Minimal active domain of human salivary histatin 1 is efficacious in promoting acute skin wound healing

Dear Editor,The skin barrier can be impaired by acute skin wounds,which may lead to a series of complications.It is essential to accelerate wound healing and rapidly restore the structural integrity and functionality of skin.One of the promising bioactive agents is human salivary histatin 1(Hst1),a 38-amino acid histidine-rich peptide that functions to maintain the homeostasis of oral mucosa with a cellular mechanism of promoting the adhesion,spreading,migration of epithelial cells and thus re-epithelialization[1].In recent years,Hst1 has been shown to be effective against various skin-related cell types,such as fibroblasts,myo-fibroblasts,keratinocytes and endothelial cells.In our latest in-vivo study,Hst1 not only promotes angiogenesis,re-epithelialization and collagen production,but also suppresses inflammation,thereby significantly accelerating acute skin wound healing in mice[2].All these studies show that Hst1 is a potent bioactive agent for accelerating acute skin wound healing.

GPCR/endocytosis/ERK signaling/S2R is involved in the regulation of the internalization,mitochondria-targeting and-activating properties of human salivary histatin 1

Human salivary histatin 1(Hst1)exhibits a series of cell-activating properties,such as promoting cell spreading,migration,and metabolic activity.We recently have shown that fluorescently labeled Hst1(F-Hst1)targets and activates mitochondria,presenting an important molecular mechanism.However,its regulating signaling pathways remain to be elucidated.We investigated the influence of specific inhibitors of G protein-coupled receptors(GPCR),endocytosis pathways,extracellular signal-regulated kinases1/2(ERK1/2)signaling,p38 signaling,mitochondrial respiration and Na+/K+-ATPase activity on the uptake,mitochondria-targeting and-activating properties of F-Hst1.We performed a si RNA knockdown(KD)to assess the effect of Sigma-2 receptor(S2R)/Transmembrane Protein 97(TMEM97)—a recently identified target protein of Hst1.We also adopted live cell imaging to monitor the whole intracellular trafficking process of F-Hst1.Our results showed that the inhibition of cellular respiration hindered the internalization of F-Hst1.The inhibitors of GPCR,ERK1/2,phagocytosis,and clathrin-mediated endocytosis(CME)as well as siRNA KD of S2R/TMEM97 significantly reduced the uptake,which was accompanied by the nullification of the promoting effect of F-Hst1 on cell metabolic activity.Only the inhibitor of CME and KD of S2R/TMEM97 significantly compromised the mitochondria-targeting of Hst1.We further showed the intracellular trafficking and targeting process of F-Hst1,in which early endosome plays an important role.Overall,phagocytosis,CME,GPCR,ERK signaling,and S2R/TMEM97 are involved in the internalization of Hst1,while only CME and S2R/TMEM97 are critical for its subcellular targeting.The inhibition of either internalization or mitochondria-targeting of Hst1 could significantly compromise its mitochondria-activating property.

Establishment of a humanized ST6GAL1 mouse model for influenza research

Background:This study aimed to construct and characterize a humanized influenza mouse model expressing hST6GAL1.Methods:Humanized fragments,consisting of the endothelial cell-specific K18 promoter,human ST6GAL1-encoding gene,and luciferase gene,were microinjected into the fertilized eggs of mice.The manipulated embryos were transferred into the oviducts of pseudopregnant female mice.The offspring were identified using PCR.Mice exhibiting elevated expression of the hST6GAL1 gene were selectively bred for propagation,and in vivo analysis was performed for screening.Expression of the humanized gene was tested by performing immunohistochemical(IHC)analysis.Hematologic and biochemical analyses using the whole blood and serum of humanized hST6GAL1 mice were performed.Results:Successful integration of the human ST6GAL1 gene into the mouse genome led to the overexpression of human SiaT ST6GAL1.Seven mice were identified as carrying copies of the humanized gene,and the in vivo analysis indicated that hST6GAL1gene expression in positive mice mirrored influenza virus infection characteristics.The IHC results revealed that hST6GAL1 was expressed in the lungs of humanized mice.Moreover,the hematologic and biochemical parameters of the positive mice were within the normal range.Conclusion:A humanized influenza mouse model expressing the hST6GAL1 gene was successfully established and characterized.

富组蛋白1促皮肤创伤愈合的细胞学研究

目的了解富组蛋白1(histatin1,Hst1)对人表皮细胞(human adult skin keratinocytos,HaCaT)、人成纤维细胞株增殖和迁移功能的影响。方法细胞增殖实验:(1)将HaCaT细胞、人成纤维细胞均分为空白对照组(1640/DMEM+1%新生牛血清)、Ⅰ组(100μg/ml Hst1)、Ⅱ组(30μg/ml Hst1)、Ⅲ组(3μg/ml Hst1),比较两种细胞的增殖数量;(2)细胞划痕实验:将两种细胞分为空白对照组(1640+1%新生牛血清)、A组(30μg/ml Hst1)、B组[10ng/ml人重组表皮生长因子(recombinant human epidermalgrowth factor,rhEGF)]、C组(30μg/ml Hst1+10ng/ml rhEGF)、D组(15μg/ml Hst1+5ng/ml rhEGF)、E组(15μg/ml Hst1+10ng/ml rhEGF),比较两种细胞体外创面愈合速度。结果 (1)3～100μg/ml的Hst1能够促进HaCaT增殖,72h时Ⅰ组细胞数高于空白对照组、Ⅱ组及Ⅲ组(P<0.01);3～100μg/ml的Hst1能够促进人成纤维细胞增殖,24h时Ⅰ、Ⅱ组细胞数高于其余各组(P<0.01);(2)30μg/ml Hst1能促进HaCaT细胞迁移,16h时A组划痕愈合率高于空白对照组(P<0.01),C、D组高于A组(P<0.05);30μg/ml Hst1能促进人成纤维细胞划痕创面愈合,与rhEGF联合应用时划痕愈合率高于单独用药。结论 Hst1能够促进HaCaT细胞和人成纤维细胞增殖和迁移,与rhEGF联合应用时对其促进体外创伤愈合具有协同作用。

富组蛋白1促进创面愈合的实验研究

[目的]探讨富组蛋白对表皮创面愈合的影响,为临床用药和创面护理提供新的思路和方向。[方法]通过细胞划痕试验,分为Hist1实验组、空白对照组、Hist1+丝裂霉素实验组、空白+丝裂霉素对照组,用丝裂霉素抑制细胞增殖,建立体外创面模型,于0h、16h、24h分别测量划痕区1.4 mm2内的愈合率。[结果]大约1.4mm2的创面16h愈合率为64.60%,24h愈合率为71.42%;而空白对照组16h愈合率为41.23%,24h愈合率为48.11%,两组相比,差异有统计学意义(P<0.05);而加入丝裂霉素后,16h愈合率为61.97%,明显高于空白+丝裂霉素对照组(32.25%)。[结论]30μg/mL生理浓度的富组蛋白1能明显促进表皮细胞增殖和迁移,且随着时间延长愈合率增高;提示富组蛋白1能促进非口腔上皮创面愈合。

煤层成因类型及对煤系砂砾岩孔隙演化的控制作用——以准噶尔盆地玛湖地区侏罗系八道湾组为例

为探讨煤系砂砾岩中不同类型煤层的差异地质响应,及对邻近砂砾岩孔隙演化的影响,以野外露头、孢粉组合、井—震剖面、岩心相序、测井响应、扫描电镜、电子探针能谱及三史(埋藏史—有机酸演化史—孔隙演化史)等资料的综合分析为基础,对准噶尔盆地玛湖斜坡区侏罗系八道湾组煤系砂砾岩中发育的早湖侵期广覆式煤层、高(低)位期局限式煤层进行了综合比对,认为在压实减孔最强烈的准同生—早成岩期,早湖侵期广覆式煤层正值煤系腐殖酸排酸高峰,对邻近砂砾岩储层储集渗流性能的影响整体以抑制性为主,高刚性颗粒含量利于孔隙保存。研究结果表明:玛湖地区八道湾组发育早湖侵期广覆式煤层、高(低)位期局限式煤层2种成因类型。早湖侵期广覆式煤层发育于湖侵体系域TST早期,煤质均一,上覆砾质强陆源阻断沉积,与顶板层之间呈相序突变接触。其分布受控于以逆冲断裂Ⅰ型、Ⅱ型为代表的盆缘边界断裂复活及盆地基底的振荡性沉降,主要分布于近湖盆区首次湖泛面附近,测井响应为极高RT、低DEN、低GR;高(低)位期局限式煤层发育于低位体系域LST、高位体系域HST中期,煤质不纯多夹于静水细粒沉积中,与顶板层、底板层之间多呈现为相序渐变接触。其分布具较明显的相控特征,多分布于水动力较弱的扇间/河道间等低能相带,测井响应为较低RT、较高DEN、较高GR。煤系腐殖酸、烃源有机酸形成的长石粒内溶孔、高岭石胶结物、高岭石完全拟颗粒、高岭石部分拟颗粒等成岩产物在赋存产状、元素组分等方面差异明显。高刚性颗粒含量是煤系砂砾岩储层孔隙有效保存的前提条件,高岭石、硅质等溶蚀产物的迁出程度进一步制约着孔隙的有效性。优质储层区带优选应重点关注高刚性颗粒含量区及水下分流河道、河口坝等高水动力沉积相带。