Faith Community Engagement to Mitigate COVID-19 Transmission Associated with Mass Gathering, Uman, Ukraine, September 2021.

Annually, ≈30,000 Hasidic and Orthodox Jews travel to Uman, Ukraine, during the Jewish New Year to pray at the burial place of the founder of the Breslov Hasidic movement. Many pilgrims come from the northeastern United States. The global health implications of this event were seen in 2019 when measles outbreaks in the United States and Israel were linked to the pilgrimage. The 2020 pilgrimage was cancelled as part of the COVID-19 travel restrictions imposed by the government of Ukraine. To prepare for the 2021 event, the National Public Health Institute, the Public Health Center of Ukraine, organized mitigation measures for pilgrims arriving in Uman, and the CDC COVID-19 International Task Force assisted with mitigation measures for pilgrims coming from the United States. We describe efforts to support COVID-19 mitigation measures before, during, and after this mass gathering and lessons learned for future mass gatherings during pandemics.

Poldip2, a novel regulator of Nox4 and cytoskeletal integrity in vascular smooth muscle cells.

RATIONALE: NADPH oxidases (Noxes) regulate vascular physiology and contribute to the pathogenesis of vascular disease. In vascular smooth muscle cells (VSMCs), the interactions of individual Nox homologs with regulatory proteins are poorly defined. OBJECTIVE: The objective of this study was to identify novel NADPH oxidase regulatory proteins. METHODS AND RESULTS: Using a yeast 2-hybrid screen, we identified a novel p22phox binding partner, Poldip2, and demonstrated that it associates with p22phox, NADPH oxidase (Nox)1, and Nox4 and colocalizes with p22phox at sites of Nox4 localization. Poldip2 increases Nox4 enzymatic activity by 3-fold and positively regulates basal reactive oxygen species production in VSMCs (O2(.-): 86.3+/-15.6% increase; H2O2: 40.7+/-4.5% increase). Overexpression of Poldip2 activates Rho (180.2+/-24.8% increase), strengthens focal adhesions, and increases stress fiber formation. These phenotypic changes are blocked by dominant negative Rho. In contrast, depletion of either Poldip2 or Nox4 results in a loss of these structures, which is rescued by adding back active Rho. Cell migration, which requires dynamic cytoskeletal remodeling, is impaired by either excess (70.1+/-14.7% decrease) or insufficient Poldip2 (63.5+/-5.9% decrease). CONCLUSIONS: These results suggest that Poldip2 associates with p22phox to activate Nox4, leading to regulation of focal adhesion turnover and VSMC migration, thus linking reactive oxygen species production and cytoskeletal remodeling. Poldip2 may be a novel therapeutic target for vascular pathologies with a significant VSMC migratory component, such as restenosis and atherosclerosis.

Nox5 mediates PDGF-induced proliferation in human aortic smooth muscle cells.

The proliferation of vascular smooth muscle cells is important in the pathogenesis of many vascular diseases. Reactive oxygen species (ROS) produced by NADPH oxidases in smooth muscle cells have been shown to participate in signaling cascades regulating proliferation induced by platelet-derived growth factor (PDGF), a powerful smooth muscle mitogen. We sought to determine the role of Nox5 in the regulation of PDGF-stimulated human aortic smooth muscle cell (HASMC) proliferation. Cultured HASMC were found to express four isoforms of Nox5. When HASMC stimulated with PDGF were pretreated with N-acetyl cysteine (NAC), proliferation was significantly reduced. Proliferation induced by PDGF was also heavily dependent on JAK/STAT activation, as the JAK inhibitor, AG490, was able to completely abolish PDGF-stimulated HASMC growth. Specific knockdown of Nox5 with a siRNA strategy reduced PDGF-induced HASMC ROS production and proliferation. Additionally, siRNA to Nox5 inhibited PDGF-stimulated JAK2 and STAT3 phosphorylation. ROS produced by Nox5 play an important role in PDGF-induced JAK/STAT activation and HASMC proliferation.

Basic mechanisms of oxidative stress and reactive oxygen species in cardiovascular injury.

The development of vascular disease has its origins in an initial insult to the vessel wall by biological or mechanical factors. The disruption of homeostatic mechanisms leads to alteration of the original architecture of the vessel and its biological responsiveness, contributing to acute or chronic diseases such as stroke, hypertension, and atherosclerosis. Endothelial dysfunction, macrophage infiltration of the vessel wall, and proliferation and migration of smooth muscle cells all involve different types of reactive oxygen species produced by various vessel wall components. Although basic science and animal research have clearly established the role of reactive oxygen species in the progression of vascular disease, the failure of clinical trials with antioxidant compounds has underscored the need for better antioxidant therapies and a more thorough understanding of the role of reactive oxygen species in cardiovascular physiology and pathology.

Tumor necrosis factor alpha stimulation of Rac1 activity. Role of isoprenylcysteine carboxylmethyltransferase.

We have previously demonstrated that both isoprenylcysteine carboxylmethyltransferase (ICMT) and one of its substrates, the RhoGTPase Rac1, are critical for the tumor necrosis factor alpha (TNF alpha) stimulation of vascular cell adhesion molecule-1 expression in endothelial cells (EC). Here, we have shown that ICMT regulates TNF alpha stimulation of Rac1 activity. TNF alpha stimulation of EC increased the membrane association of Rac1, an event that is essential for Rac1 activity. ICMT inhibitor N-acetyl-S-farnesyl-L-cysteine (AFC) blocked the accumulation of Rac1 into the membrane both in resting and TNF alpha-stimulated conditions. Similarly, the membrane-associated Rac1 was lower in Icmt-deficient versus wild-type mouse embryonic fibroblasts (MEFs). TNF alpha also increased the level of GTP-Rac1, the active form of Rac1, in EC. AFC completely suppressed the TNF alpha stimulation of increase in GTP-Rac1 levels. Confocal microscopy revealed resting EC Rac1 was present in the plasma membrane and also in the perinuclear region. AFC mislocalized Rac1, both from the plasma membrane and the perinuclear region. Mislocalization of Rac1 was also observed in Icmt-deficient versus wild-type MEFs. To determine the consequences of ICMT inhibition, we investigated the effect of AFC on p38 mitogen-activated protein (MAP) kinase phosphorylation, which is downstream of Rac1. AFC inhibited the TNF alpha stimulation of p38 MAP kinase phosphorylation in EC. TNF alpha stimulation of p38 MAP kinase phosphorylation was also significantly attenuated in Icmt-deficient versus wild-type MEFs. To understand the mechanism of inhibition of Rac1 activity, we examined the effect of ICMT inhibition on the interaction of Rac1 with its inhibitor, Rho guanine nucleotide dissociation inhibitor (RhoGDI). The association of Rac1 with its inhibitor RhoGDI was dramatically increased in the Icmt-deficient versus wild-type MEFs both in resting as well as in TNF alpha-stimulated conditions, suggesting that RhoGDI was involved in inhibiting Rac1 activity under the conditions of ICMT inhibition. These results suggest that ICMT regulates Rac1 activity by controlling the interaction of Rac1 with RhoGDI. We hypothesize that ICMT regulates the release of Rac1 from RhoGDI.