Oligodendrocyte Precursor Cells Support Blood-Brain Barrier Integrity via TGF-β Signaling

Trophic coupling between cerebral endothelium and their neighboring cells is required for the development and maintenance of blood-brain barrier (BBB) function. Here we report that oligodendrocyte precursor cells (OPCs) secrete soluble factor TGF-β1 to support BBB integrity. Firstly, we prepared conditioned media from OPC cultures and added them to cerebral endothelial cultures. Our pharmacological experiments showed that OPC-conditioned media increased expressions of tight-junction proteins and decreased in vitro BBB permeability by activating TGB-β-receptor-MEK/ERK signaling pathway. Secondly, our immuno-electron microscopic observation revealed that in neonatal mouse brains, OPCs attach to cerebral endothelial cells via basal lamina. And finally, we developed a novel transgenic mouse line that TGF-β1 is knocked down specifically in OPCs. Neonates of these OPC-specific TGF-β1 deficient mice (OPC-specific TGF-β1 partial KO mice: PdgfraCre/Tgfb1flox/wt mice or OPC-specific TGF-β1 total KO mice: PdgfraCre/Tgfb1flox/flox mice) exhibited cerebral hemorrhage and loss of BBB function. Taken together, our current study demonstrates that OPCs increase BBB tightness by upregulating tight junction proteins via TGF-β signaling. Although astrocytes and pericytes are well-known regulators of BBB maturation and maintenance, these findings indicate that OPCs also play a pivotal role in promoting BBB integrity

CD200 restrains macrophage attack on oligodendrocyte precursors via toll-like receptor 4 downregulation

There are numerous barriers to white matter repair after CNS injury and the underlying mechanisms remain to be fully understood. In this study, we propose the hypothesis that inflammatory macrophages in damaged white matter attack oligodendrocyte precursor cells (OPCs) via TLR4 signaling thus interfering with this endogenous progenitor recovery mechanism. Primary cell culture experiments demonstrate that peritoneal macrophages can attack and digest OPCs via TLR4 signaling, and this phagocytosis of OPCs can be inhibited by using CD200-Fc to downregulate TLR4. In an in vivo model of white matter ischemia induced by endothelin-1, treatment with D200-Fc suppressed TLR4 expression in peripherally circulating macrophages, thus restraining macrophage phagocytosis of OPCs and leading to improved myelination. Taken together, these findings suggest that deleterious macrophage effects may occur after white matter ischemia, whereby macrophages attack OPCs and interfere with endogenous recovery responses. Targeting this pathway with CD200 may offer a novel therapeutic approach to amplify endogenous OPC-mediated repair of white matter damage in mammalian brain

Reactive astrocytes promote adhesive interactions between brain endothelium and endothelial progenitor cells via HMGB1 and beta-2 integrin signaling

Endothelial progenitor cells (EPCs) may contribute to neurovascular repair after stroke and neurodegeneration. A key step in this process should involve adhesive interactions between EPCs and the targeted cerebral endothelium. Here, we tested the hypothesis that reactive astrocytes may play a critical role in enhancing adhesive interactions and transmigration of EPCs across cerebral endothelial cells. Transiently seeding EPCs onto a monolayer of RBE.4 rat brain endothelial cells resulted in a time-dependent adherence between the two cell types. Blocking β2 integrins on EPCs or blocking the receptor for advanced glycation endproducts (RAGE) on endothelial cells significantly decreased EPC-endothelial adherence. Next, we tested whether reactive astrocytes can enhance this process by growing EPCs, brain endothelial cells and astrocytes together in a transwell co-culture system. The presence of reactive astrocytes in the lower chamber significantly promoted adherence between EPCs and endothelial cells in the upper chamber. This process involved the release of soluble HMGB1 from reactive astrocytes that then upregulated endothelial expression of RAGE via Egr1 signaling. Directly adding HMGB1 to the transwell system also promoted EPC-endothelial adhesion and accelerated EPC transmigration into the lower chamber. These initial findings provide proof-of-concept that reactive astrocytes promote crosstalk between cerebral endothelium and EPCs. Further investigation of this phenomenon may lead to a better understanding of cell–cell interactions required for neurovascular recovery after stroke

Exploratory Assessment of SUDS Feasibility in Nhieu Loc-Thi Nghe Basin, Ho Chi Minh City, Vietnam

Aims: In recent decades, Ho Chi Minh City, Vietnam, frequently has been affected by local floods and inundation from heavy rainfall. Conventional flood mitigation measures such as building flood gates and upgrading sewerage systems have been implemented but problems persist. The objective of this research is to assess another approach for flood control measures, namely Sustainable Urban Drainage Systems (SUDS), with application to the Nhieu Loc - Thi Nghe Basin, located in the central part of Ho Chi Minh City.Methodology: A combination of the Stormwater Management Model (PCSWMM) and interviews with 140 households was used to assess the efficacy and acceptability of four of the most popular SUDS: Rainwater harvesting, green roofs, urban green space and pervious pavement. Thirteen SUDS and urban build-out scenarios were simulated under 6 design storm conditions.Results: PCSWMM results showed that inundation from intense rainfall could be reduced with proper land-use control, specifically by maintaining imperviousness at 65% or less of the surface area. With respect to SUDS performance, green roofs were best at reducing peak runoff (22% reduction), followed by pervious pavement, urban green space, and rainwater harvesting systems. Regarding environmental improvements, as represented by reduction in total suspended solids load, urban green space was best with 20% of the solids load removed compared to the base case scenario, followed by green roofs, pervious pavement, and rainwater harvesting. The household interviews revealed the majority of people preferred pervious pavement to the other SUDS options and the least preferred option was green roof technology.Conclusion: Considering the combination of water quantity and water quality controls, it seems that green roof technology was the best performer for this area of Ho Chi Minh City, followed by urban green space, pervious pavement and rainwater harvesting. However, green roof technology also was the least favored option for the public and stakeholder acceptance will impact SUDS implementation

Preliminary Observation of Native Glyptostrobus pensilis (Taxodiaceae) Stands in Vietnam

Results of preliminary studies of last remnants of Glyptostrobus pensilis native populations in Vietnam are presented in the paper in form of standard taxonomical treatment with comments on ecology, population structure and natural conditions of its habitats. Perspectives of conservation of this unique Tertiary relict are specially assessed and discussed

Job satisfaction of hospital pharmacists in a representative province in Mekong Delta, Vietnam.

BackgroundJob satisfaction is an important factor affecting job performance and turnover of healthcare workers, especially hospital pharmacists. Nevertheless, limited studies have reported this issue in the context of Vietnam.ObjectivesTo help maintain the quality and size of the limited hospital pharmacy workforce in Vietnam, especially in the Mekong Delta area, this study investigated the job satisfaction of hospital pharmacists, and the associated factors, in Vinh Long province, a representative province in the central Mekong Delta.MethodsA cross-sectional survey was conducted, recruiting hospital pharmacists working in all 17 province/district-affiliated healthcare facilities across Vinh Long province, Vietnam, between August and September 2022.ResultsAmong the 235 survey participants (representing a response rate of 97.1%), 189 pharmacists (80.4%) reported that they were satisfied with their job. Working conditions, leadership styles, and benefits were factors found to significantly influence job satisfaction. Pharmacists who had worked in the field for 3-5 years (OR = 3.752, 95% CI = 1.036-13.595), more than 5 years (OR = 6.361, 95% CI = 2.264-17.875), did not have additional duties besides their primary responsibilities (OR = 2.046, 95% CI = 1.005-4.163), and worked in a private healthcare facility (OR = 12.021, 95% CI = 1.470-98.316), were significantly more likely to be satisfied with their job.ConclusionsMost hospital pharmacists were satisfied with their current job. To further improve job satisfaction in this population, further improvements to working conditions are necessary

Satisfaction of the surveyed hospital pharmacists (in percentages) in Vinh Long, Vietnam, separated by job activity (n = 235).

The relationship (Chi-squared test) between the drug storage/distribution activity and pharmacists’ satisfaction is p = 0.325. Other relationships were not determined due to the small percentages of responses.</p

Sociodemographic and job-related characteristics of the participated hospital pharmacists, in terms of frequency (n) and percentage (%) (n = 235); and uni-/multivariate regression analyses on the relationships between these characteristics and the pharmacists’ job satisfaction.

Sociodemographic and job-related characteristics of the participated hospital pharmacists, in terms of frequency (n) and percentage (%) (n = 235); and uni-/multivariate regression analyses on the relationships between these characteristics and the pharmacists’ job satisfaction.</p

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BackgroundJob satisfaction is an important factor affecting job performance and turnover of healthcare workers, especially hospital pharmacists. Nevertheless, limited studies have reported this issue in the context of Vietnam.ObjectivesTo help maintain the quality and size of the limited hospital pharmacy workforce in Vietnam, especially in the Mekong Delta area, this study investigated the job satisfaction of hospital pharmacists, and the associated factors, in Vinh Long province, a representative province in the central Mekong Delta.MethodsA cross-sectional survey was conducted, recruiting hospital pharmacists working in all 17 province/district-affiliated healthcare facilities across Vinh Long province, Vietnam, between August and September 2022.ResultsAmong the 235 survey participants (representing a response rate of 97.1%), 189 pharmacists (80.4%) reported that they were satisfied with their job. Working conditions, leadership styles, and benefits were factors found to significantly influence job satisfaction. Pharmacists who had worked in the field for 3–5 years (OR = 3.752, 95% CI = 1.036–13.595), more than 5 years (OR = 6.361, 95% CI = 2.264–17.875), did not have additional duties besides their primary responsibilities (OR = 2.046, 95% CI = 1.005–4.163), and worked in a private healthcare facility (OR = 12.021, 95% CI = 1.470–98.316), were significantly more likely to be satisfied with their job.ConclusionsMost hospital pharmacists were satisfied with their current job. To further improve job satisfaction in this population, further improvements to working conditions are necessary.</div