Thylakoid proteome variation of Eutrema salsugineum in response to drought and salinity combined stress

It is well known that plant responses to stress involve different events occurring at different places of the cell/leaf and at different time scales in relation with the plant development. In fact, the organelles proteomes include a wide range of proteins that could include a wide range of proteins showing a considerable change in cellular functions and metabolism process. On this basis, a comparative proteomics analysis and fluorescence induction measurements were performed to investigate the photosynthetic performance and the relative thylakoid proteome variation in Eutrema salsugineum cultivated under salt stress (200 mM NaCl), water deficit stress (PEG) and combined treatment (PEG + NaCl) as a hyperosmotic stress. The obtained results showed a significant decrease of plant growth under drought stress conditions, with the appearance of some toxicity symptoms, especially in plants subjected to combined treatment. Application of salt or water stress alone showed no apparent change in the chlorophyll a fluorescence transients, primary photochemistry (fluorescence kinetics of the O-J phase), the PQ pool state (J-I phase changes), (Fv/Fm) and (Fk/Fj) ratios. However, a considerable decrease of all these parameters was observed under severe osmotic stress (PEG + NaCl). The thylakoid proteome analysis revealed 58 proteins showing a significant variation in their abundance between treatments (up or down regulation). The combined treatment (PEG + NaCl) induced a decrease in the expression of the whole PSII core subunit (D1, D2, CP43, CP47, PsbE and PsbH), whereas the OEC subunits proteins remained constant. An increase in the amount of PsaD, PsaE, PsaF, PsaH, PsaK and PsaN was detected under drought stress (PEG5%). No significant change in the accumulation of Cyt b6 and Cyt f was observed. Some regulated proteins involved in cellular redox homeostasis were detected (glutamine synthetase, phosphoglycerate kinase, transketolase), and showed a significant decrease under the combined treatment. Some oxidative stress related proteins were significantly up-regulated under salt or drought stress and could play a crucial role in the PSI photoprotection and the control of ROS production level

Changes of Sand Fly Populations and Leishmania infantum Infection Rates in an Irrigated Village Located in Arid Central Tunisia

Citation: Barhoumi, W., Fares, W., Cherni, S., Derbali, M., Dachraoui, K., Chelbi, I., . . . Zhioua, E. (2016). Changes of Sand Fly Populations and Leishmania infantum Infection Rates in an Irrigated Village Located in Arid Central Tunisia. International Journal of Environmental Research and Public Health, 13(3), 10. doi:10.3390/ijerph13030329The current spread of zoonotic visceral leishmaniasis (ZVL) throughout arid areas of Central Tunisia is a major public health concern. The main objective of this study is to investigate whether the development of irrigation in arid bio-geographical areas in Central Tunisia have led to the establishment of a stable cycle involving sand flies of the subgenus Larroussius and Leishmania infantum, and subsequently to the emergence of ZVL. Sand flies were collected from the village of Saddaguia, a highly irrigated zone located within an arid bio-geographical area of Central Tunisia by using modified Centers for Diseases Control (CDC) light traps. Morphological keys were used to identify sand flies. Collected sand flies were pooled with up to 30 specimens per pool according to date and tested by nested Polymerase Chain Reaction (PCR) DNA sequencing from positive pools was used to identify Leishmania spp. A total of 4915 sand flies (2422 females and 2493 males) were collected from Saddaguia in September and in October 2014. Morphological identification confirmed sand flies of the subgenus Larroussius to be predominant. PCR analysis followed by DNA sequencing indicated that 15 pools were infected with L. infantum yielding an overall infection rate of 0.6%. The majority of the infected pools were of sand fly species belonging to subgenus Larroussius. Intense irrigation applied to the arid bio-geographical areas in Central Tunisia is at the origin of the development of an environment capable of sustaining important populations of sand flies of the subgenus Larroussius. This has led to the establishment of stable transmission cycles of L. infantum and subsequently to the emergence of ZVL

Altered versican cleavage in ADAMTS5 deficient mice : a novel etiology of myxomatous valve disease

AbstractIn fetal valve maturation the mechanisms by which the relatively homogeneous proteoglycan-rich extracellular matrix (ECM) of endocardial cushions is replaced by a specialized and stratified ECM found in mature valves are not understood. Therefore, we reasoned that uncovering proteases critical for ‘remodeling’ the proteoglycan rich (extracellular matrix) ECM may elucidate novel mechanisms of valve development. We have determined that mice deficient in ADAMTS5, (A Disintegrin-like And Metalloprotease domain with ThromboSpondin-type 1 motifs) which we demonstrated is expressed predominantly by valvular endocardium during cardiac valve maturation, exhibited enlarged valves. ADAMTS5 deficient valves displayed a reduction in cleavage of its substrate versican, a critical cardiac proteoglycan. In vivo reduction of versican, in Adamts5−/− mice, achieved through Vcan heterozygosity, substantially rescued the valve anomalies. An increase in BMP2 immunolocalization, Sox9 expression and mesenchymal cell proliferation were observed in Adamts5−/− valve mesenchyme and correlated with expansion of the spongiosa (proteoglycan-rich) region in Adamts5−/− valve cusps. Furthermore, these data suggest that ECM remodeling via ADAMTS5 is required for endocardial to mesenchymal signaling in late fetal valve development. Although adult Adamts5−/− mice are viable they do not recover from developmental valve anomalies and have myxomatous cardiac valves with 100% penetrance. Since the accumulation of proteoglycans is a hallmark of myxomatous valve disease, based on these data we hypothesize that a lack of versican cleavage during fetal valve development may be a potential etiology of adult myxomatous valve disease

iTRAQ proteomic analysis of extracellular matrix remodeling in aortic valve disease

Degenerative aortic stenosis (AS) is the most common worldwide cause of valve replacement. The aortic valve is a thin, complex, layered connective tissue with compartmentalized extracellular matrix (ECM) produced by specialized cell types, which directs blood flow in one direction through the heart. There is evidence suggesting remodeling of such ECM during aortic stenosis development. Thus, a better characterization of the role of ECM proteins in this disease would increase our understanding of the underlying molecular mechanisms. Aortic valve samples were collected from 18 patients which underwent aortic valve replacement (50% males, mean age of 74 years) and 18 normal control valves were obtained from necropsies (40% males, mean age of 69 years). The proteome of the samples was analyzed by 2D-LC MS/MS iTRAQ methodology. The results showed an altered expression of 13 ECM proteins of which 3 (biglycan, periostin, prolargin) were validated by Western blotting and/or SRM analyses. These findings are substantiated by our previous results demonstrating differential ECM protein expression. The present study has demonstrated a differential ECM protein pattern in individuals with AS, therefore supporting previous evidence of a dynamic ECM remodeling in human aortic valves during AS development

Reproductive biology of the cockle Cerastoderma glaucum (Mollusca: Bivalvia)

The reproductive cycle of the cockle Cerastoderma glaucum from the Gulf of Gabes (southern Tunisia) was studied during a one-year period (January to December 2007). The overall samples presented a balanced sex ratio, with males dominating among smaller individuals and females predominating in larger size classes. Males were found to mature between 12 and 20 mm shell length (SL), whereas females matured between 14 and 21 mm SL. The size at which 50% of the population reached maturity was 15.14 and 16.78 mm SL for males and females, respectively. The seasonal changes assessed through macro- and microscopic properties in the gonads of both sexes indicated a clearly defined annual reproductive cycle. Reproductive activity of C. glaucum was greatest from spring to late autumn, with two reproductive peaks (May and November). Gametogenic activity in both sexes was apparently triggered by the rising seawater temperature during spring and summer. These results support previous findings of latitudinal changes in the reproductive behaviour of C. glaucum. Due to the extensive period of gonadal activity, C. glaucum exhibited a short resting phase that occurred simultaneously in both sexes throughout January and February. Upon inspection for parasitic infections, 15% of C. glaucum were found infected by digenean trematode species. The number of specimens showing digenean infestations differed with size class, with a tendency to increase significantly with cockle size

The effect of ultrasonic wave amplitude on the physical properties of zinc oxide (ZnO) deposited by ultrasonic spray method

International audienceIn this study, high quality zinc oxide (ZnO) thin films, with improved properties, were prepared by a cost-effective ultrasonic spray pyrolysis technique via a careful optimization of the used ultrasonic wave amplitude. The deposition process was performed on glass substrate and were subsequently annealed at 400 °C. We investigated the effect of various ultrasonic wave amplitude on the structural, surface morphology, optical and electrical properties of the obtained thin films, after varying the applied wave amplitude. Furthermore, deposited thin films were studied by means of XRD, UV–vis spectrophotometer, scanning electron microscope, and four-point probe technique. XRD analysis confirmed that obtained ZnO thin films have polycrystalline structure and a wurtzite (hexagonal) phase, with a c-axis preferred orientation (0 0 2). The crystallite size was about 23–30 nm. The SEM micrographs of the surface morphology show uniform, homogenous and dense films with granular structures. The films thicknesses were found to be dependent on the used wave amplitude; they were ranged from 184 to 423.5 nm. In addition, the optical properties of the deposited thin films reveal that the films are highly transparent in the visible region above 80%, while the value of energy band gap varies from 3.24 to 3.27 eV. The Electrical properties investigation revealed a resistivity around 10-3 Ω.cm, showing also a non negligible dependency with the wave amplitude tuning. We obtained an improvement in the carrier concentration (1.6 × 1020–3.9 × 1020 cm−3) and mobility (4.2–15 cm2/V.s) with the ultrasonic wave amplitude rising. High quality ZnO thin films with enhanced properties are in demand and have a large wide of applications in optoelectronics and solar cells. © 2021 Elsevier B.V