The Asn9 variant of lipoprotein lipase is associated with the — 93G promoter mutation and an increased risk of coronary artery disease

Two mutations in the lipoprotein lipase (LPL) gene, a T to G transition at position −93 of the proximal promoter region and an Asp9Asn substitution in exon 2, were examined in 762 Dutch males with angiographically-diagnosed coronary artery disease (CAD) and 296 healthy normolipidemic Dutch males. The two mutations exhibited strong linkage disequilibrium (D'=0.975). A significantly higher proportion of cases (4.86%) than controls (1.37%) carried the −93G/Asn9 allele (p=0.008). In the combined sample of cases and controls, adjusted mean plasma total cholesterol (TC) levels were significantly higher in −93G/Asn9 carriers (6.20±0.13 mmol/l) than in non-carriers (5.93±0.03 mmol/l; p=0.048), while mean high-density lipoprotein cholesterol (HDL-C) levels were lower in carriers (0.88±0.03 mmol/l) than in non-carriers (0.98±0.01 mmol/l; p=0.002). There was a trend towards higher triglyceride (TG) levels in carriers (1.96±0.14 mmol/l) compared with non-carriers (1.73±0.03 mmol/l) (p=0.08). Additionally, carrier frequencies in tertiles of TC, HDL-C, TG, and LPL activity, suggested an association of the −93G/Asn9 variant with higher TC and TG levels, and with lower HDL-C and LPL activity levels. Logistic regression revealed a significant odds ratio (OR) for the combined −93G/Asn9 genotype in CAD cases relative to controls (OR: 5.36; 95% CI: 1.57–18.24), with age, body mass index (BMI), smoking, and plasma total- and HDL-cholesterol levels included in the model. In conclusion, we show that the LPL Asp9Asn mutation is in non-random association with a T→G substitution at position −93 of the proximal promoter region and that the combined −93G/Asn9 genotype predisposes to decreased HDL-C levels and an increased risk of CAD.     

The apolipoprotein B signal peptide insertion/deletion polymorphism is not associated with myocardial infarction in Norway

The three-amino acid insertion/deletion (I/D) polymorphism in the apoB signal peptide (27 amino acid versus 24 amino acid signal peptide) was evaluated as a possible risk factor for myocardial infarction (MI) in a case-control study population comprising 238 MI survivors and 547 controls. In controls, homozygotes for the deletion allele (DD) had the highest mean levels of both total cholesterol and low density lipoprotein (LDL) cholesterol (LDLC), the homozygotes for the insertion allele (II) had the lowest mean values, while the heterozygotes (ID) had intermediate mean levels (p < 0.05). In MI survivors, the trend was similar, but only differences in mean LDLC levels were statistically significant (p < 0.05). No differences in genotype frequencies were detected between cases and controls in univariate analysis or in multivariate logistic regression analysis. Despite the results from the lipid analyses, we conclude that the I/D polymorphism in the apoB signal peptide is unlikely to be of major importance for MI risk in relatively young Norwegians.     

RIT2 variant is not associated with Parkinson's disease in a Taiwanese population

Recent genome-wide association studies of Parkinson's disease (PD) have identified the rs12456492 variant of the novel susceptibility loci, RIT2, as being associated with disease risk in a large white population. Studies among Asians are scarce. We genotyped RIT2 rs12456492 variant in a total of 1000 participants, comprising 500 patients with PD and 500 control subjects in a Taiwanese population. The frequency of GA/AA genotype was slightly higher in PD patients compared with controls, but was without statistical significance (odds ratio = 1.03, 95% confidence interval = 0.73–1.46, p = 0.86). We failed to replicate the RIT2 rs12456492 variant as a genetic risk factor for PD in our population.     

Expression of Integrin αvβ3 in Gliomas Correlates with Tumor Grade and Is not Restricted to Tumor Vasculature

In malignant gliomas, the integrin adhesion receptors seem to play a key role for invasive growth and angiogenesis. However, there is still a controversy about the expression and the distribution of α_vβ₃ integrin caused by malignancy. The aim of our study was to assess the extent and pattern of α_vβ₃ integrin expression within primary glioblastomas (GBMs) compared with low-grade gliomas (LGGs). Tumor samples were immunostained for the detection of α_vβ₃ integrin and quantified by an imaging software. The expression of α_vβ₃ was found to be significantly higher in GBMs than in LGGs, whereby focal strong reactivity was restricted to GBMs only. Subsequent analysis revealed that not only endothelial cells but also, to a large extent, glial tumor cells contribute to the overall amount of α_vβ₃ integrin in the tumors. To further analyze the integrin subunits, Western blots from histologic sections were performed, which demonstrated a significant difference in the expression of the β₃ integrin subunit between GBMs and LGGs. The presented data lead to new insights in the pattern of α_vβ₃ integrin in gliomas and are of relevance for the inhibition of α_vβ₃ integrin with specific RGD peptides and interfering drugs to reduce angiogenesis and tumor growth.     

The maternal 14 bp Ins/Del polymorphism in HLA‐G is not associated with preeclampsia risk

The effect of HLA‐G 14 bp Ins/Del polymorphism (rs371194629) on the risk of preeclampsia has been assessed in several populations, yet the results are still conflicting. Lack of power due to small sample sizes is a common cause of inconsistencies in genetic association studies. We aimed to test whether the maternal polymorphism is associated with preeclampsia, eclampsia or HELLP syndrome (acronym for Hemolysis, Elevation of Liver enzymes, Low Platelets). To achieve a statistical power greater than 0.90, a total of 741 women (332 controls, 246 preeclampsia, 57 eclampsia and 106 HELLP) were genotyped for the 14‐bp Ins/Del polymorphism. The genetic association with disease status was assessed by Fisher's exact test and odds ratio (OR) estimates using logistic regression model adjusted for maternal age and parity status. Allele and genotype distributions were the same between control and case groups (p > .05). The polymorphism was not associated with the risk of developing preeclampsia [OR = 0.93 (0.72–1.19); p = .541], or eclampsia [OR = 0.90 (0.60–1.38); p = .628] nor HELLP syndrome [OR = 0.92 (0.66–1.28); p = .628]. This well‐powered study clearly demonstrates that the maternal HLA‐G 14‐bp Ins/Del polymorphism is not associated with preeclampsia risk. However, as the offspring genotypes were not evaluated here, we could not rule out the effect of the foetal genotype on the preeclampsia pathogenesis.     

Leukotriene (LT)‐receptor antagonist is more effective in asthmatic patients with a low baseline ratio of urinary LTE4 to 2,3‐dinor‐6‐keto‐prostaglandin (PG)F1α

BACKGROUND: To test the hypothesis that urinary levels of arachidonic acid metabolites may be a predicting factor of the effects of pranlukast, a selective leukotriene (LT) antagonist, on chronic adult asthma, we investigated the relationship between its clinical efficacy and urinary eicosanoid levels. METHODS: An open, multicenter trial was conducted involving 38 stable moderate and severe asthmatic patients (mean percent predicted FEV1 was 71%). All patients received pranlukast (225 mg twice daily) for 4 weeks after a 2-week run-in period. Urinary levels of LTE4, 11-dehydro-thromboxane (TX) B2, 2,3-dinor-6-keto-prostaglandin (PG) F1alpha, and creatinine were measured in 3-h urine collected on day 1 of the treatment. The responder was defined by an improvement of asthma symptom scores and peak expiratory flow rate (PEFR). RESULTS: One patient was excluded because of an adverse effect, nausea. Thirteen out of 37 subjects were responders and 24 were nonresponders. There were no significant differences in patients' backgrounds and urinary arachidonate levels between the two groups. The urinary LTE4 to 2,3-dinor-6-keto-PGF1alpha ratio in the responder was significantly lower (P=0.01) than that in the nonresponder. In all patients, a significant inverse correlation was revealed between the baseline urinary LTE4/2,3-dinor-6-keto-PGF1alpha ratio and the improvement of PEFR in the morning (r=-0.43, P=0.007). CONCLUSIONS: These data suggested that the urinary ratio of LTE4 to 2,3-dinor-6-keto-PGF1alpha might be one of the predictive markers of the clinical efficacy of this LT-receptor antagonist in asthmatic subjects.     

The involvement of the monocytes/macrophages in chronic inflammation associated with atherosclerosis

Atherosclerosis is a progressive chronic disease of large and medium arteries, characterized by the formation of atherosclerotic plaques. Monocytes and macrophages are key factors in lesion development, participating to the processes that mediate the progression of the atherosclerotic plaque (lipid accumulation, secretion of pro-inflammatory and cytotoxic factors, extracellular matrix remodeling). The recruitment of the monocytes in the vascular wall represents a hallmark in the pathology of the atherosclerotic lesion. Monocyte adhesion and transmigration are dependent on the complementary adhesion molecules expressed on the endothelial surface, whose expression is modulated by chemical mediators. The atherosclerotic plaque is characterized by a heterogeneous population of macrophages reflecting the complexity and diversity of the micro-environment to which cells are exposed after entering the arterial wall. Within the atherosclerotic lesions, macrophages differentiate, proliferate and undergo apoptosis. Taking into account that their behavior has a direct and critical influence on all lesional stages, the development of therapeutic approaches to target monocytes/macrophages in the atherosclerotic plaque became a focal interest point for researchers in the field.     

Lopinavir/ritonavir is associated with pneumonia resolution in COVID‐19 patients with influenza coinfection: A retrospective matched‐pair cohort study

During the early stages of the pandemic, some coronavirus disease (COVID‐19) patients were misdiagnosed as having influenza, which aroused the concern that some deaths attributed to influenza were actually COVID‐19‐related. However, little is known about whether coinfection with influenza contributes to severity of COVID‐19 pneumonia, and the optimal therapeutic strategy for these patients. We retrospectively studied 128 hospitalized patients with COVID‐19 pneumonia. All patients were positive severe acute respiratory syndrome coronavirus 2 positive by nucleic acid detection. Sixty‐four cases were coinfected with influenza A/B and the other 64 were influenza negative, matched by age, sex, and days from onset of symptoms. Among the 64 coinfected patients, 54 (84.4%) were coinfected with influenza A, and 10 (15.6%) with influenza B. The median duration of viral shedding time from admission was longer for patients with influenza coinfection (17.0 days) than for those without influenza coinfection (12.0 days) (P < .001). The multivariable Cox proportional hazards model showed that the hazards ratio of resolution in lung involvement was 1.878 (P = .020) for patients administered lopinavir/ritonavir, compared with those not administered lopinavir/ritonavir (95% confidence interval: 1.103‐3.196). Among influenza coinfected patients, those treated with lopinavir/ritonavir exhibited faster pneumonia resolution within 2 weeks after symptom onset (37% vs 1%; P = .001). There was no difference in lung involvement between influenza coinfected and noninfected groups. Lopinavir/ritonavir eliminated the difference of lung involvement between influenza coinfected and noninfected groups, indicating that lopinavir/ritonavir is associated with pneumonia resolution in COVID‐19.     

The Glu298Asp variant of the endothelial nitric oxide synthase gene is associated with an increased risk for abruptio placentae in pre-eclampsia

Attempts to define a pre-eclampsia susceptibility profile have been hampered by the wide clinical spectrum of the condition and the complex genetics underlying it. Genes that modulate blood pressure, fluid homeostasis and placental vascular development have been considered plausible candidates. Among these are the angiotensinogen (AGT) gene variant Met235Threo, which has been associated with pre-eclampsia and the endothelial nitric oxide synthase (eNOS) polymorphism Glu298Asp, which has been associated with both pre-eclampsia and abruptio placentae, a condition that often co-exists with pre-eclampsia. The aim of this study was to investigate a potential association between these gene variants and pre-eclampsia with and without abruptio placentae in a South African patient group. Fifty primigravidas with early onset, severe pre-eclampsia, 50 women presenting primarily with abruptio placentae (whether associated with pre-eclampsia or not) and a control panel of 50 healthy pregnant women constituted the study groups. The Met235Threo and Glu298Asp variants were characterised by polymerase chain reaction and restriction enzyme analysis. No association was demonstrated between the M235T variant of the AGT gene and pre-eclampsia or abruptio placentae. In contrast, the combined frequency of the eNOS variant genotypes (GT and TT) was significantly higher in the abruptio placentae group (49%) than the control group (21%) (p=0.006). Furthermore, in the pre-eclampsia patients who subsequently developed abruptio placentae, the eNOS GT genotype emerged as a major risk factor for the development of abruptio placentae (p<0.0001). These data suggest that the presence of a Glu298Asp eNOS variant may pre-dispose a pre-eclamptic woman to develop abruptio placentae or that it is a marker for predisposition.     

The functional Pro129Thr variant of the <Emphasis Type="Italic">FAAH</Emphasis> gene is not associated with various fat accumulation phenotypes in a population-based cohort of 5,801 whites

Food intake and weight gain are influenced by endocannabinoids whose actions are regulated by the fatty acid amide hydrolase (FAAH) enzyme. The homozygous Thr/Thr genotype of the functional Pro129Thr variant (rs324420) in the gene encoding FAAH was recently reported to associate with overweight and obesity in white and black populations. We investigated the Pro129Thr variant in relation to overweight and obesity in a relatively large population-based study sample of Danish whites (n=5,801). In case-control studies of obesity, a borderline association with the major Pro allele was identified; however, after correction for multiple testing, no association was found. Furthermore, a possible association between the major Pro allele and obesity was not supported by studies of obesity-related quantitative traits. In conclusion, in a large study sample, we were unable to find robust evidence of an association of the Pro129Thr FAAH variant with overweight, obesity, and any related quantitative traits among the examined whites.     

The homozygous variant c.797G>A/p.(Cys266Tyr) in PISD is associated with a Spondyloepimetaphyseal dysplasia with large epiphyses and disturbed mitochondrial function

Spondyloepimetaphyseal dysplasias (SEMD) are a group of genetically heterogeneous skeletal disorders characterized by abnormal vertebral bodies and epimetaphyseal abnormalities. We investigated two families with a new SEMD type with one proband each. They showed mild facial dysmorphism, flat vertebral bodies (platyspondyly), large epiphyses, metaphyseal dysplasia, and hallux valgus as common clinical features. By trio‐exome sequencing, the homozygous missense variant c.797G>A/p.(Cys266Tyr) in PISD was found in both affected individuals. Based on exome data analyses for homozygous regions, the two patients shared a single homozygous block on chromosome 22 including PISD, indicating their remote consanguinity. PISD encodes phosphatidylserine (PS) decarboxylase that is localized in the inner mitochondrial membrane and catalyzes the decarboxylation of PS to phosphatidylethanolamine (PE) in mammalian cells. PE occurs at high abundance in mitochondrial membranes. Patient‐derived fibroblasts showed fragmented mitochondrial morphology. Treatment of patient cells with MG‐132 or staurosporine to induce activation of the intrinsic apoptosis pathway revealed significantly decreased cell viability with increased caspase‐3 and caspase‐7 activation. Remarkably, ethanolamine (Etn) supplementation largely restored cell viability and enhanced apoptosis in MG‐132‐stressed patient cells. Our data demonstrate that the biallelic hypomorphic PISD variant p.(Cys266Tyr) is associated with a novel SEMD form, which may be treatable with Etn administration.     

The CD19/CD81 complex physically interacts with CD38 but is not required to induce proliferation in mouse B lymphocytes

In B lymphocytes, the cell surface receptor CD38 is involved in apoptosis of immature B cells, proliferation and differentiation of mature B cells. Although CD38 has been establish as a receptor, its signaling has been only partially characterized. As a result of the lack of signaling motifs in the cytoplasmic domain, CD38 must use a co-receptor to induce signaling within the cell. Accordingly, CD38 has been associated with different receptors such as the T-cell receptor/CD3 complex on T cells, CD16 on natural killer cells and MHC class II molecules on monocytes. The CD19/CD81 complex has been proposed as a co-receptor for CD38 in human B lymphocytes, but little or no characterization has been performed in mice. In this study the contribution of the CD19/CD81 complex in murine CD38 signaling was evaluated. Proliferation assays were performed using CD19(-/-) or CD81(-/-) deficient mice; CFSE-labeled B lymphocytes from wild-type mice and CD19(-/-) , CD81(-/-) and CD38(-/-) deficient mice were stimulated with agonistic antibodies against CD38. Immunoprecipitation and immunofluorescence were also performed to detect protein-protein interactions. Our results indicate that the CD19/CD81 complex interacts with CD38 but this interaction is not required to induce proliferation in mouse B lymphocytes, suggesting that other receptors may contribute to the proliferation induced by CD38 in B lymphocytes.     

The homozygous variant c.245G > A/p.G82D in PNPLA2 is associated with arrhythmogenic cardiomyopathy phenotypic manifestations

Arrhythmogenic cardiomyopathy (ACM) is a familial cardiomyopathy featured by fibrofatty replacement of cardiomyocytes. Responsible genetic factors are not discernible in approximately one-third of ACM probands. To investigate this further, we performed whole genome sequencing in 14 mutation-negative ACM probands who underwent cardiac transplantation, and we identified one ACM proband with a rare homozygous missense variant in PNPLA2 (c.245G > A, p.G82D), a rate-limiting enzyme that hydrolyzes triglycerides into fatty acids and diacylglycerol. Bioinformatic analysis suggested that this missense variant may lead to loss of function and therefore impair lipid catabolism. Genetic screening in this proband's family also inferred that the homozygous variant cosegregated with disease. To validate the pathogenicity of this variant and confirm its association with ACM, we established a knockin mouse model carrying the orthologous human homozygous PNPLA2 variant. Interestingly, mice with the homozygous variant presented with arrhythmias and significant cardiac dysfunction at 12 weeks, whereas heterozygous mice were not affected. Moreover, those homozygous mice suffered sudden death and/or heart failure by the age of 14 weeks. Pathological examination showed that extensive lipogenesis in cardiomyocytes and cardiac fibrosis were prominent in the myocardium. Herein, our data demonstrated that the homozygous missense variant PNPLA2 (c.245G > A, p.G82D) associated with a recessive form of ACM.     

The variant methylenetetrahydrofolate reductase c.1298A > C (p.E429A) is associated with multiple sclerosis in a German case-control study

Multiple sclerosis (MS) is an inflammatory demyelinating autoimmune disease of the central nervous system. We investigated the association of two missense variants of the MTHFR gene, i.e. MTHFR c.677C > T (p.A222 V) and c.1298A > C (p.E429A), in 138 patients with clinically definite multiple sclerosis of relapsing-remitting course and 138 age- and gender-matched healthy controls. No significant differences were found in the frequency of the MTHFR c.677C > T polymorphism between MS patients and healthy controls. However, the genotype frequencies of the missense variant MTHFR c.1298A > C were significantly different between patients (AA/AC/CC: 0.34/0.55/0.11) and controls (0.52/0.36/0.12; Pearson's χ² = 11.1; p = 0.004). These results suggest that homozygosity for the A allele of MTHFR c.1298A > C may be protective against the incidence of MS. If confirmed in an independent study sample, the underlying mechanisms should be investigated, which may lead to novel insights in biochemical factors influencing the aetiology and pathophysiology of MS.     

Translational repression of inducible NO synthase in macrophages by l-arginine depletion is not associated with an increased phosphorylation of eIF2α

In mouse inflammatory macrophages the cytokine-mediated expression of inducible nitric oxide synthase (iNOS) is regulated by the availability of the substrate l-arginine. Following arginine starvation the levels of iNOS mRNA remain unimpaired, whereas the translation of iNOS protein is strikingly downregulated. In the present study we addressed the question, whether arginine-deficient macrophages follow the canonical integrated stress response (ISR) that in other cell types depleted of amino acids was characterized by the accumulation of phosphorylated (i.e. inactive) eukaryotic translation initiation factor-2α (eIF2α), the attenuation of global protein synthesis and the induction of certain stress response target genes. Unexpectedly, resting as well as stimulated inflammatory macrophages constitutively exhibited high levels of phosphorylated eIF2α, which was not further increased upon l-arginine starvation. At the same time, macrophages deprived of l-arginine showed a significant upregulation of the mRNA levels of ISR genes. From these data we conclude that l-arginine deficiency blocks the translation of iNOS and elicits a stress response in macrophages, both of which, however, do not result from an enhanced phosphorylation of eIF2α. Alternative modes of translational repression of iNOS need to be considered.     

The 5‐HT2A receptor gene 102T/C polymorphism is associated with suicidal behavior in depressed patients

Several lines of evidence suggest that genetic factors constitute an important determinant of suicidal behavior. A significant association between the 5‐HT_2A‐C allele and suicidality has recently been reported. The aim of this study was to investigate whether the proposed association between 5‐HT_2A‐102T/C polymorphism and suicidality could be replicated in a larger and independent sample of Spanish patients with major depression. The 102T/C polymorphism of the 5‐HT_2A receptor gene was analyzed in 159 patients with major depression (DSM‐IV criteria) and 164 unrelated and healthy controls using a case control design. All individuals were subjects of Spanish origin. Significant differences in allele (chi‐square = 4.13, df = 1, P = 0.04) and genotype (chi‐square = 6.19, df = 2, P = 0.04) distributions were found between non–suicide attempters and suicide attempters. Moreover, those patients carrying 5‐HT_2A‐C allele had more than five times the risk for attempting suicide than noncarriers (OR = 5.50, 95% CI = 1.18–35.20, P = 0.01). Our results replicate the proposed association between 5HT_2A‐C allele and suicidality in major depression. Moreover, no overall associations are detected when patients with major depression and controls are compared for 102T/C frequencies, suggesting that the increased risk for suicidality conferred by 5‐HT_2A‐C allele is primarily associated with suicidal behavior and not with the diagnosis of major depression itself. © 2001 Wiley‐Liss, Inc.