β-catenin mRNA encapsulated in SM-102 lipid nanoparticles enhances bone formation in a murine tibia fracture repair model

Fractures continue to be a global economic burden as there are currently no osteoanabolic drugs approved to accelerate fracture healing.In this study,we aimed to develop an osteoanabolic therapy which activates the Wnt/β-catenin pathway,a molecular driver of endochondral ossification.We hypothesize that using an mRNAbased therapeutic encodingβ-catenin could promote cartilage to bone transformation formation by activating the canonical Wnt signaling pathway in chondrocytes.To optimize a delivery platform built on recent advancements in liposomal technologies,two FDA-approved ionizable phospholipids,DLin-MC3-DMA(MC3)and SM-102,were used to fabricate unique ionizable lipid nanoparticle(LNP)formulations and then tested for transfection efficacy both in vitro and in a murine tibia fracture model.Using firefly luciferase mRNA as a reporter gene to track and quantify transfection,SM-102 LNPs showed enhanced transfection efficacy in vitro and prolonged transfection,minimal fracture interference and no localized inflammatory response in vivo over MC3 LNPs.The generatedβ-cateninGOF mRNA encapsulated in SM-102 LNPs(SM-102-β-cateninGOF mRNA)showed bioactivity in vitro through upregulation of downstream canonical Wnt genes,axin2 and runx2.When testing SM-102-β-cateninGOF mRNA therapeutic in a murine tibia fracture model,histomorphometric analysis showed increased bone and decreased cartilage composition with the 45μg concentration at 2 weeks post-fracture.μCT testing confirmed that SM-102-β-cateninGOF mRNA promoted bone formation in vivo,revealing significantly more bone volume over total volume in the 45μg group.Thus,we generated a novel mRNA-based therapeutic encoding aβ-catenin mRNA and optimized an SM-102-based LNP to maximize transfection efficacy with a localized delivery.

Neuroprotective mechanisms of DNA methyltransferase in a mouse hippocampal neuronal cell line after hypoxic preconditioning

Hypoxic preconditioning has been shown to improve hypoxic tolerance in mice,accompanied by the downregulation of DNA methyltransferases(DNMTs)in the brain.However,the roles played by DNMTs in the multiple neuroprotective mechanisms associated with hypoxic preconditioning remain poorly understood.This study aimed to establish an in vitro model of hypoxic preconditioning,using a cultured mouse hippocampal neuronal cell line(HT22 cells),to examine the effects of DNMTs on the endogenous neuroprotective mechanisms that occur during hypoxic preconditioning.HT22 cells were divided into a control group,which received no exposure to hypoxia,a hypoxia group,which was exposed to hypoxia once,and a hypoxic preconditioning group,which was exposed to four cycles of hypoxia.To test the ability of hypoxic preadaptation to induce hypoxic tolerance,cell viability was measured using the 3-(4,5-dimethylthiazol-2-yl)-5(3-carboxymethonyphenol)-2-(4-sulfophenyl)-2H-tetrazolium assay.Cell viability improved in the hypoxic preconditioning group compared with that in the hypoxia group.The effects of hypoxic preconditioning on the cell cycle and apoptosis in HT22 cells were examined by western blot assay and flow cytometry.Compared with the hypoxia group,the expression levels of caspase-3 and spectrin,which are markers of early apoptosis and S-phase arrest,respectively,noticeably reduced in the hypoxic preconditioning group.Finally,enzyme-linked immunosorbent assay,real-time polymerase chain reaction,and western blot assay were used to investigate the changes in DNMT expression and activity during hypoxic preconditioning.The results showed that compared with the control group,hypoxic preconditioning downregulated the expression levels of DNMT3A and DNMT3B mRNA and protein in HT22 cells and decreased the activities of total DNMTs and DNMT3B.In conclusion,hypoxic preconditioning may exert anti-hypoxic neuroprotective effects,maintaining HT22 cell viability and inhibiting cell apoptosis.These neuroprotective mechanisms may be associated with the inhibition of DNMT3A and DNMT3B.

Association of types of diabetes and insulin dependency on birth outcomes

BACKGROUND Diabetes rates among pregnant women in the United States have been increasing and are associated with adverse pregnancy outcomes.AIM To investigate differences in birth outcomes(preterm birth,macrosomia,and neonatal death)by diabetes status.METHODS Cross-sectional design,using linked Missouri birth and death certificates(singleton births only),2010 to 2012(n=204057).Exposure was diabetes non-diabetic,pre-pregnancy diabetes-insulin dependent(PD-I),pre-pregnancy diabetes-non-insulin dependent(PD-NI),gestational diabetes-insulin dependent(GD-I),and gestational diabetes-non-insulin dependent(GD-NI).Outcomes included preterm birth,macrosomia,and infant mortality.Confounders included demographic characteristics,adequacy of prenatal care,body mass index,smoking,hypertension,and previous preterm birth.Bivariate and multivariate logistic regression assessed differences in outcomes by diabetes status.RESULTS Women with PD-I,PD-NI,and GD-I remained at a significantly increased odds for preterm birth(aOR 2.87,aOR 1.77,and aOR 1.73,respectively)and having a very large baby[macrosomia](aOR 3.01,aOR 2.12,and aOR 1.96,respectively);in reference to non-diabetic women.Women with GDNI were at a significantly increased risk for macrosomia(aOR1.53),decreased risk for their baby to die before their first birthday(aOR 0.41)and no difference in risk for preterm birth in reference to non-diabetic women.CONCLUSION Diabetes is associated with the poor birth outcomes.Clinical management of diabetes during pregnancy and healthy lifestyle behaviors before pregnancy can reduce the risk for diabetes and poor birth outcomes.

Seasonal variations in gonad morphology and hypothalamic GnRH-I and GnIH in Eurasian Tree Sparrow,a multi-brooded passerine

The hypothalamic-pituitary-gonadal(HPG)axis ubiquitously regulates seasonal reproduction,following the rhythmicity of a suite of environmental cues.Birds display prominent seasonal variations in gonad size regulated by two hypothalamic peptides,gonadotropin-releasing hormone-1(GnRH-I)and gonadotropin-inhibiting hormone(GnIH).How multi-brooded avian species adjust GnRH-I and GnIH to regulate gonadal morphology seasonally remains largely unknown.Here,we studied the variations in the hypothalamic immunoreactivity(ir)of GnRH-I and GnIH,gonadal proliferation,and apoptosis in a typical multi-brooded species,the Eurasian Tree Sparrow(Passer montanus),across the pre-breeding(PB),first breeding(FB),second breeding(SB),pre-basic molt(PM),and wintering stages(WS).Our results showed that both sexes had higher preoptic area(POA)-GnRH-I-ir but lower paraventricular nucleus(PVN)-GnIH-ir neurons during the breeding stages(FB and SB)relative to other life-history stages,with no significant differences between two broods.The testes and ovaries were significantly larger during the breeding stages.Testicular volume increased during the two broods due to anincreased diameter of seminiferous tubules.Furthermore,there were more testicular apoptotic cells in PB and WS stages than in breeding stages,and in PB stage than in PM stage.Males had higher POA-GnRH-I expression than females during the breeding stages,but both sexes had comparable PVN-GnIH expression throughout the annual cycle.Both sexes of the sparrows may undergo a similar pattern of life-history stage-dependent variation in the hypothalamic GnRH-I,GnIH,and gonadal morphology,except that during breeding stages,males may display higher expression of POA-GnRH-I relative to females.The higher expression of POA-GnRH-I-ir in breeding male sparrows may be critical for male-dependent parental care.

子宫全切术和次全切除术后性功能变化的随机对照研究

OBJECTIVE: To compare sexual functioning and health-related quality-of-li fe outcomes of total abdominal hysterectomy (TAH) and supracervical hysterectomy ( SCH) among women with symptomatic uterine leiomyomata or abnormal uterine bleedi ng refractory to hormonal management. METHODS: We randomly assigned 135 women sc heduled to undergo abdominal hysterectomy in 4 U.S. clinical centers to either a total or supracervical procedure. The primary outcome was sexual functioning at 2 years, as assessed by the Medical Outcomes Study Sexual Problems Scale. Secon dary outcomes included specific aspects of sexual functioning and health-relate d quality-of-life at 6 months and 2 years. RESULTS: Sexual problems improved d ramatically in both randomized groups during the first 6 months and plateaued by 1 year. Health-related quality-of-life scores also improved in both groups. At 2 years, both groups reported few problems with sexual functioning (mean scor e on the Sexual Problems Scale for SCH group 82, TAH group 80, on a 0-to-100 s cale with 100 indicating an absence of problems; difference = +2,95%confidence interval -8 to +11), and there were no significant differences between groups . CONCLUSION: Supracervical and total abdominal hysterectomy result in similar s exual functioning and health-related quality of life during 2 years of follow- up. This information can help guide physicians as they discuss surgical options with their patients.

Molecular design of an ultra-strong tissue adhesive hydrogel with tunable multifunctionality

Designing adhesive hydrogels with optimal properties for the treatment of injured tissues is challenging due to the tradeoff between material stiffness and toughness while maintaining adherence to wet tissue surfaces. In most cases, bioadhesives with improved mechanical strength often lack an appropriate elastic compliance, hindering their application for sealing soft, elastic, and dynamic tissues. Here, we present a novel strategy for engineering tissue adhesives in which molecular building blocks are manipulated to allow for precise control and optimization of the various aforementioned properties without any tradeoffs. To introduce tunable mechanical properties and robust tissue adhesion, the hydrogel network presents different modes of covalent and noncovalent interactions using N-hydroxysuccinimide ester (NHS) conjugated alginate (Alg-NHS), poly (ethylene glycol) diacrylate (PEGDA), tannic acid (TA), and Fe^(3+) ions. Through combining and tuning different molecular interactions and a variety of crosslinking mechanisms, we were able to design an extremely elastic (924%) and tough (4697 kJ/m3) multifunctional hydrogel that could quickly adhere to wet tissue surfaces within 5 s of gentle pressing and deform to support physiological tissue function over time under wet conditions. While Alg-NHS provides covalent bonding with the tissue surfaces, the catechol moieties of TA molecules synergistically adopt a mussel-inspired adhesive mechanism to establish robust adherence to the wet tissue. The strong adhesion of the engineered bioadhesive patch is showcased by its application to rabbit conjunctiva and porcine cornea. Meanwhile, the engineered bioadhesive demonstrated painless detachable characteristics and in vitro biocompatibility. Additionally, due to the molecular interactions between TA and Fe3+, antioxidant and antibacterial properties required to support the wound healing pathways were also highlighted. Overall, by tuning various molecular interactions, we were able to develop a single-hydrogel platform with an “all-in-one” multifunctionality that can address current challenges of engineering hydrogel-based bioadhesives for tissue repair and sealing.

Constructing CdS/Cd/doped TiO_2 Z-scheme type visible light photocatalyst for H_2 production

Constructing Z-scheme type photocatalyst is an efficient way to improve the charge separation efficiency and enhance the photocatalytic activity. In this report, the Cd：TiO2 nanoparticles are prepared via the sol-gel route and employed as a starting material. When it was reduced by NaBH4 at 300°C,the surface oxygen vacancies were produced and Cd2＋ was reduced into metal Cd0 nanoparticle（denoted as R-Cd：TiO2）.Subsequently, the formed R-Cd：TiO2 was treated with thioureain the hydrothermal reaction. Through the decomposition of thiourea, the oxygen vacancies were refilled by S2- from thiourea to form S：TiO2/TiO2（d-TiO2） and Cd was partially converted into CdS to form CdS/Cd/d-TiO2 composite. The formed CdS/Cd/d-TiO2 composite exhibits improved photocatalytic activity. Under visible light irradiation（λ〉400 nm）,the H2 production rate of CdS/Cd/d-TiO2 reaches 119 μmol h-1 with 50 mg of photocatalyst without any cocatalyst, which is about 200 and 60 times higher than that of S：TiO2/TiO2（0.57 μmol h-1）, CdS（2.03 μmol h-1） and heterojunction CdS/d-TiO2（2.17 μmol h-1） materials, respectively. The results illustrate that metal Cd greatly promotes the charge separation efficiency due to the formation of Z-scheme type composite. In addition, the photocatalytic activity in the visible light region was dramatically enhanced due to the contribution of both CdS and d-TiO2. The method could be easily extended to other wide bandgap semiconductors for constructing visible light responsive Z-scheme type photocatalysts.