Osteogenic potential of hexane and dichloromethane fraction of Cissus quadrangularis on murine preosteoblast cell line MC3T3-E1 (subclone 4)

In continuation of the investigation of osteogenic potential of solvent fractions of ethanolic extract of Cissus quadrangularis (CQ), an ancient medicinal plant, most notably known for its bone-healing properties, to isolate and identify antiosteoporotic compounds. In the current study, we report the effect of hexane fraction (CQ-H) and dichloromethane fraction (CQ-D) of CQ on the differentiation and mineralization of mouse preosteoblast cell line MC3T3-E1 (subclone 4). Growth, viability, and proliferation assays revealed that low concentrations (0.1, 1, and 100 ng/ml) of both solvent fractions were nontoxic, whereas higher concentrations were toxic to the cells. Differentiation and mineralization of MC3T3-E1 with nontoxic concentrations of CQ-D and CQ-H revealed that CQ-D delayed the mineralization of MC3T3-E1 cells. However, early and enhanced mineralization was observed in cultures treated with nontoxic concentrations of CQ-H, as indicated by Von Kossa staining and expression profile of osteoblast marker genes such as osterix, Runx2, alkaline phosphatase (ALP), collagen (Col1a1), integrin-related bone sialoprotein (IBSP), osteopontin (OPN), and osteocalcin (OCN). These findings suggest CQ-H as the most efficacious solvent fraction for further investigation to isolate and identify the active compounds in CQ-H.     

A novel frameshift mutation in BLM gene associated with high sister chromatid exchanges (SCE) in heterozygous family members

The Bloom syndrome (BS) is an autosomic recessive disorder comprising a wide range of abnormalities, including stunted growth, immunodeficiency, sun sensitivity and increased frequency of various types of cancer. Bloom syndrome cells display a high level of genetic instability, including a 10-fold increase in the sister chromatid exchanges (SCE) level. Bloom syndrome arises through mutations in both alleles of the BLM gene, which was identified as a member of the RecQ helicase family. In this study, we screened a Tunisian family with three BS patients. Cytogenetic analysis showed several chromosomal aberrations, and an approximately 14-fold elevated SCE frequency in BS cells. A significant increase in SCE frequency was observed in some family members but not reaching the BS patients values, leading to suggest that this could be due to the heterozygous profile. Microsatellite genotyping using four fluorescent dye-labeled microsatellite markers revealed evidence of linkage to BLM locus and the healthy members, sharing higher SCE frequency, showed heterozygous haplotypes as expected. Additionally, the direct BLM gene sequencing identified a novel homozygous frameshift mutation c.3617–3619delAA (p.K1207fsX9) in BS patients and a heterozygous BLM mutation in the family members with higher SCE frequency. Our findings suggest that this latter mutation likely leads to a reduced BLM activity explaining the homologous recombination repair defect and, therefore, the increase in SCE. Based on the present data, the screening of this mutation could contribute to the rapid diagnosis of BS. The genetic confirmation of the mutation in BLM gene provides crucial information for genetic counseling and prenatal diagnosis.     

Autoimmune diseases association study with the KIAA1109–IL2–IL21 region in a Tunisian population

Autoimmune diseases (ADs) share several genetic factors resulting in similarity of disease mechanisms. For instance polymorphisms from the KIAA1109–interleukin 2 (IL2)–IL21 block in the 4q27 chromosome, has been associated with a number of autoimmune phenotypes. Here we performed a haplotype-based analysis of this AD related region in Tunisian patients. Ten single nucleotide polymorphisms (rs6534347, rs11575812, rs2069778, rs2069763, rs2069762, rs6852535, rs12642902, rs6822844, rs2221903, rs17005931) of the block were investigated in a cohort of 93 systemic lupus erythematosus (SLE), 68 ulcerative colitis (UC), 39 Crohn’s disease (CD) patients and 162 healthy control subjects of Tunisian origin. In SLE population, haplotypes AGCAGGGTC, AGAAGAGTC, AGAAGGGTC and AGCCGAGTC provided significant evidence of association with SLE risk (p = 0.013, 0.028, 0.018 and 0.048, respectively). In the UC population, haplotype AGCCGGGTC provided a susceptibility effect for UC (p = 0.025). In the CD population, haplotype CAGGCC showed a protective effect against the development of CD (p = 0.038). Haplotype AAGGTT provided significant evidence to be associated with CD risk (p = 0.007). Our results support the existence of the associations found in the KIAA1109/IL2/IL21 gene region with ADs, thus confirms that the 4q27 locus may contribute to the genetic susceptibility of ADs in the Tunisian population.     

Association of BANK1 and cytokine gene polymorphisms with type 1 diabetes in Tunisia

Type 1 diabetes (T1D) is an autoimmune disease (AID) with both genetic and environmental components. We aimed to investigate the genetic association of polymorphisms in genes previously linked with other AIDs, namely BANK1, IL15 and IL2/IL21 region.     

A Comparative Study of the Oxidative Profile in Graves’ Disease, Hashimoto’s Thyroiditis, and Papillary Thyroid Cancer

The aim of this study was to evaluate and compare the oxidative profiles of three thyroid disorders: Graves’ disease (GD), Hashimoto thyroiditis (HT), and papillary thyroid cancer (PTC). Malondialdehyde levels (MDA), glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase (CAT) activities were examined in the plasma of 52 patients (29 untreated HT, 16 untreated GD, and 7 PTC who underwent surgical therapy). Results were compared with those of 30 healthy controls and among the three groups of patients. The GD, HT, and PTC patients exhibited increased plasma MDA levels and SOD activities compared with the controls (p?<?0.05, p?<?0.05, and p?<?0.001, respectively). CAT activities significantly increased only for the PTC and HT patients (p?<?0.001 and p?<?0.05, respectively), whereas GPx activities significantly decreased only in the GD and PTC (p?<?0.05 and p?<?0.01, respectively). The comparison among the three groups of patients has shown increased MDA level and SOD activity for the PTC patients as compared to the GD patients (p?<?0.01 and p?<?0.001, respectively). Compared with HT, PTC patients exhibited significant higher MDA level, SOD, and CAT activities and a significant lower GPx activity (p?<?0.01, p?<?0.001, p?<?0.05, and p?<?0.05, respectively). No significant discrepancies were noted between the GD and HT patients. Our results have clearly shown an oxidative profile that is highly disturbed for the PTC patients as compared to those of autoimmune disorders. Future studies are needed to determine whether or not the oxidative stress has a prognostic value in this pathology.     

Loss of ovule identity induced by overexpression of the fertilization-related kinase 2 (ScFRK2), a MAPKKK from Solanum chacoense

In order to gain information about protein kinases acting during plant fertilization and embryogenesis, a reverse genetic approach was used to determine the role of protein kinases expressed in reproductive tissues. Two cDNA clones named ScFRK1 and ScFRK2 (Solanum chacoense fertilization-related kinase 1 and 2) were isolated from an expressed sequence tag (EST) library normalized for weakly expressed genes in fertilized ovaries. These showed significant sequence similarities to members of the mitogen-activated protein kinase kinase kinase (MAPKKK) family. RNA gel blot and RNA in situ hybridization analyses confirmed the strong up-regulation of ScFRK2 in ovules after fertilization. In addition, ScFRK2 mRNAs accumulate during early ovule development in the megasporocyte and in the integument of developing ovules. Overexpression of ScFRK2 led to the production of fruits with a severely reduced number of seeds. The seeds that were produced also exhibited developmental retardation. Analysis of ovaries prior to fertilization showed that the seedless phenotype was caused by a homeotic conversion of ovules into carpel-like structures. The present observations are consistent with the role of ScFRK2 in pre- and post-fertilization events. Furthermore, overexpression of ScFRK2 led to changes in the expression of the class D floral homeotic gene ScFBP11, suggesting that the ScFRK2 kinase may interact, directly or indirectly, with the FBP7/11 pathway that directs establishment of ovule identity.     

An SopB-mediated immune escape mechanism of Salmonella enterica can be subverted to optimize the performance of live attenuated vaccine carrier strains

Salmonellae have evolved several mechanisms to evade host clearance. Here, we describe the influence on bacterial immune escape of the effector protein SopB, which is translocated into the cytosol through a type III secretion system. Wild-type bacteria, as well as the sseC and aroA attenuated mutants exerted a stronger cytotoxic effect on dendritic cells (DC) than their SopB-deficient derivatives. Cells infected with the double sseC sopB, phoP sopB and aroA sopB mutants also exhibited higher expression of MHC, CD80, CD86 and CD54 molecules, and showed a stronger capacity to process and present an I-E(d)-restricted epitope from the influenza hemagglutinin (HA) to CD4+ cells from TCR-HA transgenic mice in vitro. The incorporation of an additional mutation into the sopB locus of the attenuated sseC, phoP and aroA mutants resulted in the stimulation of improved humoral and cellular immune responses following oral vaccination. The obtained results define a new potential immune escape strategy of this important pathogen, and also demonstrate that this mechanism can be subverted to optimize the immune responses elicited using Salmonella as a live vaccine carrier.     

Collection of antimicrobial peptides database and its derivatives: Applications and beyond

Collection of antimicrobial peptides (CAMP), CAMPSign, and ClassAMP are open‐access resources that have been developed to enhance research on antimicrobial peptides (AMPs). Comprehensive information on AMPs and machine learning‐based predictive models are made available for users through these resources. As of date, CAMP_R3 has 10,247 sequences, 757 structures, and 114 family‐specific signatures of AMPs along with associated tools for AMP sequence and structure analysis. CAMPSign uses family‐specific sequence conservation, in the form of patterns and hidden Markov models for identification of AMPs. ClassAMP can be used to classify AMPs as antibacterial, antifungal, or antiviral based on sequence information. Here we describe CAMP and its derivatives and illustrate, with a few examples, the contribution of these online resources to the advancement of our current understanding of AMPs.     

Mitochondrial disease patients with novel ND4 12058A > C and ND1 m.3911A > G variations: implications for a role in the phenotype following a bioinformatic investigation

Molecular Biology Reports - Mitochondrial diseases include a wide group of clinically heterogeneous disorders caused by a dysfunction of the mitochondrial respiratory chain and can be related to...