Upregulation of gingival tissue miR-200b in obese periodontitis subjects.

Increased local immune and inflammatory responses in obese individuals with periodontitis may explain the aggressive clinical presentation and altered treatment response when compared to that of normal weight subjects. Our goal was to identify any differences in microRNA (miRNA) expression profiles of gingival tissue in periodontitis when obesity is present, which may suggest novel molecular pathways that this miRNA network may affect. Total RNA was extracted from gingival tissue biopsies collected from normal weight and obese individuals with periodontitis; miRNA expression profiling was performed with Affymetrix GeneChip miRNA 3.0 arrays; and results were validated with quantitative reverse transcription polymerase chain reaction (qRT-PCR). In silico identification of previously confirmed miRNA gene targets was conducted through miRTarBase and miRWalk databases, and pathway enrichment analysis identified enriched miRNA gene sets. Expression of selected genes in the same biopsy samples was tested with qRT-PCR. The gingival tissue miRNA profile of obese patients, compared to that of normal weight patients, showed 13 upregulated and 22 downregulated miRNAs, among which miR-200b was validated by qRT-PCR to be significantly increased in obesity. Functional analysis of 51 experimentally validated miR-200b gene targets identified enrichment of genes involved in cell motility, differentiation, DNA binding, response to stimulus, and vasculature development pathways not previously identified in the obesity-specific disease profile. Furthermore, the expression of the miR-200b gene targets ZEB1/2, GATA2, and KDR was confirmed by qRT-PCR as being lower in obese patients with periodontitis versus normal weight patients, suggesting a role of miR-200b in regulation of a set of gene targets and biological pathways relevant to wound healing and angiogenesis. Functional studies to explore the role of miR-200b in the above processes may offer new insights on putative therapeutic targets for this group of patients.

KIR genotype distribution among symptomatic patients with and without Helicobacter pylori infection: is there any role for the B haplotype?

UNLABELLED: Contact of peripheral blood lymphocytes with Helicobacter pylori was proved to induce non- major histocompatibility complex-restricted cytotoxicity and natural killer cells are thought to play an important role in the immunity against H. pylori. AIMS: In this research, we investigated any possible association between killer immunoglobulin-like receptors (KIR) genotypes and H. pylori infection. METHODS: KIR genotype was analysed in 101 Lebanese symptomatic patients (51 H. pylori positive and 50 H. pylori-negative) using the KIR Genotyping SSP kit. RESULTS: Among the H. pylori-positive patients, the AA, AB and BB genotypical frequencies were, respectively, 43.14%, 41.18% and 15.68% with an A:B ratio of 1.76:1. The AA, AB and BB genotypes frequencies for H. pylori-negative individuals were 18%, 62% and 20%, respectively, with an A:B ratio of 0.96:1. No significant difference between patients and controls was detected. CONCLUSIONS: We noticed a reduced distribution of A haplotype among the 'H. pylori-negative' patients as compared with the "H. pylori-positive" group. This is the first study in the international literature that targets the correlation between KIR genotypes and H. pylori.

KIR genotype distribution among patients with multiple myeloma: Higher prevalence of KIR 2DS4 and KIR 2DS5 genes.

INTRODUCTION: Natural killer (NK) cells possess an antitumor activity against multiple myeloma cells proven by the susceptibility of plasmocytes to NK lysis. In the early stage of MM, the killing of MM cells is mediated by natural cytotoxicity receptors (NRC) and NKG2D-dependent pathway, while in the late stage, NK cells lose their killing potential against MM cells due to the high expression of HLA class I molecules on MM cells. AIM: The aim of this paper is to study KIR expression of NK cells in MM patients and in healthy controls, to check for any association between KIR genotypes and MM. METHODS: KIR genotype was analyzed in 120 healthy Lebanese individuals and 34 MM patients using the KIR Genotyping SSP kit. RESULTS: KIR 2DS4*001/002 and KIR 2DS5 were found to be significantly more prevalent among MM patients as compared to controls. For MM patients, the AA, AB, and BB genotype frequencies were, respectively, 38.23%, 47.06% and 14.71% with an A:B ratio of 1.62:1. As for the healthy controls, the AA, AB, and BB genotype frequencies were, respectively, 39.17%, 50%, and 10.83% with an A:B ratio of 1.80:1. CONCLUSION: The interesting observation of the significant presence of KIR2DS4 and KIR2DS5 genes more among multiple myeloma patients than controls is worth further clinical, translational as well as survival research studies in these cases.

Study of KIR genes in Lebanese patients with tuberculosis.

A total of 103 Lebanese tuberculosis (TB) cases and 38 controls without TB were studied for the killer cell immunoglobulin-like receptors (KIR) genotypic profile using polymerase chain reaction sequence-specific primers. Patients and controls were assigned to the AA, AB or BB genotypes based on their A or B haplotype genetic make-up, and KIR gene frequencies were compared. We found an increase in the KIR A haplotype in TB patients compared to controls, and only KIR 2DL3 was found to be significantly more prevalent among TB patients. This confirms the findings of another unique international study performed in the Mexican population showing a greater repertoire of inhibitory KIR genes among TB patients than controls.