Characterization of two rat models of cystic fibrosis—KO and F508del CFTR—Generated by Crispr-Cas9

Background: Genetically engineered animals are essential for gaining a proper understanding of the disease mechanisms of cystic fibrosis(CF). The rat is a relevant laboratory model for CF because of its zootechnical capacity, size, and airway characteristics, including the presence of submucosal glands.Methods: We describe the generation of a CF rat model(F508 del) homozygous for the p.Phe508 del mutation in the transmembrane conductance regulator(Cftr) gene. This model was compared to new Cftr-/-rats(CFTR KO). Target organs in CF were examined by histological staining of tissue sections and tooth enamel was quantified by micro-computed tomography. The activity of CFTR was evaluated by nasal potential difference(NPD) and short-circuit current measurements. The effect of VX-809 and VX-770 was analyzed on nasal epithelial primary cell cultures from F508 del rats.Results: Both newborn F508 del and Knock out(KO) animals developed intestinal obstruction that could be partly compensated by special diet combined with an osmotic laxative. The two rat models exhibited CF phenotypic anomalies such as vas deferens agenesis and tooth enamel defects. Histology of the intestine, pancreas, liver, and lungs was normal. Absence of CFTR function in KO rats was confirmed ex vivo by short-circuit current measurements on colon mucosae and in vivo by NPD, whereas residual CFTR activity was observed in F508 del rats. Exposure of F508 del CFTR nasal primary cultures to a combination of VX-809 and VX-770 improved CFTR-mediated Cl-transport.Conclusions: The F508 del rats reproduce the phenotypes observed in CFTR KO animals and represent a novel resource to advance the development of CF therapeutics.

Effect of the Ethanolic Extract of Khaya senegalensis on Some Biochemical Parameters on Rabbit’s in Glucose Overload Condition

The effect of the ethanolic extract Khaya senegalensis on some biochemical parameters was tested in rabbits with normal glucose and glucose overload. Phytochemical screening after three batches of 6 rabbits race (TBD) were treated with the extract in oral doses of respectively 10, 25 and 50 mg/kg body weight for 30 days;three other groups receiving respectively these doses of the extract were placed under a priori temporary overload of glucose;a control group received instead distilled water treatment. Blood glucose, triglycerides and total cholesterol were measured by spectrophotometry and weight gain of the animals was performed at the beginning of the experiment and every 2 weeks during the study period. The phytochemical screening revealed the presence of polyphenolic compounds (majority) of saponins of anthracene derivatives and steroids in the extract. The test results indicate that under the dose of 50 mg/kg body weight (BW) there was a significant decrease (p < 0.05) in blood glucose after 24 hours. The extract had no effect on the lipid profile or body weight of rabbits.

Fish Assemblages in the Degraded Mangrove Ecosystems of the Coastal Zone, Benin, West Africa: Implications for Ecosystem Restoration and Resources Conservation

Mangrove forests are unique habitats in their function as potential food source and nurseries, and support an important fisheries resource. In the Benin coastal zone, the mangrove fishes have been surveyed to investigate fish species diversity, community structures and ecosystem degradation impacts in order to protect and to improve the mangrove fish resources. Results from wet, high-water and dry season samplings revealed that the two dominant mangrove species, Rizophora racemosa and Avicennia africana, are being intensively degraded for domestic use such as firewood and house building. Fifty one (51) fish species belonging to 25 families were recorded with Eleotridae (7 species), Cichlidae (5 species), and Mugilidae (5 species), the most speciose families. Dominant trophic guilds were detritivores (54.57%) and planktinovores/microcarnivores (30.41%). Six (6) species, Sarotherodon melanotheron, Dormitator lebretonis, Gerres melanopterus, Hemichromis fasciatus, Ethmalosa fimbriata, and Aplocheilichthys spilauchen, dominated the samples and accounted for about 80.27%. Sarotherodon melanotheron constituted the major dominant species and accounted numerically for about 29% of the total catches and 46.7% of the total biomass. The Margalef index of species richness ranged between 2.42 and 4.43, the Shannon-Weaver index of species diversity between 1.39 and 2.27, and the evenness between 0.50 and 0.62. Lower indices were observed for the highly degraded and the moderately degraded sites whereas higher indices were recorded for the less degraded and the restored sites. Species richness, species diversity and dominant species abundance were positively correlated with depth and transparency and negatively correlated with temperature. Multi-species fisheries dominate the coastal zone with Sarotherodon melanotheron, Dormitator lebretonis, Gerres melanopterus, Ethmalosa fimbriata, Liza falcipinus, Mugil sp. and Chrysichthys nigrodigitatus, the major species in the commercial catches. In addition to the mangrove destruction, the hydro electrical dam have greatly modified the Mono River flooding regime, water quality and the fish composition of the Benin coastal lagoon system. An integrated approach of the mangrove resource management/conservation, including intensive mangrove restoration, management of key fish species, freshwater prawns (Macrobrachiun sp.), peneids shrimps, mangrove oysters (Crassostrea sp.), and crabs (Callinectes sp., Cardiosoma sp.), and habitat protection is required for ecosystem recovery and sustainable exploitation.

MCANISMES MOLCULAIRES IMPLIQUS DANS L'ALTRATION DU PHNOTYPE DES CELLULES PITHLIALES TUBULAIRES PAR LES CALPANES EXTRACELLULAIRES

Objectif Rechercher les mecanismes moleculaires par lesquels des calpaines extracellulaires affectent l＇adherence et la mobilite des cellules epitheliales HK-2 derivees du tubule proximal humain. Mdthodes Western blot pour detecter le clivage des chaines α des integrines; dosage radioimraunologique pour mesurer V AMP cyclique intraceUulaire; fluorescence-activated cell sorting （FACS） pour tester l＇apoptose cellulaire. La morpholo- gie des ceUules HK-2 a ete observee et photographiee. Rdsultats （ 1 ） L ＇ exposition des ceUules HK-2 a la calpaine μ n＇a pas entratne de clivage des chaines α3 et αV des integrines; （2）V exposition des cellules HK-2 -2 la calpaine μ entrafnait une augmentation progressive de V accumulation intraceUulaire d＇ AMP cyclique（ P 〈 O. 05） qui etait associee une resistance ceUulaire a Vapoptose（ P 〈 O. 05 ） ; （3）Vaddition d＇un inhibiteur pharmacologique de la protdine kinase A （ PKA ） prevenait totalement les modifications d＇ adherence et de mobilite cellulaires induites par calpaine μ. Conclusion Les calpaines externalieses peuvent modifier V adherence et la mobilite ceUulaires via un mecanisme qui implique V accumulation d＇ AMP cyclique et 1＇ activation de la PKA. Par ces mecanismes, les calpaYnes externalisees pourraient jouer un role dans Vinduction de la reparation au cours de l＇insuffucance renale aigue.

Diet breadth variation and trophic plasticity behavior of the African bonytongue <i>Heterotis niloticus</i>(Cuvier, 1829) in the SôRiver-Lake Hlan aquatic system (Benin, West Africa): Implications for species conservation and aquaculture development

The African bonytongue, Heterotis niloticus (Pisces: Osteoglossidae), is an omnivore foraging mainly on aquatic insects, microcrustacea, seeds and detritus. We examined the diet breadth and the trophic plasticity behavior of this species (1461 specimens) in the S? River and Lake Hlan water system located in the southern Benin (West Africa). Overall, the mean diet breadths of the two populations of Heterotis from both habitats were not significantly (p ≥ 0.05) different and were not associated with seasons. However, in Lake Hlan, mean diet breadths tended to increase with size (r = 0.81) and gut length (r = 0.82) indicating that bonytongues ingest a broader range of food resources as they grow. In both habitats, the positive correlation of both standard length (Log SL) and gut length (Log GL) with the volumetric proportions of detritus and with the volumetric proportions of seeds suggests that the consumption of these two food resources increased with the size of Heterotis and with the development of the digestive tract. Likewise, the negative correlation of both (Log SL) and (Log GL) with the volumetric proportions of aquatic insects and with the volumetric proportions of microcrustacea suggests that the consumption of these two food categories decreased as the size and the gut length of Heterotis increased. The differences in the consumption of microcrustacea (13.77% in Lake Hlan versus 2.63% in S? River) and mollusks (0.73% in Lake Hlan versus 4.91% in S? River) evidenced that Heterotis shifts his trophic structure according to resource availlability in the habitat. This foraging behavior suggests a degree of trophic plasticity in Heterotis. The specialized morphological structure of Heterotis, mainly the presence of a relatively high number of gill rakers (42 - 94 rakers on the first branchial arch) during its whole life, allowing sieving of zooplankton and other microcrustacea, and the presence of the gizzard favored this trophic plasticity. The broader diet breadth coupled with the trophic plasticity behavior is probably an advantage because it enables Heterotis not only to colonize and to adapt to unstable and changing aquatic habitats, but also to invade and to well-establish in various ecosystems, such as freshwater lakes, swamps, inundated plains, streams, rivers and fish farming ponds. As a result, the wider diet breadths and the trophic plasticity behavior depicted are useful eco-ethological tool for the conservation and the aquaculture development of H. niloticus.