Biomedical subjects

Tao Sun

Publications and source records attributed to Tao Sun.

At least 19 recordsLinked to original sources

PubMed2026

Vortex-assisted liquid-liquid microextraction based on natural deep eutectic solvents for the determination of pyrethroid pesticides in urine.

A novel, facile, and environmentally friendly analytical method was developed based on vortex-assisted liquid-liquid microextraction and high-performance liquid chromatography with diode-array detection for detecting pyrethroid pesticides (PPs) in urine. Natural deep eutectic solvents (NADESs) were prepared using plant essential oil-derived monoterpenoids (thymol, carvacrol, and menthol) combined with aromatic primary alcohols (benzyl alcohol, phenethyl alcohol, and phenylpropyl alcohol) as hydrogen bond donors and acceptors. These solvents served as environmentally benign extraction media, thereby avoiding the use of conventional volatile, toxic organic solvents. NADESs are naturally derived, easy to prepare, biodegradable, and environmentally friendly solvents. Hydrophobic and π-π interactions between the NADESs and PPs may contribute to enhancing the affinity of PPs toward the NADESs phase. Vortex technology, accelerating mass transfer between the sample and extractant phases, enables fast extraction of PPs. Under optimized conditions, the method achieved a low detection limit (0.002 mg L-1), satisfactory precision with relative standard deviations (0.3%-2.4%), and acceptable recovery (80.7%-86.2%). The method demonstrated excellent performance in urine analysis and was feasible as a facile and green strategy for monitoring the content of PPs in biological matrices and assessing exposure risk.

Liquid Phase Microextraction↗

PubMed2026

Spermidine and melatonin ameliorate heat stress-induced decline in sheep semen quality.

Heat stress impairs reproductive performance in sheep through endocrine disruption and oxidative stress. This study evaluated the protective effects of spermidine (SPD) and melatonin (MT) supplementation on semen quality in Dorper rams during summer. Twenty-four rams were randomly assigned to a control group, an SPD group (5 mg/kg, dietary supplementation), or an MT group (60 mg, subcutaneous implantation) and treated for 60 days. The temperature-humidity index (THI) was monitored throughout the experimental period. Compared with the control group, MT significantly reduced serum cortisol concentration on day 30 (P < 0.05), whereas no significant differences were observed at the other sampling time points. Serum testosterone, spermidine, and melatonin concentrations remained unchanged throughout the study (P > 0.05). SPD supplementation significantly increased ejaculate volume on day 35 and sperm motility on day 42 (P < 0.05), whereas MT did not significantly affect these parameters. Neither treatment reduced the overall sperm abnormality rate. However, both SPD and MT significantly decreased the proportion of acephalic and decaudated sperm on day 56 (P < 0.05). Neither treatment significantly affected pregnancy rate, delivery rate, or the expression of PMFBP1 and SUN5 proteins in semen (P > 0.05). Regarding oxidative stress, MT significantly downregulated CAT protein expression (P < 0.05), whereas SPD significantly reduced MDA content and SOD1 protein expression (P < 0.05); MT showed similar but non-significant trends for these two markers (P > 0.05). Collectively, these findings demonstrate that SPD and MT exert distinct protective effects against heat stress, with SPD improving selected semen quality traits and both treatments reducing sperm head-tail separation, although these benefits did not translate into improved reproductive performance.

Animals↗

PubMed2026

Integration of metabolomics and proteomics reveals the toxicological mechanisms of environmentally relevant concentrations of cadmium on juvenile rockfish (Sebastes schlegelii).

As a highly toxic heavy metal, cadmium (Cd) is widely distributed in the coastal environments of the Bohai Sea, posing significant ecological and health risks. This is of particular concern for Sebastes schlegelii, a rockfish species commonly found along the Bohai coast and consumed by local populations. In this study, juvenile S. schlegelii were randomly assigned to three groups (control, 5 and 50 μg/L Cd) for a 14-day exposure period, followed by analysis of Cd bioaccumulation, as well as metabolomic and proteomic profiling. ICP-MS analysis indicated dose-dependent Cd bioaccumulation in the whole body, with 0.11 ± 0.07 μg/g dry weight in the 5 μg/L group and 0.38 ± 0.09 μg/g dry weight in the 50 μg/L group (9.5-fold higher than the control, p < 0.05). An iTRAQ-based proteomic analysis determined 168 differentially expressed proteins, while 1H NMR-based metabolomic profiling identified 34 metabolites with significant alterations. Integrated analysis of the proteomic and metabolomic data provided insights into the molecular responses of juvenile rockfish to Cd exposure. Specifically, metabolomic results indicated significant alterations in key metabolites, including lactate, phosphocholine, adenosine triphosphate, alanine, and inosine in the Cd-treated groups. Proteomic analysis further suggested that Cd exposure was associated with immune and oxidative stress responses, neurotoxicity, cellular damage, and disruptions in critical metabolic pathways, such as glycolysis, the tricarboxylic acid cycle, amino acid and lipid metabolism. Overall, this study demonstrates the utility of integrating proteomics and metabolomics to characterize molecular responses to Cd stress in juvenile S. schlegelii.

Animals↗

PubMed2026

The gut microbiota-obesity axis in the pathogenesis and prognosis of breast cancer.

BACKGROUND: Breast cancer (BC) remains a major global health concern, accounting for 11.7% of all cancer cases and ranking as the second leading cause of female cancer-related deaths worldwide. Increasing evidence highlights the interplay between gut microbiota (GM) dysbiosis and obesity-associated metabolic dysfunction in BC progression. This review aims to elucidate the role of GM in obese patients with BC. METHODS: A systematic literature search was conducted in PubMed and Web of Science databases for publications from July 2015 to January 2025. Search terms combined BC, GM, obesity, dysbiosis, immunity, and microbiome. Article selection prioritized studies investigating microbial alterations in BC patients, mechanistic links between obesity and cancer progression, and GM-targeted interventions. Both original studies and authoritative reviews were included, supplemented by manual reference screening. DISCUSSION: Obesity may trigger systemic inflammation, altered adipokine secretion, and disrupted steroid hormone metabolism via gut-derived β-glucuronidase activity, thereby exacerbating BC occurrence and recurrence. GM dysbiosis-driven metabolites such as branched-chain amino acids (BCAAs) and short-chain fatty acids (SCFAs) can activate oncogenic signaling pathways and immunosuppressive myeloid-derived suppressor cells (MDSCs), fostering tumor immune evasion. Conversely, dietary interventions, probiotics, and fecal microbiota transplantation (FMT) can alleviate dysbiosis, strengthen gut barriers, and restore anti-tumor immunity, improving chemotherapy response and reducing recurrence. However, challenges persist in deciphering BC subtype-related microbial signatures and optimizing microbiota-targeted therapies. CONCLUSION: Future longitudinal studies are needed to clarify causal relationships, validate microbial biomarkers, and translate preclinical findings into clinical applications. Addressing the gut-breast axis may offer transformative potential for precision oncology in obesity-driven BC.

Humans↗

PubMed2007

Development of a 3D cell culture system for investigating cell interactions with electrospun fibers.

There are many variables to be considered in studying how cells interact with 3D scaffolds used in tissue engineering. In this study we investigated the influence of the fiber diameter and interfiber spaces of 3D electrospun fiber scaffolds on the behavior of human dermal fibroblasts. Fibers of two dissimilar model materials, polystyrene and poly-L-lactic acid, with a broad range of diameters were constructed in a specifically developed 3D cell culture system. When fibroblasts were introduced to freestanding fibers, and encouraged to "walk the plank," a minimum fiber diameter of 10 microm was observed for cell adhesion and migration, irrespective of fiber material chemistry. A distance between fibers of up to 200 microm was also observed to be the maximum gap that could be bridged by cell aggregates--a behavior not seen in conventional 2D culture. This approach has identified some basic micro-architectural parameters for electrospun scaffold design and some key differences in fibroblast growth in 3D. We suggest the findings will be of value for optimizing the integration of cells in these scaffolds for skin tissue engineering.

Biocompatible Materials↗

PubMed2007

Hyrtiosal, a PTP1B inhibitor from the marine sponge Hyrtios erectus, shows extensive cellular effects on PI3K/AKT activation, glucose transport, and TGFbeta/Smad2 signaling.

Protein tyrosine phosphatase 1B (PTP1B) negatively regulates insulin signaling, and PTP1B inhibitors have been seen as promising therapeutic agents against obesity and type 2 diabetes. Here we report that the marine natural product hyrtiosal, from the marine sponge Hyrtios erectus, has been discovered to act as a PTP1B inhibitor and to show extensive cellular effects on PI3K/AKT activation, glucose transport, and TGFbeta/Smad2 signaling. This inhibitor wad able to inhibit PTP1B activity in dose-dependent fashion, with an IC(50) value of 42 microM in a noncompetitive inhibition mode. Further study with an IN Cell Analyzer 1000 cellular fluorescence imaging instrument showed that hyrtiosal displayed potent activity in abolishing the retardation of AKT membrane translocation caused by PTP1B overexpression in CHO cells. Moreover, it was found that this newly identified PTP1B inhibitor could dramatically enhance the membrane translocation of the key glucose transporter Glut4 in PTP1B-overexpressed CHO cells. Additionally, in view of our recent finding that PTP1B was able to modulate insulin-mediated inhibition of Smad2 activation, hyrtiosal was also tested for its capabilities in the regulation of Smad2 activity through the PI3K/AKT pathway. The results showed that hyrtiosal could effectively facilitate insulin inhibition of Smad2 activation. Our current study is expected to supply new clues for the discovery of PTP1B inhibitors from marine natural products, while the newly identified PTP1B inhibitor hyrtiosal might serve as a potential lead compound for further research.

Animals↗

PubMed2007

EphB/ephrin-B interaction mediates adult stem cell attachment, spreading, and migration: implications for dental tissue repair.

Human adult dental pulp stem cells (DPSCs) reside predominantly within the perivascular niche of dental pulp and are thought to originate from migrating neural crest cells during development. The Eph family of receptor tyrosine kinases and their ligands, the ephrin molecules, play an essential role in the migration of neural crest cells during development and stem cell niche maintenance. The present study examined the expression and function of the B-subclass Eph/ephrin molecules on DPSCs. Multiple receptors were primarily identified on DPSCs within the perivascular niche, whereas ephrin-B1 and ephrin-B3 were expressed by the surrounding pulp tissue. EphB/ephrin-B bidirectional signaling inhibited cell attachment and spreading, predominately via the mitogen-activated protein kinase (MAPK) pathway for forward signaling and phosphorylation of Src family tyrosine kinases via reverse ephrin-B signaling. DPSC migration was restricted through unidirectional ephrin-B1-activated EphB forward signaling, primarily signaling through the MAPK pathway. Furthermore, we observed that ephrin-B1 was downregulated in diseased adult teeth compared with paired uninjured controls. Collectively, these studies suggest that EphB/ephrin-B molecules play a role in restricting DPSC attachment and migration to maintain DPSCs within their stem cell niche under steady-state conditions. These results may have implications for dental pulp development and regeneration.

Adult↗

PubMed2006

Protein tyrosine phosphatase 1B regulates TGF beta 1-induced Smad2 activation through PI3 kinase-dependent pathway.

Insulin is known to modulate transforming growth factor-beta (TGFbeta) signaling. In this report, by using the IN Cell Analyzer 1000, the fluorescence cell imaging instrument, we demonstrated that protein tyrosine phosphatase 1B (PTP1B) could regulate TGFbeta1-induced Smad2 activation in a PI3 kinase-dependent manner. By using the CHO cells stably expressing EGFP-Smad2, we showed that TGFbeta1 effectively stimulated Smad2 nuclear translocation in CHO cells. When pretreated with insulin, TGFbeta1-induced Smad2 nuclear entry was dramatically decreased. Furthermore, both the PI3K inhibitor LY294002 and the dominant negative AKT (DN-AKT) abolished the inhibitory effects of insulin, demonstrating that the inhibition of Smad2 activation by insulin was PI3K/AKT dependent. Since PTP1B negatively modulates insulin signaling, we further addressed the effects of PTP1B on insulin-mediated inhibition of Smad2 activation. Our data showed that overexpression of PTP1B effectively attenuated insulin-induced inhibition of Smad2 stimulation. Moreover, the PTP1B inhibitor, 3-(3,5-dibromo-4-hydroxy-benzoyl)-2-ethyl-benzofuran-6-sulfonicacid-(4-(thiazol-2-ylsulfamyl)-phenyl)-amide (Compound-2), recovered insulin inhibition of Smad2 activation. In conclusion, our data revealed the insulin inhibitory effects on TGFbeta1-induced Smad2 activation and the regulation role of PTP1B in the inhibition events.

Animals↗

PubMed2006

Quantitative characterization of 15-deoxy-delta(12,14)-prostaglandin J2 in regulating EGFPSmad2 translocation in CHO cells through PPARgamma/TGFbeta/Smad2 pathway.

Smad2 is an important factor in TGFbeta/Smad2 signal transduction pathway with ability for signal propagation, it could translocate from cytoplasm to nucleus after the TGFbeta receptor-mediated phosphorylation. 15-deoxy-delta(12,14)-prostaglandin J2 (15d-PGJ2), a natural agonist of the peroxisome proliferator-activated receptor gamma (PPARgamma), is found recently to be able to function in the regulation of Smad2 activity. However, no quantification data have been yet reported, and it still keeps suspenseful whether or not 15d-PGJ2 could regulate Smad2 activity by depending on PPARgamma through PPAR gamma/TGFbeta/ Smad2 pathway. In this work, by analyzing the EGFP-Smad2 location in CHO cells according to the Nucleus Trafficking Analysis Module based on IN Cell Analyzer 1000 platform, TGFbeta stimulated EGFP-Smad2 translocation regulated by 15d-PGJ2 was quantitatively investigated. The results showed that TGFbeta could induce EGFP-Smad2 translocation from cytoplasm to nucleus by EC50 of 8.83 pM, and 15d-PGJ2 could impede the TGFbeta-stimulated Smad2 translocation by IC50 of 0.68 microM. Moreover, GW9662, a PPARgamma antagonist, could attenuate such a 15d-PGJ2 inhibitory activity by almost one order of magnitude. This result thereby implies that 15d-PGJ2 might inhibit Smad2 translocation through PPARgamma/TGFbeta/Smad2 pathway. Further investigation discovered that different from the case for 15d-PGJ2, rosiglitazone, another PPARgamma agonist, could enhance Smad2 translocation to nucleus, suggesting that rosiglitazone and 15d-PGJ(2) might take different modes in the activation of PPARgamma within the signaling pathway.

Anilides↗

PubMed2006

Development of NG2 neural progenitor cells requires Olig gene function.

In the adult central nervous system, two distinct populations of glial cells expressing the chondroitin sulfate proteoglycan NG2 have been described: bipolar progenitor cells and more differentiated "synantocytes." These cells have diverse neurological functions, including critical roles in synaptic transmission, repair, and regeneration. Despite their potential importance, the genetic factors that regulate NG2 cell development are poorly understood, and the relationship of synantocytes to the oligodendroglial lineage, in particular, remains controversial. Here, we show that >90% of embryonic and adult NG2 cells express Olig2, a basic helix-loop-helix transcription factor required for oligodendrocyte lineage specification. Analysis of mice lacking Olig function demonstrates a failure of NG2 cell development at embryonic and perinatal stages that can be rescued by addition of a transgene containing the human OLIG2 locus. These findings show a general requirement for Olig function in NG2 cell development and highlight further roles for Olig transcription factors in neural progenitor cells.

Animals↗

PubMed2006

Radical scavenging activities of alpha-alanine C60 adduct.

Water-soluble alpha-alanine C60 adduct was synthesized, and its scavenging abilities for superoxide anion O2- and hydroxyl radical *OH were studied by the spectrophotometry and chemiluminescence. It was found that alpha-alanine C60 adduct showed an excellent efficiency in eliminating superoxide anion and hydroxyl radical. The 50% inhibiting concentration (IC50) for superoxide was 184 microg/mL by spectrophotometry and 292 microg/mL by chemiluminescence. The IC50 for hydroxyl radical was 42 microg/mL. In different test systems, the results showed that alpha-alanine C60 adduct had comparable radical scavenging abilities as thiourea and ascorbic acid, and was proved to be an effective scavenger for superoxide anion and hydroxyl radical. It can be prospected that water-soluble alpha-alanine C60 adduct will be useful in radical related biomedical fields.

Alanine↗

PubMed2006

Real-time in vivo blood-flow imaging by moving-scatterer-sensitive spectral-domain optical Doppler tomography.

We present a moving-scatterer-sensitive optical Doppler tomography (MSS-ODT) technique for in vivo blood flow imaging in real time by using a spectral-domain optical coherence tomography system. In MSS-ODT the influence of stationary scatterers is suppressed by subtracting adjacent complex axial scans before calculating the Doppler frequency shift. We demonstrate that MSS-ODT is a useful technique for accurate determination of blood vessel size by imaging flow in a small capillary tube with a 75 microm inner diameter. The flow profile obtained with MSS-ODT yields a substantially more accurate tube diameter than that obtained with the conventional phase-resolved method, which underestimates the diameter by about 23%. We also demonstrate that MSS-ODT provides improved sensitivity over the conventional phase-resolved method for imaging in vivo blood flow in small vessels in a mouse ear.

Algorithms↗

PubMed2006

In situ image analysis of interactions between normal human keratinocytes and fibroblasts cultured in three-dimensional fibrin gels.

The non-invasive investigation of different cells to interact and become spatially organised in a three-dimensional (3D) environment or scaffold is an important challenge in tissue engineering and tissue physiology. The aim of the present study was to develop 3D cell culture systems using fibrin gels, which would allow for the single and co-culture of different cell types with in situ image analysis. Two chambers were constructed for mono-culture and co-culture of human dermal fibroblasts and keratinocytes. During cell culture, in situ imaging and morphological characterisation of cells was assessed using brightfield light and/or fluorescence microscopy, and later confirmed by staining of fixed cells using immunofluorescence microscopy. The results showed that it was possible to investigate fibroblast and keratinocyte interactions in a fibrin scaffold for at least 12 days. Using this model system it was found that when a co-culture of fibroblasts and keratinocytes were plated on top of the fibrin gels, fibroblasts were seen to migrate into the gels within 2-3 days in contrast to keratinocytes, which did not enter. However, keratinocytes were found to retard fibroblast migration into gels when compared to fibroblasts cultured on their own, illustrating the dependency of intracellular communication on cell position for reconstructive approaches.

Cell Communication↗

PubMed2006

Evidence for motoneuron lineage-specific regulation of Olig2 in the vertebrate neural tube.

Within the motoneuron precursor (pMN) domain of the developing spinal cord, the bHLH transcription factor, Olig2, plays critical roles in pattern formation and the generation of motor neuron and oligodendrocyte precursors. How are the multiple functions of Olig2 regulated? We have isolated a large BAC clone encompassing the human OLIG2 locus that rescues motor neuron and oligodendrocyte development but not normal pattern formation in Olig2(-/-) embryos. Within the BAC clone, we identified a conserved 3.6 kb enhancer sub-region that directs reporter expression specifically in the motor neuron lineage but not oligodendrocyte lineage in vivo. Our findings indicate complex regulation of Olig2 by stage- and lineage-specific regulatory elements. They further suggest that transcriptional regulation of Olig2 is involved in segregation of pMN neuroblasts.

Animals↗

PubMed2006

Culture of skin cells in 3D rather than 2D improves their ability to survive exposure to cytotoxic agents.

In this study, we asked the question of whether cells in 3D culture cope more effectively with cytotoxic agents than cells in 2D. The sensitivities of human skin cells (keratinocytes, dermal fibroblasts and endothelial cells) to oxidative stress (hydrogen peroxide) and to a potentially toxic heavy metal (silver) when cultured under 2D and 3D conditions were investigated. The results show a marked resistance of cells to a given dose of hydrogen peroxide or silver nitrate causing a 50% loss of viability in 3D cultures, when compared to the same cells grown in 2D. There was also an improvement in the ability of cells to withstand both stresses when cells were in co-culture rather than in mono-culture. Foetal calf serum was found to have a mild protective effect in 2D culture but this was not extended to findings in 3D culture. This study suggests that dermatotoxicity testing using 3D co-cultures might be more likely to reflect true physiological responses to xenobiotic materials than existing models that rely on 2D mono-cultures.

Cell Culture Techniques↗

PubMed2006

A hospital-based retrospective survey of human cystic and alveolar echinococcosis in Ningxia Hui Autonomous Region, PR China.

A retrospective study of in-patient records for the period 1985-2001 collected from 11 hospitals in Ningxia Hui Autonomous Region (NHAR), China revealed a total of 2216 cases of echinococcosis. The survey showed that cystic echinococcosis (CE) occurs throughout NHAR but that human alveolar echinococcosis (AE) cases were only located in a confluence area of three counties, Xiji, Haiyuan and Guyuan. Incidence rates between counties within southern NHAR showed a highly heterogeneous distribution of cases, suggestive of different echinococcal transmission patterns. There was a significant difference in incidence between males and females, and farm labourers accounted for the majority of cases. Radical surgery with or without albendazole/mebendazole drug treatment was the major method of treatment for CE and repeat surgery was common; drug treatment alone was used mainly for AE. Epigastric pain was the main reason for patients seeking medical advice, the liver was the primary location of echinococcosis lesions and the majority of echinococcosis cases were diagnosed by ultrasound. Over a 12 year period, the average bed utilization rate in the Second Provincial Hospital of NHAR for patients with echinococcosis was 78% and echinococcosis cases accounted, on average, for 0.7% among the total hospital in-patients. Taking inflation into account, charges for echinococcosis hospitalization and treatment increased three-fold over the period 1994-2002. This study indicates that echinococcosisis is a significant public health problem in NHAR, especially in the south. The data from the hospital retrospective study are clearly underestimates and community surveys are required to determine the true echinococcosis prevalence levels, especially in the more remote areas of NHAR.

China↗

PubMed2006

A novel deletion mutation in CCM1 gene (krit1) is detected in a Chinese family with cerebral cavernous malformations.

Cerebral Cavernous Malformations (CCM) are vascular malformations that are mostly located in the central nervous system (CNS) and occasionally within the skin and retina, which are classified into three types (CCM1, CCM2 and CCM3) by being located at different loci on chromosomes. At present, CCM1 (7q21), CCM2 (7p13-p15) and CCM3 (3q25.2-q27) are respectively linked to krit1 (Krev interaction trapped gene 1), MGC4607 and PDCD10 (programmed cell death 10). In this work, we identified a novel "GTA" deletion mutation at the acceptor splicing site of intron9/exon10 on krit1. The mutation results in an abnormally spliced protein by creating a premature termination code at the 23rd amino acid downstream from the sequence alteration. Our results are consistent with previous research on krit1 mutations and confirm the conclusion that KRIT1 haploinsufficiency may be the underlying mechanism of CCM1.

Adult↗

PubMed2006

Site-specific fabrication and epitaxial conversion of functional oxide nanodisk arrays.

Nanodisk arrays of technologically important magnetic (CoFe(2)O(4)) and ferroelectric (BaTiO(3)) oxides are fabricated on diverse substrates with well-defined size and separation using the soft-eBL approach. We demonstrate that below a certain pattern size, the as-deposited amorphous nanodisks can be readily converted into dense, single-crystal form that exhibit cube-on-cube heteroepitaxy with respect to the underlying single-crystal substrate. Such single-crystal disks show well-defined truncated-pyramid morphology that is consistent with Wulff construction. The mechanism of morphology development with the pattern size change is discussed. Localized characterization of the crystallinity, chemical composition, and magnetic behavior of the CFO nanodisk patterns are carried out using analytical transmission electron microscopy and magnetic force microscopy. Such solution-based epitaxial conversion of patterned arrays of multifunctional oxides has potential for viable cost-effective technological applications.

Ceramics↗