WLS

The regulatory network between signaling pathways and transcription factors (TFs) is crucial for the maintenance of pluripotent stem cells. However, little is known about how the key TF OCT4 coordinates signaling pathways to regulate self-renewal and lineage differentiation of porcine pluripotent stem cells (pPSCs). Here, we explored the function of OCT4 in pPSCs by transcriptome and chromatin accessibility analysis. The TFs motif enrichment analysis revealed that, following OCT4 knockdown, the regions of increased chromatin accessibility were enriched with EOMES, GATA6, and FOXA1, indicating that pPSCs differentiated toward the mesoendoderm (ME) lineage. Besides, pPSCs rapidly differentiated into ME when the WNT/β-catenin inhibitor XAV939 was removed. However, the ME differentiation of pPSCs caused by OCT4 knockdown did not rely on the activation of WNT/β-catenin signaling because the target gene of WNT/β-catenin signaling, AXIN2 was not upregulated after OCT4 knockdown, despite significant upregulation of WLS and some WNT ligands. Importantly, OCT4 is directly bound to the promoter and enhancers of EOMES and repressed its transcription. Overexpression of EOMES was sufficient to induce ME differentiation in the presence of XAV939. These results demonstrate that OCT4 can regulate WNT/β-catenin signaling and prevent ME differentiation of pPSCs by repressing EOMES transcription.

HIV and EBV co-infection has been linked to increased immune activation and larger HIV reservoir. We assessed whether anti-EBV humoral responses are associated with increased cerebrospinal fluid (CSF) inflammation and with neurocognitive impairment (NCI) in people with HIV (PWH).

Cross-sectional analysis in 123 EBV-seropositive PWH either on antiretroviral therapy (n = 70) or not.

Serum and CSF anti-EBV Viral Capsid Antigen Immunoglobulin G (anti-EVI) and CSF EBV DNA were measured by commercial immunoassay and RT-PCR. Seventy-eight participants without neurological confounding factors underwent neurocognitive assessment (Global Deficit Score, GDS). CSF total tau and 181-phosphorylated-tau (ptau) were measured by immunoassays together with biomarkers of blood-brain barrier (BBB) integrity, immune activation, astrocytosis, and intrathecal synthesis. Logistic and linear regressions and moderation analysis were used to investigate the relationships between CSF anti-EVI, GDS, and biomarkers.

Twenty-one (17.1%) and twenty-two participants (17.9%) had detectable CSF anti-EVI (10.5-416.0 U/mL) and CSF EBV DNA (25-971 cp/mL). After adjusting for BBB integrity, age, and clinical factors, the presence of CSF anti-EVI was only associated with serum levels of anti-EVI, and not with CSF EBV DNA. CSF anti-EVI and tau and ptau showed reciprocal interactions affecting their associations with GDS. After adjusting for demographics and clinical parameters, higher CSF anti-EVI levels were associated with worse GDS (aβ 0.45, p < 0.001), and CSF levels of tau and ptau had moderate the strength of this association (models'p < 0.001).

Humoral immune responses against EBV within the central nervous system may contribute to NCI of PWH through mechanisms that involve neuronal injury.

Ion channels play critical roles in the physiology and function of the nervous system and contractile tissue; however, their role in non-contractile tissue and embryonic development has yet to be understood. Tracheobronchomalacia (TBM) and complete tracheal rings (CTR) are disorders affecting the muscle and cartilage of the trachea and bronchi, whose etiology remains poorly understood. We demonstrated that trachealis muscle organization and polarity are disrupted after epithelial ablation of Wls, a cargo receptor critical for the Wnt signaling pathway, in developing trachea. The phenotype resembles the anomalous trachealis muscle observed after deletion of ion channel encoding genes in developing mouse trachea. We sought to investigate whether and how the deletion of Wls affects ion channels during tracheal development. We hypothesize that Wnt signaling influences the expression of ion channels to promote trachealis muscle cell assembly and patterning. Deleting Wls in developing trachea causes differential regulation of genes mediating actin binding, cytoskeleton organization, and potassium ion channel activity. Wnt signaling regulated expression of Kcnj13, Kcnd3, Kcnj8, and Abcc9 as demonstrated by in vitro studies and in vivo analysis in Wnt5a and β-catenin deficient tracheas. Pharmacological inhibition of potassium ion channels and Wnt signaling impaired contractility of developing trachealis smooth muscle and formation of cartilaginous mesenchymal condensation. Thus, in mice, epithelial-induced Wnt/β-catenin signaling mediates trachealis muscle and cartilage development via modulation of ion channel expression, promoting trachealis muscle architecture, contractility, and cartilaginous extracellular matrix. In turn, ion channel activity may influence tracheal morphogenesis underlying TBM and CTR.