Transgenerational exposure to marine heatwaves ameliorates the lethal effect on tropical copepods regardless of predation stress

Marine heatwaves (MHWs) are emerging as a severe stressor in marine ecosystems. Extreme warm sea surface temperatures during MHWs often exceed the optimal thermal range for more than one generation of tropical coastal zooplankton. However, it is relatively unknown whether transgenerational plasticity (TGP) to MHWs may shape the offspring''s fitness, particularly in an ecologically relevant context with biotic interactions such as predation stress. We addressed these novel research questions by determining the survival, reproductive success, and grazing rate of the copepod Pseudodiaptomus incisus exposed to MHW and fish predator cues (FPC) for two generations (F1 and F2). The experiment was designed in a full orthogonal manner with 4 treatments in F1 and 16 treatments in F2 generation. In both generations, MHW reduced P. incisus survival, reproductive parameters, and grazing by 10%–62% in MHW, but these parameters increased by 2%–15% with exposure to FPC, particularly at control temperature. F2 reproductive success and grazing rate as indicated by cumulative fecal pellets were reduced by 20%–30% in F1‐MHW, but increased by ~2% in F1‐FPC. Strikingly, MHW exposure reduced 17%–18% survival, but transgenerational exposure to MHWs fully ameliorated its lethal effect and this transgenerational effect was independent of FPC. Increased survival came with a cost of reduced reproductive success, constrained by reduced grazing. The rapid transgenerational MHW acclimation and its associated costs are likely widespread and crucial mechanisms underlying the resilience of coastal tropical zooplankton to MHWs in tropical coastal marine ecosystems.     

Les corps myéloïdes de l'épithelium pigmentaire rétinien

Résumé La morphologie (forme, taille, structure) des corps myéloïdes de l'épithelium pigmentaire rétinien est décrite, ainsi que leur répartition chez les différentes classes de vertébrés. On définit les critères d'identification de ces corps: Ils ne sont jamais limités par une membrane, sont en continuité avec le reticulum endoplasmique lisse, sont formés de saccules aplatis, liés deux à deux par des complexes de jonction. Ils établissent des relations de continuité avec la membrane nucléaire. Les confusions entre corps myéloïdes et diverses autres structures (phagosomes en particulier) sont discutées. Il n'existe pas de corps myéloïdes dans la rétine des Mammifères.

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Myeloid bodies of the retinal pigment epitheliumI. Distribution, morphology and connections with cytoplasmic organels

Summary The morphology (shape, dimensions, structure) of the myeloid bodies of the retinal pigment epithelium and their distribution through several classes of vertebrates is described. The criteria of identity of these bodies are defined: They are never membrane-bounded, they are in direct continuity with the smooth endoplasmic reticulum, they are made of flattened discs linked two and two by junction complexes. They are in direct relation with the nuclear membrane. The confusion between myeloïd bodies and other structures, like phagosomes, is discussed. The retina of Mammals does not contain myeloïd bodies.

Chargé de recherche à l'INSERM. Travail réalisé grace à une subvention de l'INSERM.     

Enzymatic degradation of polar lipids in Vigna unguiculata leaves and influence of drought stress

¹⁴C-labelled polar lipids (monogalactosyl-diacylglycerol [MGDG], digalactosyl-diacylglycerol [DGDG], phosphatidylcholine [PC] and phosphatidylglycerol [PG]), purified from Vigna unguiculata leaves, were used as substrates to study the lipolytic activities of Vigna unguiculata leaf extracts. Analysis of the radioactive degradation products revealed the presence of at least three enzyme activities contributing to the hydrolysis of the four main leaf membrane lipids: Lipolytic acyl hydrolase (LAH) activities responsible for the deacylation of galactolipids and phospholipids, phospholipase D (PLD, EC 3.1.4.4) activity which gives rise to phosphatidic acid, and as suggested by the presence of diacylglycerols in minor quantities after phospholipid hydrolysis, phosphatidate phosphohydrolase (PAP, EC 3.1.3.4) and/or phospholipase C (PLC, EC 3.1.4.3.) activity. Under the conditions described in the present paper, the presence of phospholipase A (PLA₁, EC 3.1.1.3 and PLA₂, EC 3.1.1.4) activities remains hypothetical, due to the absence of lysophospholipids. LAH and PLD were partially soluble and partially associated with the membranes. When Vigna unguiculata plants were submitted to drought, the enzymatic degradation of galactolipids and phospholipids increased. The stimulation of lipolytic activities was greater in the drought-sensitive cultivar of Vigna unguiculata (cv. 1183) than in the drought-tolerant (cv. EPACE-1) one. In cv. 1183, MGDG- and DGDG-LAH activities in the membrane fractions were dramatically stimulated at a rather moderate water deficit (?0.75 MPa). A sharp increase in membrane phospholipolytic activities was also observed at mild drought stress (?1.2 MPa). In contrast, in cv. EPACE-1, the stimulation of lipolytic activities was less drastic and occurred at lower leaf water potentials (below ?1.2 MPa for galactolipases, and below ?1.4 MPa for phospholipases). Our results confirm the presence in leaves of higher plants of a very active LAH acting on galactolipids, whereas PLD is the main enzyme responsible for the degradation of phospholipids, particularly when plants are submitted to drought stress. The differences in stimulation of lipolytic activities between the two Vigna cultivars was in accordance with the different levels of membrane lipid degradation shown previously and could explain their different capacity to sustain drought.     

Association of Allergic Symptoms with Dengue Infection and Severity: A Systematic Review and Meta-analysis

The relationship between the severity of dengue infection and allergy is still obscure. We conducted an electronic search across 12 databases for relevant articles reporting allergic symptoms, dengue infection, and dengue classification. These studies were categorized according to dengue severity and allergy symptoms, and a meta-analysis was performed by pooling the studies in each category. Among the included 57 articles, pruritus was the most common allergic sign followed by non-specified allergy and asthma(28.6%, 13%, and 6.5%, respectively). Despite the reported significant association of dengue with pruritus and total Ig E level(P \ 0.05), in comparison with non-dengue cases and healthy controls, there was no association between the different severe dengue group with pruritus, skin allergy, food allergy or asthma. However,removing the largest study revealed a significant association between asthma with dengue hemorrhagic fever(DHF) rather than dengue fever(DF). In comparison with DF, DHF was associated with Ig E positivity. Furthermore, specific-Ig E level was higher in secondary DF rather than primary DF. There was a possible association between allergy symptoms and dengue severity progression. Further studies are needed to clarify this association.     

microRNA-21在食管癌细胞增殖、迁移和凋亡中的作用

本研究检测了40例食管癌组织和40例癌旁组织中的miR-21、PTEN、PI3K和AKT表达,并通过转染miR-21抑制剂来敲低人食管癌细胞系EC9706的miR-21表达,考察了miR-21对食管癌细胞生长的影响。研究发现,食管癌组织中PTEN蛋白的阳性染色评分低于癌旁组织(p<0.05),而PI3K和AKT蛋白的阳性染色评分高于癌旁组织(p<0.05)。miR-21在人食管癌组织中被上调(3.56 vs 1.21,p<0.05)。转染miR-21抑制剂导致PTEN蛋白表达升高,而PI3K和AKT蛋白表达降低(p<0.05)。转染miR-21抑制剂抑制了EC9706细胞的增殖和迁移,但促进了细胞凋亡(p<0.05)。miR-21的上调可通过激活PTEN/PI3K/AKT信号通路来促进食道癌细胞的增殖和迁移,并抑制细胞凋亡。     

Berberine ameliorates cellular senescence and extends the lifespan of mice via regulating p16 and cyclin protein expression

Although aging and senescence have been extensively studied in the past few decades, however, there is lack of clinical treatment available for anti‐aging. This study presents the effects of berberine (BBR) on the aging process resulting in a promising extension of lifespan in model organisms. BBR extended the replicative lifespan, improved the morphology, and boosted rejuvenation markers of replicative senescence in human fetal lung diploid fibroblasts (2BS and WI38). BBR also rescued senescent cells with late population doubling (PD). Furthermore, the senescence‐associated β‐galactosidase (SA‐β‐gal)‐positive cell rates of late PD cells grown in the BBR‐containing medium were ~72% lower than those of control cells, and its morphology resembled that of young cells. Mechanistically, BBR improved cell growth and proliferation by promoting entry of cell cycles from the G₀ or G₁ phase to S/G₂‐M phase. Most importantly, BBR extended the lifespan of chemotherapy‐treated mice and naturally aged mice by ~52% and ~16.49%, respectively. The residual lifespan of the naturally aged mice was extended by 80%, from 85.5 days to 154 days. The oral administration of BBR in mice resulted in significantly improved health span, fur density, and behavioral activity. Therefore, BBR may be an ideal candidate for the development of an anti‐aging medicine.     

Boosted Growth Performance,Mucosal and Serum Immunity,and Disease Resistance Nile Tilapia ( Oreochromis niloticus ) Fingerlings Using Corncob-Derived Xylooligosaccharide and Lactobacillus plantarum CR1T5

The present work, herein, studied the effects of corncob-derived xylooligosaccharides (CDXOS) and Lactobacillus plantarum CR1T5 (LP) integrated into fish d