Increases in adolescent firearm injuries were associated with school closures during COVID-19.

BACKGROUND: Mitigation measures, including school closures, were enacted to protect the public during the COVID-19 pandemic. However, the negative effects of mitigation measures are not fully known. Adolescents are uniquely vulnerable to policy changes since many depend on schools for physical, mental, and/or nutritional support.  This study explores the statistical relationships between school closures and adolescent firearm injuries (AFI) during the pandemic. METHODS: Data were drawn from a collaborative registry of 4 trauma centers in Atlanta, GA (2 adult and 2 pediatric). Firearm injuries affecting adolescents aged 11-21 years from 1/1/2016 to 6/30/2021 were evaluated. Local economic and COVID data were obtained from the Bureau of Labor Statistics and the Georgia Department of Health. Linear models of AFI were created based on COVID cases, school closure, unemployment, and wage changes. RESULTS: There were 1,330 AFI at Atlanta trauma centers during the study period, 1,130 of whom resided in the 10 metro counties. A significant spike in injuries was observed during Spring 2020. A season-adjusted time series of AFI was found to be non- stationary (p = 0.60). After adjustment for unemployment, seasonal variation, wage changes, county baseline injury rate, and county-level COVID incidence, each additional day of unplanned school closure in Atlanta was associated with 0.69 (95% CI 0.34- 1.04, p < 0.001) additional AFIs across the city. CONCLUSION: AFI increased during the COVID pandemic. This rise in violence is statistically attributable in part to school closures after adjustment for COVID cases, unemployment, and seasonal variation. These findings reinforce the need to consider the direct implications on public health and adolescent safety when implementing public policy.

Lack of Evidence for Kidney Invasion by SARS-CoV-2 in a Lethal Mouse Model

Background: There is an ongoing controversy as to whether SARS CoV-2 can infect the kidney parenchyma directly. To date, the presence of SARS CoV-2 in the kidney has been described mainly post-mortem in autopsy studies of patients who died of or with COVID-19, but this has not been examined in an experimental model where the timing of SARS-CoV-2 infection can be defined. We used transgenic mice expressing human ACE2 (k18hACE2) susceptible to lethal SARS-CoV-2 infection to study this issue directly on kidney tissue taken at defined time points and using lung tissue as positive control. Method(s): Transgenic k18hACE2 mice were inoculated with 3x104 PFU SARSCoV-2 in a BSL-3 facility. Kidneys and lungs were removed from the animals sacrificed on days 5 to 7 and used for histology (PAS-staining), immunofluorescence (IF) of the S1 spike protein of SARS-CoV-2 and measurement of viral load by plaque assay. Kidney samples were additionally evaluated by IF using kidney injury markers NGAL and KIM-1. Result(s): Kidney tissue stained using an anti-S1-spike antibody showed negative results in all samples (n=15). By plaque assay, viral titers were also not detectable in any of the kidneys. By contrast, lungs from infected mice showed strong staining for the S1 spike protein in 13 of 14 cases and this was associated with positive viral titers in all lung samples. Despite severe lung disease, only mild and variable kidney damage was observed by histopathology. Positive staining for NGAL in the proximal tubules was consistently seen, while KIM-1 staining was rarely positive. Conclusion(s): In a transgenic mouse model with lethal SARS-CoV-2 infection and severe lung but mild kidney disease there is no evidence of S1 spike protein in the kidney, which is consistent with lack of detection of replicating virus by plaque assay.

Neutralization of the Omicron Variant of SARS-CoV-2 Is Effective by a Human and a Mouse Soluble ACE2 Protein

Background: We have previously reported that ACE2 618-DDC-ABD, a soluble ACE2 protein with extended duration of action and increased binding affinity for SARSCoV-2, provides lung and kidney protection in a lethal mouse model of SARS-CoV-2 infection. Moreover, we showed that this protein also neutralizes the gamma and delta variant SARS-CoV-2 infection in Vero E6 cells. As omicron is most prevalent SARSCoV-2 variant we tested whether ACE2 618-DDC-ABD can also neutralize this variant and hypothesized that it is more sensitive to mouse ACE2 as well as human ACE2. Method(s): The omicron BA.1 SARS-CoV-2 strain was incubated with various concentrations of ACE2 618-DDC-ABD (0-180ug/ml) for 1 hour at 37degreeC. Human ACE2 1-740 and mouse ACE2 1-740 were used as controls at the same concentrations. These mixtures were then used to infect Vero E6 cells. Cells were allowed to grow for 3-4 days until a noticeable cytopathic effect was observed in control wells (0mug/ml soluble ACE2 proteins). Cell numbers were assessed by staining cells with crystal violet and reading absorbance of each well at 595 nm. Values were then normalized to the 0mug/ml control and expressed as a percentage of the mock (no virus) control wells. Result(s): ACE2 618-DDC-ABD (red) neutralized the omicron BA.1 variant at all concentrations tested and to a similar extent as native human soluble ACE2 1-740 (blue) used as control. Native mouse ACE2 1-740 (black) also neutralized infection completely at high concentrations while lower concentrations were less effective as compared to low concentrations of ACE2 618-DDC-ABD or human ACE2 1-740.

AKI in a mouse model of COVID-19: Therapeutic potential of a novel soluble ACE2 variant

Background: We have previously shown that in the ischemia reperfusion model of AKI kidney ACE2 activity decreases and that the administration of a shorter soluble ACE2 variant markedly attenuates AKI in terms of GFR and kidney histology (Shirazi et al, ASN 2019). Here, we report the effect of a novel ACE2 variant designed to prevent/ treat SARS-CoV-2 in transgenic k18-hACE2 mice infected with a lethal viral dose. Methods: In a BSL-3 facility, transgenic k18-hACE2 mice were infected intranasally with 2×104 PFU SARS-CoV-2. ACE2 1-618-DDC-ABD was administered intranasally and intra-peritoneally 1 hour prior to viral challenge as well as 24 and 48 hours afterwards for a total of 3 doses. Infected control animals received PBS at the same time-points. Kidneys were removed from all animals and examined by light microscopy (LM) histologically and for apoptosis, using PAS and TUNEL staining, respectively. Results: In mice infected with SARS-CoV-2, variable degrees of AKI were found by LM with the following features seen in the few most severe cases: proximal tubule brush border loss (black arrows, figure 1A and B), cytolysis (red arrow, figure 1A), tubular basement membrane disruption (blue arrows, figure 1A and B) and apoptosis (white arrows, figure 1A, B, D and E). In animals treated with ACE2 1-618-DDC-ABD, survival was near 100% and proximal tubular kidney injury was absent or markedly attenuated with less proximal tubule injury (figure 1C) and minimal apoptosis (figure 1F). Glomeruli appeared ischemic (figure 1B, green arrow) but otherwise normal without evidence of thrombosis. Conclusions: Kidneys from a transgenic mouse susceptible to SARS-CoV-2 infection, like patients with COVID-19, displays variable degrees of proximal tubular injury suggesting that this model can be useful to study AKI in COVID-19. Mice that received soluble ACE2 1-618-DDC-ABD protein were essentially protected from AKI suggesting a potential preventative/therapeutic role for soluble ACE2 in this otherwise pharmacologically untreatable devastating disease.

A novel soluble ACE2 protein protects from lethal SARS-CoV-2 infection

Background: Severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) uses full-length angiotensin converting enzyme 2 (ACE2) as the main receptor to enter the target cells. A novel soluble ACE2 protein with increased duration of action and binding capacity to exert a decoy effect as a way to intercept SARS-CoV-2 from binding to membrane-bound ACE2 was generated. The protein was administered to a lethal mouse model of COVID-19 to examine its efficacy. Methods: A human soluble ACE2 variant fused with a 5kD albumin binding domain (ABD) was linked via a dimerization motif hinge-like 4-cysteine dodecapeptide to improve binding capacity to the SARS-CoV-2. This novel protein (ACE2 1-618-DDCABD) was administered intranasally and intraperitoneally prior to viral inoculation and on the two following consecutive days. Infected animals were observed for weight, clinical score and mortality in a BSL-3 facility. Upon sacrifice, lung histopathology was evaluated, and viral loads were measured by plaque assay. Results: Infected mice that received ACE2-1-618-DDC-ABD developed only moderate disease assessed by a clinical score, modest weight loss and lung histology. At 6 days, mortality was totally prevented in the treated group (figure), lung histopathology was markedly improved and viral lung and brain titers reduced or non-detectable. By contrast, in untreated animals, lung histology revealed extensive pulmonary alveolar hemorrhage and mononuclear infiltrates, and they all became severely ill and had to be euthanized by day 6/7 (figure). Conclusions: This study demonstrates for the first time in vivo the preventative/ therapeutic efficacy of a soluble ACE2 protein in a preclinical animal model.

SSRIs: Applications in inflammatory lung disease and implications for COVID-19.

Selective serotonin reuptake inhibitors (SSRIs) have anti-inflammatory properties that may have clinical utility in treating severe pulmonary manifestations of COVID-19. SSRIs exert anti-inflammatory effects at three mechanistic levels: (a) inhibition of proinflammatory transcription factor activity, including NF-κB and STAT3; (b) downregulation of lung tissue damage and proinflammatory cell recruitment via inhibition of cytokines, including IL-6, IL-8, TNF-α, and IL-1ß; and (c) direct suppression inflammatory cells, including T cells, macrophages, and platelets. These pathways are implicated in the pathogenesis of COVID-19. In this review, we will compare the pathogenesis of lung inflammation in pulmonary diseases including COVID-19, ARDS, and chronic obstructive pulmonary disease (COPD), describe the anti-inflammatory properties of SSRIs, and discuss the applications of SSRIS in treating COVID-19-associated inflammatory lung disease.