Ca2+ oscillation in vascular smooth muscle cells control myogenic spontaneous vasomotion and counteract post-ischemic no-reflow.

Ischemic stroke produces the highest adult disability. Despite successful recanalization, no-reflow, or the futile restoration of the cerebral perfusion after ischemia, is a major cause of brain lesion expansion. However, the vascular mechanism underlying this hypoperfusion is largely unknown, and no approach is available to actively promote optimal reperfusion to treat no-reflow. Here, by combining two-photon laser scanning microscopy (2PLSM) and a mouse middle cerebral arteriolar occlusion (MCAO) model, we find myogenic vasomotion deficits correlated with post-ischemic cerebral circulation interruptions and no-reflow. Transient occlusion-induced transient loss of mitochondrial membrane potential (ΔΨm) permanently impairs mitochondria-endoplasmic reticulum (ER) contacts and abolish Ca2+ oscillation in smooth muscle cells (SMCs), the driving force of myogenic spontaneous vasomotion. Furthermore, tethering mitochondria and ER by specific overexpression of ME-Linker in SMCs restores cytosolic Ca2+ homeostasis, remotivates myogenic spontaneous vasomotion, achieves optimal reperfusion, and ameliorates neurological injury. Collectively, the maintaining of arteriolar myogenic vasomotion and mitochondria-ER contacts in SMCs, are of critical importance in preventing post-ischemic no-reflow.

Synaptic-like transmission between neural axons and arteriolar smooth muscle cells drives cerebral neurovascular coupling.

Neurovascular coupling (NVC) is important for brain function and its dysfunction underlies many neuropathologies. Although cell-type specificity has been implicated in NVC, how active neural information is conveyed to the targeted arterioles in the brain remains poorly understood. Here, using two-photon focal optogenetics in the mouse cerebral cortex, we demonstrate that single glutamatergic axons dilate their innervating arterioles via synaptic-like transmission between neural-arteriolar smooth muscle cell junctions (NsMJs). The presynaptic parental-daughter bouton makes dual innervations on postsynaptic dendrites and on arteriolar smooth muscle cells (aSMCs), which express many types of neuromediator receptors, including a low level of glutamate NMDA receptor subunit 1 (Grin1). Disruption of NsMJ transmission by aSMC-specific knockout of GluN1 diminished optogenetic and whisker stimulation-caused functional hyperemia. Notably, the absence of GluN1 subunit in aSMCs reduced brain atrophy following cerebral ischemia by preventing Ca2+ overload in aSMCs during arteriolar constriction caused by the ischemia-induced spreading depolarization. Our findings reveal that NsMJ transmission drives NVC and open up a new avenue for studying stroke.

Newcastle disease virus nucleocapsid protein mediates the degradation of 14-3-3ε to antagonize the interferon response and promote viral replication.

Newcastle disease virus (NDV) is responsible for outbreaks that pose a threat to the global poultry industry. NDV triggers an interferon (IFN) response in the host upon infection. However, it also employs mechanisms that counteract this response. One important component in IFN-related signaling pathways is 14-3-3ε, which is known to interact with retinoic acid-inducible gene I (RIG-I) and mitochondrial antiviral signaling protein (MAVS). The relationship between 14 and 3-3ε and NDV infection has not been previously explored; therefore, this study aimed to investigate this relationship in vivo and in vitro using overexpressed and knockdown 14-3-3ε experiments, along with co-immunoprecipitation analysis. We found that NDV infection led to the degradation of 14-3-3ε. Furthermore, 14-3-3ε inhibited the replication of NDV, suggesting that NDV may enhance its own replication by promoting the degradation of 14-3-3ε during infection. The study revealed that 14-3-3ε is degraded by lysosomes and the viral protein nucleocapsid protein (NP) of NDV induces this degradation. It was also observed that 14-3-3ε is involved in activating the IFN pathway during NDV infection and mediates the binding of MDA5 to MAVS. Our study reveals that NDV NP mediates the entry of 14-3-3ε into lysosomes and facilitates its degradation. These findings contribute to the existing knowledge on the molecular mechanisms employed by NDV to counteract the IFN response and enhance its own replication.

RNA sequencing reveals CircRNA expression profiles in chicken embryo fibroblasts infected with velogenic Newcastle disease virus.

Introduction: Newcastle disease virus (NDV) is an important avian pathogen prevalent worldwide; it has an extensive host range and seriously harms the poultry industry. Velogenic NDV strains exhibit high pathogenicity and mortality in chickens. Circular RNAs (circRNAs) are among the most abundant and conserved eukaryotic transcripts. They are part of the innate immunity and antiviral response. However, the relationship between circRNAs and NDV infection is unclear. Methods: In this study, we used circRNA transcriptome sequencing to analyze the differences in circRNA expression profiles post velogenic NDV infection in chicken embryo fibroblasts (CEFs). Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were used to reveal significant enrichment of differentially expressed (DE) circRNAs. The circRNA- miRNA-mRNA interaction networks were further predicted. Moreover, circ-EZH2 was selected to determine its effect on NDV infection in CEFs. Results: NDV infection altered circRNA expression profiles in CEFs, and 86 significantly DE circRNAs were identified. GO and KEGG enrichment analyses revealed significant enrichment of DE circRNAs for metabolism-related pathways, such as lysine degradation, glutaminergic synapse, and alanine, aspartic-acid, and glutamic-acid metabolism. The circRNA- miRNA-mRNA interaction networks further demonstrated that CEFs might combat NDV infection by regulating metabolism through circRNA-targeted mRNAs and miRNAs. Furthermore, we verified that circ-EZH2 overexpression and knockdown inhibited and promoted NDV replication, respectively, indicating that circRNAs are involved in NDV replication. Conclusions: These results demonstrate that CEFs exert antiviral responses by forming circRNAs, offering new insights into the mechanisms underlying NDV-host interactions.

Proteins secreted by brain arteriolar smooth muscle cells are instructive for neural development.

Intercellular communication between vascular and nerve cells mediated by diffusible proteins has recently emerged as a critical intrinsic program for neural development. However, whether the vascular smooth muscle cell (VSMC) secretome regulates the connectivity of neural circuits remains unknown. Here, we show that conditioned medium from brain VSMC cultures enhances multiple neuronal functions, such as neuritogenesis, neuronal maturation, and survival, thereby improving circuit connectivity. However, protein denaturation by heating compromised these effects. Combined omics analyses of donor VSMC secretomes and recipient neuron transcriptomes revealed that overlapping pathways of extracellular matrix receptor signaling and adhesion molecule integrin binding mediate VSMC-dependent neuronal development. Furthermore, we found that human arterial VSMCs promote neuronal development in multiple ways, including expanding the time window for nascent neurite initiation, increasing neuronal density, and promoting synchronized firing, whereas human umbilical vein VSMCs lack this capability. These in vitro data indicate that brain arteriolar VSMCs may carry direct instructive information for neural development through intercellular communication in vivo.

[Values of MCV,MCH,ROFT and HbA2 for Screening α-Thalassemia in Guangdong Area].

OBJECTIVE: To investigate the values of mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), red cell osmotic fragility test(ROFT) and hemoglobin A2(HbA2) in screening of α-thalassemia in Guangdong area. METHODS: A total of 285 peripheral blood samples in patients treated in our hospital from January 2017 to December 2017 were collected. The detection of thalassemia gene was used as the gold standard, while blood routine examination, hemoglobin electrophoresis, and red cell osmotic fragility test were simultaneously performed. The optimal cut-off values in MCV, MCH, ROFT and HbA2 in α-thalassemia were determined by receiver operator characteristic curve (ROC curve). RESULTS: The most common types of α-thalassemia gene was --SEA/αα (54.59%). Compared with the control group, the differences in MCV, MCH, ROFT and HbA2 showed statistically significantce between different types of α-thalassemia (P<0.05). The best cut-off values of MCV, MCH, ROFT, and HbA2 in the diagnosis of α-thalassemia were 81.45 fl, 27.35 pg, 79.95%, and 2.55% respectively. CONCLUSION: For different laboratories, the cut-off values need to be established for screening α-thalassemia suitable in their own local region．The values of MCV, MCH, ROFT and HbA2 shows higher accuracy and sensitivity in the diagnosis of α-thalassemia. It is recommended to use MCV<81.45fl, MCH<27.35 pg, ROFT<79.95% and HbA2<2.55% as the standards for screening α-thalassemia in Guangdong area.