The effect of penicillin administration in early life on murine gut microbiota and blood lymphocyte subsets.

BACKGROUND AND AIM: Antibiotics have many beneficial effects but their uncontrolled use may lead to increased risk of serious diseases in the future. Our hypothesis is that an early antibiotic exposition may affect immune system by altering gut microbiota. Therefore, the aim of the study was to determine the effect of penicillin treatment on gut microorganisms and immune system of mice. METHODS: 21-days old C57BL6/J/cmdb male mice were treated with low-dose of penicillin (study group) or water only (control group) for 4 weeks. Tissue and stool samples for histology or microbiome assessment and peripheral blood for CBC and flow cytometry evaluation were collected. RESULTS: We found high variability in microbiota composition at different taxonomic levels between littermate mice kept in the same conditions, independently of treatment regimen. Interestingly, low-dose of penicillin caused significant increase of Parabacteroides goldsteinii in stool and in colon tissue in comparison to control group (9.5% vs. 4.9%, p = 0.008 and 10.7% vs. 6.1%, p = 0.008, respectively). Moreover, mice treated with penicillin demonstrated significantly elevated percentage of B cells (median 10.5% vs 8.0%, p = 0.01) and decrease in the percentage of total CD4+ cell (median 75.4% vs 82.5%, p = 0.0039) with subsequent changes among subsets - increased percentage of regulatory T cells (Treg), T helper 1 (Th1) and T helper 2 (Th2) cells. CONCLUSION: Our study showed significant effect of penicillin on B and T cells in peripheral blood of young mice. This effect may be mediated through changes in gut microbiota represented by the expansion of Parabacteroides goldsteinii.

Population specificity of the DNAI1 gene mutation spectrum in primary ciliary dyskinesia (PCD).

BACKGROUND: Mutations in the DNAI1 gene, encoding a component of outer dynein arms of the ciliary apparatus, are the second most important genetic cause of primary ciliary dyskinesia (PCD), the genetically heterogeneous recessive disorder with the prevalence of ~1/20,000. The estimates of the DNAI1 involvement in PCD pathogenesis differ among the reported studies, ranging from 4% to 10%. METHODS: The coding sequence of DNAI1 was screened (SSCP analysis and direct sequencing) in a group of PCD patients (157 families, 185 affected individuals), the first ever studied large cohort of PCD patients of Slavic origin (mostly Polish); multiplex ligation-dependent probe amplification (MLPA) analysis was performed in a subset of ~80 families. RESULTS: Three previously reported mutations (IVS1+2-3insT, L513P and A538T) and two novel missense substitutions (C388Y and G515S) were identified in 12 families (i.e. ~8% of non-related Polish PCD patients). The structure of background SNP haplotypes indicated common origin of each of the two most frequent mutations, IVS1+2-3insT and A538T. MLPA analysis did not reveal any significant differences between patients and control samples. The Polish cohort was compared with all the previously studied PCD groups (a total of 487 families): IVS1+2-3insT remained the most prevalent pathogenetic change in DNAI1 (54% of the mutations identified worldwide), and the increased global prevalence of A538T (14%) was due to the contribution of the Polish cohort. CONCLUSIONS: The worldwide involvement of DNAI1 mutations in PCD pathogenesis in families not preselected for ODA defects ranges from 7 to 10%; this global estimate as well as the mutation profile differs in specific populations. Analysis of the background SNP haplotypes suggests that the increased frequency of chromosomes carrying A538T mutations in Polish patients may reflects local (Polish or Slavic) founder effect. Results of the MLPA analysis indicate that no large exonic deletions are involved in PCD pathogenesis.

Gut microbiome as a biomarker of cardiometabolic disorders.

INTRODUCTION AND OBJECTIVE: Cardiovascular diseases are the leading cause of death in Europe and worldwide. One of the most important risk factors for atherosclerosis are lipid metabolism disorders, in particular hipercholesterolaemia. The aim of the study was to determine the correlation between gut microbiota composition and atherosclerosis risk factors, so in order that it might be used as a biomarker for coronary artery disease diagnosis. MATERIAL AND METHODS: The study involved middle-aged men in eastern Poland with central obesity (n=20), subjects with atherosclerosis (n=15) and those with no cardiovascular diseases (n=5). The gut microbiota composition was determined using tag-encoded 16S rRNA gene using Illuminal MiSeq. Data were analyzed with the use of t-test. RESULTS: Firmicutes (49.26%) and Bacteroidetes (44.46%) were the dominant Phyla in the middle-aged men in eastern Poland. Subjects with improper levels of total cholesterol were enriched in Prevotella (p=0.03) and decreased level of Clostridium (p=0.02). They also showed a falling tendency in Faecalibacterium (p=0.07). An upward trend was observed in Prevotella (p=0.07) in subjects with improper LDL-C values. CONCLUSIONS: The study showed that intestinal microbiome is likely to play a role in the pathogenesis of atherosclerosis through its role in lipid metabolism. Bacterial genera of particular importance were Prevotella, Bacteroides, Clostridium, Faecalibacterium. However, further studies involving larger groups of subjects are required to confirm these observations.

Genetic characterization of Polish ccRCC patients: somatic mutation analysis of PBRM1, BAP1 and KDMC5, genomic SNP array analysis in tumor biopsy and preliminary results of chromosome aberrations analysis in plasma cell free DNA.

BACKGROUND: Mutation analysis and cytogenetic testing in clear cell renal cell carcinoma (ccRCC) is not yet implemented in a routine diagnostics of ccRCC. MATERIAL AND METHODS: We characterized the chromosomal alterations in 83 ccRCC tumors from Polish patients using whole genome SNP genotyping assay. Moreover, the utility of next generation sequencing of cell free DNA (cfDNA) in patients plasma as a potential tool for non-invasive cytogenetic analysis was tested. Additionally, tumor specific somatic mutations in PBRM1, BAP1 and KDM5C were determined. RESULTS: We confirmed a correlation between deletions at 9p and higher tumor size, and deletion of chromosome 20 and the survival time. In Fuhrman grade 1, only aberrations of 3p and 8p deletion, gain of 5q and 13q and gains of chromosome 7 and 16 were present. The number of aberrations increased with Fuhrman grade, all chromosomes displayed cytogenetic changes in G3 and G4. ccRCC specific chromosome aberrations were observed in cfDNA, although discrepancies were found between cfDNA and tumor samples. In total 12 common and 94 rare variants were detected in PBRM1, BAP1 and KDM5C, with four potentially pathogenic variants. We observed markedly lower mutation load in PBRM1. CONCLUSIONS: Cytogenetic analysis of cfDNA may allow more accurate diagnosis of tumor aberrations and therefore the correlation between the chromosome aberrations in cfDNA and clinical outcome should be studied in larger cohorts. The functional studies on in BAP1, KDM5C, PBRM1 mutations in large, independent sample set would be necessary for the assessment of their prognostic and diagnostic potential.