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The impact of two high‐head dams on macroinvertebrate communities within the regulated reaches of the Wujiang River in China was explored, using longitudinal monitoring data spanning from 2006 to 2016. In this study, we set up 10 sampling sites categorized into four areas based on different stressors and defined three stages based on the timeline of dam construction. Our findings revealed significant changes in community composition before and after dam impoundment. While certain original dominant taxa, such as Rivularia globosa and Lithoglyphopsis ovatus, remained dominant throughout the stages, mayflies and caddisflies nearly vanished in the downstream reaches of the dams. This trend was accompanied by the disappearance of taxa with low adaptability and the emergence of tolerant taxa downstream of the dams. Additionally, typical limnological taxa colonized the inundated reaches. Dam impoundment affected not only macroinvertebrate community composition but also diversity. In this study, the recovery effect of communities downstream of dams was not observed due to the limited distance, but the presence of Wujiangdu Dam upstream of the two dams for over 20 years makes us believe that in a large river system, macroinvertebrate communities downstream of high‐head dams may fully recover if the distance from the dams is long enough. The original and vulnerable species R. globosa, which demonstrated remarkable adaptability and thrived downstream of dams, should be further studied in the future. [ABSTRACT FROM AUTHOR]

In this study, we investigated the plankton, water, and macroinvertebrates in Nanwan Reservoir, a subtropical eutrophic reservoir with thermal stratification. We evaluated the status of macroinvertebrate communities and explored the relationships between macroinvertebrate community status and both abiotic and biotic factors. This reservoir exhibited the worst water quality and a high risk of algal blooms in the autumn, whereas it had the best water quality in the spring. The presence of thermal stratification adversely affected macroinvertebrate communities, leading to decreases in species richness, abundance, and diversity. The water characteristics and dominant macroinvertebrate species confirmed that the reservoir was experiencing progressive eutrophication. During the thermal stratification period, the reservoir exhibited a worse status of macroinvertebrate communities, accompanied by an abundance of plankton. The results of PLSR and the Spearman rank test revealed that several abiotic factors, such as water temperature, chlorophyll-a, soluble phosphate, pH, and transparency, as well as biotic factors including the abundance of protozoans, Cyanobacteria, phytoplankton, Bacillariophyta, and Euglenophyta, were the most important factors affecting macroinvertebrate communities. The results of PLS-SEM revealed that both abiotic factors and biotic factors had non-negligible effects on the status of macroinvertebrate communities, with higher effect from abiotic factors compared to biotic factors. [ABSTRACT FROM AUTHOR]

The Big East Lake water network (BELWN), located in Wuhan city, China, is mainly composed of six lakes and isolated from the Yangtze river. At the background of restoring the hydrological connectivity between rivers and lakes, four season investigations were conducted during 2014–2015 to study the spatial distribution and seasonal dynamics of macroinvertebrate communities, explore their relationships with environmental factors, and forecast the change trends in assemblages in a long period after restoration measures. A total of 40 species were recorded, oligochaetes and chironomids dominated the communities. Season variation in density and biomass were distinct and the community differences in lakes related to the degrees of organic pollution. In comparison with the historical data, the species richness of mollusks in Donghu lake sharply decreased due to water pollution and the loss of diverse habitat. Concerning on the whole BELWN, the whole taxa recorded in our study was slightly fewer than the previous study. A new recorded species polychaete Nephtys sp. was first collected with an important ecological interest. As an urban lake system dominated by eutrophication, the water nutrients significantly affected the distribution of macroinvertebrates. According to the GAM models, the dominant species responded to environmental gradients with different response curves. After restoring the hydrological connectivity between rivers and lakes, the macroinvertebrate communities would change and the biodiversity would steadily increase with time. Additionally, the new recorded species Nephtys sp. would spread into the whole BELWN in the foresee future.

The morphology and phylogeny of Pleuronema binucleatum n. sp., P. parawiackowskii n. sp., and P. marinum Dujardin 1841, collected from Hangzhou Bay estuary, China, were investigated using standard methods. Pleuronema binucleatum n. sp. can be identified by possessing about 90-120 × 35-50 μm cell size in vivo, reniform body outline, two macronuclei, six to eight preoral kineties, 32-41 somatic kineties, and posterior end of the anterior fragment of membranelle 2 (M2a) hook-like. Pleuronema parawiackowskii n. sp. is characterized by the combination of the following characters: body size about 60-90 × 20-40 μm in vivo, elliptical in outline, four to eight preoral kineties, 20-29 somatic kineties, posterior portion of the M2a slightly curved but nonhooked, and single macronucleus sausage-like. After comparison with other populations of P. marinum, it is suggested that many misidentifications exist in previous studies. And an improved diagnosis of P. marinum was supplied: cell about 95-180 μm long, elliptical in outline; 2-4 preoral kineties and 53-70 somatic kineties; both membranelle 1 and membranelle 3 three-rowed; posterior end of the M2a straight; single contractile vacuole characteristically positioned near mid-body. The small subunit rRNA genes of three forms were sequenced. Phylogenetic analyses indicate that the monophyly of the genus Pleuronema is still not supported. [ABSTRACT FROM AUTHOR]

Hepatic fibrosis, which results from chronic liver disease, currently lacks effective treatment. MicroRNAs, a group of small noncoding RNA molecules, have been observed to play an essential role in liver diseases, including hepatic fibrosis. In this study, we described the regulation of nuclear factor kappa B ( NF-κB) inhibitor alpha ( IκBα) and its possible signaling pathway by miR-126 in human hepatic stellate cell (HSC) line LX-2. The 3′-untranslated region (3′-UTR) of IκBα combined with miR-126 was analyzed by using a dual-luciferase reporter assay. Furthermore, the effects of miR-126 on IκBα mRNA and protein and NF-κB protein expression were assessed by real-time quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) and western blot analysis in the human HSC LX-2 cell line transfected with miR-126 mimic or inhibitor. Moreover, to understand the molecular mechanism of miR-126 in promoting liver fibrosis through NF-κB signaling pathway, the NF-κB downstream signaling factors expression such as transforming growth factor (TGF)-β1 and collagen I mRNA were detected by real-time qRT-PCR. We identified that IκBα is a potential target gene of miR-126, by directly targeting its 3′-UTR. Endogenous miR-126 and exogenous miR-126 mimic inhibited IκBα expression. Moreover, overexpression of miR-126 reduced total and the cytoplasm IκBα protein expression and increased total and cytoblast NF-κB protein expression of LX-2. Conversely, knockdown of miR-126 could inhibit NF-κB activation by upregulation of IκBα protein expression. Further, miR-126 promoted TNF-a-induced TGF-β1 and collagen I mRNA expression in LX-2 cells. miR-126 may play an important role in hepatic fibrosis by downregulating the expression of IκBα partly through the NF-κB signaling pathway. [ABSTRACT FROM AUTHOR]

Increasing evidence suggests that miRNAs are widely dysregulated in ulcerative colitis (UC), potentially affecting UC pathogenesis, diagnosis, and therapy. microRNA (miR) -206 has been reported to be upregulated in UC; however, its function and role in UC remain unknown. Here, we elucidate the function of miR-206 in the pathogenesis of UC. In patients with active-UC, miR-206 and adenosine A3 receptor (A3AR) levels were significantly upregulated and downregulated, respectively, and were inversely correlated. A3AR was expressed in the colon mucosa (particularly in colon epithelial-cell membranes). In HT-29 cells, miR-206 downregulated A3AR mRNA/protein expression by directly targeting the A3AR 3'-UTR; miR-206 overexpression and knockdown respectively increased and decreased TNF-α-induced nuclear NF-κB/p65, p-IκB-α, IKKα, p-IKKα and IL-8/IL-1β secretion. However, A3AR-siRNA reversed the miR-206 inhibitory effect. Furthermore, miR-206 increased dextran sodium sulphate-induced colitis severity (i.e., increased bodyweight loss, DAI score, colon shrinkage, and MPO activity), which was partially ameliorated by miR-206-antagomir treatment. miR-206-agomir treatment potently suppressed A3AR expression and increased NF-κB signalling and downstream cytokine (TNF-α/IL-8/IL-1β) expression in the mouse colon, in contrast to miR-206-antagomir administration. Taken together, our results demonstrated that miR-206 has a proinflammatory role in UC by downregulating A3AR expression and activating NF-κB signalling.