Development of mouse preimplantation embryos in space.

The development of life beyond planet Earth is a long-standing quest of the human race, but whether normal mammalian embryonic development can occur in space is still unclear. Here, we show unequivocally that preimplantation mouse embryos can develop in space, but the rate of blastocyst formation and blastocyst quality are compromised. Additionally, the cells in the embryo contain severe DNA damage, while the genome of the blastocysts developed in space is globally hypomethylated with a unique set of differentially methylated regions. The developmental defects, DNA damage and epigenetic abnormalities can be largely mimicked by the treatment with ground-based low-dose radiation. However, the exposure to simulated microgravity alone does not cause major disruptions of embryonic development, indicating that radiation is the main cause for the developmental defects. This work advances the understanding of embryonic development in space and reveals long-term extreme low-dose radiation as a hazardous factor for mammalian reproduction.

Recombinant buckwheat trypsin inhibitor decreases fat accumulation via the IIS pathway in Caenorhabditis elegans.

Buckwheat trypsin inhibitor (BTI) is a low molecular weight polypeptide that can help to prevent metabolic diseases such as obesity, hyperglycemia and hyperlipidemia. Herein, the effects of recombinant BTI (rBTI) on fat accumulation in Caenorhabditis elegans were studied. rBTI prevented fat accumulation under normal and high glucose conditions, and led to significantly shorter body widths without affecting C. elegans feeding behavior. Results also indicate that rBTI altered fat breakdown, synthesis, and accumulation by altering the transcription, expression and activity of key enzymes in lipolysis and fat synthesis. In daf-2 and daf-16 mutants, rBTI did not prevent fat accumulation, indicating that rBTI activity relies on the insulin/insulin-like growth factor (IIS) pathway. Overall rBTI may regulate changes in lipolysis and fat synthesis by down-regulating the IIS pathway, which can affect fat accumulation. These findings support the application of rBTI in preventing obesity, hyperglycemia and hyperlipemia.

Chemerin/ChemR23 axis promotes inflammation of glomerular endothelial cells in diabetic nephropathy.

Diabetic nephropathy (DN) is characterized by inflammation of renal tissue. Glomerular endothelial cells (GEnCs) play an important role in inflammation and protein leakage in urine in DN patients. Chemerin and its receptor ChemR23 are inducers of inflammation. The aim of this study was to investigate the function of chemerin/ChemR23 in GEnCs of DN patients. Immunohistochemical staining and qRT-PCR were used to measure the expression of chemerin, ChemR23 and inflammatory factors in renal tissues of DN patients. Db/db mice were used as animal model. ChemR23 of DN mice was knocked down by injecting LV3-shRNA into tail vein. Inflammation, physiological and pathological changes in each group was measured. GEnCs were cultured as an in vitro model to study potential signalling pathways. Results showed that expression of chemerin, ChemR23 and inflammatory factors increased in DN patients and mice. LV3-shRNA alleviated renal damage and inflammation in DN mice. GEnCs stimulated by glucose showed increased chemerin, ChemR23 and inflammatory factors and decreased endothelial marker CD31. Both LV3-shRNA and SB203580 (p38 MAPK inhibitor) attenuated chemerin-induced inflammation and injury in GEnCs. Taken together, chemerin/ChemR23 axis played an important role in endothelial injury and inflammation in DN via the p38 MAPK signalling pathway. Suppression of ChemR23 alleviated DN damage.

Self-recoverable Pd-Ru/TiO2 nanocatalysts with ultrastability towards ethanol electrooxidation.

Self-recoverable Pd-Ru/TiO2 nanocatalysts have been prepared by electrochemical stripping of Pd-Ru/TiO2 precursors. For the ethanol oxidation reaction (EOR), these Pd-Ru/TiO2 nanocatalysts are used as an anode catalyst. The characterization of catalysts via chronoamperometry has been repeated 15 times. After 15 stability tests, the Pd1Ru0.69/TiO2 nanocatalysts still achieve a factor of 9.4 enhancement at the residual current density (309.42 mA mgPd-1) for the EOR over commercial Pd/C catalysts (33.01 mA mgPd-1). From the 5th to 15th test, when each 10 000 s stability test is performed in a fresh ethanol electrolyte, the initial and residual current density of the catalysts could recover to the original or even better value in a few hours before performing another 10 000 s stability test. Herein, these Pd-Ru/TiO2 nanocatalysts with ultrastability towards ethanol electrooxidation are self-recoverable. Density functional theory calculations reveal that the introduction of oxophilic metal Ru and a TiO2 support into Pd-based catalysts and the synergistic effects between Ru and TiO2 have led to the ultrastability towards the EOR. The introduction of oxophilic metal Ru and a TiO2 support into catalysts can reduce the adsorption energy of OHads on the Pd-Ru/TiO2 nanocatalysts, and it will inhibit the COads produced and adsorbed on the Pd surface.

Expansion of Hair Follicle Stem Cells Sticking to Isolated Sebaceous Glands to Generate in Vivo Epidermal Structures.

Hair follicle stem cells (HFSCs) are considered one of the useful donor cell types for skin regenerative medicine owing to their robust proliferative capacity and multipotency. However, methods for easily and effectively obtaining HFSCs from a limited skin biopsy are still lacking. Here we report a novel approach for obtaining a subpopulation of HFSCs from a small skin sample from the rat tail, which uses the sebaceous glands (SGs) to capture the adjacent HFSCs. By means of organ culture, keratinocytes were expanded from the detached SGs, which also included adherent HFSCs from the hair follicle that could be passaged at the single-cell level. These SG-captured keratinocytes strongly expressed the basal layer markers K14, integrin α6, and p63; the bulge stem cell marker K15; and the upper isthmus stem cell marker Plet1. Furthermore, we reconstituted new epidermis, hair follicles, and SGs from the SG-captured keratinocytes using an easily operated, modified skin reconstitution assay based on silicone gel sheeting. This study suggests that the SGs could be an accessible capturer to harvest the adjacent HFSC subpopulation, particularly when the donor tissue is limited.

Exogenous R-Spondin1 Induces Precocious Telogen-to-Anagen Transition in Mouse Hair Follicles.

R-spondin proteins are novel Wnt/ß-catenin agonists, which signal through their receptors leucine-rich repeat-containing G-protein coupled receptor (LGR) 4/5/6 and substantially enhance Wnt/ß-catenin activity. R-spondins are reported to function in embryonic development. They also play important roles in stem cell functions in adult tissues, such as the intestine and mammary glands, which largely rely on Wnt/ß-catenin signaling. However, in the skin epithelium and hair follicles, the information about R-spondins is deficient, although the expressions and functions of their receptors, LGR4/5/6, have already been studied in detail. In the present study, highly-enriched expression of the R-spondin family genes (Rspo1/2/3/4) in the hair follicle dermal papilla is revealed. Expression of Rspo1 in the dermal papilla is specifically and prominently upregulated before anagen entry, and exogenous recombinant R-spondin1 protein injection in mid-telogen leads to precocious anagen entry. Moreover, R-spondin1 activates Wnt/ß-catenin signaling in cultured bulge stem cells in vitro, changing their fate determination without altering the cell proliferation. Our pioneering study uncovers a role of R-spondin1 in the activation of cultured hair follicle stem cells and the regulation of hair cycle progression, shedding new light on the governance of Wnt/ß-catenin signaling in skin biology and providing helpful clues for future treatment of hair follicle disorders.

[Clinical observation of dysphagia after cerebral infarction treated with awn-like needle at Tiantu(CV 22)].

OBJECTIVE: To observe the effect difference between awn-like needle at Tiantu(CV 22) and filiform needle for dysphagia after cerebral infarction. METHODS: One hundred patients were randomly assigned into an awn-like needle group and a filiform needle group,50 cases in each one. Based on the conventional western medicine for all the patients,awn-like needle was applied at Tiantu(CV 22) in the awn-like needle group;while acupuncture was used at Fengchi(GB 20),Shanglianquan(Extra),Shuigou(GV 26) and Tongli(HT 5) in the filiform needle group,combined with pricking at Jinjin(EX-HN 12), Yuye(EX-HN 13),posterior pharyngeal wall with three-edged needle method. All the treatment was given once a day for two weeks. Standard swallowing assessment scale(SSA) and modified Bathel index for daily life ability(MBI) were used and the efficacy was calculated after treatment. RESULTS: The scores of SSA and MBI were improved after treatment in the two groups(all P<0.01),and the results were better in the awn-like needle group than those in the filiform needle group(both P<0.05). The cured and effective rate of the awn-like needle group was 56.0%(28/50), which was obviously better than 30.0%(15/50) of the filiform needle group(P<0.05). CONCLUSIONS: Based on the conventional western treatment,awn-like needle and filiform needle can both improve dysphagia and daily life after cerebral infarction. But awn-like needle achieves better effect.

Spatiotemporal Expression of p63 in Mouse Epidermal Commitment.

The embryonic surface ectoderm is a simple flat epithelium consisting of cells that express the cytokeratins K8/K18. Before stratification, K5/K14 expression substitutes K8/K18 expression, marking the event called epidermal commitment. Previous studies show that the transcription factor p63 plays an essential role in epidermal commitment. However, detailed expression information of p63 during early epidermal development in mice is still unclear. We systematically studied the expression pattern of p63 in mouse epidermal commitment, together with K8 and K5. We show that p63 expression could be detected as early as E8.5 in mouse embryos preceding epidermal commitment. p63 expression first appears near the newly formed somites and the posterior part of the embryo, further expanding to the whole embryonic surface with particular enrichment in the first branchial arches and the limb buds. ΔNp63 is the major class of isoforms expressed in this period. Relative expression intensity of p63 depends on the embryonic position. In summary, there is a sequential and regular expression pattern of K8, p63 and K5 in mouse epidermal commitment. Our study not only contributes to understanding the early events during epidermal development but also provides a basal tool to study the function of p63 in mammals.

[Observation on Therapeutic Effects of Acupuncture Combined with Cutaneous Electrical Stimulation for Dysphagia in Patients with Cerebral 1nfarction].

OBJECTIVE: To observe the clinical effect of acupuncture combined with neck-skin electrical stimulation (NSES) on dysphagia in patients with cerebral infarction (CI). METHODS: A total of 120 CI patients with dysphagia were randomly divided into acupuncture group, NSES group and acupuncture + NSES group (combined treatment group, n = 40 in each group). Acupuncture stimulation of Fengchi (GB20), Yifeng (TE 17), etc., and blood-letting of Jinjin (EX-HN 12) and Yuye (EX-HN 13) were administrated. NSES was applied to the bilateral sites of the neck-median line. The treatment was given once daily for two weeks. The swallow function and swallow dysfunction degree of the dysphasia patients were evaluated by water swallow test and food-intake scale, respectively. RESULTS: After one week's and two weeks' treatment, the water swallow score and swallow dysfunction score were significantly improved in the acupuncture, NSES and combined treatment groups (P<0. 01), and the difference values between pre- and post-treatment of the water swallow score and swallow ability score in the combined treatment group were obviously higher than those of the acupuncture and NSES groups (P<0. 01, P<0. 05). No significant differences were found between the acupuncture and NSES groups in both the water swallow score and swallow ability score after one and two weeks' treatment (P>0. 05). Of the three 40 cases in the acupuncture, NSES and combined treatment groups, 16, 18 and 27 were basically cured, 2, 3 and 5 experienced marked improvement, 15, 13 and 7 were improved, and 7, 6 and 1 failed in the treatment, with the effective rates being 82.5%, 85.0% and 97. 5%, respectively. The therapeutic effect of the combined treatment group was apparently superior to that of the simple acupuncture and simple NSES groups (P<0. 01). CONCLUSION: Acupuncture and NSES intervention is effective in improving dysphasia in CI patients and the effect of combined treatment of acupuncture and NSES is obviously better than that of the simple acupuncture and simple NSES.

Ovine Hair Follicle Stem Cells Derived from Single Vibrissae Reconstitute Haired Skin.

Hair follicle stem cells (HFSCs) possess fascinating self-renewal capacity and multipotency, which play important roles in mammalian hair growth and skin wound repair. Although HFSCs from other mammalian species have been obtained, the characteristics of ovine HFSCs, as well as the methods to isolate them have not been well addressed. Here, we report an efficient strategy to obtain multipotent ovine HFSCs. Through microdissection and organ culture, we obtained keratinocytes that grew from the bulge area of vibrissa hair follicles, and even abundant keratinocytes were harvested from a single hair follicle. These bulge-derived keratinocytes are highly positive for Krt15, Krt14, Tp63, Krt19 and Itga6; in addition to their strong proliferation abilities in vitro, these keratinocytes formed new epidermis, hair follicles and sebaceous glands in skin reconstitution experiments, showing that these are HFSCs from the bulge outer root sheath. Taken together, we developed an efficient in vitro system to enrich ovine HFSCs, providing enough HFSCs for the investigations about the ovine hair cycle, aiming to promote wool production in the future.

Senescence of human skin-derived precursors regulated by Akt-FOXO3-p27(KIP¹)/p15(INK4b) signaling.

Multipotent skin-derived precursors (SKPs) are dermal stem cells with the capacity to reconstitute the dermis and other tissues, such as muscles and the nervous system. Thus, the easily available human SKPs (hSKPs) hold great promises in regenerative medicine. However, long-term expansion is difficult for hSKPs in vitro. We previously demonstrated that hSKPs senesced quickly under routine culture conditions. To identify the underlying mechanisms so as to find an effective way to expand hSKPs, time-dependent microarray analysis of gene expression in hSKPs during in vitro culture was performed. We found that the senescence of hSKPs had a unique gene expression pattern that differs from reported typical senescence. Subsequent investigation ruled out the role of DNA damage and classical p53 and p16(INK4a) signaling in hSKP senescence. Examination of cyclin-dependent kinase inhibitors revealed the involvement of p15(INK4b) and p27(KIP1). Further exploration about upstream signals indicated the contribution of Akt hypo-activity and FOXO3 to hSKP senescence. Forced activation of Akt and knockdown of FOXO3, p15(INK4b) and p27(KIP1) effectively inhibited hSKP senescence and promoted hSKP proliferation. The unique senescent phenotype of human dermal stem cells and the role of Akt-FOXO3-p27(KIP1)/p15(INK4b) signaling in regulating hSKP senescence provide novel insights into the senescence and self-renewal regulation of adult stem cells. The present study also points out a way to propagate hSKPs in vitro so as to fulfill their promises in regenerative medicine.

mTOR signaling promotes stem cell activation via counterbalancing BMP-mediated suppression during hair regeneration.

Hair follicles (HFs) undergo cycles of degeneration (catagen), rest (telogen), and regeneration (anagen) phases. Anagen begins when the hair follicle stem cells (HFSCs) obtain sufficient activation cues to overcome suppressive signals, mainly the BMP pathway, from their niche cells. Here, we unveil that mTOR complex 1 (mTORC1) signaling is activated in HFSCs, which coincides with the HFSC activation at the telogen-to-anagen transition. By using both an inducible conditional gene targeting strategy and a pharmacological inhibition method to ablate or inhibit mTOR signaling in adult skin epithelium before anagen initiation, we demonstrate that HFs that cannot respond to mTOR signaling display significantly delayed HFSC activation and extended telogen. Unexpectedly, BMP signaling activity is dramatically prolonged in mTOR signaling-deficient HFs. Through both gain- and loss-of-function studies in vitro, we show that mTORC1 signaling negatively affects BMP signaling, which serves as a main mechanism whereby mTORC1 signaling facilitates HFSC activation. Indeed, in vivo suppression of BMP by its antagonist Noggin rescues the HFSC activation defect in mTORC1-null skin. Our findings reveal a critical role for mTOR signaling in regulating stem cell activation through counterbalancing BMP-mediated repression during hair regeneration.

GPR39 marks specific cells within the sebaceous gland and contributes to skin wound healing.

G protein-coupled receptors (GPCRs) mediate multiple key biological processes in the body. The orphan receptor GPR39 has been reported to be involved in various pathophysiological events. However, the function of GPR39 in skin biology remains unknown. Using a genetically engineered mouse strain in which lacZ expression faithfully replaced endogenous Gpr39 expression, we discovered a unique expression pattern of Gpr39 in the sebaceous gland (SG). Using various methods, we confirmed that GPR39 marked a specific cell population at the opening of the SG and colocalised with the SG stem cell marker Blimp1. Further investigations showed that GPR39 was spatiotemporally expressed during skin wound repair. Although it was dispensable for skin development and homeostasis, GPR39 contributed positively to skin wound healing: its loss led to a delay in wound healing during the intermediate stage. The present study reveals a novel role of GPR39 in both dermatology and stem cell biology that has not been previously recognised.

Rotary suspension culture enhances mesendoderm differentiation of embryonic stem cells through modulation of Wnt/ß-catenin pathway.

Recently, physical factors in the local cellular microenvironment have been confirmed with strong influences on regulating stem cell fate. Despite the recent identification of the rotary cell culture system (RCCS) as a bioreactor for culturing stem cells, the underlying biological role provided by RCCS in the lineage differentiation of embryonic stem cells (ESCs) remains largely undefined. Here, we explored the embryoid body (EB) formation and subsequent differentiation of mouse ESCs in RCCS. We demonstrated that EBs formed in RCCS were more homogeneous and bigger in size compared with those in the static condition. Further, we determined that mesendoderm differentiation was prominently enhanced, while neuroectodermal differentiation was significantly suppressed in RCCS. Surprisingly, we found that Wnt/ß-catenin signaling was greatly enhanced mainly due to the increased expression of Wnt3 during ESC differentiation in RCCS. Inhibition of Wnt/ß-catenin signaling by DKK1 decreased the expression of Brachyury and attenuated mesendoderm differentiation in RCCS. Intriguingly, Wnt3a markedly increased Brachyury expression under static condition rather than in RCCS. Taken together, our findings uncover a new role of rotary suspension culture in initializing the early differentiation of ESCs.

Three-dimensional hydrogel scaffolds facilitate in vitro self-renewal of human skin-derived precursors.

Skin-derived precursors (SKPs) are multipotent cells with dermal stem cell properties. These easily available cells possess the capacity to reconstitute the skin in vivo, as well as a broader differentiation potential in vitro, which endows them with great prospects in regenerative medicine. However, the present authors' group and others previously found that adult human SKPs (hSKPs) expanded deficiently in vitro, which largely counteracted their research and practical values. Taking the physiological micro-environment of hSKPs into consideration, the authors sought to establish a hydrogel scaffold-based three-dimensional (3-D) culture system for hSKPs in the present study. After comparing their morphology, growth characteristics, signature gene expression and differentiation potential in different hydrogels, the present authors found that a chemically defined hyaluronic acid and denatured collagen-based hydrogel system that mimicked the natural niche of hSKPs in the dermis could alleviate hSKP senescence, support hSKP proliferation as spheres, while largely retaining their properties and potential. This study suggested that recapitulating the in vivo stem cell niche by providing them with 3-D extracellular matrix environments could help them achieve better self-renewal in vitro. In addition, the animal-origin-free and biocompatible 3-D hydrogel system will certainly benefit fundamental research and clinical applications of hSKPs in the near future.

[The protective effects of sacral nerve electrostimulation on intestinal mucosal mechanical barrier in rats with spinal cord injury].

OBJECTIVE: To study the protective effects of sacral nerve root electrostimulation on intestinal mechanical barrier in rats with spinal cord injury (SCI). METHODS: Fifty six Wistar rats were divided into normal group, SCI control group and SCI group with sacral nerve root electrostimulation (8 rats in each subgroup at 24, 48, 72 h after spinal cord injury). The following experiments were performed respectively in rats from the 3 groups: bacteria culture from intestinal mesentery lymph nodes, liver, spleen, intestinal morphology observation and detection the protein expression level of ZO-1. RESULTS: The intestinal mucosa appeared different degree of damage in SCI control group; cell-cell connections between intestinal epithelial cells were destroyed; Endotoxin levels in blood and the number of bacterial translocation increased obviously. Sacral nerve stimulation was found toimprove the intestinal mucosal, reduce the endotoxin content in the blood to normal level and the decrease the incidences of bacterial translocation of the gut origin. The expression of tight junction protein ZO-1 of rat intestinal tissue had no statistical differences among the 3 groups. On the other hand, the distribution of tight junction protein ZO-1 appeared different degrees of scattered and irregular in the control group while that in the experimental group appeared different degree of improvement as determined by the immunohistochemistry of rat intestinal tissue. CONCLUSION: sacral nerve root electrostimulation can rehabilitate the peristalsis of denervated colon, promote defeacation and decrease bacterial amount, protection of the intestinal mechanical barrier between intestinal epithelial cells and tight junction, reducing the endotoxin content in the blood and suppressing bacterial translocation from the gut.

Genetic deletion of Cxcl14 in mice alters uterine NK cells.

The uterine natural killer cells (uNK cells) are the major immune cells in pregnant uterus and the number of uNK cells is dramatically increased during placentation and embryo development. The uNK cells are necessary for the immune tolerance, cytokine secretion and angiogenesis of placenta. Former studies indicated that the population expansion of uNK cells was accomplished through recruitment of NK cell precursors from the spleen and bone marrow, but not proliferation of NK cells. However, the necessary molecules within this process were little understood. Here in our study, we found the co-localized expression of Cxcl14 protein with uNK cells in E13.5 pregnant uterus. Moreover, we used Cxcl14 knockout mice to examine uNK cells in mesometrial lymphoid aggregate of pregnancy (MLAp) and decidua basalis (DB) of E13.5 pregnant uterus and found significantly decreased uNK cells in Cxcl14(-/-) pregnant uteri compared with Cxcl14(+/-) pregnant uteri. To further explorer the molecular change in MLAp and DB after Cxcl14 knockout, we isolated the MLAp and DB from Cxcl14(+/+) and Cxcl14(-/-) pregnant uteri and performed microarray analysis. We found many genes were up and down regulated after Cxcl14 knockout. In conclusion, our results suggested the important function of Cxcl14 in uNK cells and the proper level of Cxcl14 protein were required to recruit NK cells to pregnant uterus.

Hair follicle stem cells derived from single rat vibrissa via organ culture reconstitute hair follicles in vivo.

Hair follicle stem cells (HFSCs) are potentially useful for the treatment of skin injuries and diseases. To achieve clinical application, a prerequisite must be accomplished: harvesting enough HFSCs from limited skin biopsy. The commonly used sorting approach for isolating HFSCs, however, suffers from its intrinsic disadvantages, such as requirement of large-scale skin biopsy. Here, we report an efficient organ culture method to isolate and expand rat HFSCs from limited skin biopsy and these HFSCs could reconstitute the epidermis and the hair follicles (HFs). Seventy-three percent of cultured HFs formed hair follicle stem cell colonies from the bulge, and a single hair follicle provided all the HFSCs used in this research, demonstrating the high efficiency of this method. Quantitative RT-PCR and immunofluorescent staining results revealed that these stem cells obtained from the bulge highly expressed basal layer markers K14 and alpha-6 integrin, epithelial stem cell marker P63, and bulge stem cell marker K15. After long-term culture in vitro, GFP-labeled hair follicle stem cells formed new hair follicles, epidermis, and sebaceous glands following xenotransplantation into the back of nude mice. This study indicated that multipotent hair follicle stem cells could be efficiently harvested through organ culture from limited skin material-even a single hair follicle-and reconstitute hair follicles in vivo after long-term expansion culture, providing the basis for future clinical applications.