Evaluation of Latent Tuberculosis Infection Using the ESAT6-CFP10 Skin Test Among International Freshmen With Diverse Skin Tones at a University - Nanjing City, Jiangsu Province, China, September 2023.

Introduction: Newer skin tests, including the ESAT6-CFP10 (EC) skin test, were recommended for diagnosing Mycobacterium tuberculosis (M. tb) infection. However, no data exist assessing the diagnostic performance of the EC skin test among foreign students with different skin tones. Methods: A cohort study at Nanjing Medical University screened incoming foreign freshmen. The EC skin test was used to assess for M. tb infection, and results were read at 24, 48, 72, and 96-hours post-administration. Results: Among 96 participants, M. tb infection rates at 24, 48, 72, and 96-hours post-injection were 3.13%, 7.29%, 13.54%, and 9.38%, respectively. While infection rates were lower among individuals with darker skin tones, the difference was not statistically significant (P=0.186), and variations were consistent across different measurement times. Trajectory analysis revealed 5.3% in the continuous-increasing group, 86.5% in the low-stable group, and 5.2% in the elevated-decreasing group. Notably, participants in the elevated-decreasing group had lighter skin tones, with trajectory patterns consistent across different skin colors. Discussion: The EC skin test is safe, and redness diameter is a more reliable indicator than induration. Results should be collected within 48 to 72 hours, with verification at 72 hours crucial if initial results are negative. Importantly, skin color does not affect EC skin test outcomes.

Dietary bile acids supplementation decreases hepatic fat deposition with the involvement of altered gut microbiota and liver bile acids profile in broiler chickens.

BACKGROUND: High-fat diets (HFD) are known to enhance feed conversion ratio in broiler chickens, yet they can also result in hepatic fat accumulation. Bile acids (BAs) and gut microbiota also play key roles in the formation of fatty liver. In this study, our objective was to elucidate the mechanisms through which BA supplementation reduces hepatic fat deposition in broiler chickens, with a focus on the involvement of gut microbiota and liver BA composition. RESULTS: Newly hatched broiler chickens were allocated to either a low-fat diet (LFD) or HFD, supplemented with or without BAs, and subsequently assessed their impacts on gut microbiota, hepatic lipid metabolism, and hepatic BA composition. Our findings showed that BA supplementation significantly reduced plasma and liver tissue triglyceride (TG) levels in 42-day-old broiler chickens (P < 0.05), concurrently with a significant decrease in the expression levels of fatty acid synthase (FAS) in liver tissue (P < 0.05). These results suggest that BA supplementation effectively diminishes hepatic fat deposition. Under the LFD, BAs supplementation increased the BA content and ratio of Non 12-OH BAs/12-OH BAs in the liver and increased the Akkermansia abundance in cecum. Under the HFD, BA supplementation decreased the BAs and increased the relative abundances of chenodeoxycholic acid (CDCA) and cholic acid (CA) in hepatic tissue, while the relative abundances of Bacteroides were dramatically reduced and the Bifidobacterium, Escherichia, and Lactobacillus were increased in cecum. Correlation analyses showed a significant positive correlation between the Akkermansia abundance and Non 12-OH BA content under the LFD, and presented a significant negative correlation between the Bacteroides abundance and CA or CDCA content under the HFD. CONCLUSIONS: The results indicate that supplementation of BAs in both LFD and HFD may ameliorate hepatic fat deposition in broiler chickens with the involvement of differentiated microbiota-bile acid profile pathways.

Effects of TET2-mediated methylation reconstruction on A2058 melanoma cell sensitivity to matrix stiffness in a 3D culture system.

Matrix stiffness is a crucial factor in the tumor microenvironment, impacting tumor progression and development. TET2 is vital for epigenetic regulation in melanoma and is significantly reduced in advanced melanomas compared with nevi and thin melanomas. However, it is unclear how TET2 mediates the effect of matrix stiffness on melanoma cells. This study utilized A2058 cell lines and prepared different stiffness collagen hydrogels to evaluate TET2 overexpression (TET2OE) and mutant (TET2M) melanoma cells' activity, proliferation, and invasion. A2058 melanoma cells' viability and invasion decreased with increased matrix stiffness, with TET2OE cells experiencing a more significant impact than TET2M cells. Methylation analysis revealed that TET2 determines gene methylation levels, influencing cell-ECM interactions. Transcriptome analysis confirmed that TET2 promotes matrix stiffness's effect on melanoma cell fate. This research provides promising directions and opportunities for melanoma treatment.

Activation of P2X7 Receptor Mediates the Abnormal Ovulation Induced by Chronic Restraint Stress and Chronic Cold Stress.

Chronic stress has become a major problem that endangers people's physical and mental health. Studies have shown that chronic stress impairs female reproduction. However, the related mechanism is not fully understood. P2X7 receptor (P2X7R) is involved in a variety of pathological changes induced by chronic stress. Whether P2X7R is involved in the effect of chronic stress on female reproduction has not been studied. In this study, we established a chronic restraint stress mouse model and chronic cold stress mouse model. We found that the number of corpora lutea was significantly reduced in the two chronic stress models. The number of corpora lutea indirectly reflects the ovulation, suggesting that chronic stress influences ovulation. P2X7R expression was significantly increased in ovaries of the two chronic stress models. A superovulation experiment showed that P2X7R inhibitor A-438079 HCL partially rescued the ovulation rate of the two chronic stress models. Further studies showed that activation of P2X7R signaling inhibited the cumulus expansion and promoted the expression of NPPC in granulosa cells, one key negative factor of cumulus expansion. Moreover, sirius red staining showed that the ovarian fibrosis was increased in the two chronic stress models. For the fibrosis-related factors, TGF-ß1 was increased and MMP2 was decreased. In vitro studies also showed that activation of P2X7R signaling upregulated the expression of TGF-ß1 and downregulated the expression of MMP2 in granulosa cells. In conclusion, P2X7R expression was increased in the ovaries of the chronic restraint-stress and chronic cold-stress mouse models. Activation of P2X7R signaling promoted NPPC expression and cumulus expansion disorder, which contributed to the abnormal ovulation of the chronic stress model. Activation of P2X7R signaling is also associated with the ovarian fibrosis changes in the chronic stress model.

Ambient air pollution contributed to pulmonary tuberculosis in China.

Published studies on outdoor air pollution and tuberculosis risk have shown heterogeneous results. Discrepancies in prior studies may be partially explained by the limited geographic scope, diverse exposure times, and heterogeneous statistical methods. Thus, we conducted a multi-province, multi-city time-series study to comprehensively investigate this issue. We selected 67 districts or counties from all geographic regions of China as study sites. We extracted data on newly diagnosed pulmonary tuberculosis (PTB) cases, outdoor air pollutant concentrations, and meteorological factors in 67 sites from January 1, 2014 to December 31, 2019. We utilized a generalized additive model to evaluate the relationship between ambient air pollutants and PTB risk. Between 2014 and 2019, there were 172,160 newly diagnosed PTB cases reported in 67 sites. With every 10-µg/m3 increase in SO2, NO2, PM10, PM2.5, and 1-mg/m3 in CO, the PTB risk increased by 1.97% [lag 0 week, 95% confidence interval (CI): 1.26, 2.68], 1.30% (lag 0 week, 95% CI: 0.43, 2.19), 0.55% (lag 8 weeks, 95% CI: 0.24, 0.85), 0.59% (lag 10 weeks, 95% CI: 0.16, 1.03), and 5.80% (lag 15 weeks, 95% CI: 2.96, 8.72), respectively. Our results indicated that ambient air pollutants were positively correlated with PTB risk, suggesting that decreasing outdoor air pollutant concentrations may help to reduce the burden of tuberculosis in countries with a high burden of tuberculosis and air pollution.

Long-term agricultural cultivation decreases microbial nutrient limitation in coastal saline soils.

Soil enzyme activities are pivotal for diverse biochemical processes and are sensitive to land use changes. They can indicate soil microbial nutrient limitations. Nonetheless, the mechanism governing the response of soil microbial nutrient limitation to land use alterations in coastal regions remains elusive. We assessed soil nutrients, microbial biomass, and extracellular enzyme activities across various land use types-natural (wasteland and woodland) and agricultural (farmland and orchard)-in the Hangzhou Bay area, China. All four land use types experience co-limitation by carbon (C) and phosphorus (P). However, the extent of microbial resource limitations varies among them. Long-term agricultural practices diminish microbial C and P limitations in farmland and orchard soils compared to natural soils, as evidenced by lower ecoenzymatic C:N ratios and vector lengths, alongside higher microbial carbon use efficiency (CUE). Soil nutrient stoichiometric ratios and CUE are primary factors influencing microbial C and P limitations. Thus, fostering appropriate land use and management practices proves imperative to regulate soil nutrient cycles and foster the sustainable management of coastal areas.

Mechanism of acupuncture and moxibustion in ameliorating liver injury induced by cisplatin by regulating IRE-1 signaling pathway. / "扶正益肝"é’ˆç¸ç©´æ–¹åŸºäºŽè‚Œé†‡éœ€æ±‚é ¶1ä¿¡å·é€šè·¯æ”¹å–„é¡ºé“‚è‡´å°é¼ è‚æŸä¼¤çš„æœºåˆ¶.

OBJECTIVES: To investigate the mechanism of the effect of acupuncture and moxibustion on improving liver injury in cisplatin (DDP) induced liver injury model mice by observing the changes of inositol-requiring enzyme (IRE) -1 signaling pathway. METHODS: Forty KM mice were randomly divided into control, model, acupuncture and moxibustion groups, with 10 mice in each group. The liver injury model was replicated by intraperitoneal injection of DDP (10 mg/kg). In the acupuncture group and the moxibustion group, acupuncture and moxibustion were performed at "Dazhui"(GV14), and bilateral "Ganshu"(BL18), "Shenshu" (BL23), and "Zusanli"(ST36), respectively for 6 min, once per day for 7 d. The apoptosis of hepatocytes was detected by TUNEL staining. The expression of phosphorylation(p)-IRE-1α, glucose-regulated protein (Grp) 78 and cysteine aspartic protease (Caspase) -12 in liver tissue were detected by immunohistochemistry and Western blot, respectively. The expression levels of Grp78 and Caspase-12 mRNA in liver tissue were detected by quantitative real-time PCR. RESULTS: Compared with the control group, the apoptosis rate of hepatocytes was increased (P<0.05), the positive expression and protein expression of p-IRE-1α, Grp78, and Caspase-12 were increased (P<0.05), the expression levels of Grp78 and Caspase-12 mRNA were increased (P<0.05) in the model group. Compared with the model group, all these indicators showed opposite trends (P<0.05) in the acupuncture and moxibustion groups. CONCLUSIONS: Acupuncture and moxibustion can reduce liver injury due to DDP chemotherapy by modulating IRE-1 signaling pathway, inhibiting the excessive activation of endoplasmic reticulum stress, and reducing liver cell apoptosis.

[Exploration of cancer biological characteristics in people with different five movements and six climates constitution based on pan-cancer Bulk RNA-Seq].

According to the theory of five movements and six climates, the innate constitution plays a crucial role in determining the underlyingpa thological mechanisms of diseases later in life. Previous studies have demonstrated a close association between the constitution, as defined by the theory of five movements and six climates, and the development of various types of tumors. Furt hermore,the tumorsubtype determined by the constitution has prognostic implications. This highlights the potential of utilizing the fivemovements and six climates theory to guide the implementation of precision medicine strategies in thefield of oncology. However, no resear ch has yet been conducted to investigate the use of this theory in guiding the development of tumor molecular classification and precisi onmedicine strategies. The objective of this research is to uncover the biological characteristics of each constitution within a pancanc ercohort and identify potential anti-tumor drugs that are applicable to patients with different constitutional types. By doing so, we aimto c ontribute to the establishment of a precision medicine strategy for tumors derived from the original concepts of traditional Chi nesemedicine(TCM). In this study, we obtainedpan-cancer Bulk RNA-Seq data from UCSC Xena, GWAS cohort data from the UKBiobank, and cis-eQTLs data from eQ TLGen and GTEx V8. We employed machine learning methods to screen for hub genes associated with each constitution. Subsequently, we utilized informatics tools to explore the biological characteristics of each constitut iondefined by the theory of five movements and six bioclimates. Further, potential anti-tumor drugs suitable for patients with differen tconstitutional types were identified through mendelian randomization, molecular docking, and drug-like prediction techniques. Withinthe pan-cancer cohort, significant differences were observed among different constitutions in terms of progression-free interval, biological f unctions, immune cell abundance, tumor drug sensitivity, and immunotherapy response. These findings suggest that the five movements and six climates theory can guide tumor molecular classification and the development of precision medicine strategies. Moreover,the biological characteristics inherent to each constitution partially shed light on the scientific implications of Chinese medicinetheories, offering a fresh perspective towards clinical cancer treatment. Through molecular docking and drug-like prediction, several po tential anti-tumor drugs such as 17-beta-estradiol, serotonin, trans-resveratrol, and linoleic acid were identified. Overall, the util izationof multi-omics approaches pro vides a powerful tool to unravel the scientific foundations of TCM theories. The elucidation of themu lti-omics features associated witheach constitution in tumors serves as the basis for applying the five movements and six climates theoryto tumor molecular classification and the development of precision medicine strategies.

3D bioprinting of an in vitro hepatoma microenvironment model: Establishment, evaluation, and anticancer drug testing.

Tumor behavior, including its response to treatments, is influenced by interactions between mesenchymal and malignant cells, as well as their spatial arrangement. To study tumor biology and evaluate anticancer drugs, accurate 3D tumor models are essential. Here, we developed an in vitro biomimetic hepatoma microenvironment model by combining an extracellular matrix (3DM-7721). Initially, the internal grid structure, composed of 10/6 % GelMA/gelatin loaded with SMMC-7721 cells, was printed using 3D bioprinting. The external component consisted of fibroblasts and human umbilical vein endothelial cells loaded with 10/3 % GelMA/gelatin. A control model (3DP-7721) lacked external cell loading. GelMA/gelatin hydrogels provided robust structural support and biocompatibility. The SMMC-7721 cells in the 3DM-7721 model exhibit superior tumor-associated gene expression and proliferation characteristics when compared to the 3DP-7721 model. Furthermore, the 3DM-7721 type exhibited increased resistance to anticancer agents. SMMC-7721 cells in the 3DM-7721 model exhibit significant tumorigenicity in nude mice. The 3DM-7721 model group showed pathological characteristics of malignant tumors, with a high degree of deterioration, and a significant positive correlation between malignant tumor-related gene pathways. This high-fidelity 3DM-7721 tumor microenvironment model is invaluable for studying tumor progression, devising effective treatment strategies, and discovering drugs. STATEMENT OF SIGNIFICANCE.

Nynrin preserves hematopoietic stem cell function by inhibiting the mitochondrial permeability transition pore opening.

Mitochondria are key regulators of hematopoietic stem cell (HSC) homeostasis. Our research identifies the transcription factor Nynrin as a crucial regulator of HSC maintenance by modulating mitochondrial function. Nynrin is highly expressed in HSCs under both steady-state and stress conditions. The knockout Nynrin diminishes HSC frequency, dormancy, and self-renewal, with increased mitochondrial dysfunction indicated by abnormal mPTP opening, mitochondrial swelling, and elevated ROS levels. These changes reduce HSC radiation tolerance and promote necrosis-like phenotypes. By contrast, Nynrin overexpression in HSCs diminishes irradiation (IR)-induced lethality. The deletion of Nynrin activates Ppif, leading to overexpression of cyclophilin D (CypD) and further mitochondrial dysfunction. Strategies such as Ppif haploinsufficiency or pharmacological inhibition of CypD significantly mitigate these effects, restoring HSC function in Nynrin-deficient mice. This study identifies Nynrin as a critical regulator of mitochondrial function in HSCs, highlighting potential therapeutic targets for preserving stem cell viability during cancer treatment.

Novel organic-inorganic composite pea protein silica food-grade aerogel materials: Fabrication, mechanisms, high oil-holding property and curcumin delivery capacity.

The fragility of the skeleton and poor bioaccessibility limit Silica aerogel's application in the food industry. In this study, composite gels were obtained by cross-linking pea proteins isolate (PPI) with Tetraethoxysilane (TEOS)to improve the bioavailability of silica-derived aerogels. It indicated that TEOS first condensed with H+ to form secondary particles and then complexed with PPI via hydroxyl groups to form a composite aerogel. Meanwhile, the PPI-Si composite aerogel formed a dense mesoporous structure with a specific surface area of 312.5 g/cm3. This resulted in a higher oil holding percentage of 89.67 % for the PPI (10 %)-Si aerogel, which was 34.1 % higher than other studies, leading to a more stable oleogel. Finally, as a delivery system, the composite oleogel not only could significantly increase the bioaccessibility rate by 27.4 % compared with silica aerogel, but also could efficiently inhibit the premature release of curcumin in the simulated gastric fluids, while allowed sustainably release in the simulated intestinal fluids. These results provided a theoretical basis for the application of silica-derived aerogels in food and non-food applications.

Chemo-Phosphoproteomic Profiling with ATR Inhibitors Berzosertib and Gartisertib Uncovers New Biomarkers and DNA Damage Response Regulators.

The ATR kinase protects cells against DNA damage and replication stress and represents a promising anti-cancer drug target. The ATR inhibitors (ATRi) berzosertib and gartisertib are both in clinical trials for the treatment of advanced solid tumors as monotherapy or in combination with genotoxic agents. We carried out quantitative phospho-proteomic screening for ATR biomarkers that are highly sensitive to berzosertib and gartisertib, using an optimized mass spectrometry pipeline. Screening identified a range of novel ATR-dependent phosphorylation events, which were grouped into three broad classes: (i) targets whose phosphorylation is highly sensitive to ATRi and which could be the next generation of ATR biomarkers; (ii) proteins with known genome maintenance roles not previously known to be regulated by ATR; (iii) novel targets whose cellular roles are unclear. Class iii targets represent candidate DNA damage response proteins and, with this in mind, proteins in this class were subjected to secondary screening for recruitment to DNA damage sites. We show that one of the proteins recruited, SCAF1, interacts with RNAPII in a phospho-dependent manner and recruitment requires PARP activity and interaction with RNAPII. We also show that SCAF1 deficiency partly rescues RAD51 loading in cells lacking the BRCA1 tumor suppressor. Taken together these data reveal potential new ATR biomarkers and new genome maintenance factors.

High-Entropy Ceramics Enhanced Droplet Electricity Generator for Energy Harvesting and Bacterial Detection.

The droplet electricity generator (DEG) is a solid-liquid triboelectric nanogenerator with transistor-inspired bulk effect, which is regarded as an effective strategy for raindrop energy harvesting. However, further enhancement of DEG output voltage is necessary to enable its widespread applications. Here, high-entropy ceramics are integrated into the design of DEG intermediate layer for the first time, achieving a high output voltage of 525 V. High-entropy ceramics have colossal dielectric constant, which can help to reduce the triboelectric charge decay for DEG. Furthermore, the effect of factors on DEG output performance when employing high-entropy ceramics as the intermediate layer is extensively analyzed, and the underlying mechanisms and mathematical models are explored. Finally, the enhanced output voltage of DEG not only facilitates faster energy harvesting but also develops a novel method for rapid bacterial detection. This work successfully integrates high-entropy ceramics into DEG design, significantly enhances the output voltage, and offers a novel direction for DEG development.

Effects of different solid particle sizes on oat protein isolate and pectin particle-stabilized Pickering emulsions and their use as delivery systems.

Oat protein isolate (OPI)/high methoxyl pectin (HMP) complexes (OPP) were prepared to stabilized Pickering emulsions and applied as nutraceutical delivery systems. The different mass ratios and pH changed the interactions between OPI and HMP that caused the different size of OPP. Specifically, smaller particle size of OPP (125.7-297.6 nm) were formed when hydrophobic interactions along with electrostatic forces predominant in OPP (OPI:HMP = 3:1, pH 4, 5). Among these particles, OPP-2 could stabilize Pickering emulsion efficiently through formation of dense interfacial film, which exhibited the highest apparent viscosity and the smallest average droplet size (23.39 µm). Moreover, OPP-2 stabilized Pickering emulsions with superior stability not only exhibited higher encapsulation efficiency of 85.63%, but also could control curcumin release in simulated gastrointestinal fluids to improve curcumin's bioaccessibility. These results verified the possibility of OPP to be a Pickering emulsions stabilizer, and also identified its potential to be a stable delivery system for bioactive compounds.

Genome-wide identification of replication fork stalling/pausing sites and the interplay between RNA Pol II transcription and DNA replication progression.

BACKGROUND: DNA replication progression can be affected by the presence of physical barriers like the RNA polymerases, leading to replication stress and DNA damage. Nonetheless, we do not know how transcription influences overall DNA replication progression. RESULTS: To characterize sites where DNA replication forks stall and pause, we establish a genome-wide approach to identify them. This approach uses multiple timepoints during S-phase to identify replication fork/stalling hotspots as replication progresses through the genome. These sites are typically associated with increased DNA damage, overlapped with fragile sites and with breakpoints of rearrangements identified in cancers but do not overlap with replication origins. Overlaying these sites with a genome-wide analysis of RNA polymerase II transcription, we find that replication fork stalling/pausing sites inside genes are directly related to transcription progression and activity. Indeed, we find that slowing down transcription elongation slows down directly replication progression through genes. This indicates that transcription and replication can coexist over the same regions. Importantly, rearrangements found in cancers overlapping transcription-replication collision sites are detected in non-transformed cells and increase following treatment with ATM and ATR inhibitors. At the same time, we find instances where transcription activity favors replication progression because it reduces histone density. CONCLUSIONS: Altogether, our findings highlight how transcription and replication overlap during S-phase, with both positive and negative consequences for replication fork progression and genome stability by the coexistence of these two processes.

Tumor burden score and carcinoembryonic antigen predict outcomes in patients with intrahepatic cholangiocarcinoma following liver resection: a multi­institutional analysis.

BACKGROUND: The prognostic significance of tumor burden score (TBS) in relation to carcinoembryonic antigen (CEA) has not been investigated among patients undergoing hepatectomy for intrahepatic cholangiocarcinoma (ICC). This study aimed to develop and validate a simplified model, a combination of TBS and CEA (CTC grade), for predicting the long-term outcomes of postoperative ICC patients. METHODS: Patients who underwent curative - intent resection of ICC between 2011 and 2019 were identified from a large multi - institutional database. The impact of TBS, CEA, and the CTC grade on overall survival (OS) and recurrence - free survival (RFS) was evaluated in both the derivation and validation cohorts. The receiver operating characteristic curve was utilized for assessing the predictive accuracy of the model. Subgroup analyses were performed across 8th TNM stage system stratified by CTC grade to assess the discriminatory capacity within the same TNM stage. RESULTS: A total of 812 patients were included in the derivation cohort and 266 patients in the validation cohort. Survival varied based on CEA (low: 36.7% vs. high: 9.0%) and TBS (low: 40.3% vs. high: 17.6%) in relation to 5 - year survival (both p < 0.001). As expected, patients with low CTC grade (i.e., low TBS/low CEA) were associated with the best OS as well as RFS, while high CTC grade (i.e., high TBS/high CEA) correlated to the worst outcomes. The model exhibited well performance in both the derivation cohort (area under the curve of 0.694) and the validation cohort (0.664). The predictive efficacy of the CTC grade system remains consistently stable across TNM stages I and III/IV. CONCLUSION: The CTC grade, a composite parameter derived from the combination of TBS and CEA levels, served as an easy - to - use tool and performed well in stratifying patients with ICC relative to OS and RFS.

The role of kinesin family members in hepatobiliary carcinomas: from bench to bedside.

As a major component of the digestive system malignancies, tumors originating from the hepatic and biliary ducts seriously endanger public health. The kinesins (KIFs) are molecular motors that enable the microtubule-dependent intracellular trafficking necessary for mitosis and meiosis. Normally, the stability of KIFs is essential to maintain cell proliferation and genetic homeostasis. However, aberrant KIFs activity may destroy this dynamic stability, leading to uncontrolled cell division and tumor initiation. In this work, we have made an integral summarization of the specific roles of KIFs in hepatocellular and biliary duct carcinogenesis, referring to aberrant signal transduction and the potential for prognostic evaluation. Additionally, current clinical applications of KIFs-targeted inhibitors have also been discussed, including their efficacy advantages, relationship with drug sensitivity or resistance, the feasibility of combination chemotherapy or other targeted agents, as well as the corresponding clinical trials. In conclusion, the abnormally activated KIFs participate in the regulation of tumor progression via a diverse range of mechanisms and are closely associated with tumor prognosis. Meanwhile, KIFs-aimed inhibitors also carry out a promising tumor-targeted therapeutic strategy that deserves to be further investigated in hepatobiliary carcinoma (HBC).

Cerebral endothelial cells mediated enhancement of brain pericyte number and migration in oxygen-glucose deprivation involves the HIF-1α/PDGF-ß signaling.

The present study focused on whether hypoxia-inducible factor-1alpha (HIF-1α) and platelet-derived factor-beta (PDGF-ß) are involved in the crosstalk between brain microvascular endothelial cells (BMECs) and brain vascular pericytes (BVPs) under ischaemic-hypoxic conditions. Mono-cultures or co-cultures of BVPs and BMECs were made for the construction of the blood-brain barrier (BBB) model in vitro and then exposed to control and oxygen-glucose deprivation (OGD) conditions. BBB injury was determined by assessing the ability, apoptosis, and migration of BVPs and the transendothelial electrical resistance and horseradish peroxidase permeation of BMECs. Relative mRNA and protein levels of HIF-1α and PDGF-ß, as well as tight junction proteins ZO-1 and claudin-5 were analyzed by western blotting, reverse transcription quantitative PCR, and/or immunofluorescence staining. Dual-luciferase reporter assays assessed the relationship between PDGF-ß and HIF-1α. Co-culturing with BMECs alleviated OGD-induced reduction in BVP viability, elevation in BVP apoptosis, and repression in BVP migration. Co-culturing with BVPs protected against OGD-induced impairment on BMEC permeability. OGD-induced HIF-1α upregulation enhanced PDGF-ß expression in mono-cultured BMECs and co-cultured BMECs with BVPs. Knockdown of HIF-1α impaired the effect of BMECs on BVPs under OGD conditions, and PDGFR-ß silencing in BVPs blocked the crosstalk between BMECs and BVPs under OGD conditions. The crosstalk between BMECs and BVPs was implicated in OGD-induced BBB injury through the HIF-1α/PDGF-ß signaling.

A heparin-functionalized bioink with sustained delivery of vascular endothelial growth factor for 3D bioprinting of prevascularized dermal constructs.

Skin tissue engineering faces challenges due to the absence of vascular architecture, impeding the development of permanent skin replacements. To address this, a heparin-functionalized 3D-printed bioink (GH/HepMA) was formulated to enable sustained delivery of vascular endothelial growth factor (VEGF), comprising 0.3 % (w/v) hyaluronic acid (HA), 10 % (w/v) gelatin methacrylate (GelMA), and 0.5 % (w/v) heparin methacrylate (HepMA). The bioink was then used to print dermal constructs with angiogenic functions, including fibroblast networks and human umbilical vein endothelial cell (HUVEC) networks. GH/HepMA, with its covalently cross-linked structure, exhibits enhanced mechanical properties and heparin stability, allowing for a 21-day sustained delivery of VEGF. Cytocompatibility experiments showed that the GH/HepMA bioink supported fibroblast proliferation and promoted collagen I production. With VEGF present, the GH/HepMA bioink promoted HUVEC proliferation, migration, as well as the formation of a richer capillary-like network. Furthermore, HA within the GH/HepMA bioink enhanced rheological properties and printability. Additionally, 3D-bioprinted dermal constructs showed significant deposition of collagen I and III and mature stable capillary-like structures along the axial direction. In summary, this study offers a promising approach for constructing biomimetic multicellular skin substitutes with angiogenesis-induced functions.