Polymorphism, Expression of Natural Resistance-associated Macrophage Protein 1 Encoding Gene (NRAMP1) and Its Association with Immune Traits in Pigs.

Natural resistance-associated macrophage protein 1 encoding gene (NRAMP1) plays an important role in immune response against intracellular pathogens. To evaluate the effects of NRAMP1 gene on immune capacity in pigs, tissue expression of NRAMP1 mRNA was observed by real time quantitative polymerase chain reaction (PCR), and the results revealed NRAMP1 expressed widely in nine tissues. One single nucleotide polymorphism (SNP) (ENSSSCG00000025058: g.130 C>T) in exon1 and one SNP (ENSSSCG00000025058: g.657 A>G) in intron1 region of porcine NRAMP1 gene were demonstrated by DNA sequencing and PCR-RFLP analysis. A further analysis of SNP genotypes associated with immune traits including contain of white blood cell (WBC), granulocyte, lymphocyte, monocyte (MO), rate of cytotoxin in monocyte (MC) and CD4/CD8 T lymphocyte subpopulations in blood was carried out in four pig populations including Large White and three Chinese indigenous breeds (Wannan Black, Huai pig and Wei pig). The results showed that the SNP (ENSSSCG00000025058: g.130 C>T) was significantly associated with level of WBC % (p = 0.031), MO% (p = 0.024), MC% (p = 0.013) and CD4(-)CD8(+) T lymphocyte (p = 0.023). The other SNP (ENSSSCG00000025058: g.657 A>G) was significantly associated with the level of MO% (p = 0.012), MC% (p = 0.019) and CD4(-)CD8(+) T lymphocyte (p = 0.037). These results indicate that the NRAMP1 gene can be regarded as a molecular marker for genetic selection of disease susceptibility in pig breeding.

Serum iron levels in tuberculosis patients and household contacts and its association with natural resistance-associated macrophage protein 1 polymorphism and expression.

BACKGROUND: Iron deficiency can impair immune function, increasing tuberculosis (TB) susceptibility and severity. The research aimed to investigate iron deficiency anemia in TB patients and household contacts and its association with natural resistance-associated macrophage protein 1 (NRAMP1) polymorphism and expression. METHODS: The levels of iron, ferritin, and transferrin were measured in the serum by ELISA (Enzyme-Linked Immunosorbent Assay). NRAMP1 polymorphisms were determined by polymerase chain reaction (PCR) and sequencing. NRAMP1 gene expression was measured by real-time PCR. Interferon-gamma release assay (IGRA) checked on household contacts to screen household contacts with positive IGRA as the control. RESULTS: This study involved 35 TB cases and 35 TB contacts. The results showed that the serum Fe levels were found to be lower in the TB case group (median 149.6 µmol/L) than in the positive IGRA household contacts group (median 628.53 µmol/L) with a p-value <0.001. Meanwhile, ferritin levels in TB cases tended to be higher, in contrast to transferrin, which was found to tend to be lower in TB cases than household contacts but did not show a significant difference. This study found no association between the polymorphism of exon 15 D543 and active TB. However, NRAMP1 gene expression was lower in TB cases than in positive IGRA household contacts (p = 0.011). Besides, there was a positive correlation between NRAMP1 gene expression and serum Fe levels (r = 0.367, p = 0.006). TB was associated with decreased NRAMP1 gene expression (OR 0.086 95% CI 0.02-0.366, p = 0.001). Besides, TB was associated with low Fe levels (OR 0.533 95% CI 0.453-0.629, p < 0.001). CONCLUSION: Comparing the TB case to the household contacts group, decreased serum Fe levels were discovered in the TB case group. This study also shows a correlation of NRAMP1 gene expression to Fe levels in TB patients and household contacts and describes that TB may lead to decreased Fe levels by downregulating NRAMP1 expression.

Collocating Novel Targets for Tuberculosis (TB) Drug Discovery.

BACKGROUND: Mycobacterium tuberculosis, being a resistive species is an incessant threat to the world population for the treatment of Tuberculosis (TB). An advanced genetic or a molecular level approach is mandatory for both diagnosis and therapy as the prevalence of multi drug-resistant (MDR) and extensively drug- resistant (XDR) TB. METHODS: A literature review was conducted, focusing essentially on the development of biomarkers and targets to extrapolate the Tuberculosis Drug Discovery process. RESULTS AND DISCUSSION: In this article, we have discussed several substantial targets and genetic mutations occurring in a diseased or treatment condition of TB patients. It includes expressions in Bhlhe40, natural resistance associated macrophage protein 1 (NRAMP1) and vitamin D receptor (VDR) with its mechanistic actions that have made a significant impact on TB. Moreover, recently identified compounds; imidazopyridine amine derivative (Q203), biphenyl amide derivative (DG70), azetidine, thioquinazole, tetrahydroindazole and 2- mercapto- quinazoline scaffolds for several targets such as adenosine triphosphate (ATP), amino acid and fatty acid have been briefed for their confirmed hits and therapeutic activity.

Exploring genetic polymorphism in innate immune genes in Indian cattle (Bos indicus) and buffalo (Bubalus bubalis) using next generation sequencing technology.

Activation of innate immunity initiates various cascades of reactions that largely contribute to defense against physical, microbial or chemical damage, prompt for damage repair and removal of causative organisms as well as restoration of tissue homeostasis. Genetic polymorphism in innate immune genes plays prominent role in disease resistance capabilities in various breeds of cattle and buffalo. Here we studied single nucleotide variations (SNP/SNV) and haplotype structure in innate immune genes viz CHGA, CHGB, CHGC, NRAMP1, NRAMP2, DEFB1, BNBD4, BNBD5, TAP and LAP in Gir cattle and Murrah buffalo. Targeted sequencing of exonic regions of these genes was performed by Ion Torrent PGM sequencing platform. The sequence reads obtained corresponding to coding regions of these genes were mapped to reference genome of cattle BosTau7 by BWA program using genome analysis tool kit (GATK). Further variant analysis by Unified Genotyper revealed 54 and 224 SNPs in Gir and Murrah respectively and also 32 SNVs was identified. Among these SNPs 43, 36, 11,32,81,21 and 22 variations were in CHGA, CHGB, CHGC, NRAMP1, NRAMP2, DEFB1 and TAP genes respectively. Among these identified 278 SNPs, 24 were found to be reported in the dbSNP database. Variant analysis was followed by structure formation of haplotypes based on multiple SNPs using SAS software revealed a large number of haplotypes. The SNP discovery in innate immune genes in cattle and buffalo breeds of India would advance our understanding of role of these genes in determining the disease resistance/susceptibility in Indian breeds. The identified SNPs and haplotype data would also provide a wealth of sequence information for conservation studies, selective breeding and designing future strategies for identifying disease associations involving samples from distinct populations.

The complex interplay of iron metabolism, reactive oxygen species, and reactive nitrogen species: insights into the potential of various iron therapies to induce oxidative and nitrosative stress.

Production of minute concentrations of superoxide (O2(*-)) and nitrogen monoxide (nitric oxide, NO*) plays important roles in several aspects of cellular signaling and metabolic regulation. However, in an inflammatory environment, the concentrations of these radicals can drastically increase and the antioxidant defenses may become overwhelmed. Thus, biological damage may occur owing to redox imbalance-a condition called oxidative and/or nitrosative stress. A complex interplay exists between iron metabolism, O2(*-), hydrogen peroxide (H2O2), and NO*. Iron is involved in both the formation and the scavenging of these species. Iron deficiency (anemia) (ID(A)) is associated with oxidative stress, but its role in the induction of nitrosative stress is largely unclear. Moreover, oral as well as intravenous (iv) iron preparations used for the treatment of ID(A) may also induce oxidative and/or nitrosative stress. Oral administration of ferrous salts may lead to high transferrin saturation levels and, thus, formation of non-transferrin-bound iron, a potentially toxic form of iron with a propensity to induce oxidative stress. One of the factors that determine the likelihood of oxidative and nitrosative stress induced upon administration of an iv iron complex is the amount of labile (or weakly-bound) iron present in the complex. Stable dextran-based iron complexes used for iv therapy, although they contain only negligible amounts of labile iron, can induce oxidative and/or nitrosative stress through so far unknown mechanisms. In this review, after summarizing the main features of iron metabolism and its complex interplay with O2(*-), H2O2, NO*, and other more reactive compounds derived from these species, the potential of various iron therapies to induce oxidative and nitrosative stress is discussed and possible underlying mechanisms are proposed. Understanding the mechanisms, by which various iron formulations may induce oxidative and nitrosative stress, will help us develop better tolerated and more efficient therapies for various dysfunctions of iron metabolism.

NRAMP1 gene polymorphisms in patients with rheumatoid arthritis in Koreans

Natural resistance-associated macrophage protein 1 (Nramp1) is a genetic locus associated with innate resistance or susceptibility of murine hosts to infection with intracellular pathogens such as Salmonella, Leishmania and Mycobacterium. The human homologue of the Nramp1 gene, designated NRAMP1, has been investigated as a candidate gene for genetic susceptibility to autoimmune diseases as well as infections. This study tries to determine whether NRAMP1 polymorphisms are associated with susceptibility to rheumatoid arthritis in Koreans. The nine NRAMP1 polymorphisms (1 microsatellite, 1 variation in 3' UTR, 5 silent substitution, 2 amino acid substitution) were typed by PCR-RFLP in 74 patients with rheumatoid arthritis (RA) and 53 healthy controls in Koreans. The distribution of allele and genotype frequencies were compared between patients and controls. Three NRAMP1 polymorphisms (823C/T, D543N and 1729+55del4) were significantly associated with RA. In addition, there were significant differences in the genotype frequencies for 823C/T, D543N and 1729+ 55del4 polymorphisms between RA patients and controls. Genotypes of A/A homozygote for D543N and TGTG deletion homozygote for 1729+55del4 were only detected in the patient group. These data indicate that genetic polymorphisms of NRAMP1 might be associated with the susceptibility to rheumatoid arthritis in Koreans.