An Ixodes persulcatus Inhibitor of Plasmin and Thrombin Hinders Keratinocyte Migration, Blood Coagulation, and Endothelial Permeability

The skin is the first host tissue that the tick mouthparts, tick saliva, and a tick-borne pathogen contact during feeding. Tick salivary glands have evolved a complex and sophisticated pharmacological arsenal, consisting of bioactive molecules, to assist blood feeding and pathogen transmission. In this work, persulcatin, a multifunctional molecule that targets keratinocyte function and hemostasis, was identified from Ixodes persulcatus female ticks. The recombinant persulcatin was expressed and purified and is a 25-kDa acidic protein with 2 Kunitz-type domains. Persulcatin is a classical tight-binding competitive inhibitor of proteases, targeting plasmin (Ki: 28 nM) and thrombin (Ki: 115 nM). It blocks plasmin generation on keratinocytes and inhibits their migration and matrix protein degradation; downregulates matrix metalloproteinase 2 and matrix metalloproteinase 9; and causes a delay in blood coagulation, endothelial cell activation, and thrombin-induced fibrinocoagulation. It interacts with exosite I of thrombin and reduces thrombin-induced endothelial cell permeability by inhibiting vascular endothelial-cadherin disruption. The multifaceted roles of persulcatin as an inhibitor and modulator within the plasminogen-plasmin system and thrombin not only unveil further insights into the intricate mechanisms governing wound healing but also provide a fresh perspective on the intricate interactions between ticks and their host organisms.

Hydrocarbon-based plastics: Progress and perspectives on consumption and biodegradation by insect larvae

The obvious contrast between the remarkable durability and the high consumption of plastic products leads to the deposition of at least 100 million tons of plastics per year in nature. Since 2010, several studies have shown the potential of insect larvae to biodegrade different types of plastics, at higher rates than those reported for microorganisms. This review discusses a compilation of studies about the consumption and biodegradation of hydrocarbon-based plastics, particularly PE, PS, PP and PVC, by lepidopteran and coleopteran larvae. Insects of the Coleoptera order seem to have a better adaptation for PS biodegradation, while those of the Lepidoptera order can better biodegrade PE. Tenebrio molitor biomineralize PE and PS into CO₂, and PVC into HCl; while Tenebrio obscurus and Zophobas atratus converts PE and PS into CO₂, respectively. Plastic biodegradation by T. molitor has been shown to be dependent on microbiota, exception for PE. Similar PS and PE biodegradation profile has been shown for T. obscurus. PS, PP and PE biodegradation by Z. atratus is also reported to be microbial-dependent. For Galleria mellonella, microbial role on PE biodegradation is still controversial, but the PS metabolism was proved to be microbiota-independent. Advances in this field has stimulated new studies with other insect species, which need to be better explored. Uncovering and understanding the chemical processes behind the innate plastic biodegradation by insect larvae will open the perspective to new eco-friendly innovative biotechnological solutions for the challenge of plastic waste.

Emergence of the novel SARS-CoV-2 lineage VUI-NP13L and massive spread of P.2 in South Brazil

In this study, we analyzed 340 whole genomes of SARS-CoV-2, which were sampled between April and November 2020 in 33 cities of Rio Grande do Sul, South Brazil. We demonstrated the circulation of two novel emergent lineages, VUI-NP13L and VUI-NP13L-like, and five major lineages that had already been assigned (B.1.1.33, B.1.1.28, P.2, B.1.91, B.1.195). P.2 and VUI-NP13L demonstrated a massive spread in October 2020. Constant and consistent genomic surveillance is crucial to identify newly emerging SARS-CoV-2 lineages in Brazil and to guide decision making in the Brazilian Public Healthcare System.

SARS-CoV-2 introduction and lineage dynamics across three epidemic peaks in Southern Brazil: massive spread of P.1

Genomic surveillance of SARS-CoV-2 is paramount for understanding viral dynamics, contributing to disease control. This study analyzed SARS-CoV-2 genomic diversity in Rio Grande do Sul (RS), Brazil, including the first reported case in each Regional Health Coordination and cases from three epidemic peaks. Ninety SARS-CoV-2 genomes from RS were sequenced and analyzed through comparison with SARS-CoV-2 datasets available in GISAID for phylogenetic inference and mutation analysis. Among the first reported cases, we found the following lineages: B.1 (33.3%), B.1.1.28 (26.7%), B.1.1 (13.3%), B.1.1.33 (10.0%), and A (6.7%), evidencing SARS-CoV-2 introduction by both international origin and community-driven transmission. We found predominance of B.1.1.33 (50.0%) and B.1.1.28 (35.0%) during the first epidemic peak (July-August 2020), emergence of P.2 (55.6%) in the second peak (November-December 2020), and massive spread of P.1 and related sequences (78.4%), such as P.1-like-II, P.1.1 and P.1.2 in the third peak (February-April, 2021). Eighteen novel mutation combinations were found among P.1 genomes, and 22 different spike mutations and/or deletions among P.1 and related sequences. This study shows the dispersion of SARS-CoV-2 lineages in Southern Brazil and describes SARS-CoV-2 diversity during three epidemic peaks, highlighting the spread of P.1 and the high genetic diversity of currently circulating lineages. Genomic monitoring of SARS-CoV-2 is essential to guide health authorities' decisions to control COVID-19 in Brazil.

Genome Mining for Antimicrobial Compounds in Wild Marine Animals-Associated Enterococci

New ecosystems are being actively mined for new bioactive compounds. Because of the large amount of unexplored biodiversity, bacteria from marine environments are especially promising. Further, host-associated microbes are of special interest because of their low toxicity and compatibility with host health. Here, we identified and characterized biosynthetic gene clusters encoding antimicrobial compounds in host-associated enterococci recovered from fecal samples of wild marine animals remote from human-affected ecosystems. Putative biosynthetic gene clusters in the genomes of 22 Enterococcus strains of marine origin were predicted using antiSMASH5 and Bagel4 bioinformatic software. At least one gene cluster encoding a putative bioactive compound precursor was identified in each genome. Collectively, 73 putative antimicrobial compounds were identified, including 61 bacteriocins (83.56%), 10 terpenes (13.70%), and 2 (2.74%) related to putative nonribosomal peptides (NRPs). Two of the species studied, Enterococcus avium and Enterococcus mundtti, are rare causes of human disease and were found to lack any known pathogenic determinants but yet possessed bacteriocin biosynthetic genes, suggesting possible additional utility as probiotics. Wild marine animal-associated enterococci from human-remote ecosystems provide a potentially rich source for new antimicrobial compounds of therapeutic and industrial value and potential probiotic application.

Modulation of peptidases by 2,4-diamine-quinazoline derivative induces cell death in the amitochondriate parasite Trichomonas vaginalis

Trichomonas vaginalis is an amitochondriate protozoan and the agent of human trichomoniasis, the most prevalent non-viral sexually transmitted infection (STI) in the world. In this study we showed that 2,4-diamine-quinazoline derivative compound (PH100) kills T. vaginalis. PH100 showed activity against fresh clinical and American Type Culture Collection (ATCC) T. vaginalis isolates with no cytotoxicity against cells (HMVI, 3T3-C1 and VERO) and erythrocytes. In addition, PH100 showed synergistic action with metronidazole, indicating that these compounds act by different mechanisms. When investigating the mechanism of action of PH100 to ATCC 30236, apoptosis-like characteristics were observed, such as phosphatidylserine exposure, membrane alterations, and modulation of gene expression and activity of peptidases related to apoptosis. The apoptosis-like cell death features were not observed for the fresh clinical isolate treated with PH100 revealing distinct profiles. Our data revealed the heterogeneity among T. vaginalis isolates and contribute with the understanding of mechanisms of cell death in pathogenic eukaryotic organisms without mitochondria.

Binge drinking and insomnia in students from health sciences at one university in Rio de Janeiro, Brazil

In spite of the many studies examining alcohol consumption, recent reviews have indicated that binge drinking has not been extensively studied. Furthermore, it is becoming increasingly clear that sleep is associated with many physiological functions and to drug addictions. The present study aimed to evaluate the relationship between alcohol binge drinking and insomnia in college students of health sciences. All first-year health sciences students (n=286) were evaluated in a cross-sectional study. Envelopes containing the Insomnia Severity Index (ISI), the Alcohol, Smoking, and Substance Involvement Screening Test (ASSIST), and questions capturing sociodemographic data were distributed and collected in classes. It was found that most non-drinkers were female (70.6%), although there were no sex-related differences in the number of binge drinkers (more than 5 drinks on each occasion at least once a week), allowing statistical comparison. The Mann-Whitney U test indicated that the ISI scores were significantly greater in female than male binge drinkers (P=0.014). Moderate or severe insomnia was reported by 23% of the sample, with alcohol being the most frequently associated substance. A specialized intervention was suggested by ASSIST: brief for marijuana (19.2%) and tobacco (23.3%) use, and moderate (31.5%) or intensive (1.4%) for alcohol consumers. The data highlighted the need to pay attention to the habits of college students beyond obtaining scientific information. New data suggesting the influence of genetics on insomnia may be of importance when performing additional studies on the sex differences in alcohol binge drinking.

Gender, Race and Parenthood Impact Academic Productivity During the COVID-19 Pandemic: From Survey to Action

The coronavirus disease 2019 (COVID-19) pandemic is altering dynamics in academia, and people juggling remote work and domestic demands - including childcare - have felt impacts on their productivity. Female authors have faced a decrease in paper submission rates since the beginning of the pandemic period. The reasons for this decline in women's productivity need to be further investigated. Here, we analyzed the influence of gender, parenthood and race on academic productivity during the pandemic period based on a survey answered by 3,345 Brazilian academics from various knowledge areas and research institutions. Productivity was assessed by the ability to submit papers as planned and to meet deadlines during the initial period of social isolation in Brazil. The findings revealed that male academics - especially those without children - are the least affected group, whereas Black women and mothers are the most impacted groups. These impacts are likely a consequence of the well-known unequal division of domestic labor between men and women, which has been exacerbated during the pandemic. Additionally, our results highlight that racism strongly persists in academia, especially against Black women. The pandemic will have long-term effects on the career progression of the most affected groups. The results presented here are crucial for the development of actions and policies that aim to avoid further deepening the gender gap in academia.

Gender, Race and Parenthood Impact Academic Productivity During the COVID-19 Pandemic: From Survey to Action

The coronavirus disease 2019 (COVID-19) pandemic is altering dynamics in academia, and people juggling remote work and domestic demands - including childcare - have felt impacts on their productivity. Female authors have faced a decrease in paper submission rates since the beginning of the pandemic period. The reasons for this decline in women's productivity need to be further investigated. Here, we analyzed the influence of gender, parenthood and race on academic productivity during the pandemic period based on a survey answered by 3,345 Brazilian academics from various knowledge areas and research institutions. Productivity was assessed by the ability to submit papers as planned and to meet deadlines during the initial period of social isolation in Brazil. The findings revealed that male academics - especially those without children - are the least affected group, whereas Black women and mothers are the most impacted groups. These impacts are likely a consequence of the well-known unequal division of domestic labor between men and women, which has been exacerbated during the pandemic. Additionally, our results highlight that racism strongly persists in academia, especially against Black women. The pandemic will have long-term effects on the career progression of the most affected groups. The results presented here are crucial for the development of actions and policies that aim to avoid further deepening the gender gap in academia.

A physiologic overview of the organ-specific transcriptome of the cattle tick Rhipicephalus microplus

To further obtain insights into the Rhipicephalus microplus transcriptome, we used RNA-seq to carry out a study of expression in (i) embryos; (ii) ovaries from partially and fully engorged females; (iii) salivary glands from partially engorged females; (iv) fat body from partially and fully engorged females; and (v) digestive cells from partially, and (vi) fully engorged females. We obtained > 500 million Illumina reads which were assembled de novo, producing > 190,000 contigs, identifying 18,857 coding sequences (CDS). Reads from each library were mapped back into the assembled transcriptome giving a view of gene expression in different tissues. Transcriptomic expression and pathway analysis showed that several genes related in blood digestion and host-parasite interaction were overexpressed in digestive cells compared with other tissues. Furthermore, essential genes for the cell development and embryogenesis were overexpressed in ovaries. Taken altogether, these data offer novel insights into the physiology of production and role of saliva, blood digestion, energy metabolism, and development with submission of 10,932 novel tissue/cell specific CDS to the NCBI database for this important tick species.

The extremophile Anoxybacillus sp. PC2 isolated from Brazilian semiarid region (Caatinga) produces a thermostable keratinase

The aim of this study was to select and identify thermophilic bacteria from Caatinga biome (Brazil) able to produce thermoactive keratinases and characterize the keratinase produced by the selected isolate. After enrichment in keratin culture media, an Anoxybacillus caldiproteolyticus PC2 was isolated. This thermotolerant isolate presents a remarkable feature producing a thermostable keratinase at 60°C. The partially purified keratinase, identified as a thermolysin-like peptidase, was active at a pH range of 5.0-10.0 with maximal activity at a temperature range of 50-80°C. The optimal activity was observed at pH 7.0 and 50-60°C. These characteristics are potentially useful for biotechnological purposes such as processing and bioconversion of keratin.

1212 A Systematic Assessment Of Engagement, Functionality, Aesthetics, Information, And Recommendation Features In Sleep Mobile Applications

Introduction

Initial download and use of sleep tracking is very high, but prolonged use is very low. Poor prolonged use may be attributable to several factors such as engagement, functionality, aesthetics, information, and recommendation. We appraised these five factors in 16 consumer- and research/medical- grade digital sleep devices.

Methods

Three reviewers independently assessed 16 consumer- and medical-grade sleep digital devices using the Mobile Application Rating Scale (MARS) App quality ratings, which measures engagement (engagement, entertainment, interest, customization, interactivity, target group), functionality (functionality, performance, ease of use, navigation, gestural design), aesthetics (layout, graphics, visual appeal), information (Accuracy. Goals, Quality of information, Quantity of information, Visual information, Credibility, and Evidence base) and recommended on a Likert scale, with 1- Inadequate to 5 Excellent. Each subcategory is rated on a 1-5 Likert scale which is summed for each category: engagement (30), functionality (25), aesthetics (15), information (35) and recommended (yes or no).

Results

Devices that had the highest engagement score were Fitbit (27), Apple Watch (27), Garmin (27), and Dreem 2 headband (25.5). Apple Watch (30) had highest score; while Fitbit (13), Apple Watch (13), Garmin (13), Samsung Gear (13) had highest aesthetic score. While for information, ActiGraph (35), SOMNOwatch plus (35), CleveMed SleepView Monitor (35), CleveMed Sapphire PSG (35), SOMNOscreen plus (35), Nox T3 Sleep Monitor (35) and Nox A1 PSG System (35) had the highest ratings. The Dreem 2 headband has the potential induce prolong use among users with and without sleep disorders, based on high scores on engagement (25.5), Functionality (20.5), and Information (26.5).

Conclusion

Consumer- and research-grade digital devices that measure sleep have varying levels of engagement, functionality, aesthetics, information and recommendations to facilitate prolong use. Consumer grade devices had higher engagement, functionality and aesthetics scores, while research grade devices had higher information and recommendation scores. If consumer- and research-grade devices are to have prolonged use, standardization is needed across the five MARS components.

Support

K01HL135452, R01MD007716, R01HL142066, and K07AG052685

1062 The Role of Sleep in Sex and Racial/Ethnic Differences in 10-Year CVD Risk in the Sleep Heart Health Study: The Use of Machine-Learnt and Precision Insights to Understand Racial/Ethnic and Sex Differences in Sleep-CVD Disparity

Introduction

The current study investigated whether insufficient sleep (<7 hrs.) explains differences in 10-year CVD risk, using Framingham risk (FRS) and Reynolds risk (RRS) scores, between blacks and whites and characterized risk and protective CVD risk profiles.

Methods

Using the Sleep Heart Health Study (SHHS) (N=6,441) data, we investigated the independent role of insufficient sleep in explaining differences in 10-years CVD between blacks and whites via a proportional odds model of four 10-year CVD risk groups: low (<5%), low-medium (5% to <10%), medium-high (10% to <20%) and high (≥20%), adjusting for age, sex, and apnea-hypopnea index (AHI). We performed two levels of cluster analyses; via hierarchical cluster algorithm with entire sample (Level 1), and latent profiles in the low (protective profiles) and high (risk profiles) CVD risk groups (Level 2) to determine overall CVD risk, and risk and protective CVD profiles.

Results

Blacks had a higher prevalence of smoking behavior, diabetes, mean systolic blood pressure, body mass index, total cholesterol compared to whites. Conversely, whites had a higher mean HDL cholesterol, sleep hours, and sleep efficiency compared to blacks. Men had higher 10-year CVD risk than women. AHI and race/ethnicity-sleep interaction were positively associated, while sleep was negatively associated with FRS and RRS. Across all CVD risk groups, whites who slept less than 5.5 hrs. had a higher CVD risk and those who slept more than 6.5 hrs. had a lower CVD risk compared to blacks. In Level 1 cluster analyses, we found two clusters: Cluster 1 (n= 3233): 6.17 sleep hours, apnea-index 11.84, age 59, SBP 125.43, total cholesterol 209, HDL 51.39, BMI 29.03, and slightly more than 50% female; and Cluster 2 (n=1657): 5.61 sleep hours, apnea-index 13.41, age 74, SBP 131, total cholesterol 204, HDL 50.30, BMI 26.45, and slightly less than 50% female. In Level 2 cluster analyses, we found two profiles within the low and high CVD risk groups.

Conclusion

These findings suggest that blacks may not receive full protection from long-term CVD risk with longer sleep duration, as their white counterparts.

Support

K01HL135452, R01MD007716, R01HL142066, K07AG052685

0406 Daytime Sleepiness in The Community: Implications for Sleep, Circadian, and Physical Health

Introduction

Daytime sleepiness impacts performance and well-being. The present study used validated measures to explore associations of community-level daytime sleepiness with sleep health, preferred sleep phase, physical inactivity, and overall health.

Methods

Data were from the Sleep and Healthy Activity, Diet, Environment, and Socialization (SHADES) study of N=1007 adults age 22-60 from the community. Daytime sleepiness was assessed with the Epworth Sleepiness Scale (ESS). Outcomes of interest included the Insomnia Severity Index (ISI), Pittsburgh Sleep Quality Index (PSQI), endorsement of a preference for an advanced or delayed sleep phase on the Sleep Disorders Symptom Check List (SDSCL), STOP-BANG sleep apnea questionnaire score, sedentary time assessed with the International Physical Activity Questionnaire (IPAQ), and the global health item on the SF-12, operationalized as excellent/good or fair/poor health. Through regression analyses, we assessed whether daytime sleepiness was independently associated with several sleep, circadian and physical health outcomes, adjusting for habitual sleep duration and sociodemographic factors like age, sex, education, and race/ethnicity.

Results

Our adjusted models indicate that daytime sleepiness was associated with insomnia (B=0.57; 95%CI: 0.50, 0.65; p<0.0001), sleep quality (B=0.34; 95%CI: 0.29, 0.39; p<0.0001), advanced sleep phase (OR=1.06; 95%CI: 1.03, 1.09; p<0.0001), delayed sleep phase (OR=1.05; 95%CI: 1.02, 1.07; p=0.0003), STOP-BANG score (B=0.08; 95%CI: 0.07, 0.10; p<0.0001), sedentary minutes (B=6.12; 95%CI: 2.77, 9.47; p=0.0004), and overall poor health (OR=1.10; 95%CI: 1.07, 1.13; p<0.0001). After additional adjustment for habitual sleep duration, all relationships were maintained.

Conclusion

Daytime sleepiness is associated with more severe insomnia, preference for advanced or delayed sleep timing, worse sleep quality, and greater risk of sleep apnea. Moreover, daytime sleepiness was associated with greater sedentary time and worse overall health. Since these relationships are independent of sleep duration, they likely do not reflect an effect of sleep deprivation.

Support

This work was supported by a grant from Jazz Pharmaceuticals. The SHADES study was funded by R21ES022931. Dr. Grandner is supported by R01MD011600.

1058 Modeling Self-reported Sleep Duration And Hypertension Using Deep Learning Network: Analysis Of The National Health And Nutrition Examination Survey Data

Introduction

Epidemiologic data show strong associations between self-reported sleep duration and hypertension (HTN). Modeling these associations is suboptimal when utilizing traditional logistic regressions. In this study, we modeled the associations of sleep duration and HTN using Deep Learning Network.

Methods

Data were extracted from participants (n=38,540) in the National Health and Nutrition Examination Survey (2006-2016), a nationally representative study of the US civilian non-institutionalized population. Self-reported demographic, medical history and sleep duration were determined from household interview questions. HTN was determined as SBP ≥ 130 mmHg and DBP ≥ 80 mmHg. We used a deep neural network architecture with three hidden layers with two input features and one binary output to model associations of sleep duration with HTN. The input features are the hours of sleep (limited to between 4 and 10 hours) and its square; and the output variable HTN. Probability predictions were generated 100 times from resampled (with replacement) data and averaged.

Results

Participants ranged from 18 to 85 years old; 51% Female, 41% white, 22% black, 26% Hispanic, 46% married, and 25% < high school. The model showed that sleeping 7 hours habitually was associated with the least observed HTN probabilities (P=0.023%). HTN probabilities increased as sleep duration decreased (6hrs=0.05%; 5hrs=0.110%; 4hrs=0.16%); HTN probabilities for long sleepers were: (8hrs=0.027; 9hrs=0.024; 10hrs=0.022). Whites showed sleeping 7hrs or 9hrs was associated with lowest HTN probabilities (0.008 vs. 0.005); blacks showed the lowest HTN probabilities associated with sleeping 8hrs (0.07), and Hispanics showed the lowest HTN probabilities sleeping 7hrs (0.04).

Conclusion

We found that sleeping 7 hours habitually confers the least amount of risk for HTN. Probability of HTN varies as a function of individual’s sex and race/ethnicity. Likewise, the finding that blacks experience the lowest HTN probability when they sleep habitually 8 hours is of great public health importance.

Support

This study was supported by funding from the NIH: R01MD007716, R01HL142066, R01AG056531, T32HL129953, K01HL135452, and K07AG052685.

1102 Relationship Between Emotional Distress And Sleep Duration Among Hispanics Using The 2018 National Health Interview Survey Dataset

Introduction

Although Hispanics experience a high level of shorter sleep duration (< 7 hrs./24 period), a clear mechanism or cause is lacking. Previous research indicate that emotional distress may explain the burden of shorter sleep among blacks. Applying these findings to Hispanics, we investigated whether emotional distress explains the burden of short sleep duration (< 7 hrs.) among Hispanics and if this relationship varies by sex

Methods

We used data from the 2018 National Health Interview Survey (NHIS) dataset, a nationally representative sample, in which only Hispanic ethnicity participants (N=3,091) were analyzed. Average sleep duration was self-reported and measured in hours. Emotional distress was measured using Kessler 6, which measures how an individual felt over the past 30 days: nervous, hopeless, restless/fidgety, depressed, effortful and worthless. To assess the association between short sleep duration and emotional distress, we performed Pearson correlation, hierarchical regression analyses, and stratified this relationship by sex to determine if this relationship differed between males and females, adjusting for covariates.

Results

Of the total sample of 3,091 Hispanics, 1,762 were female, and 1,329 were male. Sleep duration and emotional distress were negatively correlated among females (r = -.27, p <.001) and males (r=-.18, p <.001). Among Hispanic females, sleep duration significantly predicted emotional distress, β = -.27, t = -11.60, p <.001, and explained a significant portion of variance in emotional distress, R2 = .07, F= 134.63, p <.001. While, among Hispanic males, sleep significantly predicted emotional distress (β = -.18, t =-6.5, p <.001) and explained a significant portion of the variance in emotional distress (R2 = .03, F= 42.37, p <.001).

Conclusion

Our findings indicate that a negative sleep-ED relationship, suggesting that shorter sleep was predictive of higher levels of emotional distress among Hispanics and that this relationship is greater among Hispanic females, compared males.

Support

K01HL135452, R01MD007716, R01HL142066, and K07AG052685

1113 Physical Activity Moderates The Sleep-emotional Distress Relationship, But Less So Among Blacks Vs. Whites

Introduction

Emotional distress (ED) is associated with poor sleep. Research shows that minority populations experience greater vulnerabilities to both ED and poor sleep. Interventions such as relaxation training and behavioral therapy address this relationship but are not always successful. Research shows that physical activity (PA) is negatively associated with ED and positively associated with sleep duration. However, it is unclear whether PA attenuates the relationship between ED and sleep, and if this relationship differs by race/ethnicity.

Methods

We analyzed data from the 2005-2015 National Health Interview Survey (NHIS), a nationally representative dataset of 416,152 participants. ED, hours of PA per day, and average sleep duration were collected. Regression models with covariates (age, sex, employment status, BMI) were used to analyze the moderation effect of PA within sleep and ED. Regression models were stratified by race/ethnicity.

Results

261,686 participants (45,926 blacks, 17.55%, and 215,760 whites, 82.45%) responded with the required variables for analysis. 63% of participants reported at least some physical activity. The results of the regression showed that a significant amount of variance in ED stemmed from sleep duration; F (7, 121088) = 1,619.72, p < 0.001. PA was found to have a significant main effect, t(121,088) = 9.01, p= <0.001. There was a significant moderation effect of PA, t(121088) =7.26, p < 0.001. Stratification showed that the moderation effect of PA was not significant among blacks t(121,088) = -1.45, p=0.149 and significant among whites b = -.08, t(101,754) = -7.82, p < 0.001.

Conclusion

The present study found support for moderation of PA in the sleep-ED relationship. However, it found that blacks do not experience the same benefits of PA in this relationship as whites. Further research should be performed to understand the connection of PA to sleep duration and ED.

Support

This study was supported by funding from the NIH: R01MD007716, R01HL142066, R01AG056531, K01HL135452, and K07AG052685

0013 Mobile Device Use in Bed and Relationships to Work Productivity: Impact of Anxiety

Introduction

Mobile phone use at night is associated with worse sleep quality. It may also be associated with daytime productivity, possibly via anxiety.

Methods

Data were obtained from the Sleep and Healthy Activity, Diet, Environment, and Socialization (SHADES) study, including N=1007 adults age 22–60. Mobile device use in bed was assessed as the frequency that participants reported: a device in the bedroom, use of the device in bed, texting, emails, internet browsing, calls, and/or social networking in bed, being woken up by the device in a planned (alarm) or unplanned (alert/call/message) way, and checking the phone at night. Each of these were coded as “never,” “rarely,” or “often.” Work productivity was assessed with the Well-Being Assessment of Productivity (WBA-P; scores 0–22 measure productivity loss). Regressions with WBA-P score as outcome and mobile phone variables as predictors were adjusted for age, sex, race/ethnicity, education, and income level. Post-hoc analyses included GAD7 score to examine the mediating role of anxiety.

Results

The presence of a device was not associated with productivity loss, but frequent use (“often”) was (B=1.26,p=0.01). Increased productivity loss was also seen in those who frequently (“often”) sent texts (B=1.20,p=0.008), browsed internet (B=1.14,p=0.01), emailed (B=2.09,p<0.0005), called (B=1.42,p=0.004), and used social media (B=1.26,p=0.004). Productivity loss was associated with being woken by a call/alert “rarely” (B=1.20,p=0.001) or “often” (B=1.72,p=0.005), but not by alarm. Checking the phone at night “rarely” (B=0.89,p=0.01) and “often” (B=1.73,p<0.0005) were also associated with productivity loss. When anxiety was entered into the model, all relationships except those with frequent emails and calls in bed became nonsignificant.

Conclusion

Anxiety may be the underlying cause for both increased mobile phone usage and reduced productivity. Reducing anxiety levels may indirectly aid in decreasing nighttime mobile phone use and increasing daytime productivity.

Support

The SHADES study was funded by R21ES022931

Dr. Grandner is supported by R01MD011600

1189 Recruiting, Training, And Implementing Sleep Health Educators In Community-based Research To Improve Sleep Health

Introduction

Adherence to OSA assessment and treatment is low among racial/ethnic minorities, particularly among blacks. Navigating patients along the continuum of care from assessment to treatment adherence requires motivation, social support, and self-efficacy. Previous studies indicate that community health educators can provide motivation, social support, and skills to patients to better navigate the complex OSA care continuum. However, recruiting, training, and implementing sleep health educators in clinical or research settings is complex. For the current study, we describe how we recruit, train, and implement sleep health educators in research and clinical settings and assess what makes a sleep health educator successful.

Methods

We recruited and trained twenty-five self-identified black sleep health educators for a randomized clinical trial (R01MD007716) focused on increasing OSA assessment and treatment adherence among blacks. During recruitment, we assessed key personality attributes that translate to being an effective sleep health educator, via behavioral and personality surveys, focused groups, and process forms filled out by educators. Sleep health educators underwent an 8-week training program on sleep health and motivational interviewing. In order to be certified, sleep health educators had to pass a written and scenario-based assessment. During the implementation phase of the trial, we assessed how many interviews each health educator conducted and whether individual characteristics were related to how many interviews.

Results

Of the trained educators, 80% were female, ranging from 25 to 58 years old. They all completed at least high school. All educators rated the program highly and were very satisfied with dispensing tailored sleep health education. Educators who displayed the highest knowledge about sleep health, provided frequent emotional and strategic support, committed to helping their assigned participants, and who rated their rapport highly with their assigned participants were most effective in getting their participant to adhere to OSA assessment and treatment.

Conclusion

Sleep health educators can be vital to increasing OSA assessment and treatment adherence among blacks. In order to ensure success, sleep health educators must undergo a thorough recruitment, training, and implementation and dissemination process.

Support

K01HL135452, R01MD007716, R01HL142066, K01HL135452,and K07AG052685

1053 Sleep Duration And Timing Associated With History Of Breast Prostate And Skin Cancer: Data From A Nationally-representative Sample

Introduction

Sleep disturbances are a common problem among cancer survivors. Also, cancer patients can have altered circadian rhythms and these changes can continue to affect the patient long after the conclusion of their treatment. This analysis aims to investigate how the sleep and wake times of cancer survivors differ from the rest of the population, depending on the type of cancer.

Methods

Data from the 2015-2016 National Health and Nutrition Examination Survey were used. Population-weighted data on N=5,581 individuals provided complete data. History of breast, prostate, and skin cancer (melanoma or other) was self-reported. Sleep duration was self-reported in half-hour increments, and typical bedtime and waketime was self-reported. Covariates included age, sex, and race/ethnicity. Weighted linear regressions with sleep duration, bedtime and waketime were examined, with each cancer type as predictor.

Results

Prevalence was 1.7% for prostate cancer, 1.5% for breast cancer, 2.3% for non-melanoma skin cancer, and 0.8% for melanoma. In adjusted analyses, prostate cancer was associated with an additional 26.5 minutes of average total sleep (95%CI 2.2,50.9, p=0.03), a 23.1 bedtime minutes earlier (95%CI -40.4,-5.8, p=0.009), and no difference in waketime. Breast cancer was associated with a bedtime that was 41.1 minutes later (95%CI 10.3,72.0, p=0.009) and a waketime that was 48.7 minutes later (95%CI 12.5,84.9, p=0.008), but no difference in sleep duration. No statistically significant effects were seen for either type of skin cancer, melanoma or non-melanoma.

Conclusion

Prostate cancer was associated with an earlier bedtime and associated increased sleep time. Breast cancer, on the other hand, was associated with a phase delay of the sleep period but no change in sleep duration. Skin cancer was not associated with differences in sleep duration or timing. These findings may have implications for not only treatment of sleep problems in different types of cancer, but also possible circadian mechanisms.

Support

Dr. Grandner is supported by R01MD011600

1213 Sleepfect Tracker: A Crossplatform Mobile Researchkit App For Sleep Self-management

Introduction

We created Sleepfect Tracker, a researchkit-based cross platform app to explore the feasibility and acceptability of a sleep tracking app for sleep self-management.

Methods

We developed Sleepfect Tracker app on Appbakery, a DIY app making platform using ResearchKit for iOS and ResearchDroid for Android users. Sleepfect allows participants to track their sleep behavior (weekly via sleep diary) and environment (monthly), as well as their total sleep time and step counts data via Apple’s HealthKit, Android step count sensors, or Fitbit (wearable). Three hundred and ninety-five (395) individual from around the globe downloaded the app and 163 unique users answered surveys on their sleep behavior, environment, and architecture. In total we collected 6429 sleep and 2882 step data points and provided insights into user sleep behavior and sleep environment. We also analyzed whether sleep duration was associated with steps.

Results

Regarding immediate sleep environment and behavior, 11.1% worked or studied in bed, 27.0% reported having pets in bed, 39.7% red in bed prior to sleep, 40.3% watched TV in bed prior to sleep, 11.3% drank alcohol prior to bed, 9.8% smoked prior to bed or wake during night, 8.1% ate snack at bedtime, and 6.5% ate when they awake at night. 74.3% of the participants used electronic devices in their bedroom. Of the participants who used electronic devices in the bedroom, 52.1% had an average sleep duration of 6-8 hours and 29.8% reported sleeping 4-6 hours. Of the participants who did not use electronic devices in bedroom, 30.1% slept 4-6 hours, 31.8% slept 6-8 hours, and 32.45% slept 8-10 hours, on average. The relationship between steps count and sleep hours was trending, r=.16, p=.07.

Conclusion

Users can evaluate their sleep habits, monitor daily sleep-related behaviors through Sleepfect tracker. The app demonstrated initial usability and feasibility, but long-term usability and effectiveness must be evaluated. Further investigations on which functions will be more useful to help user to improve their sleep and engage users should be considered.

Support

K01HL135452, R01MD007716, R01HL142066, and K07AG052685

0621 Utilization of the Ares to Predict OSA Among Blacks Using Home-Based Watchpat Recording

Introduction

In two waves of data we collected in Brooklyn New York, we observed blacks were at high risk for obstructive sleep apnea (OSA). In the NIH-funded study ‘Metabolic Syndrome Outcome Study (MetSO), blacks enrolled from primary-care settings had a 59% risk of OSA. Similarly, blacks surveyed in churches and barbershops had a 43% risk of OSA. While these studies showed higher than expected risk as noted in the general population (29%), it remains uncertain how many of those blacks would be diagnosed with OSA in that population. The purpose of this study was to explore the rate of OSA using the WatchPat device in a community-based setting.

Methods

Data were collected from an NIH-funded study ‘Peer-Enhanced Education to Reduce Sleep Ethnic Disparities, designed to navigate blacks at risk of OSA to receive timely diagnosis and treatment using peer-delivered linguistically and culturally tailored sleep health education. Blacks were screened for OSA using the Apnea Risk Evaluation System (ARES) Questionnaire; a score ≥6 denoted moderate-high OSA risk. Individuals were asked to wear the WatchPAT 200 for one night during a week-long sleep assessment. WatchPat 200 measures SaO2 to determine respiratory-related arousals, defined as an Apnea-Hypopnea Index (AHI) ≥5, which is used to identify and diagnose OSA. We used SPSS 25.0 to perform logical regression analysis to assess associations between ARES and WatchPat AHI.

Results

A sample of 111 blacks provided valid ARES and WatchPat data for the present analyses. Of the sample, the mean age was 62.26 (SD=13.52 years; female = 55%); 49% reported annual income >20K and 79.5% reported a high school education. Moreover, 27% reported high blood pressure, 13%, diabetes, and 65% were overweight/obese. Multivariate-adjusted logical regression analyses indicated that blacks at risk for OSA were 66% more likely to receive an OSA diagnosis based on WatchPat AHI data (OR = 1.662, p < 0.01). The model adjusted for age, sex, income, and education.

Conclusion

The present study demonstrated that blacks at risk for OSA at the community level have a significant likelihood of receiving an OSA diagnosis using home-based recordings.

Support

NIH Support (T32HL129953, RO1MD007716, K01HL135452 and K07AG052685).

1114 Urbanicity And The Sleep-mental Health Relationship

Introduction

Inadequate sleep has been found to be associated with poor mental health. This is especially true in low-income and minority populations, who are concentrated in cities. It is not understood to what degree living in a city vs. a rural environment affects sleep and resulting mental health outcomes. This study seeks to understand how living in an urban environment affects the relationship between inadequate sleep and mental health.

Methods

The study used data from the 2018 US Behavioral Risk Factor Surveillance System (BRFSS,) a nationwide health dataset collected by telephone. Respondents were classified as living in either an urban or rural environment based on their zip code. Respondents reported hours of sleep per night and mental health status. This study classified mental health status based on whether the respondent reported one or more incidences of poor mental health in the previous 30 days.

Results

After filtration, 348,540 respondents were split into urban and rural groups. Binary logistic regression was run in each group to compare how much living in an urban environment contributed to the relationship between sleep duration and mental health. Sleep in the analysis was found to significantly contribute to both models; urban X2(15, N=295,796) = 11,485.70, p <0.001 rural X2(15, N=52,744) = 2,465.64, p <0.001. The estimated odds ratio resulted in a decrease of 13.9% [Exp(B) = 0.861] in reported poor mental health for every unit increase of sleep in the urban population, and decrease of 14.9% [Exp(B) = 0.851] in the rural population.

Conclusion

In urban and rural dwellers, sleep duration predicted poor mental health. Contrary to expectations, sleep was more strongly tied to mental health in rural than urban populations. This was true even after controlling for sex, income, and education level. Further research should seek to understand how environment affects sleep and mental health.

Support

This study was supported by funding from the NIH: R01MD007716, R01HL142066, R01AG056531, K01HL135452, and K07AG052685.

1046 Assessing Sleep-Related Hypertension Risks Using JNC 8 Guidelines: Analysis Of The National Health And Nutrition Examination Survey Data

Introduction

Associations between self-reported sleep duration and risk of hypertension (HTN) are well established. The level of sleep-related HTN risk based on the new JNC 8 classification guidelines requires further research. In this study, we modeled the associations of insufficient sleep with HTN using the National Health and Nutrition Examination Survey (NHANES).

Methods

Data were extracted from the 2006-2016 NHANES (n=38,540), a nationally representative study of the US civilian population. Self-reported demographic and sleep duration were determined from household interview questions. Insufficient sleep was categorized as sleeping <7hrs. Using 2017 ACC/AHA guidelines, HTN was classified as elevated (SBP:120-129mmHg and DBP <80mmHg, Stage I (SBP:130-139mmHg and DBP:80-89mmHg), or Stage II (SBP ≥140mmHg and DBP ≥90mmHg). Logistic regression modeling was performed using R.

Results

Participants’ ages ranged from 18-85 years. Of the sample, 51% were female, 41% white, 22% black, 26% Hispanic, 8% others; 46% were married, and 25% completed <high school. The model showed strong age and BMI-adjusted associations of insufficient sleep with HTN at all levels: (elevated: OR=1.079, CI=1.03-1.13; Stage I: OR=1.127, CI=1.07-1.18, and Stage II: OR=1.334, CI=1.17-1.52). Important sex and race/ethnicity differences in sleep-related HTN risks were observed: males (elevated: OR=1.024, CI=0.95-1.10; Stage I: OR=1.077, CI=1.01-1.15, and Stage II: OR=1.254, CI=1.06-1.48); females (elevated: OR=1.125, CI=1.05-1.21; Stage I: OR=1.170, CI=1.08-1.26, and Stage II: OR=1.445, CI=1.17-1.79); whites (elevated: OR=1.007, CI=0.93-1.08; Stage I: OR=1.030, CI=0.95-1.12, and Stage II: OR=1.131, CI=0.90-1.43); blacks (elevated: OR=1.047, CI=0.94-1.16; Stage I: OR=1.080, CI=0.97-1.20, and Stage II: OR=1.179, CI=0.95-1.46); and Hispanics (elevated: OR=1.066, CI=0.94-1.21; State I: OR=1.089, CI=0.96-1.24, and Stage II: OR=1.337, CI=0.92-1.92).

Conclusion

Our analyses showed that sleep-related HTN risks vary as a function of individual’s sex and race/ethnicity. Increasing sleep duration at all HTN severity level is important and males and Hispanics at Stage II HTN might benefit the most.

Support

This study was supported by funding from the NIH: R01MD007716,R01HL142066, R01AG056531, T32HL129953, K01HL135452 and K07AG052685

1093 Population-level Suicide Ideation: Impact Of Combined Roles Of Sleep Duration, Sleep Disturbance, And Daytime Sleepiness

Introduction

Poor sleep has been shown to be related to suicide ideation and depressed mood, but population-level studies have not been done to explore the specific issues within sleep that effect mood, specifically leading to suicide ideation.

Methods

Data from adults 18 and older in the 2015-2016 National Health and Nutrition Examination Survey (NHANES) who provided complete data were used (N=5,123). Suicide ideation was recorded as the presence of thinking that “you would be better off dead” in the past 2 weeks. Sleep duration was recorded in half-hour increments and transformed to represent absolute distance from 7 hours (to model u-shaped association). Sleep disturbance was recorded as presence of “difficulty falling asleep, staying asleep, or sleeping too much” non, several days, or more than half the days of the past 2 weeks. Sleepiness was frequency feeling “overly sleepy during the day” in the past 12 months. Covariates included age, sex, race/ethnicity, and presence of depressed mood in the past 2 weeks. Additional impact of difficulty thinking/concentrating in the past 2 weeks was explored. NHANES sample weights were used in analyses.

Results

In adjusted analyses, increase likelihood of suicide ideation was associated with distance from 7hrs (OR=1.24/hr, p=0.008), sleep difficulties most of the time (OR=2.46, p=0.001), but not sleepiness. When both sleep variables were adjusted for each other, results remained significant for U-shaped sleep duration (OR=1.21/hr, p=0.02) and sleep disturbance (OR=2.31, p=0.003). These were attenuated but remained significant when difficulty thinking/concentrating was introduced; a significant sobel test (p<0.0001) suggested partial mediation, with this variable accounting for approximately 13% of the variance of the relationship to sleep.

Conclusion

In the population, improper and poor sleep was associated with a greater risk of suicide ideation.

Support

Dr. Grandner is supported by R01MD011600

0140 Dietary Macronutrients and Sleep Duration, Sleep Disturbance, and Daytime Fatigue

Introduction

We examined nationally-representative data on macronutrients associated with multiple dimensions of sleep health.

Methods

Data were obtained from the 2015–2016 National Health and Nutrition Examination Survey, (N=5,266 adults). Standard 24-h dietary recall procedures were analyzed to establish daily consumption of protein, carbohydrates, sugar, fiber, total fat, and saturated fat. Self-reported habitual sleep duration was categorized as very short (<5h), short (5–6.5h), normal (7-8h), and long (>8h). Sleep disturbance and daytime tiredness/fatigue were self-reported as either none, mild, moderate, or severe. Weighted multinomial logistic regressions with sleep variables as outcome/dependent variable and percent of each macronutrient as independent variable were adjusted for age, sex, race/ethnicity, education, and body mass index.

Results

Increased protein was associated with a decreased likelihood of very short sleep (RRR=0.01, p=0.019) and severe fatigue (RRR=0.06, p=0.020). Increased carbohydrates was associated with an increased likelihood of very short (RRR=61.17, p=0.001), short (RRR=3.96, p=0.017), and long (RRR=2.58, p=0.041) sleep, severe sleep disturbance (RRR=9.37, p=0.010) and fatigue (RRR=7.61, p=0.009). Increased sugar was associated with an increased likelihood of very short (RRR=24.17, p=0.001), short (RRR=3.29, p=0.017), and long (RRR=2.22, p=0.046) sleep, as well as mild (RRR=2.36, p=0.041) and severe (RRR=10.70, p=0.001) sleep disturbance, and severe fatigue (RRR=12.98, p<0.0005). Increased fiber was associated with a decreased likelihood of long (RRR=0.01, p=0.032) sleep and severe sleep disturbance (RRR<0.01, p<0.0005), as well as moderate (RRR<0.01, p=0.026) and severe (RRR<0.01, p<0.0005) fatigue. Increased fat was associated with a decreased likelihood of very short sleep (RRR=0.01, p=0.010). Increased saturated fat was associated with a decreased likelihood of very short sleep (RRR<0.01, p=0.017).

Conclusion

Protein and fiber were associated with better sleep profiles overall and carbohydrate and sugar were associated with worse sleep, as well as increased prevalence of sleep disturbances and fatigue.

Support

Dr. Grandner is supported by R01MD011600

0235 Sleep Duration and Timing Associated with Eating Behaviors: Data from NHANES 2015–2016

Introduction

Previous studies have shown that, in the laboratory, sleep deprivation leads to unhealthy eating patterns. In real-world samples, lack of sleep is associated with obesity. Few real-world studies of sleep and food intake patterns exist, especially from nationally-representative samples.

Methods

Data from the 2015–2016 National Health and Nutrition Examination Survey (NHANES) were used. NHANES is a national-representative survey collected by the CDC. N=6,291 participants provided data about dietary behaviors and sleep timing. Dietary behaviors included the number of meals not made at home in the past 7 days (NOTHOME), number of fast food/pizza meals in the past 7 days (FASTFOOD), number of pre-made meals in the past 30 days (PREMADE), and number of frozen meals in the past 30 days (FROZEN). Linear regression models examined these as outcomes and predictors including bedtime (minutes), waketime (minutes), sleep duration (hours), and daytime tiredness/fatigue (never, rarely, sometimes, often). Covariates included age, sex, education, income/poverty ratio, race/ethnicity, and body mass index.

Results

Number of meals not made at home (NOTHOME) was associated with a later bedtime (B=2.25, p=0.01) and shorter sleep duration (B=-0.12, p=0.01). FASTFOOD was associated with shorter sleep (B=-0.13,p=0.003) and tiredness/sleepiness sometimes (B=0.77, p=0.007) and often (B=0.55, p=0.03). FROZEN meals were associated with a later waketime (B=3.31, p=0.003) and tiredness/sleepiness sometime (B=1.20, p=0.025) and often (B=1.60, p=0.04). A sleep duration by bedtime interaction was not significant for any outcomes. In models that included overall levels of anxiety, these relationships were maintained.

Conclusion

This is one of the largest studies to show that habitual sleep patterns are associated with real-world food choices. In particular, shorter sleep duration and tiredness/sleepiness are associated with more ready-made and fast food meals. It is possible that lack of sleep leads to worse food choices, or that stress leads to both lack of sleep and easier food options. Given the often poor nutritive value of foods consumed outside the home and pre-prepared foods, these associations may in part explain the influence of sleep on cardiometabolic risk factors.

Support

Dr. Grandner is supported by R01MD011600

Rhipicephalus microplus cystatin as a potential cross-protective tick vaccine against Rhipicephalus appendiculatus

Rhipicephalus appendiculatus, the brown ear tick, is an important disease vector of livestock in eastern, central and southern Africa. Rhipicephalus appendiculatus acaricide resistance requires the search for alternative methods for its control. Cystatins constitute a superfamily of cysteine peptidase inhibitors vital for tick blood feeding and development. These inhibitors were proposed as antigens in anti-tick vaccines. In this work, we applied structural and biochemical approaches to characterize a new cystatin named R. appendiculatus cystatin 2a (Racys2a). Structural modeling showed that this new protein possesses characteristic type 2 cystatin motifs, besides conservation of other structural patterns along the protein. Peptidase inhibitory assays with recombinant Racys2a showed modulation of tick and host cathepsins involved in blood digestion and immune system responses, respectively. A heterologous tick challenge with R. appendiculatus in rabbits immunized with recombinant Rhipicephalus microplus cystatin 2c (rBmcys2c) was performed to determine cross-reactivity. Histological staining showed that rBmcys2c vaccination caused damage to the gut, salivary gland and ovary tissues in R. appendiculatus. Furthermore, cystatin vaccine reduced the number of fully engorged adult females in 11.5 %. Consequently, strategies to increase the protection rate are necessary, including the selection of two or more antigens to compose a vaccine cocktail.

Blood anticlotting activity of a Rhipicephalus microplus cathepsin L-like enzyme

In parasites, cathepsins are implicated in mechanisms related to organism surveillance and host evasion. Some parasite cathepsins have fibrinogenolytic and fibrinolytic activity, suggesting that they may contribute to maintain blood meal fluidity for extended feeding periods. Here, it is shown that BmGTI (Rhipicephalus [Boophilus] microplus Gut Thrombin Inhibitor), a protein previously described as an inhibitor of fibrinogen hydrolysis and platelet aggregation by thrombin, and BmCL1 (Rhipicephalus [Boophilus] microplus Cathepsin-L like 1) are the same protein, hereinafter referred to using the earliest name (BmCL1). To further characterize BmCL1, Rhipicephalus microplus native and recombinant (rBmCL1) proteins were obtained. Native BmCL1 was isolated using thrombin-affinity chromatography, and it displays thrombin inhibition activity. We subsequently investigated rBmCL1 interaction with thrombin. We show that rBmCL1 and thrombin have a dissociation constant (Κ_D) of 130.2 ± 11.2 nM, and this interaction likely occurs due to a more electronegative surface of BmCL1 at pH 7.5 than at pH 5.0, which may favor an electrostatic binding to positively charged thrombin exosites. During BmCL1-thrombin interaction, thrombin is not degraded or inhibited. rBmCL1 impairs thrombin-induced fibrinogen clotting via a fibrinogenolytic activity. Fibrinogen degradation by BmCL1 occurs by the hydrolysis of Aα- and Bβ-chains, generating products similar to those produced by fibrinogenolytic cathepsins from other organisms. In conclusion, BmCL1 likely has an additional role in R. microplus blood digestion, besides its role in hemoglobin degradation at acid pH. BmCL1 fibrinogenolytic activity indicates a proteolytic activity in the neutral lumen of tick midgut, contributing to maintain the fluidity of the ingested blood, which remains to be confirmed in vivo.

Peptidase inhibitors in tick physiology

Peptidase inhibitors regulate a wide range of physiological processes involved in the interaction between hematophagous parasites and their hosts, including tissue remodeling, the immune response and blood coagulation. In tick physiology, peptidase inhibitors have a crucial role in adaptation to improve parasitism mechanisms, facilitating blood feeding by interfering with defense-related host peptidases. Recently, a larger number of studies on this topic led to the description of several new tick inhibitors displaying interesting novel features, for example a role in pathogen transmission to the host. A comprehensive review discussing these emerging concepts can therefore shed light on peptidase inhibitor functions, their relevance to tick physiology and their potential applications. Here, we summarize and examine the general characteristics, functional diversity and action of tick peptidase inhibitors with known physiological roles in the tick-host-pathogen interaction.

A proteomic insight into vitellogenesis during tick ovary maturation

Ticks are arthropod ectoparasites of importance for public and veterinary health. The understanding of tick oogenesis and embryogenesis could contribute to the development of novel control methods. However, to date, studies on the temporal dynamics of proteins during ovary development were not reported. In the present study we followed protein profile during ovary maturation. Proteomic analysis of ovary extracts was performed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) using shotgun strategy, in addition to dimethyl labelling-based protein quantification. A total of 3,756 proteins were identified, which were functionally annotated into 30 categories. Circa 80% of the annotated proteins belong to categories related to basal metabolism, such as protein synthesis and modification machineries, nuclear regulation, cytoskeleton, proteasome machinery, transcriptional machinery, energetic metabolism, extracellular matrix/cell adhesion, immunity, oxidation/detoxification metabolism, signal transduction, and storage. The abundance of selected proteins involved in yolk uptake and degradation, as well as vitellin accumulation during ovary maturation, was assessed using dimethyl-labelling quantification. In conclusion, proteins identified in this study provide a framework for future studies to elucidate tick development and validate candidate targets for novel control methods.