Phosphodiesterase 8 (PDE8): Distribution and Cellular Expression and Association with Alzheimer's Disease.

Phosphodiesterase 8 (PDE8), as a member of PDE superfamily, specifically promotes the hydrolysis and degradation of intracellular cyclic adenosine monophosphate (cAMP), which may be associated with pathogenesis of Alzheimer's disease (AD). However, little is currently known about potential role in the central nervous system (CNS). Here we investigated the distribution and expression of PDE8 in brain of mouse, which we believe can provide evidence for studying the role of PDE8 in CNS and the relationship between PDE8 and AD. Here, C57BL/6J mice were used to observe the distribution patterns of two subtypes of PDE8, PDE8A and PDE8B, in different sexes in vivo by western blot (WB). Meanwhile, C57BL/6J mice were also used to demonstrate the distribution pattern of PDE8 in selected brain regions and localization in neural cells by WB and multiplex immunofluorescence staining. Furthermore, the triple transgenic (3×Tg-AD) mice and wild type (WT) mice of different ages were used to investigate the changes of PDE8 expression in the hippocampus and cerebral cortex during the progression of AD. PDE8 was found to be widely expressed in multiple tissues and organs including heart, kidney, stomach, brain, and liver, spleen, intestines, and uterus, with differences in expression levels between the two subtypes of PDE8A and PDE8B, as well as two sexes. Meanwhile, PDE8 was widely distributed in the brain, especially in areas closely related to cognitive function such as cerebellum, striatum, amygdala, cerebral cortex, and hippocampus, without differences between sexes. Furthermore, PDE8A was found to be expressed in neuronal cells, microglia and astrocytes, while PDE8B is only expressed in neuronal cells and microglia. PDE8A expression in the hippocampus of both female and male 3×Tg-AD mice was gradually increased with ages and PDE8B expression was upregulated only in cerebral cortex of female 3×Tg-AD mice with ages. However, the expression of PDE8A and PDE8B was apparently increased in both cerebral cortex and hippocampus in both female and male 10-month-old 3×Tg-AD mice compared WT mice. These results suggest that PDE8 may be associated with the progression of AD and is a potential target for its prevention and treatment in the future.

Effects of an integrated ambulatory care program on healthcare utilization and costs in older patients with multimorbidity: a propensity score-matched cohort study.

BACKGROUND: Population aging has increased the prevalence of multimorbidity, jeopardizing the sustainability and efficiency of healthcare systems. This study aimed to evaluate the effects of an integrated ambulatory care program (IACP) on healthcare utilization and costs among older patients with multimorbidity while accounting for the confounding effects of frailty. METHODS: A retrospective cohort study using propensity matching including patients aged 65 or older with two or more chronic conditions attending the outpatient clinic at our hospital between June 1 and December 31, 2019, was conducted. Exposure was defined as receipt of IACP care. Patients not undergoing the IACP comprised the unexposed group and were matched at a ratio of 1:4 to patients undergoing the IACP group according to sex, age, Charlson Comorbidity Index score, multimorbidity frailty index score, and number of outpatient visits within 6 months before the index date. Outcomes were changes in healthcare utilization and related costs between 6 months before and after receiving IACP care. Multivariate regression analyses were used for data analysis and the Generalized Estimation Equation method was used to fit the regression models. RESULTS: A total of 166 (IACP) and 664 (non-exposed) patients were analyzed. The mean participant baseline ages were 77.15 ± 7.77 (IACP) and 77.28 ± 7.90 years (unexposed). In univariate analyses, the IACP group demonstrated greater reductions than the unexposed group in the frequency of outpatient visits (-3.16 vs. -1.36, p < 0.001), number of physicians visited (-0.99 vs. -0.17, p < 0.001), diagnostic fees (-1300 New Taiwan Dollar [NTD] vs. -520 NTD, p < 0.001), drug prescription fees (-250 NTD vs. -70 NTD, p < 0.001), and examination fees (-1620 NTD vs. -700 NTD, p = 0.014). Multivariate analyses demonstrated that patients in the IACP group experienced significant reduction in the frequency of outpatient visits (95% CI: -0.357 to -0.181, p < 0.001), number of physicians visited (95% CI: -0.334 to -0.199, p < 0.001), and overall outpatient costs (95% CI: -0.082 to -0.011, p = 0.01). However, emergency department utilization, hospitalization, and costs did not differ significantly. CONCLUSIONS: Expanding IACPs may help patients with multimorbidity reduce their use of outpatient clinics at the 6-month follow-up, reduce care fragmentation, and promote sustainability of the healthcare system.

A2AR-mediated lymphangiogenesis via VEGFR2 signaling prevents salt-sensitive hypertension.

AIMS: Excess dietary sodium intake and retention lead to hypertension. Impaired dermal lymphangiogenesis and lymphatic dysfunction-mediated sodium and fluid imbalance are pathological mechanisms. The adenosine A2A receptor (A2AR) is expressed in lymphatic endothelial cells (LECs), while the roles and mechanisms of LEC-A2AR in skin lymphangiogenesis during salt-induced hypertension are not clear. METHODS AND RESULTS: The expression of LEC-A2AR correlated with lymphatic vessel density in both high-salt diet (HSD)-induced hypertensive mice and hypertensive patients. Lymphatic endothelial cell-specific A2AR knockout mice fed HSD exhibited 17 ± 2% increase in blood pressure and 17 ± 3% increase in Na+ content associated with decreased lymphatic density (-19 ± 2%) compared with HSD-WT mice. A2AR activation by agonist CGS21680 increased lymphatic capillary density and decreased blood pressure in HSD-WT mice. Furthermore, this A2AR agonist activated MSK1 directly to promote VEGFR2 activation and endocytosis independently of VEGF as assessed by phosphoprotein profiling and immunoprecipitation assays in LECs. VEGFR2 kinase activity inhibitor fruquintinib or VEGFR2 knockout in LECs but not VEGF-neutralizing antibody bevacizumab suppressed A2AR activation-mediated decrease in blood pressure. Immunostaining revealed phosphorylated VEGFR2 and MSK1 expression in the LECs were positively correlated with skin lymphatic vessel density and A2AR level in hypertensive patients. CONCLUSION: The study highlights a novel A2AR-mediated VEGF-independent activation of VEGFR2 signaling in dermal lymphangiogenesis and sodium balance, which might be a potential therapeutic target in salt-sensitive hypertension.

Antiviral Effect of Extracellular Matrix Protein ABI3BP on Vesicular Stomatitis Virus and Its Mechanism: A Preliminary Study In Vitro.

Objective To explore the influence of extracellular matrix protein ABI-interactor 3-binding protein (ABI3BP) on vesicular stomatitis virus (VSV) genome replication and innate immune signaling pathway.Methods The small interfering RNA (siRNA) was transfected to knock down ABI3BP gene in human skin fibroblast BJ-5ta cells. VSV-green fluorescent protein (VSV-GFP)-infected cell model was established. The morphological changes and F-actin stress fiber formation were detected on ABI3BP knockdown cells by phalloidin immunofluorescence staining. The mRNA level of virus replication was detected by RT-qPCR in BJ-5ta cells after VSV-GFP infection; western blotting was performed to detect the changes in interferon regulatory factor 3 (IRF3) and TANK-binding kinase 1 (TBK1) phosphorylation levels.Results The VSV-GFP-infected BJ-5ta cell model was successfully established. Efficient knockdown of ABI3BP in BJ-5ta cells was achieved. Phalloidin immunofluorescence staining revealed structural rearrangement of intracellular F-actin after ABI3BP gene knockdown. Compared with the control group, the gene copy number of VSV-GFP in ABI3BP knockdown cells increased by 2.2 - 3.5 times (P<0.01) and 2.2 - 4.0 times (P<0.01) respectively when infected with VSV of multiplicity of infection 0.1 and 1. The expression of viral protein significantly increased in ABI3BP knockdown cells after virus infection. The activation of type-I interferon pathway, as determined by phosphorylated IRF3 and phosphorylated TBK1, was significantly decreased in ABI3BP knockdown cells after VSV-GFP infection.Conclusions Extracellular matrix protein ABI3BP plays an important role in maintaining the formation and rearrangement of actin structure. ABI3BP gene deletion promotes RNA virus replication, and ABI3BP is an important molecule that maintains the integrity of type I interferon pathway.

Palmitic acid induces GSDMD-mediated pyroptosis in periodontal ligament cells via the NF-κB pathway.

OBJECTIVE: Obesity can affect periodontal tissues and exacerbate periodontitis. Pyroptosis, a newly identified type of inflammatory cell death, is involved in the development of periodontal inflammation. The saturated fatty acid palmitic acid (PA) is elevated in obese patients. The effect of PA on pyroptosis in periodontal ligament cells (PDLCs) and its underlying mechanisms remain unknown. MATERIALS AND METHODS: Human PDLCs were isolated from healthy individuals and cultured for experiments. The effects of PA on PDLC pyroptosis and the underlying mechanisms were examined by transmission electron microscopy, quantitative real-time PCR and western blotting. RESULTS: The morphology of PDLCs in the PA group indicated pyroptotic characteristics, including swollen cells, plasma membrane rupture and changes in subcellular organelles. PA induced inflammatory responses in PDLCs, as indicated by an increase in IL-1ß in the cell culture supernatant. Furthermore, we found that the pyroptosis-related proteins caspase-1, caspase-4 and GSDMD were involved in PA-induced cell death. GSDMD and caspase-4 inhibitors alleviated pyroptotic death of PDLCs. Moreover, PA promoted NF-κB P65 phosphorylation. A NF-κB inhibitor decreased IL-1ß expression and partly rescued cell death induced by PA. CONCLUSION: PA activated the NF-κB pathway and induced the inflammatory response in PDLCs. Caspase-4/GSDMD mediated PDLC pyroptosis induced by PA.

Imbalance of multiple neurotransmitter pathways leading to depression-like behavior and cognitive dysfunction in the triple transgenic mouse model of Alzheimer disease.

Depression is among the most frequent psychiatric comorbid conditions in Alzheimer disease (AD). However, pharmacotherapy for depressive disorders in AD is still a big challenge, and the data on the efffcacy of current antidepressants used clinically for depressive symptoms in patients with AD remain inconclusive. Here we investigated the mechanism of the interactions between depression and AD, which we believe would aid in the development of pharmacological therapeutics for the comorbidity of depression and AD. Female APP/PS1/Tau triple transgenic (3×Tg-AD) mice at 24 months of age and age- and sex-matched wild-type (WT) mice were used. The shuttle-box passive avoidance test (PAT) were implemented to assess the abilities of learning and memory, and the open field test (OFT) and the tail suspension test (TST) were used to assess depression-like behavior. High-performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS) was used to detect the level of neurotransmitters related to depression in the hippocampus of mice. The data was identified by orthogonal projections to latent structures discriminant analysis (OPLS-DA). Most neurotransmitters exert their effects by binding to the corresponding receptor, so the expression of relative receptors in the hippocampus of mice was detected using Western blot. Compared to WT mice, 3×Tg-AD mice displayed significant cognitive impairment in the PAT and depression-like behavior in the OFT and TST. They also showed significant decreases in the levels of L-tyrosine, norepinephrine, vanillylmandelic acid, 5-hydroxytryptamine, and acetylcholine, in contrast to significant increases in 5-hydroxyindoleacetic acid, L-histidine, L-glutamine, and L-arginine in the hippocampus. Moreover, the expression of the alpha 1a adrenergic receptor (ADRA1A), serotonin 1 A receptor (5HT1A), and γ-aminobutyric acid A receptor subunit alpha-2 (GABRA2) was significantly downregulated in the hippocampus of 3×Tg-AD mice, while histamine H3 receptor (H3R) expression was significantly upregulated. In addition, the ratio of phosphorylated cAMP-response element-binding protein (pCREB) and CREB was significantly decreased in the hippocampus of 3×Tg-AD mice than WT mice. We demonstrated in the present study that aged female 3×Tg-AD mice showed depression-like behavior accompanied with cognitive dysfunction. The complex and diverse mechanism appears not only relevant to the imbalance of multiple neurotransmitter pathways, including the transmitters and receptors of the monoaminergic, GABAergic, histaminergic, and cholinergic systems, but also related to the changes in L-arginine and CREB signaling molecules.

Genetic connection of carotid atherosclerosis with coat color and body weight in an intercross between hyperlipidemic mouse strains.

Atherosclerosis in the carotid artery is a major cause of ischemic stroke and has a strong genetic component. The aim of this study was to identify genetic factors contributing to carotid atherosclerosis. One hundred fifty-four female F2 mice were generated from an intercross between LP/J and BALB/cJ Apoe-null (Apoe-/-) mice and fed 12 wk of Western diet. Atherosclerotic lesions, body weight, and coat color were measured and genotyping was performed using miniMUGA genotyping arrays. A significant quantitative trait locus (QTL) on chromosome (Chr) 7, named Cath20, and five suggestive QTL on Chr 6, 12, 13, 15, and X were identified for carotid lesions. Three significant QTL, Bwfq2, Bw1n, Bwtq6, on Chr 2, 7, and 15 were identified for body weight. Two significant QTL, Chop2 and Albc2, on Chr 4 and 7 were identified for coat color, with Tyr, encoding tyrosinase, being the causal gene of Albc2. Cath20 overlapped with or was close to QTL Bw1n and Albc2 on Chr7. Carotid lesion sizes were significantly correlated with body weight and graded coat color in F2 mice. Cath20 on Chr7 disappeared after adjustment for coat color but remained after adjustment for body weight. Tyr was abundantly expressed in atherosclerotic lesions. These results demonstrate genetic connections of carotid atherosclerosis with body weight and coat color in hyperlipidemic mice and suggest a potential role for Tyr in carotid atherosclerosis.

Factors associated with early 14-day unplanned hospital readmission: a matched case-control study.

BACKGROUND/PURPOSE: Early unplanned hospital readmissions are burdensome health care events and indicate low care quality. Identifying at-risk patients enables timely intervention. This study identified predictors for 14-day unplanned readmission. METHODS: We conducted a retrospective, matched, case-control study between September 1, 2018, and August 31, 2019, in an 1193-bed university hospital. Adult patients aged ≥ 20 years and readmitted for the same or related diagnosis within 14 days of discharge after initial admission (index admission) were included as cases. Cases were 1:1 matched for the disease-related group at index admission, age, and discharge date to controls. Variables were extracted from the hospital's electronic health records. RESULTS: In total, 300 cases and 300 controls were analyzed. Six factors were independently associated with unplanned readmission within 14 days: previous admissions within 6 months (OR = 3.09; 95 % CI = 1.79-5.34, p < 0.001), number of diagnoses in the past year (OR = 1.07; 95 % CI = 1.01-1.13, p = 0.019), Malnutrition Universal Screening Tool score (OR = 1.46; 95 % CI = 1.04-2.05, p = 0.03), systolic blood pressure (OR = 0.98; 95 % CI = 0.97-0.99, p = 0.01) and ear temperature within 24 h before discharge (OR = 2.49; 95 % CI = 1.34-4.64, p = 0.004), and discharge with a nasogastric tube (OR = 0.13; 95 % CI = 0.03-0.60, p = 0.009). CONCLUSIONS: Factors presented at admission (frequent prior hospitalizations, multimorbidity, and malnutrition) along with factors presented at discharge (clinical instability and the absence of a nasogastric tube) were associated with increased risk of early 14-day unplanned readmission.

Predictive modeling for 14-day unplanned hospital readmission risk by using machine learning algorithms.

BACKGROUND: Early unplanned hospital readmissions are associated with increased harm to patients, increased medical costs, and negative hospital reputation. With the identification of at-risk patients, a crucial step toward improving care, appropriate interventions can be adopted to prevent readmission. This study aimed to build machine learning models to predict 14-day unplanned readmissions. METHODS: We conducted a retrospective cohort study on 37,091 consecutive hospitalized adult patients with 55,933 discharges between September 1, 2018, and August 31, 2019, in an 1193-bed university hospital. Patients who were aged < 20 years, were admitted for cancer-related treatment, participated in clinical trial, were discharged against medical advice, died during admission, or lived abroad were excluded. Predictors for analysis included 7 categories of variables extracted from hospital's medical record dataset. In total, four machine learning algorithms, namely logistic regression, random forest, extreme gradient boosting, and categorical boosting, were used to build classifiers for prediction. The performance of prediction models for 14-day unplanned readmission risk was evaluated using precision, recall, F1-score, area under the receiver operating characteristic curve (AUROC), and area under the precision-recall curve (AUPRC). RESULTS: In total, 24,722 patients were included for the analysis. The mean age of the cohort was 57.34 ± 18.13 years. The 14-day unplanned readmission rate was 1.22%. Among the 4 machine learning algorithms selected, Catboost had the best average performance in fivefold cross-validation (precision: 0.9377, recall: 0.5333, F1-score: 0.6780, AUROC: 0.9903, and AUPRC: 0.7515). After incorporating 21 most influential features in the Catboost model, its performance improved (precision: 0.9470, recall: 0.5600, F1-score: 0.7010, AUROC: 0.9909, and AUPRC: 0.7711). CONCLUSIONS: Our models reliably predicted 14-day unplanned readmissions and were explainable. They can be used to identify patients with a high risk of unplanned readmission based on influential features, particularly features related to diagnoses. The operation of the models with physiological indicators also corresponded to clinical experience and literature. Identifying patients at high risk with these models can enable early discharge planning and transitional care to prevent readmissions. Further studies should include additional features that may enable further sensitivity in identifying patients at a risk of early unplanned readmissions.

Difference in demographics and motivation to study medicine with respect to medical students' channel of admission: A national study.

INTRODUCTION: Medical schools employ various tools to select suitable medical students (MS). This study investigated whether MS who were admitted through multiple mini-interviews (MMI) and MS who were admitted through Taiwan's Joint College Entrance Written Test (JCEWT) differed in their characteristics. METHODS AND SUBJECTS: First-year MS from seven medical schools completed a semi-structured questionnaire that inquired into their channel of admission (MMI or JCEWT), gender, location (metropolitan or rural), high school type (public or private), parents' socioeconomic status (SES), and motivations to study medicine. RESULTS: In total, 513 MS participated, 493 (96%) returned valid questionnaires, and 397 were enrolled in the study, (MMI group: 205 MS; JCEWT group: 192 MS). Irrespective of channel of admission, most MS came from metropolitan areas (80%-86%), belonged to high-SES families (73%-76%), and had mixed motivations (51%-96%). Female applicants, private school leavers, and those who were less motivated by the physician's SES were more likely to be selected through the MMI channel than the JCEWT channel. CONCLUSION: Irrespective of the channels of entry, MS had similar demographics and motivations for studying medicine. MS selected through MMI had different characteristics than those selected through a JCEWT.