Laboratoires de Biomarqueurs Moléculaires, PCR, qPCR, RNA
Système immunitaire et méthamphétamine
Gabriellamai 1, 20210 Comments
Système immunitaire et méthamphétamine: base moléculaire d’une relation
Use of methamphetamine (Meth) as a drug of abuse is on the rise worldwide. Besides its effect on the function of the brain, Meth has detrimental effects on how the immune system functions. As documented in the literature, various experimental models (cellular, animal, mice, and non-human primates) have been used that have contributed to the overall knowledge about immune system impairments from Meth exposure. It has to be noted that while Meth is used in very few treatments, it affects a broad range of biological mechanisms, not only immune regulation, in a negative manner.
Undoubtfully, the effect of Meth is highly complex; moreover, the initial molecular triggers remain unknown. Analyses of available literature suggests that the effect of Meth is not prompted by one underlying mechanism. Whether the effect of Meth is acute or long-lasting, the overall effect is negative. Further advancement of our knowledge on Meth’s specific actions will require systematic experimental approaches using all available models. In addition, bioinformatic analyses are necessary to build a comprehensive model as a needed tool to fill the gap in knowledge.
La curcumine régule la progression du cancer: focus sur les ARNnc et les voies de signalisation moléculaire
Curcumin [(1E,6E) ‑1,7‑bis(4‑hydroxy‑3‑methoxyphenyl) hepta‑1,6‑diene‑3,5‑ dione] is a natural polyphenol derived from the rhizome of the turmeric plant Curcuma longa. Accumulated evidences have presented curcumin’s function in terms of anti-inflammatory, antioxidant properties, and especially anti-tumor activities. Studies demonstrated that curcumin could exert anti-tumor activity via multiple biological signaling pathways, such as PI3K/Akt, JAK/STAT, MAPK, Wnt/β-catenin, p53, NF-ĸB and apoptosis related signaling pathways. Moreover, Curcumin can inhibit tumor proliferation, angiogenesis, epithelial-mesenchymal transition (EMT), invasion and metastasis by regulating tumor related non-coding RNA (ncRNA) expression.
In this review, we summarized the roles of curcumin in regulating signaling pathways and ncRNAs in different kinds of cancers. We also discussed the regulatory effect of curcumin through inhibiting carcinogenic miRNA and up regulating tumor suppressive miRNA. Furthermore, we aim to illustrate the cross regulatory relationship between ncRNA and signaling pathways, further to get a better understanding of the anti-tumor mechanism of curcumin, thus lay a theoretical foundation for the clinical application of curcumin in the future.
Mécanismes moléculaires sous-jacents à l’activité antitumorale de la protéine de lactosérum de chameau contre les cellules de myélome multiple
Treating drug-resistant cancer cells is a clinical challenge and it is also vital to screen for new cancer drugs. Multiple myeloma (MM) is a plasma cell clonal cancer that, despite many experimental therapeutics, remains incurable. In this study, two MM cell line lines U266 and RPMI 8226 were used to determine the impact of camel whey protein (CWP). The CWP IC50 was calculated by MTT examination, while the flow cytometry analysis was used to investigate the chemotaxis responses of MM cells in relation to CXCL12 and the pro-apoptotic effect of CHP. MM cells were treated with CWP and Western blot analysis was used to determine the underlying molecular mechanisms.
Dose and time based on the impact of CWP on the cell viability of MM cells with IC50 of 50 μg/ml, without affecting the viability of normal healthy PBMCs. CWP reduced chemotaxis of MM cells significantly from the CXC chemokine ligand 12 (CXCL12). Using Western blot analysis, we found that CWP decreased the activation of AKT, mTOR, PLCβ3, NFαB and ERK, which was mechanistically mediated by CXCL12/CXCR4. In both U266 and RPMI 8226, CWP induced apoptosis by upregulating cytochrome C expression.
In addition, CWP mediated the growth arrest of MM cells by robustly decreasing the expression of the anti-apoptotic Bcl-2 family members Bcl-2, Bcl-XL and Mcl-1. Conversely, the expression of pro-apoptotic Bcl-2 family members Bak, Bax and Bim was increased after treatment with CWP. Our data indicates CWP’s therapeutic potential for MM cells.
Identification moléculaire de Campanulotes bidentatus Scopoli, 1763 (Phthiraptera, Philopteridae) infectant le pigeon domestique Columba livia d’Arabie saoudite.
The taxonomy of the order Phthiraptera is unstable and still problematic to researchers. Most of the current taxon classifications are mainly based on morphological features. <i>Campanulotes bidentatus</i> belongs to the chewing lice of the Philopteridae family that mostly parasitic on birds. There is a lack of sequence data and phylogenetic analyses on the family Philopteridae. In the current study, <i>C. bidentatus</i> was collected from the domestic pigeon <i>Columba livia</i> and identified morphologically and molecularly based on the mitochondrial cytochrome <i>c</i> oxidase subunit 1 gene (<i>COI</i>).
The infection rate of the <i>Campanulotes</i> genus was approximately 58.82% in this study. Phylogenetic analysis based on the mt <i>COI</i> gene was informative for members of Philopteridae and the group taxon genera formed distinct clades. Future studies were recommended using the <i>16s rRNA</i> to enhance the tree topology and obtain clear differentiation between genera.
Escherichia coli multirésistante dans le lait cru: caractérisation moléculaire et impact potentiel de l’urine de chameau en tant qu’agent antibactérien
Raw milk is one of the most important vehicles for transmitting various pathogens, especially Escherichia coli (E. coli). Multidrug-resistant pathogens are highly prevalent among mastitic cows in various dairy farms worldwide. Therefore, our current study is based on the identification of E. coli from mastitic cow’s milk and their resistance to various antibacterial agents. As well, the impact of camel’s urine on multi-drug resistant E. coli were also evaluated. Thirty-three E. coli isolates were recovered from 254 milk samples. All strains were initially identified phenotypically by culturing on specific media and Vitek 2 Compact System. The protein fingerprinting technique was used as a confirmatory method. The Stx1, Stx2 and eae genes were also verified by polymerase chain reaction (PCR). The antimicrobial resistance of E. coli strains was tested by the Vitek 2 AST-GN69 cards.
Thirty multi-drug resistant E. coli strains (20 from mastitic milk and 10 from clinical samples) were laboratory tested with different concentrations (100%, 75%, 50% and 25%) of virgin and breeding camel’s urine, using the paper disc diffusion method. Our findings showed that 93.94% of E. coli strains were recognized by the Vitek™ 2 system. The results of proteomic investigation illustrated that 100% of E. coli strains were identified at log values ≥2.00. The genotypic identification of the three virulence genes illustrated that 90.1%, 63.64%, and 30.55% of E. coli strains were able to carry the Stx1, eae, and Stx2 genes, respectively.
Most strains of E. coli showed strong resistance against cefazolin (78.79%), ceftazidime (66.67%), cefotaxime (60.61%), ceftriaxone (54.55%), and cefepime (39.40%). The results of the antibacterial effect of camel’s urine revealed that the mean inhibitory zones of virgin camel’s urine were 28 mm, 17 mm, and 14 mm, for the concentrations of 100%, 75%, and 50%, respectively. Whereas; the inhibitory zones for the breeding camel’s urine were 18 mm, 0 mm, and 0 mm, for the concentrations of 100%, 75%, and 50%, respectively. We concluded that the majority of E. coli strains were able to harbor some virulence genes and resist many antibiotics. Our study also provided a robust evidence that the camel’s urine, particularly from the virgin camels has robust antimicrobial activity against multidrug-resistant E. coli strains.
