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Association of Vitamin D Polygenic Risk Scores and Disease Outcome in People With Multiple Sclerosis.

BACKGROUND AND OBJECTIVES: Observational studies suggest low levels of 25-hydroxyvitamin D (25[OH]D) may be associated with increased disease activity in people with multiple sclerosis (PwMS). Large-scale genome-wide association studies (GWAS) suggest 25(OH)D levels are partly genetically determined. The resultant polygenic scores (PGSs) could serve as a proxy for 25(OH)D levels, minimizing potential confounding and reverse causation in analyses with outcomes. Herein, we assess the association of genetically determined 25(OH)D and disease outcomes in MS. METHODS: We generated 25(OH)D PGS for 1,924 PwMS with available genotyping data pooled from 3 studies: the CombiRx trial (n = 575), Johns Hopkins MS Center (n = 1,152), and Immune-Mediated Inflammatory Diseases study (n = 197). 25(OH)D-PGS were derived using summary statistics (p < 5 &#xd7; 10-8) from a large GWAS including 485,762 individuals with circulating 25(OH)D levels measured. We included clinical and imaging outcomes: Expanded disability status scale (EDSS), timed 25-foot walk (T25FW), nine-hole peg test (9HPT), radiologic activity, and optical coherence tomography-derived ganglion cell inner plexiform layer (GCIPL) thickness. A subset (n = 935) had measured circulating 25(OH)D levels. We fitted multivariable models based on the outcome of interest and pooled results across studies using random effects meta-analysis. Sensitivity analyses included a modified p value threshold for inclusion in the PGS (5 &#xd7; 10-5) and applying Mendelian randomization (MR) rather than using PGS. RESULTS: Initial analyses demonstrated a positive association between generated 25(OH)D-PGS and circulating 25(OH)D levels (per 1SD increase in 25[OH]D PGS: 3.08%, 95% CI: 1.77%, 4.42%; p = 4.33e-06; R2 = 2.24%). In analyses with outcomes, we did not observe an association between 25(OH)D-PGS and relapse rate (per 1SD increase in 25[OH]D-PGS: 0.98; 95% CI: 0.87-1.10), EDSS worsening (per 1SD: 1.05; 95% CI: 0.87-1.28), change in T25FW (per 1SD: 0.07%; 95% CI: -0.34 to 0.49), or change in 9HPT (per 1SD: 0.09%; 95% CI: -0.15 to 0.33). 25(OH)D-PGS was not associated with new lesion accrual, lesion volume or other imaging-based outcomes (whole brain, gray, white matter volume loss or GCIPL thinning). The results were similarly null in analyses using other p value thresholds or those applying MR. DISCUSSION: Genetically determined lower 25(OH)D levels were not associated with worse disease outcomes in PwMS and raises questions about the plausibility of a treatment effect of vitamin D in established MS.

Humans↗

Polygenic risk scores in major depressive disorder: A systematic review across diagnostic, treatment, course/severity, and subtype domains.

BACKGROUND: Major depressive disorder (MDD) is heterogeneous across diagnostic, treatment-related, course/severity, and subtype domains. Polygenic risk score (PRS) studies have examined these domains, but differences in PRS sources, samples, methods, and endpoint definitions have fragmented the evidence. We synthesised findings and examined potential contributors to heterogeneity. METHODS: PubMed/MEDLINE, Embase, PsycINFO, and Web of Science were searched for studies published from January 2016 through 25 November 2025. Result records were synthesised using SWiM, and certainty was assessed with an adapted GRADE framework. RESULTS: Sixty studies contributed 493 retained records; 450 were descriptively classified as positive, null, or reverse, although records were not independent. Positive findings accounted for 44/56 diagnostic, 61/273 treatment-related, 64/100 course/severity, and 14/21 subtype records. For MDD/depression-derived PRSs and case-control MDD status, all 10 contributing studies showed higher liability in cases (exploratory exact sign test p&#xa0;=&#xa0;0.002; FDR q&#xa0;=&#xa0;0.004). The same PRS group showed positive findings for overall depressive symptom severity (14/18), although the study-level test was imprecise (5/5 studies; p&#xa0;=&#xa0;0.063). Pharmacological response/remission findings for these PRSs were mostly null or directionally mixed (10 positive, 18 null, and 9 reverse). Treatment-resistant depression (TRD) findings differed by operational definition. Atypical and psychotic subtype signals arose mainly from single-study PRS and endpoint contrasts. CONCLUSIONS: PRS evidence was clearest for MDD diagnostic status and showed a tentative pattern for overall symptom burden. Treatment and subtype findings were less consistent or less replicated. Larger, ancestrally diverse studies with standardised endpoints and transparent PRS methods are needed.

Humans↗

Obesity Polygenic Risk and Healthy Lifestyle Interactions on Weight Trajectories in Women and Men.

BACKGROUND: Genetics and environmental factors contribute to obesity risk, but the extent to which healthy behaviors can offset genetic susceptibility remains unclear. We examined the interaction between obesity polygenic risk and a composite healthy lifestyle score on body mass index (BMI) trajectories in women and men. METHODS: We analyzed 13&#x2009;780 women from the Nurses' Health Study and 8242 men from the Health Professionals Follow-Up Study, all of European ancestry and free of major chronic disease at baseline. The lifestyle score comprised American Heart Association Essential 8 components (nonsmoking, physical activity, healthy eating, adequate sleep) plus moderate alcohol intake, modeled as a time-varying variable. A genome-wide polygenic score for BMI was derived from genome-wide association study. Adjusted linear mixed-effects models estimated associations and interactions on biennial BMI measures over up to 26&#x2009;years. RESULTS: Each SD increase in the polygenic score was associated with 1.80&#x2009;kg/m2 (95% CI, 1.72-1.87) and 1.12&#x2009;kg/m2 (95% CI, 1.06-1.19) higher BMI in women and men, respectively. Significant interactions between the polygenic score and healthy lifestyle score (both P<0.05) showed a dose-response attenuation of the genetic effects with healthier lifestyles. Comparing the healthiest with the least healthy lifestyle groups, genetic effects on BMI were 35% lower in women and 28% lower in men. In sensitivity analyses, higher diet quality and physical activity consistently attenuated genetic associations in both cohorts, whereas current smoking showed similar effects in women only. CONCLUSIONS: Adherence to a healthier lifestyle attenuated the association between obesity polygenic risk and BMI in a dose-response manner.

Humans↗

The Collaborative Cross, a community resource for the genetic analysis of complex traits.

The goal of the Complex Trait Consortium is to promote the development of resources that can be used to understand, treat and ultimately prevent pervasive human diseases. Existing and proposed mouse resources that are optimized to study the actions of isolated genetic loci on a fixed background are less effective for studying intact polygenic networks and interactions among genes, environments, pathogens and other factors. The Collaborative Cross will provide a common reference panel specifically designed for the integrative analysis of complex systems and will change the way we approach human health and disease.

Animals↗

Genetics of diabetic nephropathy.

Diabetic nephropathy (DN) develops in approximately 40% of type 1 diabetic patients and is a leading cause of end-stage renal failure. Its rate of progression varies greatly among individuals. Several factors, including genetic predisposition, metabolic and haemodynamic alterations and various growth factors, may contribute to the initiation and progression of DN. The genetic background of DN is believed to be polygenic. Polymorphisms of different genes, mainly from the renin-angiotensin system, have been studied extensively, and some of them have been suggested to contribute to the development of DN. A search for genes and combinations of genes which could influence the development and progression of DN is in progress.

Diabetes Mellitus, Type 1↗

Estimation of effects of single genes on quantitative traits.

Studies involving the effects of single genes on quantitative traits may involve closed populations, selection may be practiced, and the quantitative trait of concern may also be influenced by background genes that are inherited in a polygenic manner. It is shown analytically that analysis of such data by ordinary least squares, the usual method of analysis, can lead to finding an excess of spurious significant effects of single genes, when no effect exists, for both randomly and directionally selected populations and can lead to bias in estimates of single-gene effects when selection has been practiced. The bias depends on heritability of the polygenic effects on the trait, selection intensity, mode of inheritance, magnitude of gene effect, gene frequency, and data structure. It is argued that when genotypes of individuals can be identified for all individuals with observations on the trait, use of mixed-model procedures under an animal model treating single-gene effects as fixed effects can provide unbiased estimates of single-gene effects and exact tests of associated hypotheses for pedigreed populations, even when selection is practiced. Results are illustrated through computer simulation.

Animals↗

The dual AngII/AVP receptor gene N119S/C163R variant exhibits sodium-induced dysfunction and cosegregates with salt-sensitive hypertension in the Dahl salt-sensitive hypertensive rat model.

BACKGROUND: Essential hypertension is a prevalent complex polygenic disease and a major risk factor for cardiovascular disease, the leading cause of death in developed countries. Because of its complex and multifactorial nature, its genetic determinants still remain largely unknown. The Dahl salt-sensitive hypertensive rat model exhibits impaired sodium handling, which is hypothesized to play a key role in the pathophysiology of polygenic hypertension. Thus, genes associated with renal regulation of salt and water balance are a priori likely candidates for a causative role in hypertension pathogenesis. The functional properties and renal-specific expression of the recently characterized AngII/AVP receptor suggest a putative modulator role in tubular sodium and fluid reabsorption. Based on these observations, we investigated the potential involvement of the AngII/AVP receptor in salt-sensitive hypertension. MATERIALS AND METHODS: We performed cosegregation analysis of the AngII/AVP receptor locus with salt-sensitive hypertension in an F2 (Dahl S X Dahl salt-resistant [R]) hybrid male cohort characterized for blood pressure by radiotelemetry after 8 weeks of high salt challenge. Further molecular analysis was done to identify putative AngII/AVP receptor molecular variants that could account for the AngII/ AVP receptor involvement in salt-sensitive hypertension pathogenesis. RESULTS: The AngII/AVP receptor was mapped to rat chromosome 1, 1.7 cM centromeric to the D1Rat188 marker by radiation hybrid mapping analysis. Quantitative trait locus (QTL) analysis detected a highly significant linkage of the AngII/AVP receptor locus with high blood pressure (LRS = 13.8, p= 0.0002). Molecular characterization of the Dahl S and Dahl R AngII/AVP receptor cDNAs revealed two amino acid substitutions in the Dahl S AngII/AVP receptor (N119S, C163R) when compared to the Dahl R AngII/AVP receptor. These mutations are associated with an increased receptor affinity for both ligands (AVP and AngII) and an enhanced G(s)-coupling by the receptor resulting in increased activation of adenylate cyclase with concomitant increase in cAMP production. CONCLUSIONS: The observed molecular dysfunction in the Dahl S AngII/AVP receptor is consistent with increased tubular sodium and fluid reabsorption observed in Dahl S rats. Interestingly, the AngII/AVPr locus is within the narrowed chromosome 1 QTL region for blood pressure detected in different rat intercross linkage analyses. Altogether, the data strongly suggest that the AngII/AVP receptor is a hypertension susceptibility gene in the Dahl S rat model, as well as raises the hypothesis that it too underlies the chromosome 1 blood pressure QTL identified in other hypertension rat models.

Allosteric Regulation↗

Negative association between smoking and anti-saccharomyces cerevisiae antibodies in Crohn's disease.

BACKGROUND: Crohn's disease (CD) is a polygenic multifactorial heterogeneous disease. Anti-Saccharomyces Cerevisiae antibodies (ASCA) correlate highly with CD and are present in 50-80% of patients. The reason for ASCA positivity or negativity in CD is unknown. The aim of our work was to analyse clinical, epidemiological and genetic characteristics in ASCA+ or ASCA- CD patients. METHODS: 113 patients with CD were tested for ASCA (IgA and IgG) by using a commercial kit (Medipan Diagnostica). Age, gender, systemic manifestations, familial form of disease, age at diagnosis, location and behaviour of the disease, smoking habit as well as genotyping for -308 TNF gene polymorphisms were determined. RESULTS: 38.9% CD patients were negative for both IgA and IgG ASCA while 61.1% were ASCA positive (respectively IgA and IgG: 31.9%; IgA only: 9.7%; IgG only: 19.5%). The only significant difference between ASCA+ and ASCA- patients was for smoking habit: there were 29% smokers in ASCA+ versus 50% in ASCA- CD patients (P = 0.03). This low proportion of smokers was more prominent in ASCA IgA+ patients than in isolated ASCA IgG+ patients (25.6% versus 45.5%) and was minimal in patients with high titers of ASCA IgA (0/8). Logistic regression showed smoking habit still borderline for significance (P = 0.057). CONCLUSIONS: Our results suggest a negative association between smoking and ASCA positivity in CD. This association was more prominent for ASCA IgA+. It indicates that smoking habit should be taken into account when analysing ASCA status in CD patients and may suggest an influence of smoking on immunization against intestinal material.

Adult↗

Pathophysiology of hypertension: differences between young and elderly.

Pathogenesis of hypertension: Primary hypertension has a multifactorial background, consisting of three main elements, (1) polygenic predisposition, (2) excitatory environmental effects and (3) structural upward resetting of the heart and vessels. These three elements are inter-related, since excitatory environmental effects are usually needed to precipitate the functional expression of genetic predisposition (particularly in man) and structural upward resetting is sometimes genetically facilitated. As hypertension progresses, the structural upward resetting becomes the dominating element, underlying the elevation in both pressure and resistance. Progression of hypertension: In the early phases of both human and animal models of primary hypertension, interactions between the genetic predisposition and excitatory environmental effects are often expressed mainly as mildly enhanced central neurohormonal activity. Not infrequently, cardiac output is increased more than systemic resistance. The structural factor, at this point, is still mainly expressed as a fairly reversible cardiac and vascular muscle hypertrophy (or hyperplasia), and a modest degree of resistance vascular narrowing. Aging effects on hypertension: The normal aging process affects the cardiovascular system to a greater degree in hypertensives than normotensives, implying more pronounced reductions in cardiac and vascular compliance, muscle strength and contractile speed, and in renal functional capacity. With age and a prolonged positive-feedback interaction between genetic/environmental factors and structural adaptation at the systemic resistance level, the structurally based elevation in resistance becomes even more dominant, and is further complicated by increasing interstitial involvement and therefore reduced reversibility.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

The genetic basis of systemic lupus erythematosus.

Although cumulative evidence suggests that a genetic predisposition plays a major role in the development of systemic lupus erythematosus (SLE), the susceptibility genes are mostly unknown. The difficulty in identifying susceptibility genes is due in part to the inherent nature of this polygenic complex disease and the diverse genetic backgrounds of human populations. Murine SLE models that have homogenous genetic backgrounds are less complex for genetic dissection. Genome-wide linkage studies of murine SLE have mapped the position of a number of susceptibility loci. Recently, several of these major murine loci have been shown to link to different clinical and laboratory features of lupus-like phenotypes. In addition, evidence for additional genetic contributions via interaction between murine loci has been reported. In human SLE, many polymorphic genes (which have potential roles in SLE, as suggested by their known functions) have been associated with SLE or SLE subsets by population-based case-control or within-case studies. Because more compelling genetic evidence includes linkage analysis, our group has used the identified murine susceptibility loci as a guide and conducted linkage analysis of genetic markers located within a specific, possibly syntenic human chromosomal region. Evidence for linkage of a chromosome 1q41-42 region was observed in SLE-affected sibling pairs from multiple ethnic groups. This article summarizes recent developments and outlines possible future directions in delineating the genetic basis of SLE.

Animals↗

Addition of CAD polygenic risk score to coronary artery calcium score enhances prediction of MACE.

BACKGROUND: Coronary heart disease (CHD) is prevalent in the United States, highlighting the need for accurate risk prediction to inform primary prevention strategies. While multivariate risk models like the Framingham Risk Score and ACC/AHA Pooled Cohort Equations are commonly utilized, novel risk markers, such as the coronary artery calcium score (CACS) and polygenic risk score (PRS), are increasingly gaining recognition. OBJECTIVES: This study aimed to compare the diagnostic utility of CACS and CAD PRS, both individually and in combination, for predicting major adverse cardiovascular events (MACE). METHODS: We conducted a retrospective analysis of a cohort comprising 1,380 predominantly Caucasian participants from the Sanford Health System. CAD PRS was constructed using genetic variants, while CACS was assessed via cardiac computed tomography (CT). Statistical analyses evaluated the relationship between each modality and MACE. RESULTS: Both CAD PRS and CACS were significantly associated with future MACE. Following the adjustment for covariates, the area under the curve (AUC) for both the CACS and PRS models was comparable, indicating similar predictive capabilities for MACE. However, the combination of CAD PRS with CACS significantly enhanced predictive accuracy, outperforming either modality alone. CONCLUSIONS: This study underscores the value of integrating CACS and CAD PRS in predicting MACE. The synergistic effect of CAD PRS combined with CACS markedly improves predictive power. Further research and prospective studies are necessary to validate these findings and assess their clinical implications. Investigating the interactions between PRS and CACS will be crucial for refining cardiovascular risk prediction and optimizing prevention strategies.

cardiac genetics↗

Associations Between Polygenic Risk Score for Blood Pressure and Risk of Hypertension in Northeast Asian Individuals.

BACKGROUND: Data on associations between genetic predisposition to high blood pressure (BP) and hypertension and its complications in non-European populations are limited. The current study investigated associations between polygenic risk scores (PRSs) for BP and risks of hypertension, cardiovascular disease, and chronic kidney disease in Northeast Asian populations. METHODS: A genome-wide association study of systolic BP (SBP) and diastolic BP (DBP) was conducted using data from the KoGES (Korean Genome and Epidemiology Study). Results were meta-analyzed using summary statistics from Biobank Japan to construct PRSs. RESULTS: Compared with a PRS in the lowest 5 percentiles, a PRS in the highest 5 percentiles was associated with an increased risk of hypertension (hazard ratio [HR], 2.44 [95% CI, 1.67-3.56] for PRS for SBP; and HR, 1.77 [95% CI, 1.20-2.62] for PRS for DBP) and earlier onset of hypertension (by a median of 8.5&#x2009;years for PRS for SBP and 8.0&#x2009;years for PRS for DBP). These associations remained significant when continuous PRS was analyzed. The genetic risk of hypertension incidence was attenuated by moderate to vigorous physical activity. Adding the PRS for BP to the clinical risk factors improved the predictive value for hypertension (both area under the curve values, 0.787&#xa0;[95% CI, 0.771-0.803]; P=0.063 for PRS for SBP and [95% CI, 0.771-0.804]; P=0.031 for PRS for DBP). However, neither PRS for SBP nor PRS for DBP was associated with the incidence of cardiovascular or chronic kidney disease. CONCLUSIONS: The PRS for BP was associated with a higher risk of incident hypertension and earlier-onset hypertension in a Northeast Asian population. PRS may facilitate early identification and targeted management of individuals at high risk of developing hypertension.

Adult↗

Polygenic Risk Scores for Preeclampsia Prediction Beyond Gold-Standard Clinical Models in Multiethnic Populations.

BACKGROUND: Preeclampsia is a major cause of maternal and fetal mortality and morbidity. Early risk stratification enables timely preventative therapy in high-risk women. Polygenic risk scores (PGS) improve prediction in complex diseases, but their added value for preeclampsia remains unclear, particularly in comparison to gold-standard first-trimester prediction models and across non-European ancestries. METHODS: We evaluated the performance of both a preeclampsia and systolic blood pressure PGS in 2 prospective pregnancy cohorts with detailed phenotyping: the Fetal Medicine Foundation study (n=5207; 2127 cases) and the Pregnancy Outcome Prediction study (n=3659; 228 cases). Risk models included (1) clinical factors; (2) clinical factors plus PGS; (3) advanced model including first-trimester mean arterial pressure, PAPP-A (pregnancy-associated plasma protein-A), and uterine artery pulsatility index; and (4) advanced model plus PGS. Discriminative performance, measured by the area under the receiver operating characteristic curve, was assessed overall and by ancestry. RESULTS: The preeclampsia PGS was independently associated with preeclampsia (odds ratio per SD, 1.24 [95% CI, 1.17-1.31]; P<0.001). It modestly improved prediction over clinical models (area under the receiver operating characteristic curve 0.746 versus 0.750; P=0.017) but not over the advanced model (area under the receiver operating characteristic curve 0.817 versus 0.818; P=0.326). The systolic blood pressure PGS showed stronger performance, improving prediction over both models in women of European ancestry. No improvement was observed with either score in women of African ancestry. CONCLUSIONS: PGSs for preeclampsia and SBP provide modest added predictive value beyond clinical risk factors in European ancestry women. Limited utility in African ancestry women reflects underrepresentation in the genome-wide association studies used to develop current scores. As cohort sizes grow and models are refined, PGSs may become important tools for equitable risk stratification in maternal health.

Adult↗

Evaluation of population-specific polygenic risk scores for blood lipids: insights from Taiwanese cohorts and multiancestry meta-analysis.

BACKGROUND: Blood lipids are heritable risk factors for cardiovascular disease (CVD), a leading cause of mortality worldwide. However, the genetic architecture of lipid traits and the performance of polygenic risk scores (PRSs) remain underexplored in East Asian (EAS) populations, including Taiwanese Han individuals. METHODS: We conducted genome-wide association studies and PRS analyses for five lipid traits: total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, and the ratio of low-density lipoprotein cholesterol to total cholesterol. Lipid profile data were obtained from the China Medical University Hospital cohort. PRSs were evaluated on the basis of their correlations with measured lipid levels. To evaluate trans-ancestry PRS transferability, localized models were systematically compared against models derived from discovery-stage GWAS meta-analyses incorporating five ancestry groups from the Global Lipids Genetics Consortium. The performance of the PRS models in predicting lipid-related diseases was evaluated through receiver operating characteristic curve analyses. RESULTS: The population-specific PRS models explained 11%-40% of the variance in lipid levels within the target cohort. Models leveraging global multiancestry GWAS meta-analysis weights revealed limited predictive performance (r 2 = 0.04-0.19), whereas analyses incorporating EAS-specific data yielded higher correlations (r 2 = 0.13-0.30), although these correlations did not exceed those derived from the hospital-based cohort alone. When combined with age and sex, the PRS models demonstrated strong predictive performance for coronary artery disease, atherosclerosis, and ischemic stroke, with area under the curve values of 0.910, 0.926, and 0.854, respectively. CONCLUSION: Population-specific PRS models derived from a Taiwanese population outperformed meta-analysis-derived frameworks in predicting lipid levels and demonstrated substantial potential for predicting CVD risk, indicating the importance of ancestry-matched genetic studies in precision medicine.

LDL-C/TC ratio↗

Integrative post-GWAS analysis prioritizes immune regulatory pathways and candidate effector signals in systemic lupus erythematosus.

BACKGROUND: Systemic lupus erythematosus (SLE) has a complex polygenic architecture, but translating genome-wide association signals into biologically interpretable candidates remains challenging. We applied an integrative post-GWAS framework to refine SLE-associated loci and prioritize candidate regulatory mechanisms. METHODS: European-ancestry SLE GWAS summary statistics from FinnGen and Bentham et al. were meta-analysed, comprising 8417 cases and 354,277 controls. After quality filtering, 6,782,131 SNPs were retained. Downstream analyses included LAVA regional prioritization, Bayesian colocalization with GTEx v8 whole-blood and spleen eQTLs, independent replication in the Juli&#xe0; et al. Spanish cohort, pathway enrichment, bivariate LAVA cross-trait local genetic correlation, and therapeutic annotation. RESULTS: The discovery meta-analysis identified 46 genome-wide significant SLE-associated loci, including putative novel signals requiring database/literature qualification. LAVA identified 14 candidate index variants across 12 high-confidence regions, of which nine index variants were retained as the primary prioritized set based on LAVA support and/or convergent regulatory evidence. The strongest association mapped to the chr6p21.3/MHC region (rs389884), where four genes showed colocalization support, including CLIC1 in whole blood and C4A in spleen. Because the chr6p21.3/MHC rs389884 region lead variant was unavailable for replication and no suitable proxy was identified, this signal was interpreted as an emerging candidate for functional validation rather than a replicated causal signal. Seven available variants replicated with concordant effects. An exploratory Roadmap immune chromatin-state overlap analysis placed 15 of 45 non-MHC lead variants (33.3%) directly, and 34 of 45 (75.6%) within &#xb1;10&#x202f;kb, in active immune enhancer/promoter states. Pathway analyses highlighted type I interferon, JAK-STAT signaling, cytokine regulation, and antigen presentation, while bivariate LAVA analyses supported shared local genetic architecture with rheumatoid arthritis, systemic sclerosis, and Sj&#xf6;gren syndrome. CONCLUSIONS: This integrative post-GWAS analysis refines SLE association signals into biologically interpretable candidate regions and supports interferon and JAK-STAT signaling as central genetically supported pathways in SLE.

CLIC1↗

77 C/G mutation in the tyrosine phosphatase CD45 gene and autoimmune hepatitis: evidence for a genetic link.

Autoimmune hepatitis is a chronic immune-mediated disease characterized by a loss of tolerance against liver resident antigens. The genetic background of autoimmune hepatitis is considered to be polygenic. Here we analyzed the genetic association of the tyrosine phosphatase CD45 and autoimmune hepatitis. CD45 plays an important role in normal antigen receptor mediated signaling in T and B cells. A point mutation at nucleotide position 77 of the CD45 gene results in abnormal CD45 splicing. In this study a significantly higher frequency of the 77 C/G genotype was observed in 190 autoimmune hepatitis patients when compared to 210 healthy blood donors. Our data identify CD45 as a gene associated with AIH, and further substantiates the hypothesis that CD45 represents a modifier gene of human autoimmunity.

Confidence Intervals↗

A metabolic syndrome of hypertension, hyperinsulinaemia and hypercholesterolaemia in the New Zealand obese mouse.

BACKGROUND: New Zealand obese (NZO) mice exhibit a polygenic obesity associated with hyperinsulinaemia and hyperglycaemia. Here we show that the strain presents additional features of a metabolic syndrome, i.e. elevated blood pressure, serum cholesterol and serum triglyceride levels. MATERIALS AND METHODS: A back-cross model of NZO mice with the lean Swiss Jackson Laboratory (SJL) strain was established in order to investigate further the correlation between hypertension, obesity, serum insulin and hyperglycaemia. RESULTS: Systolic blood pressure was significantly elevated at 6 weeks of age and appeared to parallel the weight gain of the animals. Serum insulin levels, presumably reflecting insulin resistance, and systolic blood pressure values were significantly correlated with the body mass index (r2 = 0.707 and 0.486, respectively) in the back-cross mice. In contrast, blood pressure was only weakly correlated with serum insulin (r2 = 0.288) in non-diabetic mice, and was independent of serum insulin levels in diabetic animals. CONCLUSION: The data are consistent with the concept that hypertension and insulin resistance are a characteristic consequence of the genetic constellation leading to obesity in the NZO strain, and that these traits reflect related mechanisms. It appears unlikely, however, that hypertension is a direct consequence of hyperinsulinaemia.

Animals↗

Effect of He-Ne laser (632.8 nm) and Polygen on CHO cells.

OBJECTIVE: We determined the effect of He-Ne laser biostimulation in combination with Polygen (PG) on Chinese hamster ovary (CHO) cells. BACKGROUND DATA: Several studies have shown that He-Ne laser (632.8 nm), growth factors, and growth hormone can enhance cellular proliferation and that the use of low-level laser stimulation combined with growth factor stimulation has scientific support. PG, an animal protein extract containing a blend of growth factors and growth hormone, was used together with a He-Ne laser to determine their efficacy in the enhancement of cellular proliferation. METHODS: The dose-response curves for the colony-forming ability of CHO cells in 5% FCS-MEM with 6-125 microg/ml PG and He-Ne laser with an optimum power density of 1.25 mW/cm2 and cumulative doses of 60-600 mJ/cm2 was given for 3 consecutive days. The combined effects of He-Ne laser 180 mJ/cm2 with 6 and 12 microg/ml PG were determined. Quadruplicate cultures were performed. The student's t-test was used to ascertain differences of treated groups from controls. RESULTS: The mean number of colonies (MNC) was increased using 180 mJ/cm2 laser by 13.2% (p < 0.01); 6 and 12 microg/ml PG by 19.2% (p < 0.0025) and 13.2% (p = 0.01); laser + PG 6 microg/ml by 23.2% (p < 0.001) and laser + PG 12 microg/ml by 20.5% (p < 0.001). An additional significant increase of 8.8% (p < 0.05) and an insignificant 6.4% (p = 0.086) by laser + PG 6 microg/ml and laser + PG 12 microg/ml were observed, respectively, when compared to the solitary effect of laser. CONCLUSIONS: Results suggest that the He:Ne laser or PG can stimulate CHO cell proliferation and that further stimulation can be achieved by using the He:Ne laser and PG simultaneously. This combination could be useful as a new treatment modality.

Animals↗