Predictors of Global Disparities in COVID-19 Vaccination Coverage - 219 Countries and Territories, December 2020-July 2022.

What is already known about this topic?: The significant disparities in global coronavirus disease 2019 (COVID-19) vaccine coverage hamper the pace of epidemic control. There is a need to better understand the factors contributing to disparities in COVID-19 vaccination rates across countries. What is added by this report?: This report revealed significant associations between vaccination coverage and various country-level indicators. Better pandemic preparedness, higher levels of trust, and a lower proportion of young population aged 0-14 were strongly correlated with higher COVID-19 vaccination coverage. What are the implications for public health practices?: Our findings emphasize the need for enhanced pandemic preparedness and governance, coupled with building trust in government and healthcare systems. It also needs to address the hesitancy of vaccinating children and adolescents aged 0-14 as the vaccination campaign progresses.

The whole-of-society approach of mass COVID-19 vaccination in China: a qualitative study.

BACKGROUND: Many countries have an inefficient vaccination system, which hinders global exit from the COVID-19 pandemic. It is vital to summarize COVID-19 vaccination practices in countries with high vaccination coverage and provide implications for other countries. This study aimed to investigate China's COVID-19 vaccination system and to summarize its implementation experience from a health system perspective. METHODS: We conducted key informant interviews in five representative cities of China in late 2021. Guided by the health systems framework proposed by WHO, we developed our interview guidelines which included seven building blocks-leadership and governance, health workforce, vaccination service delivery, vaccination mobilization and communication, financing, access to vaccines, and information systems. Semi-structured interviews and COVID-19 vaccination policy documents were collected and coded using a thematic analysis approach. RESULTS: A total of 61 participants (nine vaccination programme directors of the local Center for Disease Control and Prevention, four government staff and 48 vaccination service workers) were interviewed. We found that China adopted a whole-of-society approach with adequate government engagement and linked health and non-health sectors to promote COVID-19 vaccination. Key measures included the collaboration of multiple systems and departments from a governance perspective, allocating sufficient health workers and resources, large-scale vaccination mobilization and communication, expansion of vaccine financing channels, localized production and digital information systems. With the vaccination system strengthening, the two-doses vaccination coverage reached 89.5% for the total population but relatively lower coverage for older adults as of July 2022. CONCLUSIONS: Our study highlights the importance of a government-led whole-of-society approach to promote mass vaccination. The low vaccination coverage among older adults should be paid the greatest attention to. The experiences and lessons from China may serve as a reference for other countries.

Erratum: Author Correction: Mapping global acceptance and uptake of COVID-19 vaccination: a systematic review and meta-analysis.

[This corrects the article DOI: 10.1038/s43856-022-00177-6.].

Mapping global acceptance and uptake of COVID-19 vaccination: A systematic review and meta-analysis.

Background: The COVID-19 pandemic exit strategies depend on widespread acceptance of COVID-19 vaccines. We aim to estimate the global acceptance and uptake of COVID-19 vaccination, and their variations across populations, countries, time, and sociodemographic subgroups. Methods: We searched four peer-reviewed databases (PubMed, EMBASE, Web of Science, and EBSCO) for papers published in English from December 1, 2019 to February 27, 2022. This review included original survey studies which investigated acceptance or uptake of COVID-19 vaccination, and study quality was assessed using the Appraisal tool for Cross-Sectional Studies. We reported the pooled acceptance or uptake rates and 95% confidence interval (CI) using meta-analysis with a random-effects model. Results: Among 15690 identified studies, 519 articles with 7,990,117 participants are eligible for meta-analysis. The global acceptance and uptake rate of COVID-19 vaccination are 67.8% (95% CI: 67.1-68.6) and 42.3% (95% CI: 38.2-46.5), respectively. Among all population groups, pregnant/breastfeeding women have the lowest acceptance (54.0%, 46.3-61.7) and uptake rates (7.3%, 1.7-12.8). The acceptance rate varies across countries, ranging from 35.9% (34.3-37.5) to 86.9% (81.4-92.5) for adults, and the lowest acceptance is found in Russia, Ghana, Jordan, Lebanon, and Syria (below 50%). The acceptance rate declines globally in 2020, then recovers from December 2020 to June 2021, and further drops in late 2021. Females, those aged < 60 years old, Black individuals, those with lower education or income have the lower acceptance than their counterparts. There are large gaps (around 20%) between acceptance and uptake rates for populations with low education or income. Conclusion: COVID-19 vaccine acceptance needs to be improved globally. Continuous vaccine acceptance monitoring is necessary to inform public health decision making.

Design, Synthesis and Biological Activity Testing of Library of Sphk1 Inhibitors.

Our team discovered a moderate SphK1 inhibitor, SAMS10 (IC50 = 9.8 µM), which was screened by computer-assisted screening. In this study, we developed a series of novel diaryl derivatives with improved antiproliferative activities by modifying the structure of the lead compound SAMS10. A total of 50 new compounds were synthesized. Among these compounds, the most potent compound, named CHJ04022Rb, has significant anticancer activity in melanoma A375 cell line (IC50 = 2.95 µM). Further underlying mechanism studies indicated that CHJ04022R exhibited inhibition effect against PI3K/NF-κB signaling pathways, inhibited the migration of A375 cells, promoted apoptosis and exerted antiproliferative effect by inducing G2/M phase arrest in A375 cells. Furthermore, acute toxicity experiment indicated CHJ04022R exhibited good safety in vivo. Additionally, it showed a dose-dependent inhibitory effect on the growth of xenograft tumor in nude mice. Therefore, CHJ04022R may be a potential candidate for the treatment of melanoma.

Public Interest in Distribution and Determinants of Influenza and Pneumonia Vaccination during the COVID-19 Pandemic: An Infodemiology and Cross-Sectional Study from China.

BACKGROUND: Following the COVID-19 pandemic, global interest in influenza vaccines and pneumonia vaccines has increased significantly. We aimed to examine public interest in and actual market circulation of influenza and pneumonia vaccines before and after the initial outbreak of COVID-19 and estimate the coverage and determinants of influenza and pneumonia vaccination uptake following the COVID-19 pandemic. METHODS: We obtained search volume data for vaccines using the Baidu search index and collected the numbers of vaccines issued from the National Institutes for Food and Drug Control. We also conducted a cross-sectional survey among 3346 adult residents to evaluate the coverage and determinants of influenza and pneumonia vaccination uptake in the Yangtze River delta, China, from 29 January to 4 February 2021. RESULTS: Public searches and the number of vaccines issued for the influenza vaccines and pneumonia vaccines obviously increased after the initial outbreak of COVID-19. In the total sample, 12.5% were vaccinated against influenza, and 21.5% had at least one family member vaccinated against pneumonia. A minority of participants perceived that they were highly or very highly susceptible to influenza (15.9%) and COVID-19 (6.7%). A range of socio-economic factors and perceived susceptibility to COVID-19 were associated with influenza and pneumonia vaccination uptake. CONCLUSIONS: Public interest in and issued volumes of influenza and pneumonia vaccines increased nationally following the COVID-19 pandemic. Perceptions of high susceptibility to COVID-19 were associated with the uptake of the influenza and pneumonia vaccines. Targeted interventions were needed to improve vaccination coverage.

Molecular Evidence of Bartonella melophagi in Ticks in Border Areas of Xinjiang, China.

Bartonella are gram-negative intracellular bacteria; certain species of Bartonella can cause diseases in mammals and humans. Ticks play a major role in the transmission of Bartonella. Xinjiang is the largest province in China according to land area and has one-third of the tick species in China; the infection rate of Bartonella in ticks in the Xinjiang border areas has not been studied in detail. Therefore, this study investigated tick infections by Bartonella in Xinjiang border areas, and the purpose of the study was to fill in gaps in information regarding the genetic diversity of tick infections by Bartonella in Xinjiang. We tested 1,549 tick samples from domestic animals (sheep and cattle) for Bartonella using ribC-PCR. Positive samples from the ribC-PCR assay for Bartonella spp. were further subjected to PCR assays targeting the ITS, rpoB and gltA genes followed by phylogenetic analyses. Bartonella DNA was detected in 2.19% (34/1,549) of tick samples, and the ITS, rpoB and gltA genes of ribC gene-positive samples were amplified to identify nine samples of Bartonella melophagi. In this study, molecular analysis was used to assess the presence and genetic diversity of B. melophagi in ticks collected from sheep and cattle from Xinjiang, China. This study provides new information on the presence and identity of B. melophagi in ticks from sheep and cattle.

Comparison of Public Responses to Containment Measures During the Initial Outbreak and Resurgence of COVID-19 in China: Infodemiology Study.

BACKGROUND: COVID-19 cases resurged worldwide in the second half of 2020. Not much is known about the changes in public responses to containment measures from the initial outbreak to resurgence. Monitoring public responses is crucial to inform policy measures to prepare for COVID-19 resurgence. OBJECTIVE: This study aimed to assess and compare public responses to containment measures during the initial outbreak and resurgence of COVID-19 in China. METHODS: We curated all COVID-19-related posts from Sina Weibo (China's version of Twitter) during the initial outbreak and resurgence of COVID-19 in Beijing, China. With a Python script, we constructed subsets of Weibo posts focusing on 3 containment measures: lockdown, the test-trace-isolate strategy, and suspension of gatherings. The Baidu open-source sentiment analysis model and latent Dirichlet allocation topic modeling, a widely used machine learning algorithm, were used to assess public engagement, sentiments, and frequently discussed topics on each containment measure. RESULTS: A total of 8,985,221 Weibo posts were curated. In China, the containment measures evolved from a complete lockdown for the general population during the initial outbreak to a more targeted response strategy for high-risk populations during COVID-19 resurgence. Between the initial outbreak and resurgence, the average daily proportion of Weibo posts with negative sentiments decreased from 57% to 47% for the lockdown, 56% to 51% for the test-trace-isolate strategy, and 55% to 48% for the suspension of gatherings. Among the top 3 frequently discussed topics on lockdown measures, discussions on containment measures accounted for approximately 32% in both periods, but those on the second-most frequently discussed topic shifted from the expression of negative emotions (11%) to its impacts on daily life or work (26%). The public expressed a high level of panic (21%) during the initial outbreak but almost no panic (1%) during resurgence. The more targeted test-trace-isolate measure received the most support (60%) among all 3 containment measures in the initial outbreak, and its support rate approached 90% during resurgence. CONCLUSIONS: Compared to the initial outbreak, the public expressed less engagement and less negative sentiments on containment measures and were more supportive toward containment measures during resurgence. Targeted test-trace-isolate strategies were more acceptable to the public. Our results indicate that when COVID-19 resurges, more targeted test-trace-isolate strategies for high-risk populations should be promoted to balance pandemic control and its impact on daily life and the economy.

7,8-Dihydroxyflavone Enhanced Colonic Cholinergic Contraction and Relieved Loperamide-Induced Constipation in Rats.

BACKGROUND: Whether 7,8-dihydroxyflavone (7,8-DHF), a tyrosine kinase receptor B (TrkB) agonist, modulates colonic smooth muscle motility and/or alleviates constipation has not yet been studied. AIMS: Here, we aimed to determine how 7,8-DHF influences carbachol (CCh)-stimulated contraction of colonic strips and the in vivo effect of 7,8-DHF on constipation. METHODS: Muscle strips were isolated from rat colons for recording contractile tension and performing western blotting. Constipation was induced in rats with loperamide. RESULTS: Although it specifically activated TrkB, 7,8-DHF applied alone neither activated PLCγ1 in the colonic strips nor induced colonic strip contraction. However, 7,8-DHF enhanced CCh-stimulated PLCγ1 activation and strip contraction. The PLCγ1 antagonist U73122 suppressed both CCh-stimulated and 7,8-DHF-enhanced/CCh-stimulated contraction. While clarifying the underlying mechanism, we revealed that 7,8-DHF augmented muscarinic M3 receptor expression in the colonic strips. The M3-selective antagonist tarafenacin specifically inhibited the 7,8-DHF-enhanced/CCh-stimulated contraction of the colonic strips. Since 7,8-DHF increased Akt phosphorylation, and LY294002 (an antagonist of PI3K upstream of Akt) dramatically inhibited both 7,8-DHF-augmented M3 expression and 7,8-DHF-enhanced/CCh-stimulated contractions, we assumed that 7,8-DHF/TrkB/Akt was associated with the modulation of M3 expression in the colonic strips. ANA-12, a specific TrkB antagonist, not only inhibited TrkB activation by 7,8-DHF but also suppressed 7,8-DHF-enhanced cholinergic contraction, 7,8-DHF/CCh-mediated activation of PLCγ1/Akt, and M3 overexpression in colonic strips. In vivo 7,8-DHF, also by promoting intestinal motility and M3 expression, significantly alleviated loperamide-induced functional constipation in rats. CONCLUSIONS: Our results suggest that 7,8-DHF regulates colonic motility possibly via a TrkB/Akt/M3 pathway and may be applicable for alleviating constipation.

Coxiella burnetii is widespread in ticks (Ixodidae) in the Xinjiang areas of China.

BACKGROUND: The gram-negative Coxiella burnetii bacterium is the pathogen that causes Q fever. The bacterium is transmitted to animals via ticks, and manure, air, dead infected animals, etc. and can cause infection in domestic animals, wild animals, and humans. Xinjiang, the provincial-level administrative region with the largest land area in China, has many endemic tick species. The infection rate of C. burnetii in ticks in Xinjiang border areas has not been studied in detail. RESULTS: For the current study, 1507 ticks were collected from livestock at 22 sampling sites in ten border regions of the Xinjiang Uygur Autonomous region from 2018 to 2019. C. burnetii was detected in 205/348 (58.91%) Dermacentor nuttalli; in 110/146 (75.34%) D. pavlovskyi; in 66/80 (82.50%) D. silvarum; in 15/32 (46.90%) D. niveus; in 28/132 (21.21%) Hyalomma rufipes; in 24/25 (96.00%) H. anatolicum; in 219/312 (70.19%) H. asiaticum; in 252/338 (74.56%) Rhipicephalus sanguineus; and in 54/92 (58.70%) Haemaphysalis punctata. Among these samples, C. burnetii was detected in D. pavlovskyi for the first time. The infection rate of Rhipicephalus was 74.56% (252/338), which was the highest among the four tick genera sampled, whereas the infection rate of H. anatolicum was 96% (24/25), which was the highest among the nine tick species sampled. A sequence analysis indicated that 63 16S rRNA sequences could be found in four newly established genotypes: MT498683.1 (n = 18), MT498684.1 (n = 33), MT498685.1 (n = 6), and MT498686.1 (n = 6). CONCLUSIONS: This study indicates that MT498684.1 might represent the main C. burnetii genotype in the ticks in Xinjiang because it was detected in eight of the tick species studied. The high infection rate of C. burnetii detected in the ticks found in domestic animals may indicate a high likelihood of Q fever infection in both domestic animals and humans.

High-dose TGF-ß1 degrades human nucleus pulposus cells via ALK1-Smad1/5/8 activation.

Transforming growth factor ß1 (TGF-ß1) can promote the proliferation and differentiation of intervertebral disc cells and participates in its repair process. However, whether TGF-ß1 engages in the process of disc degeneration has not yet been fully elucidated. The present study aimed to investigate the function of high-dose TGF-ß1 on the metabolism of nucleus pulposus cells (NPCs). TGF-ß1 levels in human degenerative intervertebral disc tissues and tumor necrosis factor (TNF)-α-induced degenerative NPCs were analyzed. Furthermore, NPCs were treated with TGF-ß1 and inhibitors of TGF-ß1 receptors [ALK tyrosine kinase receptor (ALK) 1 and ALK5] to determine the effect of the receptors in the mediation of NPC degeneration. The NPC state was determined by the components of secretory collagen I/II, tissue inhibitor of metalloproteinase-3 (TIMP-3) and matrix metalloproteinase (MMP)-13. The mRNA expression of Smad1/2/3/5/8, the downstream gene of TGF-ß1 mediated by ALK, was also measured. Results showed that TGF-ß1 and ALK1 were positively associated with the degree of degeneration of NP or NPCs in vitro, but negatively associated with ALK5. Furthermore, high-doses of TGF-ß1 suppressed collagen II, but enhanced collagen I, TIMP-3, MMP-13, ALK1/5 and Smad1/2/3/5/8 expression. ALK5 inhibition induced the suppression of Smad2/3 and aggravated high-dose TGF-ß1-induced NPC degeneration, as shown by the reduction in collagen II and increase in collagen I, TIMP-3 and MMP-13. By contrast, ALK1 inhibition resulted in Smad1/5/8 suppression and alleviated high-dose TGF-ß1-induced NPC degeneration. Taken together, it was concluded that high-doses of TGF-ß1 contributed to the degeneration of NPCs via the upregulation of ALK1 and Smad1/5/8.

Ultrasound-assisted extraction extracts from Stemona japonica (Blume) Miq. and Cnidium monnieri (L.) Cuss. could be used as potential Rhipicephalus sanguineus control agents.

Nicotiana tabacum, Stemona japonica, and Cnidium monnieri are common plants that are widely used for their anti-parasitic properties. The purpose of this study was to evaluate the acaricidal activity of extracts from these plants against the brown dog tick, Rhipicephalus sanguineus. A composition analysis of crude extracts by GC-MS was conducted to discover compounds with acaricidal effects. The toxicity of extraction against the engorged nymphs of R. sanguineus was evaluated by an immersion test. The results showed that the crude extracts of S. japonica and C. monnieri in varying ratios, concentrations, and from different extraction methods, had a killing effect on R. sanguineus. Lethality reached 76.67% ± 0.04410 when using a 1:1 extract of S. japonica:C. monnieri in 75% ethanol with ultrasonic extraction; the crude extract was determined at a concentration of 0.5 g/mL. GC-MS results showed that osthole and 5-hydroxymethylfurfural (5-HMF) are the main components of the extract. These results suggested that ultrasound-assisted extraction (UAE) extracts contained acaricidal components acting against R. sanguineus, which may result in the development of effective extracts of S. japonica and C. monnieri as a source of low-toxicity, plant-based, natural acaricidal drugs.

A Novel miRNA-hlo-miR-2-Serves as a Regulatory Factor That Controls Molting Events by Targeting CPR1 in Haemaphysalis longicornis Nymphs.

Successful completion of the molting process requires new epidermal growth and ecdysis of the old cuticle in Haemaphysalis longicornis (H. longicornis). MicroRNAs (miRNAs) participate in the development of organisms by inhibiting the expression of their target mRNAs. In this study, a novel tick-specific miRNA was identified and denoted hlo-miR-2 that serves as a novel regulator of molting events in H. longicornis nymphs by targeting a cuticular protein. The full length of this cuticular protein was first obtained and named it CPR1. A qRT-PCR analysis showed that hlo-miR-2 and CPR1 exhibit significant tissue and temporal specificity and that their transcription levels are negatively correlated during the molting process. CPR1, as a direct target of hlo-miR-2, was identified by a luciferase reporter assay in vitro. Agomir treatment indicated that the overexpression of hlo-miR-2 significantly reduced the protein expression level of CPR1, decreased the molting rate and delayed the molting time point in H. longicornis nymphs. RNA interference (RNAi) experiments demonstrated that CPR1 was significantly associated with the molting process in H. longicornis nymphs. Phenotypic rescue experiments convincingly showed that hlo-miR-2 participated in molting events by targeting CPR1 in H. longicornis nymphs. In summary, we present evidence demonstrating that miRNAs constitute a novel important regulator of molting events in addition to hormones. The described functional evidence implicating CPR1 in molting events contributes to an improved understanding of the distinct functions of the CPR family in ticks and will aid the development of a promising application of cuticular protein RNAi in tick control.

Analysis of microRNA expression profiles dynamic in different life stages of Haemaphysalis longicornis ticks by deep sequencing of small RNA libraries.

The three-host tick Haemaphysalis longicornis is an obligate blood-sucking ectoparasite. In life-stage transitions, microRNAs (miRNAs) show a variety of expression changes. To investigate these changes, deep sequencing technology was applied to identify the conserved and potentially novel miRNAs expressed during the different life stages of H. longicornis. Total RNA from eggs, unfed larvae, unfed nymphs and unfed adults was extracted for deep sequence analysis. Deep sequencing on a Hiseq 4000 generated a total of 111,192,069 reads, grouped into four small RNA (sRNA) libraries, one for each of the four developmental stages of H. longicornis. Among these sequences, 78 conserved and 55 potentially novel miRNAs were identified, including stage-specific and differentially expressed miRNAs. Gene ontology (GO) analysis indicated significantly enriched GO terms related to cell proliferation and differentiation, including specific terms for the processes of development, growth, metabolism, regulation of biological functions, reproduction, and membrane enzyme regular activity. Kyoto Encyclopedia of Gene and Genomes (KEGG) analysis revealed a significant enrichment of the insulin, notch, Hippo, and Wnt signaling pathways for growth and development. Our data highlight the abundance of miRNA changes (conserved and potentially novel) in the different life stages of H. longicornis. In particular, stage-specific miRNAs, as observed, are essential regulators for the development of H. longicornis.

Effects of 7,8-dihydroxyflavone on rat jejunal dynamics subjected to ischaemia-reperfusion injury.

It is known that 7,8-dihydroxyflavone (7,8-DHF), a synthetic agonist specific for TrkB, promotes intestinal cholinergic contraction. However, after intestinal ischaemia-reperfusion (IR) injury, how 7,8-DHF affects intestinal contractile dynamics is unknown. In this study, an IR injury model was prepared with rats subjected to 45 minutes clamping of the superior mesenteric artery. The IR injury decreased postoperative food intake and body weight, delayed defecation time, lowered intestinal propulsive rate and decreased cholinergic contraction of jejunal muscle strips, indicating the occurrence of injured jejunal contraction after IR. Feeding rats with 7,8-DHF improved these intestinal activities injured by IR, which exhibited the in vivo effect of 7,8-DHF. To explore its molecular mechanism, the expression and phosphorylation of TrkB, PLC γ1, Akt, and ERK1/2 in the jejunal strips were examined with western blots. The IR injury significantly decreased the expression and phosphorylation levels of all factors studied here. However, 7,8-DHF feeding specifically enhanced the phosphorylation of TrkB, PLC γ1 and Akt factors in both sham- and IR-operated rats, indicating that 7,8-DHF may have activated TrkB which then activated its downstream PLC γ1 and Akt. Finally, we found that 7,8-DHF augmented cholinergic receptor M3 expression somehow. These results imply a possibility that 7,8-DHF might be capable of alleviating the jejunal contractile damage caused by IR through activation of TrkB and augmentation of M3 expression.

MicroRNA let-7 regulates the expression of ecdysteroid receptor (ECR) in Hyalomma asiaticum (Acari: Ixodidae) ticks.

BACKGROUND: Ticks are blood-sucking arthropods that can transmit diseases to humans and animals. These arthropods are the second most important vectors of pathogens. MicroRNAs are a class of conserved small noncoding RNAs that play regulatory roles in gene expression at the post-transcriptional level. Molting is an important biological process in arthropods. Research on the molting process is important for understanding tick physiology and control. METHODS: Dual-luciferase reporter assays were used to assess the role of miRNA let-7 in ecdysteroid receptor (ECR) biology. The expression levels of ECR and let-7 were measured by real-time qPCR before and after tick molting. To explore the function of let-7 and ECR, we performed overexpression and knocking down of let-7 and RNAi of ECR in tick nymphs. The biological function of let-7 in molting was explored by injecting nymphs, ten days after engorgement, with let-7 agomir for overexpression and let-7 antagomir for knocking down. The rate of molting was then determined. ECR dsRNA was injected into ticks to evaluate the function of ECR by gene silencing. The expression of ECR and let-7 was measured using RT-qPCR. All data were analyzed using GraphPad Prism v.6. RESULTS: The results of the luciferase assay using a eukaryotic expression system revealed that ECR was a natural target of let-7. Let-7 overexpressed by agomir affected the rate of molting (P < 0.01) and the period of molting (P < 0.01). Let-7 antagomir for knockdown affected the period of molting (P < 0.01), but there was no effect on the rate of molting (P = 0.27). ECR dsRNA gene silencing significantly affected the rate of molting (P < 0.05). CONCLUSIONS: This study demonstrated that let-7 can regulate the expression of ECR and that let-7 can affect molting in ticks. Our results help to understand the regulation of let-7 by 20-hydroxyecdysone (20E) and will provide a reference for functional analysis studies of microRNAs in ticks.

Comparative analysis of microRNA profiles between wild and cultured Haemaphysalis longicornis (Acari, Ixodidae) ticks.

The miRNA profiles of a Haemaphysalis longicornis wild-type (HLWS) and of a Haemaphysalis longicornis cultured population (HLCS) were sequenced using the Illumina Hiseq 4000 platform combined with bioinformatics analysis and real-time polymerase chain reaction (RT-PCR). A total of 15.63 and 15.48 million raw reads were acquired for HLWS and HLCS, respectively. The data identified 1517 and 1327 known conserved miRNAs, respectively, of which 342 were differentially expressed between the two libraries. Thirty-six novel candidate miRNAs were predicted. To explain the functions of these novel miRNAs, Gene Ontology (GO) analysis was performed. Target gene function prediction identified a significant set of genes related to salivary gland development, pathogen-host interaction and regulation of the defence response to pathogens expressed by wild H. longicornis ticks. Cellular component biogenesis, the immune system process, and responses to stimuli were represented at high percentages in the two tick libraries. GO enrichment analysis showed that the percentages of most predicted functions of the target genes of miRNA were similar, as were certain specific categories of functional enhancements, and that these genes had different numbers and specific functions (e.g., auxiliary transport protein and electron carrier functions). This study provides novel findings showing that miRNA regulation affects the expression of immune genes, indicating a considerable influence of environment-induced stressful stimulation on immune homeostasis. Differences in the living environments of ticks can lead to differences in miRNAs between ticks and provide a basis and a convenient means to screen for genes encoding immune factors in ticks.

7,8-dihydroxyflavone enhanced cholinergic contraction of rat gastric smooth muscle via augmenting muscarinic M3 receptor expression.

Although 7,8-dihydroxyflavone (7,8-DHF), a synthetic agonist specific for tyrosine kinase receptor B (TrkB), has been reported to promote intestinal dynamics, its effect on gastric dynamics has not been studied as yet. In this study, we explored how 7,8-DHF affected the carbachol (CCh)-induced contraction of rat gastric muscle by way of measuring the contractile tension of muscular strips. We found that although 7,8-DHF did not directly cause contraction of gastric muscle, it enhanced CCh-induced, instead of substance P- or high K+ -induced, contraction. The enhancing role of 7,8-DHF was partially blocked by ANA-12, a blocker specific for TrkB the activation of which in the gastric strips was evidenced by its phosphorylation. Although 7,8-DHF alone did not activate : phospholipase C (PLC)-γ in gastric muscle, CCh did, and importantly, the combined treatment with CCh + 7,8-DHF activated more PLC-γ. U73122, an antagonist to PLC-γ blocked both the CCh-induced and the 7,8-DHF-enhanced/CCh-induced contraction by ~30%. To pursue how 7,8-DHF could augment CCh-activated PLC-γ phosphorylation, we first examined the effect of 7,8-DHF on the expression of muscarinic receptors in gastric muscle and found that 7,8-DHF specifically increased M3 but not M2 receptor expression possibly through TrkB/Akt (protein kinase B) pathway because the Akt antagonist, LY294002 significantly suppressed the 7,8-DHF-augmemted M3 expression and completely blocked the 7,8-DHF-enhanced cholinergic contraction. Supporting the result, Akt phosphorylation in the gastric muscle was enhanced by 7,8-DHF treatment. The in vivo experiment showed that orally fed 7,8-DHF increased gastric emptying rate. The results imply a possibility that 7,8-DHF may be developed into a drug in the future for enhancing gastric dynamics.

Phosphatidylinositol 4,5-bisphosphate, cholesterol, and fatty acids modulate the calcium-activated chloride channel TMEM16A (ANO1).

The TMEM16A-mediated Ca2+-activated Cl- current drives several important physiological functions. Membrane lipids regulate ion channels and transporters but their influence on members of the TMEM16 family is poorly understood. Here we have studied the regulation of TMEM16A by phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2), cholesterol, and fatty acids using patch clamp, biochemistry and fluorescence microscopy. We found that depletion of membrane PI(4,5)P2 causes a decline in TMEM16A current that is independent of cytoskeleton, but is partially prevented by removing intracellular Ca2+. On the other hand, supplying PI(4,5)P2 to inside-out patches attenuated channel rundown and/or partially rescued activity after channel rundown. Also, depletion (with methyl-ß-cyclodextrin M-ßCD) or restoration (with M-ßCD+cholesterol) of membrane cholesterol slows down the current decay observed after reduction of PI(4,5)P2. Neither depletion nor restoration of cholesterol change PI(4,5)P2 content. However, M-ßCD alone transiently increases TMEM16A activity and dampens rundown whereas M-ßCD+cholesterol increases channel rundown. Thus, PI(4,5)P2 is required for TMEM16A function while cholesterol directly and indirectly via a PI(4,5)P2-independent mechanism regulate channel function. Stearic, arachidonic, oleic, docosahexaenoic, and eicosapentaenoic fatty acids as well as methyl stearate inhibit TMEM16A in a dose- and voltage-dependent manner. Phosphatidylserine, a phospholipid whose hydrocarbon tails contain stearic and oleic acids also inhibits TMEM16A. Finally, we show that TMEM16A remains in the plasma membrane after treatment with M-ßCD, M-ßCD+cholesterol, oleic, or docosahexaenoic acids. Thus, we propose that lipids and fatty acids regulate TMEM16A channels through a membrane-delimited protein-lipid interaction.