Background: Successful containment strategies for SARS-CoV-2, the causative virus of the COVID-19 pandemic, have involved widespread population testing that identifies infections early and enables rapid contact tracing. In this study, we developed a rapid and inexpensive RT-qPCR testing pipeline for population-level SARS-CoV-2 detection, and used this pipeline to establish a clinical laboratory dedicated to COVID-19 testing at the University of California San Diego (UCSD) with a processing capacity of 6,000 samples per day and next-day result turnaround times. Methods and findings: Using this pipeline, we screened 6,786 healthcare workers and first responders, and 21,220 students, faculty, and staff from UCSD. Additionally, we screened 6,031 preschool-grade 12 students and staff from public and private schools across San Diego County that remained fully or partially open for in-person teaching during the pandemic. Between April 17, 2020 and February 5, 2021, participants provided 161,582 nasal swabs that were tested for the presence of SARS-CoV-2. Overall, 752 positive tests were obtained, yielding a test positivity rate of 0.47%. While the presence of symptoms was significantly correlated with higher viral load, most of the COVID-19 positive participants who participated in symptom surveys were asymptomatic at the time of testing. The positivity rate among preschool-grade 12 schools that remained open for in-person teaching was similar to the positivity rate at UCSD and lower than that of San Diego County, with the children in private schools being less likely to test positive than the adults at these schools. Conclusions: Most schools across the United States have been closed for in-person learning for much of the 2020-2021 school year, and their safe reopening is a national priority. However, as there are no vaccines against SARS-CoV-2 currently available to the majority of school-aged children, the traditional strategies of mandatory masking, physical distancing, and repeated viral testing of students and staff remain key components of risk mitigation in these settings. The data presented here suggest that the safety measures and repeated testing actions taken by participating healthcare and educational facilities were effective in preventing outbreaks, and that a similar combination of risk-mitigation strategies and repeated testing may be successfully adopted by other healthcare and educational systems.

Environmental monitoring in public spaces can be used to identify surfaces contaminated by persons with COVID-19 and inform appropriate infection mitigation responses. Research groups have reported detection of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) on surfaces days or weeks after the virus has been deposited, making it difficult to estimate when an infected individual may have shed virus onto a SARS-CoV-2 positive surface, which in turn complicates the process of establishing effective quarantine measures. In this study, we determined that reverse transcription-quantitative polymerase chain reaction (RT-qPCR) detection of viral RNA from heat-inactivated particles experiences minimal decay over seven days of monitoring on eight out of nine surfaces tested. The properties of the studied surfaces result in RT-qPCR signatures that can be segregated into two material categories, rough and smooth, where smooth surfaces have a lower limit of detection. RT-qPCR signal intensity (average quantification cycle ( Cq )) can be correlated to surface viral load using only one linear regression model per material category. The same experiment was performed with infectious viral particles on one surface from each category, with essentially identical results. The stability of RT-qPCR viral signal demonstrates the need to clean monitored surfaces after sampling to establish temporal resolution. Additionally, these findings can be used to minimize the number of materials and time points tested and allow for the use of heat-inactivated viral particles when optimizing environmental monitoring methods. Importance Environmental monitoring is an important tool for public health surveillance, particularly in settings with low rates of diagnostic testing. Time between sampling public environments, such as hospitals or schools, and notifying stakeholders of the results should be minimal, allowing decisions to be made towards containing outbreaks of coronavirus disease 2019 (COVID-19). The Safer At School Early Alert program (SASEA) [1], a large-scale environmental monitoring effort in elementary school and child care settings, has processed > 13,000 surface samples for SARS-CoV-2, detecting viral signals from 574 samples. However, consecutive detection events necessitated the present study to establish appropriate response practices around persistent viral signals on classroom surfaces. Other research groups and clinical labs developing environmental monitoring methods may need to establish their own correlation between RT - qPCR results and viral load, but this work provides evidence justifying simplified experimental designs, like reduced testing materials and the use of heat-inactivated viral particles.

Environmental monitoring in public spaces can be used to identify surfaces contaminated by persons with coronavirus disease 2019 (COVID-19) and inform appropriate infection mitigation responses. Research groups have reported detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on surfaces days or weeks after the virus has been deposited, making it difficult to estimate when an infected individual may have shed virus onto a SARS-CoV-2-positive surface, which in turn complicates the process of establishing effective quarantine measures. In this study, we determined that reverse transcription-quantitative PCR (RT-qPCR) detection of viral RNA from heat-inactivated particles experiences minimal decay over 7 days of monitoring on eight out of nine surfaces tested. The properties of the studied surfaces result in RT-qPCR signatures that can be segregated into two material categories, rough and smooth, where smooth surfaces have a lower limit of detection. RT-qPCR signal intensity (average quantification cycle [Cq]) can be correlated with surface viral load using only one linear regression model per material category. The same experiment was performed with untreated viral particles on one surface from each category, with essentially identical results. The stability of RT-qPCR viral signal demonstrates the need to clean monitored surfaces after sampling to establish temporal resolution. Additionally, these findings can be used to minimize the number of materials and time points tested and allow for the use of heat-inactivated viral particles when optimizing environmental monitoring methods. IMPORTANCE Environmental monitoring is an important tool for public health surveillance, particularly in settings with low rates of diagnostic testing. Time between sampling public environments, such as hospitals or schools, and notifying stakeholders of the results should be minimal, allowing decisions to be made toward containing outbreaks of coronavirus disease 2019 (COVID-19). The Safer At School Early Alert program (SASEA) (https://saseasystem.org/), a large-scale environmental monitoring effort in elementary school and child care settings, has processed >13,000 surface samples for SARS-CoV-2, detecting viral signals from 574 samples. However, consecutive detection events necessitated the present study to establish appropriate response practices around persistent viral signals on classroom surfaces. Other research groups and clinical labs developing environmental monitoring methods may need to establish their own correlation between RT-qPCR results and viral load, but this work provides evidence justifying simplified experimental designs, like reduced testing materials and the use of heat-inactivated viral particles.

Type 1 diabetes affects 20 million patients worldwide. Insulin is the primary and commonly the sole therapy for type 1 diabetes. However, only a minority of patients attain the targeted glucose control and reduced adverse events. We tested urocortin 2 gene transfer as single-agent therapy for insulin deficiency using two mouse models. Urocortin 2 gene transfer reduced blood glucose for months after a single intravenous injection, through increased skeletal muscle insulin sensitivity, increased insulin release in response to glucose stimulation, and increased plasma insulin levels before and during euglycemic clamp. The combined increases in both insulin availability and sensitivity resulted in improved glycemic indices-events that were not anticipated in these insulin-deficient models. In addition, urocortin 2 gene transfer reduced ocular manifestations of long-standing insulin deficiency such as vascular leak and improved retinal function. Finally, mortality was reduced by urocortin 2 gene transfer. The mechanisms for these beneficial effects included increased activities of AMP-activated protein kinase and Akt (protein kinase B) in skeletal muscle, increased skeletal muscle glucose uptake, and increased insulin release. These data suggest that urocortin 2 gene transfer may be a viable therapy for new onset type 1 diabetes and might reduce insulin needs in later stage disease.

Diabetes mellitus increases the risk of heart failure. We previously showed that injection of adeno-associated virus 8 encoding urocortin 2 (AAV8.UCn2) increases glucose disposal in insulin resistance and improves function of the failing heart in mice. In the present study, we tested the hypothesis that UCn2 gene transfer would have beneficial effects in diabetic cardiomyopathy. Eight-week-old C57Bl/6J male mice were fed normal chow (NC) or a Western diet (WD, 35% kcal carbohydrate and 45% fat) for 30w, and then received saline or AAV8.UCn2 (1.9x10 13 genome copy/kg) via intravenous injection. Before and 10w after gene transfer, we measured fasting blood glucose, glucose tolerance, and cardiac function via echocardiography and rates of LV pressure development (+dP/dt) and decline (-dP/dt) using micromanometers. We also measured key signaling proteins in the left ventricle (LV). Western diet increased 12h fasting glucose levels compared to normal chow (81% increase; p<.0002). WD vs normal chow reduced LV peak +dP/dt (p=.042) and LV peak -dP/dt (p=.027), although LV ejection fraction (EF) was unchanged. Thus WD induced diabetes and cardiomyopathy with normal EF. Among mice fed WD, UCn2 gene transfer reduced fasting glucose (WD+Saline: 190±11 mg/dL, n=8; WD+UCn2: 149±6 mg/dL, n=8; p=.006), increased LV peak +dP/dt (p=.005; Fig A ), LV peak -dP/dt (p=.007; Fig B ), and reduced Tau (p=.016; Fig C ). In addition, among WD-fed mice, UCn2 gene transfer increased LV EF (p=.005) and the velocity of circumferential fiber shortening (p=.0005). LV samples from WD+UCn2 mice showed increased phosphorylation of PKA catalytic domain (WD+Saline: .2±.04, n=5; WD+UCn2: .3±.02, n=5; p=.03). In conclusion, UCn2 gene transfer increased LV systolic and diastolic function and reduced blood glucose in mice with diabetic cardiomyopathy.

A fusion protein (C1C2) constructed by fusing the intracellular C1 and C2 segments of adenylyl cyclase type 6 (AC6) retains beneficial effects of AC6 expression, without increasing cyclic adenosine monophosphate generation. The effects of cardiac-directed C1C2 expression in pressure overload is unknown. Left ventricular (LV) pressure overload was induced by transverse aortic constriction (TAC) in C1C2 mice and in transgene negative (TG-) mice. Four weeks after TAC, LV systolic function and diastolic function were measured, and Ca2+ handling was assessed. Four weeks after TAC, TG- animals showed reduced LV peak +dP/dt. LV peak +dP/dt in C1C2 mice was statistically indistinguishable from that of normal mice and was higher than that seen in TG- mice 4 weeks after TAC (p = 0.02), despite similar and substantial cardiac hypertrophy. In addition to higher LV peak +dP/dt in vivo, cardiac myocytes from C1C2 mice showed shorter time-to-peak Ca2+ transient amplitude (p = 0.002) and a reduced time constant of cytosolic Ca2+ decline (Tau; p = 0.003). Sarcomere shortening fraction (p < 0.03) and the rate of sarcomere shortening (p < 0.02) increased in C1C2 cardiac myocytes. Myofilament sensitivity to Ca2+ was increased in systole (p = 0.02) and diastole (p = 0.04) in C1C2 myocytes. These findings indicate enhanced Ca2+ handling associated with C1C2 expression. Favorable effects on Ca2+ handling and LV function were associated with increased LV SERCA2a protein content (p = 0.015) and reduced LV fibrosis (p = 0.008). Cardiac-directed C1C2 expression improves Ca2+ handling and increases LV contractile function in pressure overload. These data provide a rationale for further exploration of C1C2 gene transfer as a potential treatment for heart failure.

Type 1 diabetes (T1D) affects 1.3 million U.S. patients. Tight glucose control reduces microvascular complications and adverse cardiovascular events. Insulin therapy is essential but has shortcomings: a) only 1 in 3 patients achieve targeted glucose control; b) aggressive insulin use increases hypoglycemia; c) 25% of T1D patients develop insulin resistance. We previously reported that urocortin-2 (UCn2) gene transfer increases insulin sensitivity and release in mouse models of type 2 diabetes. In the present study, 3m-old male Akita mice with T1D (due to Ins2 mutation) received IV saline, AAV8. Null or AAV8.UCn2 (2x1012 gc/kg). Ten weeks after UCn2 gene transfer we saw normalization of fasting glucose, HbA1c and glucose tolerance (Table). Increased body weight and reduced water intake was seen after UCn2 gene transfer. Hyperinsulinemic euglycemic clamps showed increased insulin sensitivity and skeletal muscle glucose uptake. There was reduced nephropathy and retinopathy and increased survival (Table). Echocardiography showed improved ejection fraction (p UCn2 Gene Transfer in Akita Mice (Type 1 Diabetes)Saline or AAV8.Null (n)AAV8.UCn2 (n)pPlasma UCn2 (ng/mL)1±.2 (14)12±.9 (14) Disclosure M. Gao: None. N. Lai: None. D. Giamouridis: None. T.Y. Guo: None. B. Xia: None. Y. Kim: None. M.V. Estrada: None. V. Nguyen Huu: None. D. Skowronska-Krawczyk: None. H. Hammond: Stock/Shareholder; Self; Renova Therapeutics.

Background and Objective: A fusion protein (C1C2) constructed by fusing the intracellular C1 and C2 segments of adenylyl cyclase type 6 (AC6), retains beneficial effects of AC6 expression, without increasing cAMP generation. For example, transgenic mice with cardiac-directed C1C2 expression have normal left ventricular (LV) function despite reduced cAMP generation. Furthermore, sustained isoproterenol (Iso) infusion reduces LV function in normal mice, but, in contrast, C1C2 mice show increased LV function with sustained Iso infusion. The effects of C1C2 expression in pressure-overload is unknown. Methods: LV pressure overload was induced by transaortic constriction (TAC) in C1C2 mice and in transgene negative mice. Three weeks after TAC, LV systolic and diastolic function were measured, and Ca2+ handling was assessed in isolated cardiac myocytes. Results: C1C2 expression reduced LV hypertrophy (p=0.017), increased LV peak pressure development (+dP/dt, p=0.018), and improved LV peak pressure decay (-dP/dt, p=0.038) in the pressure-overload ( Table ). Cytosolic peak Ca2+ concentration was increased (p=0.047), and time to peak Ca2+ transient and Tau were decreased (p=0.002 and p=0.003, respectively) in cardiac myocytes isolated from pressure-overloaded hearts ( Table ). Conclusions: Cardiac-directed C1C2 expression reduces LV hypertrophy, improves Ca2+ handling, and increases LV systolic and diastolic function in pressure-overload. These data provide a rationale for further exploration of C1C2 gene transfer as a potential treatment for heart failure.