Inhibition of the dopamine D1 receptor signaling by PSD-95

Dopamine D1 receptors play an important role in movement, reward, and learning and are implicated in a number of neurological and psychiatric disorders. These receptors are concentrated in dendritic spines of neurons, including the spine head and the postsynaptic density. D1 within spines is thought to modulate the local channels and receptors to control the excitability and synaptic properties of spines. The molecular mechanisms mediating D1 trafficking, anchorage, and function in spines remain elusive. Here we show that the synaptic scaffolding protein PSD-95 thought to play a role in stabilizing glutamate receptors in the postsynaptic density, interacts with D1 and regulates its trafficking and function. Interestingly, the D1-PSD-95 interaction does not require the well characterized domains of PSD-95 but is mediated by the carboxyl-terminal tail of D1 and the NH(2) terminus of PSD-95, a region that is recognized only recently to participate in protein-protein interaction. Co-expression of PSD-95 with D1 in mammalian cells inhibits the D1-mediated cAMP accumulation without altering the total expression level or the agonist binding properties of the receptor. The diminished D1 signaling is mediated by reduced D1 expression at the cell surface as a consequence of an enhanced constitutive, dynamin-dependent endocytosis. In addition, genetically engineered mice lacking PSD-95 show a heightened behavioral response to either a D1 agonist or the psychostimulant amphetamine. These studies demonstrate a role for a glutamatergic scaffold in dopamine receptor signaling and trafficking and identify a new potential target for the modulation of abnormal dopaminergic function.     

Mechanistic analysis on the effects of salt concentration and pH on protein adsorption onto a mixed-mode adsorbent with cation ligand

Streamline Direct HST is a new kind of mixed-mode adsorbent with cation exchange ligand, especially developed for the expanded bed adsorption process, which can capture target protein directly from the moderate ionic strength feedstock without the need of dilution or other additives. In this study, the isotherm adsorption behaviors and the isocratic retention factors of bovine serum albumin (BSA) on Streamline Direct HST were measured, and the corresponding adsorption mechanisms were also described. The results indicated that Streamline Direct HST shows the typical property of salt-independent adsorption and the maximum binding capacity of BSA occurs near the isoelectric point of BSA. When there are some amounts of electrostatic repulsion protein-adsorbent interactions, the multilayer adsorption could be found, and high salt concentration does not favor the adsorption of protein. A patch-controlled adsorption process and an oriented adsorption model are proposed for describing the adsorption behaviors under electrostatic repulsion condition.     

Effects of Calcium Chelators on Colloidal Stability and Interfacial Activity of Egg Yolk Granules

Food Biophysics - Egg yolk granule is the sedimentary protein fraction of egg yolk. Granules are supramolecular assembly of high-density lipoprotein and phosvitin driven by Ca2+ bridges. Despite...     

Characteristics of replication and pathogenicity of SARS-CoV-2 Alpha and Delta isolates

The continuously arising of SARS-CoV-2 variants has been posting a great threat to public health safety globally, from B.1.17 (Alpha), B.1.351 (Beta), P.1 (Gamma), B.1.617.2 (Delta) to B.1.1.529 (Omicron). The emerging or reemerging of the SARS-CoV-2 variants of concern is calling for the constant monitoring of their epidemics, pathogenicity and immune escape. In this study, we aimed to characterize replication and pathogenicity of the Alpha and Delta variant strains isolated from patients infected in Laos. The amino acid mutations within the spike fragment of the isolates were determined via sequencing. The more efficient replication of the Alpha and Delta isolates was documented than the prototyped SARS-CoV-2 in Calu-3 and Caco-2 cells, while such features were not observed in Huh-7, Vero E6 and HPA-3 cells. We utilized both animal models of human ACE2 (hACE2) transgenic mice and hamsters to evaluate the pathogenesis of the isolates. The Alpha and Delta can replicate well in multiple organs and cause moderate to severe lung pathology in these animals. In conclusion, the spike protein of the isolated Alpha and Delta variant strains was characterized, and the replication and pathogenicity of the strains in the cells and animal models were also evaluated.     

DANCR contributed to hepatocellular carcinoma malignancy via sponging miR-216a-5p and modulating KLF12

Long noncoding RNA (lncRNA) differentiation antagonizing nonprotein coding RNA (DANCR) has been identified as an oncogene in several cancers. However, the biological function and role of DANCR in hepatocellular carcinoma (HCC) remain unclear. Our current study aimed to investigate the detailed mechanism of DANCR in HCC. We found that DANCR was significantly upregulated in HCC cell lines in comparison to LO2 cells. Then, we observed that knockdown of DANCR could greatly inhibit Huh7 and HepG2 cell proliferation. In addition, HCC cell apoptosis was increased by silence of DANCR and meanwhile, cell cycle progression was blocked in G1 phase. Apart from these, downregulation of DANCR repressed HCC cell migration and invasion ability obviously. As predicted by the bioinformatics analysis, microRNA-216a-5p (miR-216a-5p) could serve as a direct target of DANCR. MiR-216a-5p has been reported to be involved in many cancers. Here, the correlation between miR-216a-5p and DANCR was confirmed using dual-luciferase reporter assay and radioimmunoprecipitation assay. Subsequently, Kruppel-like factor 12 (KLF12) exerts an important role in different tumor types. KLF12 can function as a downstream target of miR-216a-5p. Finally, the in vivo experiments were used and the data proved that DANCR also strongly suppressed HCC tumor growth in vivo via targeting miR-216a-5p and KLF12. In conclusion, our study indicated that DANCR might provide a new perspective for HCC treatment.     

Spatial distribution,pollution levels,and source identification of heavy metals in wetlands of Suzhou Industrial Park,China

Wetlands Ecology and Management - As one of the earliest national demonstration ecological industrial parks (EIPs) in China, Suzhou Industrial Park (SIP) is developed on the principles of material...     

Gamma-secretase inhibitor suppressed Notch1 intracellular domain combination with p65 and resulted in the inhibition of the NF-κB signaling pathway induced by IL-1β and TNF-α in nucleus pulposus cells

In this experiment, the cross-talk betweenNotch and the NF-κB signaling pathway was examined to reveal the mechanism of slowing down the type II collagen (ColII) and aggrecan degeneration affected by inflammatory cytokines. The expression levels of ColII and aggrecan in the intervertebral disc were observed through immunohistochemistry and hematoxylin-eosin staining+alcian blue staining, respectively. The expression levels of ColII, aggrecan, Runx2, and NF-κB in the nuclei of human nucleus pulposus cells (hNPCs) in each group, as well as the phosphorylation and acetylation levels of p65, were examined through Western blot analysis. The 293T cells were transfected with a plasmid containing the overexpressed relative domain of Notch1 intracellular domain (NICD1), and immunoprecipitation (IP) was performed to observe the combination of NICD1 and p65. HNPCs were transfected with a lentiviral-contained overexpression lacking the ANK region of NICD1, and IP was performed to observe the combination of NICD1 and p65. The expression of ColII and aggrecan in the intervertebral disc culture increased when γ-secretase inhibitor N-[N-(3,5-difluorophenacetyl)-1-alanyl]-Sphenylglycine t-butyl ester (DAPT) was added to the disc culture medium. Western blot revealed that DAPT inhibited p65 phosphorylation and acetylation, and the p65 and p50 levels in the nucleus decreased. NICD1 was found to be combined with p65 in contrast to the reverse consequences after ANK domain deletion in hNPCs. In nucleus pulposus cells, the combination of p65 and the ANK domain of NICD1 is a critical procedure for the degeneration related to the NF-κB signaling pathway activation induced by IL-1β and TNF-α.     

Retracted: KDM6B promotes ovarian cancer cell migration and invasion by induced transforming growth factor-β1 expression

KDM6B, also known as JMJD3, is a member of the family of histone lysine demethylase (KDMs), which is closely related to many types of cancers. However, its role and the underlying mechanisms in ovarian cancer remain unknown. Here we show that KDM6B is elevated in epithelial ovarian cancer and its expression level is closely related with metastasis and invasion. In addition, survival analysis showed that high expression of KDM6B was associated with low overall survival in ovarian cancer patients. Overexpression of KDM6B in epithelial ovarian cancer cells promoted proliferation, epithelial-mesenchymal transition (EMT), migration and invasion in vitro, and enhanced metastatic capacities in vivo. On the contrary, silencing KDM6B in invasive and metastatic ovarian cancer cells inhibited these processes. Mechanistically, we found that KDM6B exerts its function by modulating the transforming growth factor-β1 (TGF-β1) expression, and TGF-β1 signal pathway inhibitor LY2157299 significantly inhibited KDM6B-induced proliferation, migration, metastasis, and EMT in ovarian cancer cells. Our findings, for the first time, reveal the pivotal role of KDM6B in the invasion and metastatic behavior of epithelial ovarian cancer. Thus, targeting KDM6B may be a useful strategy to interfere with these behaviors of epithelial ovarian cancer.