Genetic polymorphisms of MBL2 and tuberculosis susceptibility: a meta-analysis of 22 case-control studies

Association of MBL2 gene polymorphisms and MBL levels with dilated cardiomyopathy in a Chinese Han population

BACKGROUND

It has been reported that Mannose-binding lectin 2 (MBL2) gene polymorphisms and expression levels are related to dilated cardiomyopathy (DCM). This study aimed to investigate the potential association between MBL2 gene polymorphisms and the pathogenesis of DCM.

METHODS

Five single nucleotide polymorphisms (SNPs) of the MBL2 gene were genotyped in 440 DCM patients and 532 controls in Southwest China. A luciferase reporter assay was used to detect the transcriptional activity the different genotypes. MBL serum levels, left ventricle ejection fraction (LVEF) and lower left ventricular end-diastolic diameter (LVEDD) were measured.

RESULTS

The rs11003125 C allele increased the transcriptional activity of the MBL2 promoter compared with the rs11003125 G allele. The rs11003125 CC carriers had higher MBL serum levels, LVEF and LVEDD than the rs11003125 CG and GG carriers.

CONCLUSIONS

Our study first revealed that MBL2 polymorphisms and serum MBL levels were associated with DCM. Allele C in rs11003125 of MBL2 may upregulate the expression levels of MBL. High serum MBL levels may be a protective factor in DCM pathogenesis.

Proteins of the lectin pathway of the complement system activation: immunobiological functions, genetics and involvement in the pathogenesis of human diseases

The complement system is the most ancient components in the innate immunity, mainly functioning to primarily eliminate bacterial agents intravascularly. Moreover, the complement complex proteins play a role as a bridge between the systems of innate and adaptive immunity providing adequate conditions for maturation and differentiation of B- and T-lymphocytes. The complement system consists of plasma proteins and membrane receptors. Plasma proteins interact with each other via the three described cascade pathways lectin (which is most ancient phylogenetically), alternative and classical. Lectins are proteins comprising a separate superfamily of pattern-recognizing receptors able to sense molecules of oligo- and polysaccharide nature and induce their aggregation. Among all the lectins, ficolins (FCN) (common domain fibrinogen) and collectins (common domain collagen) mannose-binding lectin (MBL), hepatic and renal collectins have exert unique functions by complexing with carbohydrate components of microbial wall. Formation of a compound complex microbial wall polysaccharides + collectin/ficolin + specific mannose-binding lectin-associated serine proteases (MARP) results in the complement system activation, inflammatory reaction and bacterium elimination. Such scenario is proceeded along the lectin pathway compared to the two other pathways called classical and alternative. Examining a role of the complement system and congenital protein defects in the pathogenesis of various diseases is of topical interest because inborn deficiency of the complement components comprises at least 5% out of total primary immunodeficiency rate, whereas the aspects of their prevalence and pathogenesis remain unexplored. Relevance of investigating the complement system components for diverse populations is tremendous, taking into consideration accumulated evidence regarding an important role of the lectin pathway in viral infections. Lectins, the main proteins in the lectin pathway of the complement activation, are encoded by polymorphic genes, wherein single nucleotide polymorphisms (SNPs) result in altered protein conformation and expression, which, in turn, affects functionality and potential to respond to a pathogen. The distribution of the lectin polymorphic gene frequencies and their haplotypes displays extremely marked population differences. According to analyzing available data, population SNP frequencies including those associated with inborn deficiencies for components of the lectin pathway have been currently scarce or unexplored. hence, here we review major lectins and their functions, their functionally significant SNPs in diverse populations and their pathogenetic importance for host defense functions.

The association between interleukin-1β gene polymorphisms and the risk of breast cancer: a systematic review and meta-analysis

INTRODUCTION

It is reported that there is a close association between interleukin-1β (IL-1β) gene polymorphisms and breast cancer risk. However, the results remain controversial.

MATERIAL AND METHODS

Eligible published articles were searched in PubMed, Embase, and Web of Science databases up to June 2018. Odds ratios with 95% confidence intervals were used to identify potential links between IL-1β genetic polymorphisms and the risk of breast cancer.

RESULTS

From our results, we found that three common polymorphisms in IL-1β (rs16944, rs1143634, rs1143627) had no significant associations with breast cancer risk in all genetic models. Based on the analysis from ethnic subgroups, there was a higher risk of breast cancer for rs16944 polymorphism in the recessive model and heterozygous model among Asians (TT vs. CC+CT: 1.229, 95% CI: 1.063-1.422, p = 0.005; TT vs. CT: 1.211, 95% CI: 1.057-1.388, p = 0.006). For the rs1143627 polymorphism, a significantly decreased breast cancer risk was observed in the dominant model only in Asians (CT+TT vs. CC: OR = 0.944, 95% CI: 0.897-0.994, p = 0.027). After stratifying patients according to the menopausal state, we found that polymorphism of rs1143627 correlated with reduced breast cancer risk among post-menopausal women in three genotype models: allele, recessive model and homozygous model (T vs C: 0.859, 95% CI: 0.753-0.98, p = 0.024; TT vs. CC+CT: 0.727, 95% CI: 0.576-0.918, p = 0.007; TT vs. CC: 0.743, 95% CI: 0.626-0.882, p = 0.001). As for other analyses with reference to source of controls and genotyping methods, no significant association between IL-1β polymorphism and breast cancer risk was demonstrated.

CONCLUSIONS

The rs16944 and rs1143627 polymorphisms are significantly associated with the risk of breast cancer only in Asian people and in post-menopausal women respectively.

Response and Toxicity to Cytarabine Therapy in Leukemia and Lymphoma: From Dose Puzzle to Pharmacogenomic Biomarkers

Simple Summary

In this review, the authors propose a crosswise examination of cytarabine-related issues ranging from the spectrum of clinical activity and severe toxicities, through updated cellular pharmacology and drug formulations, to the genetic variants associated with drug-induced phenotypes. Cytarabine (cytosine arabinoside; Ara-C) in multiagent chemotherapy regimens is often used for leukemia or lymphoma treatments, as well as neoplastic meningitis. Chemotherapy regimens can induce a suboptimal clinical outcome in a fraction of patients. The individual variability in clinical response to Leukemia & Lymphoma treatments among patients appears to be associated with intracellular accumulation of Ara-CTP due to genetic variants related to metabolic enzymes. The review provides exhaustive information on the effects of Ara-C-based therapies, the adverse drug reaction will also be provided including bone pain, ocular toxicity (corneal pain, keratoconjunctivitis, and blurred vision), maculopapular rash, and occasional chest pain. Evidence for predicting the response to cytarabine-based treatments will be highlighted, pointing at their significant impact on the routine management of blood cancers.

Abstract

Cytarabine is a pyrimidine nucleoside analog, commonly used in multiagent chemotherapy regimens for the treatment of leukemia and lymphoma, as well as for neoplastic meningitis. Ara-C-based chemotherapy regimens can induce a suboptimal clinical outcome in a fraction of patients. Several studies suggest that the individual variability in clinical response to Leukemia & Lymphoma treatments among patients, underlying either Ara-C mechanism resistance or toxicity, appears to be associated with the intracellular accumulation and retention of Ara-CTP due to genetic variants related to metabolic enzymes. Herein, we reported (a) the latest Pharmacogenomics biomarkers associated with the response to cytarabine and (b) the new drug formulations with optimized pharmacokinetics. The purpose of this review is to provide readers with detailed and comprehensive information on the effects of Ara-C-based therapies, from biological to clinical practice, maintaining high the interest of both researcher and clinical hematologist. This review could help clinicians in predicting the response to cytarabine-based treatments.

Association Study of MBL2 Gene Polymorphisms and Risk of Tuberculosis in Southeast of Iran

Mannose-binding lectin (MBL) is an acute phase protein which recognizes the pathogens through its carbohydrate recognition domain. It is an important part of human innate immunity. The aim of the current study was to evaluate the impact of MBL2 polymorphism on pulmonary tuberculosis in a number of patients from the southeast of Iran. In this case-control study, 2 MBL gene polymorphisms (rs1800450, rs7095891) were genotyped using PCR-RFLP method and polymerase chain reaction for detection of 34bp ins/del of MBL2 gene (rs777980157) polymorphism. The study included 170 patients with PTB (pulmonary tuberculosis) and 175 control subjects. The findings indicated that the GA (GA vs. GG: OR=0.172, 95% CI=0.107-0.275, P<0.001) (OR - odds ratio; CI - confidence interval) genotype as well as GA+AA (GA+AA vs. GG: OR=0.191, 95% CI=0.120-0.302, P<0.001) genotype of rs1800450 reduced the risk of PTB compared to GG genotype. The rs7095891 variant significantly decreased the risk of PTB in codominant (GA vs. GG: OR=0.118, 95% CI=0.054-0.258, P<0.001; and AA vs. GG: OR=0.029, 95% CI=0.01-0.082, P<0.001), dominant (GA+AA vs. GG: OR=0.095, 95% CI=0.044-0.207, P<0.001) and recessive (AA vs. GA+GG: OR=0.172, CI=0.081-0.365, P<0.001) inheritance models. No significant relationship was identified between the rs777980157 variant and PTB risk/protection. In conclusion, we found that the MBL2 rs1800450 and rs7095891 polymorphisms provide relative protection against PTB. Additional studies on larger populations with different ethnicities are required to verify our findings.

Polymorphism of the mannose-binding lectin gene in the Arctic indigenous populations of the Russian Federation

Маннозосвязывающий лектин (mannose-binding lectin, MBL) – паттерн-распознающий острофазовый белок, относящийся к системе врожденного иммунитета и активно участвующий в элиминации широкого круга патогенных микроорганизмов посредством активации лектинового пути системы комплемента. Значительная часть человеческой популяции имеет врожденно низкий уровень продукции и/или низкую функциональную активность MBL вследствие носительства различных вариантов гена MBL2, что может модифицировать течение самых разнообразных инфекционных заболеваний. Частота генотипов и гаплотипов полиморфизмов в гене MBL2 имеет значительные популяционные различия. К настоящему времени данные относительно распределения генотипов гена MBL2 в коренных популяциях территорий Арктической зоны Российской Федерации отсутствуют. Цель исследования – изучение частоты и этнической специфики распределения аллельных вариантов полиморфизмов гена MBL2 rs11003125, rs7096206, rs7095891, rs5030737, rs1800450 и rs1800451 и их гаплотипов в популяциях Таймырского Долгано-Ненецкого района Красноярского края (ненцы, долганы-нганасаны, русские). В настоящем исследовании нами впервые получены данные о частотах генотипов и гаплотипов гена MBL2 у коренных народностей, проживающих на территориях Арктической зоны Российской Федерации. Частота встречаемости гаплотипа HYPA, ассоциированного с высокой концентрацией MBL, составила 35.4 % для русских новорожденных Восточной Сибири, что соответствует частотам европейских популяций (27–33 %). У новорожденных арктических популяций частота гаплотипа HYPA была статистически значимо выше, чем у русских, и составила 64 % для ненцев и 56 % для долган-нганасан, что приближается к значениям частот, выявленных для эскимосов и североамериканских индейцев (64–81 %). Популяции ненцев и долган-нганасан демонстрируют существенно более низкие частоты MBL-дефицитных гаплотипов в сравнении с европеоидами Восточной Сибири (3.9, 6.4 и 21.3 % соответственно). Мы предполагаем, что изолированные арктические популяции исторически позже столкнулись с некоторыми внутриклеточными инфекциями (туберкулезом, лепрой) и, в отличие от европеоидных популяций, сохранили сформированную на ранних этапах эволюции человека высокую активность лектинового пути активации комплемента.

The Influence of the Lectin Pathway of Complement Activation on Infections of the Respiratory System

Lung diseases are among the leading causes of morbidity and mortality. Complement activation may prevent a variety of respiratory infections, but on the other hand, could exacerbate tissue damage or contribute to adverse side effects. In this review, the associations of factors specific for complement activation via the lectin pathway (LP) with infections of the respiratory system, from birth to adulthood, are discussed. The most extensive data concern mannose-binding lectin (MBL) which together with other collectins (collectin-10, collectin-11) and the ficolins (ficolin-1, ficolin-2, ficolin-3) belong to pattern-recognition molecules (PRM) specific for the LP. Those PRM form complexes with MBL-associated serine proteases (MASP-1, MASP-2, MASP-3) and related non-enzymatic factors (MAp19, MAp44). Beside diseases affecting humanity for centuries like tuberculosis or neonatal pneumonia, some recently published data concerning COVID-19 are summarized.

Mannose-binding lectin gene polymorphisms in the East Siberia and Russian Arctic populations

Mannose-binding lectin (MBL) encoded by MBL2 gene is a protein with the ability to form carbohydrate complexes with microbial wall promoting their subsequent elimination. Genetically determined levels of MBL can modify the risk and clinical characteristics of many infectious diseases. The frequency of MBL2 genotypes exhibits significant population differences. The data on the distribution of MBL2 genotypes among the aborigines of the Russian Arctic territories have not yet been published. A total of 880 specimens of dried blood spots of the newborns were genotyped. The newborns represented four populations: Nenets, Dolgan-Nganasans, Mixed aboriginal population, and Russians (Caucasians, Krasnoyarsk). Six polymorphisms of the MBL2 gene were studied: rs11003125, rs7096206, rs7095891, rs5030737, rs1800450, and rs1800451. The frequency of the combined rare O allele (composed of the coding region variants rs5030737, rs1800450, and rs1800451) in the homozygous state was significantly higher in Russians: 10% vs 2% in Nenets and 1% in Dolgan-Nganosans (p < 0.001 for Russians vs other populations). The frequency of the high-producing haplotype (HYPA) was 35.4% in the Russian newborns, in keeping with European populations (27-33%); 64% for Nenets and 56% for Dolgan-Nganasans, similar to the estimates obtained for Eskimos and North Amerinds (64-81%). Our study results are in line with the hypothesis that human evolution has been moving in the direction of accumulation of the genotypes associated with low activity of the lectin complement activation pathway because of the prevalence of some intracellular infections such as tuberculosis, whereby low MBL activity may have a protective effect.

Association between polymorphisms in mannose-binding lectin 2 gene with pulmonary tuberculosis susceptibility

Background

Mannose-binding lectin (MBL2) is considered to play a role in the human innate immune response to tuberculosis (TB) infections, and 4 common single nucleotide polymorphisms (SNPs) may be associated with pulmonary tuberculosis (PTB) risk. To examine these potential associations, we performed a comprehensive analysis to assess the relationships between MBL2 polymorphisms and PTB.

Methods

The PubMed, Embase, and SinoMed databases were searched for articles published prior to June 13, 2019. Odds ratios with 95% confidence intervals were calculated to evaluate the strength of the relationships.

Results

There were 37 case-control studies examining the effects of the four SNPs in MBL2 on PTB. A positive association between rs11003125 and PTB risk was observed in the hospital-based subgroup. Moreover, for the combined polymorphism and PTB risk, positive associations were detected not only in the total population but also in those with Asian origins across all source of control subgroups. No associations were found for rs7096206 or rs7095891.

Conclusions

Our current study indicated that several SNPs in MBL2 may be associated with susceptibility to PTB.

Mannose-binding lectin 2 gene polymorphisms and their association with tuberculosis in a Chinese population

BACKGROUND

Immune- and inflammation-related genes (IIRGs) play an important role in the pathogenesis of tuberculosis (TB). However, the relationship between IIRG polymorphisms and TB risk remains unknown. In this study, the gene polymorphisms and their association with tuberculosis were determined in a Chinese population.

METHODS

We performed a case-control study involving 1016 patients with TB and 507 healthy controls of Han Chinese origin. Sixty-four single-nucleotide polymorphisms (SNPs) belonging to 18 IIRGs were genotyped by the PCR-MassArray assay, and the obtained data was analyzed with χ²-test, Bonferroni correction, and unconditional logistic regression analysis.

RESULTS

We observed significant differences in the allele frequency of LTA rs2229094*C (P = 0.015), MBL2 rs2099902*C (P = 0.001), MBL2 rs930507*G (P = 0.004), MBL2 rs10824793*G (P = 0.004), and IL12RB1 rs2305740*G (P = 0.040) between the TB and healthy groups. Increased TB risk was identified in the rs930507 G/G genotype (P_adjusted = 0.027) under a codominant genetic model as well as in the rs2099902 (C/T + C/C) vs T/T genotype (P_adjusted = 0.020), rs930507 (C/G + G/G) vs C/C genotype (P_adjusted = 0.027), and rs10824793 (G/A + G/G) vs A/A genotype (P_adjusted = 0.017) under a dominant genetic model after Bonferroni correction in the analysis of the overall TB group rather than the TB subgroups. Furthermore, the rs10824793_rs7916582*GT and rs10824793_rs7916582*GC haplotypes were significantly associated with increased TB risk (P = 0.001, odds ratio [OR] = 1.421, 95% confidence interval [CI]: 1.152-1.753; and P = 0.018, OR = 1.364, 95% CI: 1.055-1.765, respectively). Moreover, the rs10824793_rs7916582*AT/AT or rs10824793_rs7916582*GT/GT diplotype showed a protective (P = 0.003, OR = 0.530, 95% CI: 0.349-0.805) or harmful (P = 0.009, OR = 1.396, 95% CI: 1.087-1.793) effect against the development of TB.

CONCLUSIONS

This study indicated that MBL2 polymorphisms, haplotypes, and diplotypes were associated with TB susceptibility in the Han Chinese population. Additionally, larger sample size studies are needed to further confirm these findings in the future.