Port wine stain (PWS) is a congenital vascular malformation involving human skin. Approximately 15–20% of children a facial PWS involving the ophthalmic (V1) trigeminal dermatome are at risk for Sturge Weber syndrome (SWS), a neurocutaneous disorder with vascular malformations in the cerebral cortex on the same side of the facial PWS lesions. Recently, evidence has surfaced that advanced our understanding of the pathogenesis of PWS/SWS, including discoveries of somatic genetic mutations (GNAQ, PI3K), MAPK and PI3K aberrant activations, and molecular phenotypes of PWS endothelial cells. In this review, we summarize current knowledge on the etiology and pathology of PWS/SWS based on evidence that the activation of MAPK and/or PI3K contributes to the malformations, as well as potential futuristic treatment approaches targeting these aberrantly dysregulated signaling pathways. Current data support that: (1) PWS is a multifactorial malformation involving the entire physiological structure of human skin; (2) PWS should be pathoanatomically re-defined as “a malformation resulting from differentiation-impaired endothelial cells with a progressive dilatation of immature venule-like vasculatures”; (3) dysregulation of vascular MAPK and/or PI3K signaling during human embryonic development plays a part in the pathogenesis and progression of PWS/SWS; and (4) sporadic low frequency somatic mutations, such as GNAQ, PI3K, work as team players but not as a lone wolf, contributing to the development of vascular phenotypes. We also address many crucial questions yet to be answered in the future research investigations.
The spike protein of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) plays a crucial role in mediating viral entry into host cells. However, whether it contributes to pulmonary hyperinflammation in patients with coronavirus disease 2019 is not well known. In this study, we developed a spike protein–pseudotyped (Spp) lentivirus with the proper tropism of the SARS‐CoV‐2 spike protein on the surface and determined the distribution of the Spp lentivirus in wild‐type C57BL/6J male mice that received an intravenous injection of the virus. Lentiviruses with vesicular stomatitis virus glycoprotein (VSV‐G) or with a deletion of the receptor‐binding domain (RBD) in the spike protein [Spp (∆RBD)] were used as controls. Two hours postinfection (hpi), there were 27‐75 times more viral burden from Spp lentivirus in the lungs than in other organs; there were also about 3‐5 times more viral burden from Spp lentivirus than from VSV‐G lentivirus in the lungs, liver, kidney, and spleen. Deletion of RBD diminished viral loads in the lungs but not in the heart. Acute pneumonia was observed in animals 24 hpi. Spp lentivirus was mainly found in SPC+ and LDLR+ pneumocytes and macrophages in the lungs. IL6, IL10, CD80, and PPAR‐γ were quickly upregulated in response to infection in the lungs as well as in macrophage‐like RAW264.7 cells. Furthermore, forced expression of the spike protein in RAW264.7 cells significantly increased the mRNA levels of the same panel of inflammatory factors. Our results demonstrated that the spike protein of SARS‐CoV‐2 confers the main point of viral entry into the lungs and can induce cellular pathology. Our data also indicate that an alternative ACE2‐independent viral entry pathway may be recruited in the heart and aorta.
Preeclampsia is a hypertensive disorder of pregnancy characterized by maternal endothelial dysfunction and end-organ damage. The antiangiogenic factor, sFlt-1 (soluble FMS-like tyrosine kinase-1) has been strongly implicated in the pathogenesis of preeclampsia. sFlt-1 is secreted into the maternal circulation where it antagonizes VEGF (vascular endothelial growth factor) and ultimately disrupts vascular homeostasis. However, the upstream mechanisms regulating release of sFlt-1 are poorly characterized. We investigated the roles of key prosurvival pathways, EGFR (epidermal growth factor receptor) signaling, and the mitochondria, in regulating sFlt-1 production. We initially found that the mRNA and protein of EGFR and downstream adaptor molecules were significantly increased in preeclamptic placental tissue relative to normotensive controls. Inhibiting the EGFR signaling cascade using siRNA (small interfering ribonucleic acid) or small molecule inhibitors significantly reduced sFlt-1 release from primary cytotrophoblast (placental cells). Additionally, inhibiting the mitochondrial electron transport chain or activating downstream energy-sensing molecules (AMPK [AMP-activated kinase], SIRT1 [sirtuin 1 ], and PGC1α [PPAR-γ co-activator 1]) also significantly reduced sFlt-1 secretion from cytotrophoblast cells, without affecting EGFR signaling. In vivo, treating pregnant mice with gefitinib (an EGFR inhibitor) or resveratrol (perturbs mitochondrial function) significantly reduced circulating murine sFlt-1 compared with vehicle control. Furthermore, treating primary cytotrophoblasts with therapeutics which have been previously found to reduce sFlt-1 secretion, either reduced EGFR signaling (esomeprazole and statins) or perturbed mitochondrial function (esomeprazole, resveratrol, and metformin). Additionally, targeting both pathways simultaneously produced additive reductions in sFlt-1 secretion. Thus, we have identified 2 key survival pathways that seem to be overactive in preeclampsia and involved in the regulation of placental sFlt-1 secretion.
To provide an accessible and inexpensive method to surveil for SARS-CoV-2 mutations, we developed a multiplex real-time RT-PCR (the Spike SNP assay) to detect specific mutations in the spike receptor binding domain. A single primer pair was designed to amplify a 348 bp region of spike , and probes were initially designed to detect K417, E484K, and N501Y. The assay was evaluated using characterized variant sample pools and residual nasopharyngeal samples. Variant calls were confirmed by SARS-CoV-2 genome sequencing in a subset of samples. Subsequently, a fourth probe was designed to detect L452R. The lower limit of 95% detection was 2.46 to 2.48 log 10 GE/mL for the three initial targets (∼1-2 GE/reaction). Among 253 residual nasopharyngeal swabs with detectable SARS-CoV-2 RNA, the Spike SNP assay was positive in 238 (94.1%) samples. All 220 samples with Ct values < 30 for the SARS-CoV-2 N2 target were detected, whereas 18/33 samples with N2 Ct values ≥ 30 were detected. Spike SNP results were confirmed by sequencing in 50/50 samples (100%). Addition of the 452R probe did not affect performance for the original targets. The Spike SNP assay accurately identifies SARS-CoV-2 mutations in receptor binding domain, and it can be quickly modified to detect new mutations that emerge.
Background COVID-19 patients develop hypolipidemia. However, it is unknown whether lipid levels have improved and there are potential sequlae in recovered patients. Objective In this follow-up study, we evaluated serum lipidemia and various physiopathological laboratory values in recovered patients. Methods A 3–6 month follow-up study was performed between June 15 and September 3, 2020, to examine serum levels of laboratory values in 107 discharged COVID-19 patients (mild = 59; severe/critical = 48; diagnoses on admission). Sixty-one patients had a revisit chest CT scan. A Wilcoxon signed-rank test was used to analyze changes in laboratory values at admission and follow-up. Results LDL-c and HDL-c levels were significantly higher at follow-up than at admission in severe/critical cases (p < 0.05). LDL-c levels were significantly higher at follow-up than at admission in mild cases (p < 0.05). Coagulation and liver functional values were significantly improved at follow-up than at admission for patients (p < 0.05). Increases in HDL-c significantly correlated with increases in numbers of white blood cells (p < 0.001) during patients’ recovery. With exclusion of the subjects taking traditional Chinese medicines or cholesterol-lowering drugs, LDL-c and HDL-c levels were significantly increased at follow-up than at admission in severe/critical cases (p < 0.05). Residue lesions were observed in CT images in 72% (44 of 61) of follow-up patients. Conclusions Improvements of LDL-c, HDL-c, liver functions, and incomplete resolution of lung lesions were observed at 3–6 month follow-up for recovered patients, indicating that a long-term recovery process could be required and the development of sequelae such as pulmonary fibrosis could be expected in some patients.
Background Preeclampsia is a major complication of pregnancy with no medical treatment. It is associated with placental oxidative stress, hypoxia and inflammation leading to soluble fms-like tyrosine kinase 1 (sFlt-1) and soluble endoglin (sENG) secretion and reduced placental growth factor (PlGF). This results in widespread endothelial dysfunction causing hypertension and multisystem organ injury. Sulfasalazine is an anti-inflammatory and antioxidant medication used to treat autoimmune disease. Importantly, it is safe in pregnancy. We examined the potential of sulfasalazine to quench antiangiogenic factors and endothelial dysfunction and increase angiogenic factor secretion. Methods We performed functional experiments using primary human pregnancy tissues to examine the effects of sulfasalazine on sFlt-1, sENG and PlGF secretion. Sulfasalazine is known to inhibit nuclear factor kappa-light-chain-enhancer of activated B cells (NFkB) and upregulate heme-oxygenase 1 (HO-1) thus we explored the effect of these transcription factors on sFlt-1 secretion from human cytotrophoblasts. We examined the ability of sulfasalazine to reduce key markers of endothelial dysfunction and dilate whole blood vessels. Findings We demonstrate sulfasalazine administration reduces sFlt-1 and sENG and upregulates PlGF secretion from human placental tissues. Furthermore sulfasalazine mitigates endothelial dysfunction in several in vitro/ex vivo assays. It enhanced endothelial cell migration and proliferation, promoted blood vessel dilation (vessels obtained from women at caesarean section) and angiogenic sprouting from whole blood vessel rings. The effect of sulfasalazine on the secretion of sFlt-1 was not mediated through either the NFkB or HO-1 pathways. Interpretation We conclude that sulfasalazine reduces sFlt-1 and sENG secretion and endothelial dysfunction and upregulates PlGF. Sulfasalazine has potential to treat or prevent preeclampsia and warrants investigation in clinical trials. Funding This work was funded by The National Health and Medical Research Council of Australia (NHMRC; #1048707, #1046484. #1101871, #1064845), an Arthur Wilson RANZCOG scholarship and a Norman Beischer Medical Research Foundation grant. FB was supported by a NHMRC Early Career Fellowship (NHMRC #1142636). NJH was supported by a CR Roper Research Fellowship. The NHMRC provided salary support (#1136418 to ST #1062418 to TKL, #1064845 to SS). The funders had no role in study design, data collection, analysis, decision to publish or the preparation of the manuscript.
Coronavirus disease 2019 (COVID-19) patients show lipid metabolic alterations, but the mechanism remains unknown. In this study, we aimed to investigate whether the Spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) impairs lipid metabolism in host cells. We generated a Spike cell line in HEK293 using the pcDNA vector carrying the Spike gene expression cassette. A control cell line was generated using the empty pcDNA vector. Gene expression profiles related to lipid metabolic, autophagic, and ferroptotic pathways were investigated. Palmitic acid (PA)-overload was used to assess lipotoxicity-induced necrosis. As compared with controls, the Spike cells showed a significant increase in lipid depositions in cell membranes as well as dysregulation of expression of a panel of molecules involving lipid metabolism, autophagy, and ferroptosis. The Spike cells showed an upregulation of nuclear factor erythroid 2-related factor 2 (Nrf2), a multifunctional transcriptional factor, in response to PA. Furthermore, the Spike cells exhibited increased necrosis in response to PA-induced lipotoxicity compared to control cells in a time- and dose-dependent manner via ferroptosis, which could be attenuated by the Nrf2 inhibitor trigonelline. We conclude that the Spike protein impairs lipid metabolic and autophagic pathways in host cells, leading to increased susceptibility to lipotoxicity via ferroptosis which can be suppressed by a Nrf2 inhibitor. This data also suggests a central role of Nrf2 in Spike-induced lipid metabolic impairments.
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