Dot1l cooperates with Npm1 to repress endogenous retrovirus MERVL in embryonic stem cells.

Dot1l is a histone methyltransferase without a SET domain and is responsible for H3K79 methylation, which marks active transcription. In contradiction, Dot1l also participates in silencing gene expression. The target regions and mechanism of Dot1l in repressing transcription remain enigmatic. Here, we show that Dot1l represses endogenous retroviruses in embryonic stem cells (ESCs). Specifically, the absence of Dot1l led to the activation of MERVL, which is a marker of 2-cell-like cells. In addition, Dot1l deletion activated the 2-cell-like state and predisposed ESCs to differentiate into trophectoderm lineage. Transcriptome analysis revealed activation of 2-cell genes and meiotic genes by Dot1l deletion. Mechanistically, Dot1l interacted with and co-localized with Npm1 on MERVL, and depletion of Npm1 similarly augmented MERVL expression. The catalytic activity and AT-hook domain of Dot1l are important to suppress MERVL. Notably, Dot1l-Npm1 restricts MERVL by regulating protein level and deposition of histone H1. Furthermore, Dot1l is critical for Npm1 to efficiently interact with histone H1 and inhibit ubiquitination of H1 whereas Npm1 is essential for Dot1l to interact with MERVL. Altogether, we discover that Dot1l represses MERVL through chaperoning H1 by collaborating with Npm1. Importantly, our findings shed light on the non-canonical transcriptional repressive role of Dot1l in ESCs.

Modulation of Acute Intestinal Inflammation by Dandelion Polysaccharides: An In-Depth Analysis of Antioxidative, Anti-Inflammatory Effects and Gut Microbiota Regulation.

Acute colitis is a complex disease that can lead to dysregulation of the gut flora, inducing more complex parenteral diseases. Dandelion polysaccharides (DPSs) may have potential preventive and therapeutic effects on enteritis. In this study, LPS was used to induce enteritis and VC was used as a positive drug control to explore the preventive and therapeutic effects of DPS on enteritis. The results showed that DPS could repair the intestinal barrier, down-regulate the expression of TNF-α, IL-6, IL-1ß, and other pro-inflammatory factors, up-regulate the expression of IL-22 anti-inflammatory factor, improve the antioxidant capacity of the body, and improve the structure of intestinal flora. It is proved that DPS can effectively prevent and treat LPS-induced acute enteritis and play a positive role in promoting intestinal health.

STUB1 directs FOXQ1-mediated transactivation of Ldha gene and facilitates lactate production in mouse Sertoli cells.

Sertoli cells (SCs) preferentially use glucose to convert to lactate. As an energy source, lactate is essential for survival of developed germ cells (GCs) due to its anti-apoptotic effect. Failure to maintain lactate metabolism homeostasis leads to infertility or germ cell apoptosis. Several Sertoli cell-expressed genes, such as Foxq1 and Gata4, have been identified as critical regulators for lactate synthesis, but the pathways that potentially modulate their expression remain ill defined. Although recent work from our collaborators pointed to an involvement of STIP1 homology and U-box-containing protein 1 (STUB1) in the modulation of Sertoli cell response to GCs-derived IL-1α, a true physiological function of STUB1 signaling in SCs has not been demonstrated. We therefore conditionally ablated Stub1 in SCs using Amh-Cre. Stub1 knockout males exhibited impaired fertility due to oligozoospermia and asthenospermia, possibly caused by lactate deficiency. Furthermore, by means of chromatin immunoprecipitation, in vivo ubiquitination, and luciferase reporter assays, we showed that STUB1 directed forkhead box Q1 (FOXQ1)-mediated transactivation of the lactate dehydrogenase A (Ldha) gene via K63-linked non-proteolytic polyubiquitination, thus facilitating lactate production in follicle-stimulating hormone (FSH)-stimulated SCs. In agreement, overexpression of LDHA by lentivirus infection effectively rescued the lactate production in TM4Stub1-/- cells. Our results collectively identify STUB1-mediated transactivation of FOXQ1 signaling as a post-translationally modified transcriptional regulatory network underlying nursery function in SCs, which may nutritionally contribute to Sertoli cell dysfunction of male infertility.

Nuclear hormone receptor BmFTZ-F1 is involved in regulating the fibroin heavy chain gene in the silkworm, Bombyx mori.

BACKGROUND: The synthesis of silk protein is controlled by hormones. The expression of the nuclear hormone Bmftz-f1 in the posterior silk gland (PSG) is induced by 20-hydroxyecdysone in vivo and in vitro. However, whether Bmftz-f1 regulates silk protein expression is unknown. METHODS: In our study, western blotting and quantitative polymerase chain reactions were conducted to detect the expression of FTZ-F1 in the PSG. Electrophoretic mobility shift, chromatin immunoprecipitation, far-western blotting, bimolecular fluorescence complementation, and dual luciferase reporter assays were performed to investigate the effect of FTZ-F1 on the fibH promoter. RESULTS: (1) The expression of the hormone receptor BmFTZ-F1 was opposite to that of fibH. It was highly expressed in the PSG during the fourth molting stage and the beginning of the fifth instar, and then its expression decreased gradually until it disappeared at the end of the fifth instar and the wandering stage. (2) We identified a FTZ-F1 response element 390bp upstream of the transcription initiation site of the fibH promoter. (3) BmFTZ-F1 interacted with the basic helix-loop-helix transcription factor Bmdimm. (4) BmFTZ-F1 down-regulated fibH promoter activity and counteracted the effect of Bmdimm on fibH expression. CONCLUSIONS: Integrating these results, we conclude that BmFTZ-F1 regulates the transcription of fibH by binding to the FTZ-F1 response element in the fibH promoter and counteracts the effect of Bmdimm on fibH expression. GENERAL SIGNIFICANCE: These findings provide new insights into the mechanism of regulation of the silk protein gene.

Development and validation of an LC-ESI-MS/MS method for the quantitation of hemslecin A in rhesus monkey plasma and its application in pharmacokinetics.

In this study, a new LC-ESI-MS/MS-based method was validated for the quantitation of hemslecin A in rhesus monkey plasma using otophylloside A as internal standard (IS). Hemslecin A and the IS were extracted from rhesus monkey plasma using liquid-liquid extraction as the sample clean-up procedure, and were subjected to chromatography on a Phenomenex Luna CN column (150 × 2.0 mm, 3.0 µm) with the mobile phase consisting of methanol and 0.02 mol/mL ammonium acetate (55:45, v/v) at a flow rate of 0.2 mL/min. Detection was performed on an Agilent G6410B tandem mass spectrometer by positive ion electrospray ionization in multiple reaction monitoring mode, monitoring the transitions m/z 580.5 [M + NH4 ](+) → 503.4 and m/z 518.2 [M + NH4 ](+) → 345.0 for hemslecin A and IS, respectively. The assay was linear over the concentration range of 0.5-200 ng/mL and was successfully applied to a pharmacokinetic study in rhesus monkeys.

Lotus Leaf Extract Alleviates Lipopolysaccharide-Induced Intestinal Injury in Mice by Regulating Oxidative Stress and Inflammation.

Inflammatory bowel disease, a disease featured by intestinal epithelial barrier destruction and dysfunction, has been a constant threat to animal health. The primary objective of this research was to assess the impact of the extract derived from lotus leaves (LLE) on lipopolysaccharide (LPS) induced damage to the intestines in mice, as well as to investigate the fundamental mechanism involved. The LLE was prepared using ultrasonic extraction in this experiment, and the LLE total flavonoid content was 117.02 ± 10.73 mg/g. The LLE had strong antioxidant activity in vitro, as assessed by 2, 2-diphenyl-1-picrylhydrazyl, ferric reducing antioxidant power, and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) methods. In the vivo experiment, different doses of LLE (50, 100, and 200 mg/kg) were administered for 2 weeks before LPS treatment in mice. The results revealed that LLE alleviates intestinal tissue damage in LPS-induced mice. In the jejunum tissue, LLE significantly upregulated mRNA and protein expression levels of tight junction proteins, such as ZO-1, occludin, and claudin-1, and decreased the contents of the inflammatory cytokines, interleukin (IL)-1ß, IL-6, and tumor necrosis factor-α. Furthermore, the malondialdehyde and lactate dehydrogenase contents increased by LPS in the liver were significantly reduced after administration of LLE, and the total antioxidant capacity, superoxide dismutase, and reduced glutathione decreased by LPS were remarkably increased by LLE. It was found that LLE could relieve LPS-induced oxidative stress by upregulating mRNA and protein expression of Nrf2 and HO-1 in jejunum tissue. In conclusion, LLE alleviates LPS-induced intestinal damage through regulation of the Nrf2/HO-1 signal pathway to alleviate oxidative stress, reducing inflammatory factors and increasing the expression of tight junction proteins in mice.

Single-cell 3D genome structure reveals distinct human pluripotent states.

BACKGROUND: Pluripotent states of embryonic stem cells (ESCs) with distinct transcriptional profiles affect ESC differentiative capacity and therapeutic potential. Although single-cell RNA sequencing has revealed additional subpopulations and specific features of naive and primed human pluripotent stem cells (hPSCs), the underlying mechanisms that regulate their specific transcription and that control their pluripotent states remain elusive. RESULTS: By single-cell analysis of high-resolution, three-dimensional (3D) genomic structure, we herein demonstrate that remodeling of genomic structure is highly associated with the pluripotent states of human ESCs (hESCs). The naive pluripotent state is featured with specialized 3D genomic structures and clear chromatin compartmentalization that is distinct from the primed state. The naive pluripotent state is achieved by remodeling the active euchromatin compartment and reducing chromatin interactions at the nuclear center. This unique genomic organization is linked to enhanced chromatin accessibility on enhancers and elevated expression levels of naive pluripotent genes localized to this region. In contradistinction, the primed state exhibits intermingled genomic organization. Moreover, active euchromatin and primed pluripotent genes are distributed at the nuclear periphery, while repressive heterochromatin is densely concentrated at the nuclear center, reducing chromatin accessibility and the transcription of naive genes. CONCLUSIONS: Our data provide insights into the chromatin structure of ESCs in their naive and primed states, and we identify specific patterns of modifications in transcription and chromatin structure that might explain the genes that are differentially expressed between naive and primed hESCs. Thus, the inversion or relocation of heterochromatin to euchromatin via compartmentalization is related to the regulation of chromatin accessibility, thereby defining pluripotent states and cellular identity.

Effects of dietary supplementation with Radix Isatidis polysaccharide on egg quality, immune function, and intestinal health in hens.

This study aimed to investigate the effects of supplementing laying hen diets with Radix Isatidis Polysaccharide (RIPS) on egg quality, immune function, and intestinal health. The research was conducted using 288 Hyland Brown hens, which were randomly assigned to four dietary treatments: control (without RIPS), low dose (200 g/t), medium dose (500 g/t), and high dose (1000 g/t) of RIPS. Each dietary treatment was administered to eight replicates of nine hens for nine weeks. The results revealed that RIPS inclusion in diets significantly improved egg quality parameters such as egg shape index, yolk color, haugh unit, and protein height (P < 0.05). Additionally, RIPS supplementation enhanced immune function as evidenced by an alteration in serum biochemical parameters, an increase in the spleen index, and a decrease in the liver index. Further, an evaluation of intestinal health showed that RIPS fortified the intestinal barrier, thus increasing the population of beneficial intestinal bacteria and reducing the abundance of harmful ones. Such mechanisms promoted intestinal health, digestion, and nutrient absorption, ultimately leading to enhanced egg quality. In conclusion, supplementing laying hen diets with RIPS has been demonstrated to improve egg quality by boosting immunity and optimizing intestinal digestion and absorption.

Effectiveness of nurse-led electronic health interventions on illness management in patients with chronic heart failure: A systematic review and meta-analysis.

BACKGROUND: Chronic heart failure (CHF) is a global health concern, and nurse-led electronic health is an effective management strategy for this condition. OBJECTIVE: This systematic review and meta-analysis aimed to identify current patterns and strategies for nurse-led electronic health interventions and examine the effects of nurse-led electronic health interventions for illness management in patients with chronic heart failure. DESIGN: This study combined a systematic review and meta-analyses. PARTICIPANTS: Twenty-four articles, involving a total of 3660 patients, met the inclusion criteria. METHODS: We conducted a large amount of literature review using seven English databases: namely PubMed, Embase, Web of Science, MEDLINE, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, and SCOPUS, along with three Chinese databases: China National Knowledge Infrastructure(CNKI), WanFang, and the VIP Database. Databases were searched from inception until September 2022. This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The studies were independently screened by two reviewers who extracted of the details of those meeting the inclusion criteria study. The Joanna Briggs Institute randomized controlled trial checklist was used to evaluate the methodological value of each incorporation study. Meta-analysis was performed by the use of Manager 5.3. RESULTS: The main patterns of electronic health intervention involve smartphone, Internet and specialized (portable) electronic monitoring devices that are used for the illness management of patients with chronic heart failure, mainly including providing self-management guidance for chronic heart failure, and tracking of the patient's health information, providing peer support, and facilizing medical and health resources. The collective findings of 9 studies reported that electronic health interventions improved self-care (MD: 15.30, 95 % CI: 1.59 to 29.02, p < 0.05). Regarding psychosocial well-being outcomes, the incorporative conclusions indicated that electronic health interventions effectively increased quality of life, reduced depression and anxiety, and improved patient satisfaction. Regarding disease-related examinations, electronic health interventions significantly increased cardiac function during the 6-minute walk test. Regarding healthy economic outcomes, electronic health interventions significantly decreased the rehospitalization rate and the cost of medical care services. CONCLUSIONS: The findings of this review suggest that nurse-led electronic health interventions involving multiple patterns have an active influence on managing patients with chronic heart failure, including enhancing self-care, and medication adherence; increasing quality of life; reducing depression, anxiety, and improved patient satisfaction; increasing cardiac function, and reducing rehospitalization rate and hospitalization costs. Thus, it could be a promising alternative in the clinical settings. REGISTRATION: CRD42023389450.

Role function and job satisfaction of community nurses in China: A cross-sectional study.

AIM: To evaluate role function and job satisfaction, determine their relationship, and explore the factors influencing job satisfaction among community nurses in China. DESIGN: Cross-sectional study. METHODS: This study was conducted between March and June 2020 on a cluster random sampling of 302 community nurses from 24 community health centres and stations in Xi'an, China. Self-reported data were collected using the Demographics Questionnaire, Role Function of Community Nurses Questionnaire, and Job Satisfaction of Community Nurses Scale. Descriptive statistics, Pearson's correlation analysis, and multiple linear regression analyses were performed to analyse data. RESULTS: Community nurses' main role function was organiser and manager (M = 2.56, SD = 0.987) and coordinator (M = 2.43, SD = 0.971). The lowest job satisfaction was for salary and benefits (M = 3.12, SD = 0.891) and personal development (M = 3.65, SD = 0.738). A positive correlation was found between the roles of caregiver, educator, navigator, and salary and benefits (p < 0.05) among community nurses. Multiple linear regression analyses indicated that monthly income and working experience in nursing explained 61.1% of the variance in job satisfaction.

The Water Extract of Ampelopsis grossedentata Alleviates Oxidative Stress and Intestinal Inflammation.

Oxidative stress is recognized as a significant contributor to the development and progression of inflammation and disruptions in the balance of gut microflora, commonly referred to as intestinal dysbiosis. It is crucial that safe and effective antioxidant and anti-inflammatory agents are identified to address these conditions. Ampelopsis grossedentata, a natural plant abundant in flavonoids and primarily found in southern China, has demonstrated potent antioxidant properties. However, the extent to which flavonoids in A. grossedentata impact intestinal inflammation and alter the composition of the gut microbiome remains to be fully understood. The purpose of this study was to explore the potential benefits of using A. grossedentata as an antioxidant and anti-inflammatory agent in the context of intestinal inflammation, both in vitro and in vivo. We first conducted an initial comparison of the effects of dihydromyricetin (DMY), an alcohol extract of A. grossedentata (AEA, 82% total flavonoids), and a water extract of A. grossedentata (WEA, 57% total flavonoids) on the cell viability and intestinal barrier integrity of porcine epithelial cells IPEC-J2. Although the total flavonoid content is much lower in WEA than in AEA, the results show that they have similar effects. Subsequently, the antioxidant properties of WEA were compared with those of commonly utilized antioxidants in vitro. Lastly, the antioxidant and anti-inflammatory properties of WEA, as well as its impacts on gut microbiota, were evaluated in animal models, including mice and Drosophila. In summary, the results of our study indicate that WEA, due to its antioxidant properties, exhibits a protective effect on the intestinal barrier function in porcine epithelial cell line IPEC-J2. Additionally, WEA demonstrates a positive correlation with DPPH, ABTS radical scavenging rate, FRAP, and reducing power under in vitro settings. Furthermore, WEA was shown to effectively alleviate oxidative stress in animal models by reducing the levels of pro-inflammatory cytokines and increasing the antioxidant enzyme activity in the liver, as well as by activating the Nrf2 signaling pathway in the duodenum. Additionally, WEA was able to regulate gut microbiota, promoting the growth of beneficial bacteria and inhibiting harmful microbes, as well as extending the lifespan of Drosophila. Overall, these findings suggest that WEA may serve as a valuable dietary supplement for addressing oxidative stress and inflammation through its anti-inflammatory and prebiotic effects, which are conferred via the Nrf2/Keap1 pathway.

The Effects of Radix isatidis Raw Material on Egg Quality, Serum Biochemistry, Gut Morphology and Gut Flora.

China produces more than 30 million tons of drug residues every year. Therefore, innovative solutions are needed to mitigate environmental damage. Certain plant compounds boost hens' health and performance. Radix isatidis is promising for layer production. This study elucidates the multidimensional impact of Radix isatidis residual material (RIHR) on laying hens, focusing on the egg quality, intestinal health and the microbial landscape. A total of 288 55-week-old Peking powder laying hens with similar laying rates and body weights were randomly divided into four groups, with eight replicates per group and nine hens per replicate. The groups were divided into a control group, an RIHR low-dose group, a medium-dose group and a high-dose group according to a single-factor, completely randomized design. For the three RIHR treatment groups, the added amounts were 5 kg/t, 10 kg/t and 15 kg/t, respectively. Liquid chromatography- mass spectrometry (LC-MS), molecular docking, fluorescence quantitative PCR and other methods were used. The results showed that three main anti-inflammatory and antiviral compounds were identified in RIHR-indirubin (0.21 µg/g), deoxyvasicinone (0.18 µg/g) and epigoitrin (0.39 µg/g). RIHR significantly increased the eggshell thickness, Haugh unit and protein height (p < 0.05). It also had significant antioxidant and anti-inflammatory effects on ilea and ceca (p < 0.05). The microbial analysis demonstrated that RIHR supplementation led to a significant reduction in foregut Lactobacillus levels (p < 0.05). In the hindgut, a significant increase in pathogenic bacteria was observed (p < 0.05). The study concludes that RIHR's anti-inflammatory compounds may directly act on the intestinal tract to modulate inflammation, highlighting its potential for targeted interventions in poultry health and nutrition.

Early detection of emergency events from social media: a new text clustering approach.

Emergency events require early detection, quick response, and accurate recovery. In the era of big data, social media users can be seen as social sensors to monitor real-time emergency events. This paper proposed an integrated approach to detect all four kinds of emergency events early, including natural disasters, man-made accidents, public health events, and social security events. First, the BERT-Att-BiLSTM model is used to detect emergency-related posts from massive and irrelevant data. Then, the 3 W attribute information (what, where, and when) of the emergency event is extracted. With the 3 W attribute information, we create an unsupervised dynamical event clustering algorithm based on text similarity and combine it with the supervised logistical regression model to cluster posts into different events. Experiments on Sina Weibo data demonstrate the superiority of the proposed framework. Case studies on some real emergency events show that the proposed framework has good performance and high timeliness. Practical applications of the framework are also discussed, followed by future directions for improvement.

Determination of melamine in milk based on ß-cyclodextrin modified carbon nanoparticles via host-guest recognition.

Illegal addition of melamine (MEL) to milk has caused serious food safety accident. It is urgent to develop a highly sensitive method for detecting MEL in milk. ß-Cyclodextrin with inner hydrophobic and outer hydrophilic cavities have been widely used in smart sensors design. In this study, an "ON-OFF-ON" sensor for MEL detection was constructed based on ß-cyclodextrin modified carbon nanoparticles (ß-CD-CNPs). The sensor is switched "OFF" when Fe3+ interacts with ß-CD-CNPs and switched "ON" when MEL replaces Fe3+. Fluorescence recovery of ß-CD-CNPs exhibits good linear correlations with MEL concentration ranging from 10.00 ng/mL ~ 180.00 ng/mL and 180.00 ~ 1000.00 ng/mL, the detection limit is 6.82 ng/mL. The sensor was applied to analysis melamine in milk samples with recovery between 94.80% ~ 102.05%, and RSD bellow 12.61%. The results show that this method can meet the requirements of real sample analysis.

Multidisciplinary team management of 46,XY 17α-hydroxylase deficiency: a case report and literature review.

BACKGROUND: We report here a case study of 17α-hydroxylase deficiency in a phenotypic girl with male karyotype (46,XY). We also review the relevant literature to deepen our understanding of the disease, reduce the rate of missed diagnosis, and emphasize that holistic management of this disease requires collaborative multidisciplinary teamwork. CASE PRESENTATION: A 14-year-old patient with a female phenotype visited the endocrinology department because of hypertension. The patient had primary amenorrhea and lacked secondary sexual characteristics. Initial laboratory evaluation revealed normal levels of electrolytes, a hypergonadotropic hypogonadal state with high progesterone and low testosterone levels, and a 46,XY karyotype. She was referred to the urology department for gonadectomy and transferred to the gynecological endocrine clinic. On the basis of the patient's medical history and genetic testing results, a diagnosis of 46,XY 17α-hydroxylase deficiency was made. The patient was provided with glucocorticoids, estrogens, metformin, and psychological support. CONCLUSIONS: Patients with 17α-hydroxylase deficiency, a rare cause of congenital adrenal hyperplasia, should be treated by a multidisciplinary team. Relevant experts from different disciplines should set up a systematic and comprehensive individualized management plan to optimize the physical and mental health and quality of life of affected patients.

Single-step synthesis of eucalyptus sawdust magnetic activated carbon and its adsorption behavior for methylene blue.

Eucalyptus wood-based magnetic activated carbon (MAC) was prepared using single-step carbonization activation magnetization with FeCl3 and utilized for the adsorption of methylene blue (MB). The MAC was prepared using the following conditions: the mass ratio of FeCl3 to eucalyptus sawdust was controlled to 2 : 1, the one-step carbonated activated magnetization temperature and time was 700 °C and 75 min. The prepared MAC was evaluated for textural characteristics such as the adsorption capacity, pore structure, surface chemical functional groups, magnetic properties, microcrystalline structure, and the surface morphology using the test methods described in the National Standard of China, these were N2-adsorption-desorption isotherms, Fourier transform infrared spectroscopy (FTIR), value stream mapping (VSM), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Batch experiments were carried out to evaluate the adsorption behavior of MB on the prepared MAC at different temperatures of 298-328 K and MB initial concentration of 50.0-500.0 mg L-1. The results were as follows: the iodine number, methylene blue adsorption and phenol adsorption of the prepared MAC were 473.14, 228.22 and 70.90 mg g-1, respectively; MAC exhibited a microporous and mesoporous structure with a mesoporosity of 36%, the BET specific surface area, average pore diameter and pore volume were 645.23 m2 g-1, 2.71 nm and 0.44 cm3 g-1, respectively, and for the magnetic parameters the following results were found, a H c of 108.51 Oe, M s of 30.37 emu g-1 and M r of 2.46 emu g-1; there were OH, C-O, C[double bond, length as m-dash]O, C[double bond, length as m-dash]C, COO, C-N, and Fe-O groups on the MAC surface, and Fe3O4 existed in the pores and surfaces of the MAC. The MB adsorption on the MAC followed the Langmuir isotherm and Dubinin-Radushkevich isotherm model, the adsorption process was a spontaneous, endothermic chemisorption progress, followed by the pseudo-second-order model, and the adsorption process was influenced by multiple diffusion steps, the pore diffusion process was the rate-controlling step, however, the adsorption process was also affected by the film diffusion and surface adsorption. The results reveal that MAC efficiently adsorbs MB and can be easily separated and recovered by an external magnetic field. The as-prepared MAC could be used as a potential adsorbent for organic pollutant wastewater treatment.

Dynamic multiphoton imaging of acellular dermal matrix scaffolds seeded with mesenchymal stem cells in diabetic wound healing.

Significantly effective therapies need to be developed for chronic nonhealing diabetic wounds. In this work, the topical transplantation of mesenchymal stem cell (MSC) seeded on an acellular dermal matrix (ADM) scaffold is proposed as a novel therapeutic strategy for diabetic cutaneous wound healing. GFP-labeled MSCs were cocultured with an ADM scaffold that was decellularized from normal mouse skin. These cultures were subsequently transplanted as a whole into the full-thickness cutaneous wound site in streptozotocin-induced diabetic mice. Wounds treated with MSC-ADM demonstrated an increased percentage of wound closure. The treatment of MSC-ADM also greatly increased angiogenesis and rapidly completed the reepithelialization of newly formed skin on diabetic mice. More importantly, multiphoton microscopy was used for the intravital and dynamic monitoring of collagen type I (Col-I) fibers synthesis via second harmonic generation imaging. The synthesis of Col-I fibers during diabetic wound healing is of great significance for revealing wound repair mechanisms. In addition, the activity of GFP-labeled MSCs during wound healing was simultaneously traced via two-photon excitation fluorescence imaging. Our research offers a novel advanced nonlinear optical imaging method for monitoring the diabetic wound healing process while the ADM and MSCs interact in situ. Schematic of dynamic imaging of ADM scaffolds seeded with mesenchymal stem cells in diabetic wound healing using multiphoton microscopy. PMT, photo-multiplier tube.

PEGylated graphene oxide-mediated quercetin-modified collagen hybrid scaffold for enhancement of MSCs differentiation potential and diabetic wound healing.

Nanoscale delivery based on polyethylene glycol (PEG)ylated graphene oxide (GO-PEG) merits attention for biomedical applications owing to its functional surface modification, superior solubility/biocompatibility and controllable drug release capability. However, impaired skin regeneration in applications of these fascinating nanomaterials in diabetes is still limited, and critical issues need to be addressed regarding insufficient collagen hyperplasia and inadequate blood supply. Therefore, a high-performance tissue engineering scaffold with biocompatible and biodegradable properties is essential for diabetic wound healing. Natural and artificial acellular dermal matrix (ADM) scaffolds with spatially organized collagen fibers can provide a suitable architecture and environment for cell attachment and proliferation. Here, a novel collagen-nanomaterial-drug hybrid scaffold was constructed from GO-PEG-mediated quercetin (GO-PEG/Que)-modified ADM (ADM-GO-PEG/Que). The resulting unique and versatile hybrid scaffold exhibited multiple advantages, including the following: a biocompatible, cell-adhesive surface for accelerating mesenchymal stem cell (MSC) attachment and proliferation; superior stability and adjustability of the conduction potential of quercetin for inducing the differentiation of MSCs into adipocytes and osteoblasts; and a biodegradable nanofiber interface for promoting collagen deposition and angiogenesis in diabetic wound repair. This study provides new prospects for the design of innovative GO-PEG-based collagen hybrid scaffolds for application in efficient therapeutic drug delivery, stem cell-based therapies, tissue engineering and regenerative medicine.

Identification of MBF2 family genes in Bombyx mori and their expression in different tissues and stages and in response to Bacillus bombysepticus infection and starvation.

The Multiprotein bridge factor 2 (MBF2) gene was first identified as a co-activator involved in BmFTZ-F1-mediated activation of the Fushi tarazu gene. Herein, nine homologous genes of MBF2 gene are identified. Evolutionary analysis showed that this gene family is insect-specific and that the family members are closely related to response to pathogens (REPAT) genes. Tissue distribution analysis revealed that these genes could be expressed in a tissue-specific manner. Developmental profiles analysis showed that the MBF2 gene family members were highly expressed in the different stages. Analysis of the expression patterns of nine MBF2 family genes showed that Bacillus bombysepticus treatment induced the up-regulation of several MBF2 family genes, including MBF2-4, -7, -9, -8. Furthermore, we found the MBF2 family genes were modulated by starvation and the expression of these genes recovered upon re-feeding, except for MBF2-5, -9. These findings suggested roles for these proteins in insect defense against pathogens and nutrient metabolism, which has an important guiding significance for designing pest control strategies.

Second-harmonic generation microscopy for assessment of mesenchymal stem cell-seeded acellular dermal matrix in wound-healing.

Direct intra-skin injection of mesenchymal stem cells (MSCs) and the use of biomaterial scaffolds for grafts are both promising approaches of skin wound repair, however they still cannot generate skin that completely resembles the natural skin structures. In this study, we combined these two approaches by using acellular dermal matrix (ADM) recellularized with MSCs to repair cutaneous wounds in a murine model and two-photon fluorescence (TPF) microscopy and second-harmonic generation (SHG) microscopy to assess the effects of this therapy on wound healing. Bone marrow-derived mesenchymal stem cells (BM-MSCs) were tagged with GFP and seeded into ADM (ADM-MSC) via MSC and ADM co-culture. ADM-MSC, ADM or saline was applied to murine excisional skin wounds and wound-healing was evaluated by histological examination on days 7, 14, 21 and TFP microscopy on days 1, 3, 5 and 21 post-treatment. ADM-MSC promoted healing significantly more than treatment with ADM or saline alone, as it led to substantial neovascularization and complete skin appendage regeneration. Furthermore, the SHG microscopic imaging technique proved to be a useful tool for monitoring changes in the collagen network at the wound site during the healing process and assessing the effects of different therapies.