Virulence Factors in Colorectal Cancer Metagenomes and Association of Microbial Siderophores with Advanced Stages.

Colorectal cancer (CRC) is a growing public health challenge, featuring a multifactorial etiology and complex host-environment interactions. Recently, increasing evidence has pointed to the role of the gut microbiota in CRC development and progression. To explore the role of gut microbes in CRC, we retrieved metagenomic data from 156 stools from the European Nucleotide Archive database and mapped them against the VFDB database for virulence factors (VFs). GO annotations of VFs and KEGG pathways were then performed to predict the microbial functions and define functional pathways enriched in the tumor-associated microbiota. Interestingly, 306 VFs were detected in the metagenomic data. We revealed the enrichment of adenomas with VFs involved in cell adhesion, whereas in the early stages of CRC they were enriched in both adhesins and isochorismatase. Advanced stages of CRC were enriched with microbial siderophores, especially enterobactin, which was significantly associated with isochorismate synthase. We highlighted higher abundances of porins and transporters involved in antibiotic resistance and the development of biofilm in advanced stages of CRC. Most VFs detected in CRC, particularly in advanced stages, were shown to be included in siderophore biosynthesis pathways. This enrichment of predicted VFs supports the key role of the gut microbiota in the disease.

Diagnostic value of miR-199a and miR-21 in the plasma of infertile women with dysregulated AMH levels.

This work aimed to explore the expression pattern of circulating miR-199a-3p, miR-21-5p and miR-let7i-3p in infertile women with dysregulated AMH levels. Quantitative real-time PCR was used to measure miR-199a-3p, miR-21-5p, and miR-let7i-3p expression levels in 60 plasma samples of infertile women with low or high AMH levels. Bioinformatic analyses for microRNAs predicting target genes and molecular pathways were performed according to gene ontology (GO) analysis and KEGG pathways. Only miR-199a-3p and miR-21-5p were significantly over and under-expressed, respectively, in the plasma samples of all infertile women with low or high AMH levels versus controls (p-value = 0.01). Furthermore, the diagnostic value miR-199a-3p yielded a receiver operating characteristic (ROC) curve with area under the curve (AUC) of 0.82 with a 95% CI [0.72-0.92] and an AUC of 0.81, for miR-21-5p, 95% CI [0.69-0.92]. The combined ROC curve of miR-21 and miR-199a provided an optimal combination with AUC = 0.98, 95% CI [0.96-1], and, a cut-off point (0.42) which provided 98% sensitivity and 87% specificity. In conclusion, circulating miR-199a-3p and miR-21-5p vary significantly whenever AMH levels of infertile women are disturbed and could potentially serve as non-invasive biomarkers in distinguishing infertile from fertile women.

Analysis of Genetic Alterations in Tunisian Patients with Lung Adenocarcinoma.

The identification of the mutations that drive lung cancer have furnished new targets for the treatment of non-small cell lung cancer (NSCLC) and led to the development of targeted therapies such as tyrosine kinase inhibitors that are used to combat the molecular changes promoting cancer progression. Furthermore, biomarkers identified from gene analysis can be used to detect early lung cancer, determine patient prognosis, and monitor response to therapy. In the present study we analyzed the molecular profile of seventy-three Tunisian patients with lung adenocarcinoma (LAD). Mutational analyses for EGFR and KRAS were performed using direct sequencing, immunohistochemistry or MassARRAY. Anaplastic lymphoma kinase (ALK) rearrangement was evaluated by immunohistochemistry using the D5F3 clone, and p53 expression was also assessed. The median age of patients at diagnosis was 61 years (range 23-82 years). Using different methodologies, EGFR mutations were found in 5.47% of patients and only exon 19 deletions "E746-A750 del" were detected. KRAS mutations were present in 9.58% of cases, while only one patient was ALK-positive. Moreover, abnormal immunostaining of p53 was detected in 56.16% of patients. In conclusion, the detected rates of EGFR and KRAS mutation and ALK rearrangement were lower than those found in European and Asian countries, whereas, abnormal p53 expression was slightly more frequent. Furthermore, given the small sample size of this study, a more comprehensive analysis of this patient set is warranted.

A novel TBX1 missense mutation in patients with syndromic congenital heart defects.

Congenital heart defects represent a characteristic part of several genetic syndromes associated with chromosomal abnormalities such as 22q11.2 deletion syndrome; many genes located in this locus, mainly TBX1, are candidate genes for congenital heart defects. In our cohort of 27 subjects with congenital heart defect, both karyotype analysis and Fluorescence in situ hybridization (FISH) were performed. The TBX1 gene was sequenced in patients lacking chromosomal abnormalities. FISH analysis showed a de novo 22q11.2 deletion in two patients. The screening of TBX1 coding sequence identified a novel missense mutation c.569C > A (p.P190Q) in six unrelated patients and detected two associated known single nucleotide polymorphisms; the c.664C > T (rs2301558) in three patients and the c.420T > C (p.Phe140 Phe) (rs41298814) in one patient. Bioinformatic tools show that the novel missense mutation c.569C > A could modify the function and the stability of the TBX1 protein. The c.569C > A mutation was not found in 50 healthy controls. Ours results suggest a deleterious role of the c.569C > A mutation and strengthen the hypothesis that this mutation might be responsible for the same phenotype spectrum as the 22q11.2 deletion syndrome.

Effect of freezing-thawing process and quercetin on human sperm survival and DNA integrity.

We aimed in the first part of our work to study the effect of cryopreservation on the human sperm DNA integrity and the activation of caspase 3, the main apoptosis indicator. In the second part, we were interested in testing the effect of quercetin, as an antioxidant, in preventing sperm damage during the freeze-thawing process. Seventeen semen samples were obtained from 17 men recruited for infertility investigations. Liquefied sperm was cryopreserved using spermfreeze®. Nine of the used samples were divided into two aliquots; the first one was cryopreserved with spermfreeze only (control) and the second one was cryopreserved with spermfreeze supplemented with quercetin to a final concentration of 50 µM. Sperm motility and viability were assessed according to WHO criteria. We used TUNEL assay and the Oxy DNA assay to assess sperm DNA integrity. Activated caspase 3 levels were measured in spermatozoa using fluorescein-labeled inhibitor of caspase (FLICA). Cryopreservation led to a significant increase in sperm DNA fragmentation, DNA oxidation and caspase 3 activation (p<0.01). Supplementation of the cryopreservation medium with quercetrin induced a significant improvement in post thaw sperm parameters, compared to those of control, regarding sperm motility (p=0.007), viability (p=0.008) and DNA integrity (p=0.02); however, it had no effect on caspase 3 activation (p=0.3). We conclude that oxidative stress plays a major role in inducing sperm cryodamage but implication of apoptosis in this impairment requires further investigations. Quercetin could have protective effect during cryopreservation but further research is needed to confirm this effect.

Long-term outcome of patients with congenital adrenal hyperplasia due to 21-hydroxylase deficiency.

INTRODUCTION: Congenital adrenal hyperplasia (CAH) is an autosomal recessive disorder affecting adrenal steroid synthesis. In this study, the authors aim to evaluate the impact of CAH due to 21-hydroxylase deficiency on final height (FH), bone health, cardiometabolic risk, fertility, neurocognition and quality of life in a hospital-based sample from Tunisia. METHODS: Twenty-six patients (11 males and 15 females; mean age: 27.4 ± 8.2 years) were recruited. RESULTS: Mean FH was 159.5 ± 9.7 cm. Twenty-one patients (80.7%) had a FH below the target height. Ten patients (38.4%) exhibited bone demineralization. Eight patients (30.7%) had obesity. Lipid profile alterations and carbohydrate metabolism disorders were detected in 10 (38.4%) and 5 (19.2%) patients, respectively. Seven patients (27%) had insulin resistance. Ambulatory blood pressure monitoring showed abnormalities in 6 patients (23%). Increased carotid intima-media thickness was found in 14 patients (53.8%). Inhibin B level was decreased in 4 male patients. Semen analysis showed abnormalities in 4 of 10 patients. Testicular tumors were detected in 6 of 11 patients. Anti-Müllerian hormone level was reduced in 4 female patients. Six patients showed poly-cystic ovary syndrome. Brain magnetic resonance imaging showed abnormalities in 11 patients (42.3%). Quality of life was reduced in 14 of 22 patients (63.6%). Many of the suboptimal outcomes appeared to be related to poor adherence to medication schedules, some to overtreatment. CONCLUSION: CAH patients have a number of issues due to the disease or its treatment. Regular follow-up, early lifestyle interventions, bone health assessment, testicular ultrasound and psychological management are needed.

Sperm DNA fragmentation and oxidation are independent of malondialdheyde.

BACKGROUND: There is clinical evidence to show that sperm DNA damage could be a marker of sperm quality and extensive data exist on the relationship between DNA damage and male fertility status. Detecting such damage in sperm could provide new elements besides semen parameters in diagnosing male infertility. We aimed to assess sperm DNA fragmentation and oxidation and to study the association between these two markers, routine semen parameters and malondialdehyde formation. METHODS: Semen samples from 55 men attending the Histology-Embryology Laboratory of Sfax Faculty of Medicine, Tunisia, for semen investigations were analysed for sperm DNA fragmentation and oxidation using flow cytometry. The Sperm was also assessed spectrophotometrically for malondialdehyde formation. RESULTS: Within the studied group, 21 patients were nonasthenozoospermic (sperm motility ≥ 50%) and 34 patients were considered asthenozoospermic (sperm motility < 50%). A positive correlation was found between sperm DNA fragmentation and oxidation (p = 0.01; r = 0.33). We also found a negative correlation between sperm DNA fragmentation and some sperm parameters: total motility (p = 0.001; r = -0.43), rapid progressive motility (type a motility) (p = 0.04; r = -0.27), slow progressive motility (type b motility) (p = 0.03; r = -0.28), and vitality (p < 0.001; r = -0.65). Sperm DNA fragmentation was positively correlated with coiled tail (p = 0.01; r = 0.34). The two parameters that were found to be correlated with oxidative DNA damage were leucocytes concentrations (p = 0.01; r = 0.38) and broken neck (p = 0.02; r = 0.29). Sperm MDA levels were negatively correlated with sperm concentration (p < 0.001; r = -0.57), total motility (p = 0.01; r = -0.35) and type a motility (p = 0.03; r = -0.32); but not correlated with DNA fragmentation and DNA oxidation. CONCLUSIONS: Our results support the evidence that oxidative stress plays a key role in inducing DNA damage; but nuclear alterations and malondialdehyde don't seem to be synchronous.