(a) to the Cox model led to a significant improvement in C-statistic, net reclassification and integrated discrimination. Moreover, HR for upper versus lower tertile of change in Lp(a) was 2.68 (1.11-6.48) for CVEs after one year. CONCLUSIONS: Both baseline and on-statin treatment Lp(a) levels were associated with an increased risk of CVEs in patients with HeFH, suggesting that Lp(a) measurement might clinically help further risk stratification of FH patients.

Differences in phenotype, genotype and cardiovascular events between patients with probable and definite heterozygous familial hypercholesterolemia.

Aim: To investigated the potential differences between probable and definite heterozygous familial hypercholesterolemia (HeFH) patients diagnosed by Dutch Lipid Clinic Network criteria. Methods: Clinical characteristics, lipid profile, severity of coronary artery stenosis and gene mutations were compared. Kaplan-Meier curve was performed to evaluate the cardiovascular events. Results: Overall, 325 participants were included and divided into two groups: probable (n = 233) and definite HeFH (n = 92). Definite HeFH patients had higher low-density lipoprotein cholesterol (LDL-C), oxidized-LDL and proprotein convertase subtilisin/kexin 9 levels, and higher prevalence of tendon xanthomas. The incidence of genetic mutations was statistically higher in definite HeFH than probable HeFH patients. The coronary stenosis calculated by Gensini score was statistically severer in definite HeFH patients. The best LDL-C threshold for predicting mutations was 5.14 mmol/l. Definite HeFH had lower event-free survival rates. Conclusion: Definite HeFH patients had higher severity of phenotype and genotype, and higher risk of cardiovascular events.

Allele-selective lowering of mutant HTT protein by HTT-LC3 linker compounds.

Accumulation of mutant proteins is a major cause of many diseases (collectively called proteopathies), and lowering the level of these proteins can be useful for treatment of these diseases. We hypothesized that compounds that interact with both the autophagosome protein microtubule-associated protein 1A/1B light chain 3 (LC3)1 and the disease-causing protein may target the latter for autophagic clearance. Mutant huntingtin protein (mHTT) contains an expanded polyglutamine (polyQ) tract and causes Huntington's disease, an incurable neurodegenerative disorder2. Here, using small-molecule-microarray-based screening, we identified four compounds that interact with both LC3 and mHTT, but not with the wild-type HTT protein. Some of these compounds targeted mHTT to autophagosomes, reduced mHTT levels in an allele-selective manner, and rescued disease-relevant phenotypes in cells and in vivo in fly and mouse models of Huntington's disease. We further show that these compounds interact with the expanded polyQ stretch and could lower the level of mutant ataxin-3 (ATXN3), another disease-causing protein with an expanded polyQ tract3. This study presents candidate compounds for lowering mHTT and potentially other disease-causing proteins with polyQ expansions, demonstrating the concept of lowering levels of disease-causing proteins using autophagosome-tethering compounds.

Circulating PCSK9 and cardiovascular events in FH patients with standard lipid-lowering therapy.

BACKGROUND: Proprotein convertase subtilisin/kexin 9 (PCSK9) has been proposed as a novel target for coronary artery disease (CAD). Familial hypercholesterolemia (FH) is characterized by high prevalence of CAD and major cardiovascular events (MACEs). However, no data is available on the association between PCSK9 levels and MACEs in FH patients with standard lipid lowering therapy. METHODS: A total of 338 consecutive heterozygous FH (Dutch Lipid Clinic Network score ≥ 6) was enrolled and followed up for the occurrence of MACEs. Multidetector CT and coronary angiography were performed to determine coronary artery calcification score (CACS) and Gensini score (GS). Multivariable Cox regression analyses were used to calculate hazard ratios (HRs) with 95% confidence intervals (CIs). Plasma PCSK9 concentrations were determined by enzyme immunoassay. RESULTS: PCSK9 was independently and positively associated CACS and GS at baseline. During a mean follow-up of 3 years, 33 (9.8%) events occurred. Patients with MACEs had higher median PCSK9 compared with those without (332.47 vs. 311.89 ng/mL, p = 0.038). Kaplan-Meier analysis revealed that patients with higher PCSK9 presented lower event-free survival (p = 0.0017). PCSK9 was statistically correlated with MACEs after adjusting for confounding factors, with the HR per SD being 1.86 (1.31-2.65) and 3.70 (1.16-11.82) for the highest tertile compared with the lowest tertile. Adding PCSK9 to Cox prediction model led to a statistical improvement in net reclassification and integrated discrimination. CONCLUSION: Elevated levels of PCSK9 were positively associated with the development of CAD and future cardiovascular events, suggesting that measurement of PCSK9 concentration might be useful for cardiovascular risk stratification. Further studies are needed to confirm our results.

Validating the Performance of 5 Risk Scores for Major Adverse Cardiac Events in Patients Who Achieved Complete Revascularization After Percutaneous Coronary Intervention.

BACKGROUND: Risk scores, like the Synergy Between Percutaneous Coronary Intervention With Taxus and Cardiac Surgery (SYNTAX) score (SS), clinical SS, logistic SS (core model and extended model [LSSextended]), Age, Creatinine, and Ejection Fraction (ACEF) score, and modified ACEF score, are predictive for major adverse cardiac events (MACE; including all-cause mortality, myocardial infarction [MI], and revascularization) in patients who have undergone percutaneous coronary intervention (PCI). However, few studies have validated the performance of these scores in complete revascularization (CR) patients. We aimed to compare the performance of previous risk scores in patients who achieved CR after PCI. METHODS: All patients (N = 10,724) who underwent PCI at Fuwai Hospital in 2013 were screened, and those who achieved CR after PCI were enrolled. Risk scores were calculated by experienced cardiologists blinded to the clinical outcomes. Discrimination of risk scores was assessed according to the area under the receiver operating characteristic curve (AUC). RESULTS: Fifty-one percent (5375/10,724) of patients who underwent PCI achieved CR. At a mean follow-up of 2.4 years, the mortality, MI, revascularization, and MACE rates were 1.2%, 1.0%, 6.3%, and 7.7%, respectively. SS was not predictive for mortality (AUC, 0.51; 95% confidence interval [CI], 0.44-0.59). All scores involving clinical variables, especially modified ACEF score (AUC, 0.73; 95% CI, 0.66-0.79), could predict mortality. LSSextended was the most accurate for MI (AUC, 0.68; 95% CI, 0.61-0.75). SS and LSSextended were predictive for revascularization, with marginally significant AUCs (SS, 0.54; LSSextended, 0.55). No score was particularly accurate for predicting MACE, with AUCs ranging from 0.51 (ACEF score) to 0.58 (LSSextended). CONCLUSIONS: In CR patients, risk scores involving clinical variables might help to predict mortality; however, no risk scores showed helpful discrimination for MACE.

A Novel Modified System of Simplified Chinese Criteria for Familial Hypercholesterolemia (SCCFH).

BACKGROUND AND OBJECTIVE: The most significant clinical implication of familial hypercholesterolemia (FH) is early-onset coronary artery disease (CAD), highlighting the importance of a definitive diagnosis being available. Unfortunately, the existing algorithms are complex and it is often difficult to obtain information on the patient's family history. Hence, we aimed to establish a novel system of Simplified Chinese Criteria for FH (SCCFH). METHODS: We recruited 12,921 participants undergoing routine blood collection from November 2011 to June 2018. Clinical characteristics, laboratory examination, and genetic testing were obtained. FH was diagnosed based on the Simon Broome (SB) criteria, Dutch Lipid Clinic Network (DLCN) criteria, and SCCFH. The sensitivity, specificity, and agreement of SCCFH to these existing criteria were investigated. RESULTS: Of 12,921 participants reviewed, the prevalence of definite FH was 223 (1.73%), 202 (1.56%), and 205 (1.59%) based on the DLCN, SB, and SCCFH approaches, respectively. Compared with the DLCN and SB criteria, the SCCFH showed high sensitivity (91.9% and 100%), high specificity (100% and 99.9%), and good agreement (κ = 0.958 and 0.993). Similar results were found in several relevant clinical subgroups. CONCLUSIONS: The SCCFH system is comparable to the existing criteria with high levels of sensitivity and specificity, and is easier to use clinically. Further larger prospective studies are needed to evaluate the feasibility and reliability of this system.

cGAS facilitates sensing of extracellular cyclic dinucleotides to activate innate immunity.

Cyclic dinucleotides (CDNs) are important second messenger molecules in prokaryotes and eukaryotes. Within host cells, cytosolic CDNs are detected by STING and alert the host by activating innate immunity characterized by type I interferon (IFN) responses. Extracellular bacteria and dying cells can release CDNs, but sensing of extracellular CDNs (eCDNs) by mammalian cells remains elusive. Here, we report that endocytosis facilitates internalization of eCDNs. The DNA sensor cGAS facilitates sensing of endocytosed CDNs, their perinuclear accumulation, and subsequent STING-dependent release of type I IFN Internalized CDNs bind cGAS directly, leading to its dimerization, and the formation of a cGAS/STING complex, which may activate downstream signaling. Thus, eCDNs comprise microbe- and danger-associated molecular patterns that contribute to host-microbe crosstalk during health and disease.

Application of expanded genetic analysis in the diagnosis of familial hypercholesterolemia in patients with very early-onset coronary artery disease.

BACKGROUND: Patients with monogenic familial hypercholesterolemia (FH) have high risk for coronary artery disease (CAD). A recent FH Expert Panel suggested that FH was underdiagnosed and undertreated which needs early diagnosis. Moreover, the proportion of DNA-confirmed FH patients hospitalized with very early-onset (≤ 35 years) CAD remains uncertain. METHODS: One hundred and five patients with age ≤ 35 years and LDL-C ≥ 3.4 mmol/L were tested for 9 genes (LDLR, APOB, PCSK9, APOE, STAP1, LIPA, LDLRAP1, ABCG5/8). Dutch Lipid Clinic Network (DLCN) and Simon Broome (SB) criteria for FH were also performed. RESULTS: The prevalence of genetically confirmed FH was 38.1% (n = 40) in 105 patients. DLCN categorized 26.7% patients to probable and definite FH while SB identified 17.1% of patients with possible to definite FH. Twenty-five (62.5%) and seventeen (42.5%) patients with pathogenic mutations were undiagnosed according to SB and DLCN criteria. FH variant carriers, especially homozygotes, had significantly higher plasma LDL-C levels. The best LDL-C threshold for genetically confirmed FH was 4.56 mmol/L in the present study. CONCLUSIONS: FH is really a common cause for very young CAD patients (≤ 35 years) with a 38.1% of causative mutations in China and best LDL-C threshold for predicting mutations was 4.56 mmol/L. The underdiagnostic rate of clinical criteria was around 42.5-62.5%, suggesting that the expanded genetic testing could indeed promote the diagnosis of FH.

Nuclear cGAS suppresses DNA repair and promotes tumorigenesis.

Accurate repair of DNA double-stranded breaks by homologous recombination preserves genome integrity and inhibits tumorigenesis. Cyclic GMP-AMP synthase (cGAS) is a cytosolic DNA sensor that activates innate immunity by initiating the STING-IRF3-type I IFN signalling cascade1,2. Recognition of ruptured micronuclei by cGAS links genome instability to the innate immune response3,4, but the potential involvement of cGAS in DNA repair remains unknown. Here we demonstrate that cGAS inhibits homologous recombination in mouse and human models. DNA damage induces nuclear translocation of cGAS in a manner that is dependent on importin-α, and the phosphorylation of cGAS at tyrosine 215-mediated by B-lymphoid tyrosine kinase-facilitates the cytosolic retention of cGAS. In the nucleus, cGAS is recruited to double-stranded breaks and interacts with PARP1 via poly(ADP-ribose). The cGAS-PARP1 interaction impedes the formation of the PARP1-Timeless complex, and thereby suppresses homologous recombination. We show that knockdown of cGAS suppresses DNA damage and inhibits tumour growth both in vitro and in vivo. We conclude that nuclear cGAS suppresses homologous-recombination-mediated repair and promotes tumour growth, and that cGAS therefore represents a potential target for cancer prevention and therapy.