Peri-implant keratinized gingiva augmentation using xenogeneic collagen matrix and platelet-rich fibrin:A case report

BACKGROUND Keratinized gingival insufficiency is a disease attributed to long-term tooth loss,can severely jeopardizes the long-term health of implants.A simple and effective augmentation surgery method should be urgently developed.CASE SUMMARY A healthy female patient,45-year-old,requested implant restoration of the her left mandibular first molar and second molar.Before considering a stage II,as suggested from the probing depth measurements,the widths of the mesial,medial,and distal buccal keratinized gingiva of second molar(tooth#37)were measured and found to be 0.5 mm,0.5 mm,and 0 mm,respectively.This suggested that the gingiva was insufficient to resist damage from bacterial and mechanical stimulation.Accordingly,modified apically repositioned flap(ARF)surgery combined with xenogeneic collagen matrix(XCM)and platelet-rich fibrin(PRF)was employed to increase the width of gingival tissue.After 1 mo of healing,the widths of mesial,medial,and distal buccal keratinized gingiva reached 4 mm,4 mm,and 3 mm,respectively,and the thickness of the augmented mucosa was 4.5 mm.Subsequently,through the second-stage operation,the patient obtained an ideal soft tissue shape around the implant.CONCLUSION For cases with keratinized gingiva widths around implants less than 2mmthe soft tissue width and thickness could be increased by modified ARF surgery combined with XCM and PRF.Moreover,this surgery significantly alleviated patients’pain and ameliorated oral functional comfort.

Collagen matrix scaffolds:Future perspectives for the management of chronic liver diseases

Approximately 1.5 billion chronic liver disease(CLD)cases have been estimated worldwide,encompassing a wide range of liver damage severities.Moreover,liver disease causes approximately 1.75 million deaths per year.CLD is typically characterized by the silent and progressive deterioration of liver parenchyma due to an incessant inflammatory process,cell death,over deposition of extracellular matrix proteins,and dysregulated regeneration.Overall,these processes impair the correct function of this vital organ.Cirrhosis and liver cancer are the main complications of CLD,which accounts for 3.5%of all deaths worldwide.Liver transplantation is the optimal therapeutic option for advanced liver damage.The liver is one of the most common organs transplanted;however,only 10%of liver transplants are successful.In this context,regenerative medicine has made significant progress in the design of biomaterials,such as collagen matrix scaffolds,to address the limitations of organ transplantation(e.g.,low donation rates and biocompatibility).Thus,it remains crucial to continue with experimental and clinical studies to validate the use of collagen matrix scaffolds in liver disease.

Derived vascular endothelial cells induced by mucoepidermoid carcinoma cells:3-dimensional collagen matrix model

Mucoepidermoid carcinoma undergoes uniquely vigorous angiogenic and neovascularization processes,possibly due to proliferation of vascular endothelial cells(ECs) induced by mucoepidermoid carcinoma cells(MCCs) in their three-dimensional(3D) microenvironment.To date,no studies have dealt with tumor cells and vascular ECs from the same origin of mucoepidermoid carcinoma using the in vitro 3D microenvironment model.In this context,the current research aims to observe neovascularization with mucoepidermoid carcinoma microvascular ECs(MCMECs) conditioned by the microenvironment in the 3D collagen matrix model.We observed the growth of MCMECs purified by immunomagnetic beads and induced by MCCs,and characteristics of tubule-like structures(TLSs) formed by induced MCMECs or non-induced MCMECs.The assessment parameters involved the growth curve,the length,the outer and inner diameters,and the wall thickness of the TLSs,and the cell cycle.Results showed that MCCs induced formation of the TLSs in the 3D collagen matrix model.A statistically significant difference was noted regarding the count of TLSs between the control group and the induction group on the 4th day of culture(t=5.00,P=0.001).The outer and inner diameters(t1=5.549,P1=0.000;t2=10.663,P2=0.000) and lengths(t=18.035,P=0.000) of the TLSs in the induction group were statistically significant larger than those in the control group.The TLSs were formed at the earlier time in the induction group compared with the control group.It is concluded that MCCs promote growth and migration of MCMECs,and formation of the TLSs.The 3D collagen matrix model with MCMECs induced by MCCs in the current research may be a favorable choice for research on pro-angiogenic factors in progression of mucoepidermoid carcinoma.

Enhancement of matrix metalloproteinases 2 and 9 accompanied with neurogenesis following collagen glycosaminoglycan matrix implantation after surgical brain injury

Surgical brain injury may result in irreversible neurological deficits. Our previous report showed that partial regeneration of a traumatic brain lesion is achieved by implantation of collagen glycosaminoglycan（CGM）. Matrix metalloproteinases（MMPs） may play an important role in neurogenesis but there is currently a lack of studies displaying the relationship between the stimulation of MMPs and neurogenesis after collagen glycosaminoglycan implantation following surgical brain trauma. The present study was carried out to further examine the expression of MMP2 and MMP9 after implantation of collagen glycosaminoglycan（CGM） following surgical brain trauma. Using the animal model of surgically induced brain lesion, we implanted CGM into the surgical trauma. Rats were thus divided into three groups：（1） sham operation group： craniotomy only;（2） lesion（L） group： craniotomy ＋ surgical trauma lesion;（3） lesion ＋ CGM（L ＋ CGM） group： CGM implanted following craniotomy and surgical trauma lesion. Cells positive for SOX2（marker of proliferating neural progenitor cells） and matrix metalloproteinases（MMP2 and MMP9） in the lesion boundary zone were assayed and analyzed by immunofluorescence and ELISA commercial kits, respectively. Our results demonstrated that following implantation of CGM after surgical brain trauma, significant increases in MMP2^＋/SOX2^＋ cells and MMP9^＋/SOX2^＋ cells were seen within the lesion boundary zone in the L ＋ CGM group. Tissue protein concentrations of MMP2 and MMP9 also increased after CGM scaffold implantation. These findings suggest that implantation of a CGM scaffold alone after surgical brain trauma can enhance the expression of MMP2 and MMP9 accompanied by neurogenesis.

Non-Invasive Second Harmonic Generation (SHG) in Macroscopy (MacroSHG) as Bio-Diagnosis to Image Collagen Network Organization in Extracellular Matrix

In this work, we have considered a new multimodality imaging for macroscopy based on Second Harmonic Generation (SHG) method to monitor invasivelessly the matrix collagen. As the triple helicoidally structure of collagen molecules appearing as not centrosymetric, very organized and spatially oriented, collagen fibrils give rise to a very strong SHG signal and can be imaged without any exogenous dye. To integrate a multidimensional scale with a large field of view (non-sliced samples), we have adapted and validated an instrumental coupling between a two photon excitation laser and a macroscope to collect cartography of SHG signal. We introduced an index (F-SHG) based on decay time response measured by TCSPC for respectively Fluorescence (F) and Second Harmonic Generation (SHG) values. For various sample where protein collagen is the major component of extracellular matrix (vessel, skin, carotide vessel, rat femoral head cartilage, mouse tumor, human wharton’s jelly and rat tendon) or not (nacre), we compared the index distribution obtained with MacroSHG. In this work, we showed for the first time that multiscale large field imaging (Macroscopy) combined to Multimodality approaches (SHG-TCSPC) could be an innovative and non-invasive technique to detect and identify some biological interest molecules (collagen) in biomedical topics.

TGF-β1、MMP-3及Collagen Ⅲ在POP患者子宫主韧带组织中的表达及意义

目的探讨转化生长因子-β1(TGF-β1)、基质金属蛋白酶-3(MMP-3)及胶原蛋白Ⅲ型(CollagenⅢ)在盆腔器官脱垂(POP)患者子宫主韧带组织中的表达及意义。方法选取2017年1月至2018年5月治疗的POP患者45例(POP组),其中Ⅲ期25例,Ⅳ期20例,同时选取无POP患者50例作为对照组,采用免疫组化染色分析子宫主韧带组织中TGF-β1、MMP-3及CollagenⅢ表达情况,Western blot检测各指标表达的灰度值。结果POP组TGF-β1和CollagenⅢ阳性表达率及平均灰度值均明显低于对照组(P<0.05),而MMP-3阳性表达率及平均灰度值明显高于对照组(P<0.05)。POP组绝经前后后患者TGF-β1、CollagenⅢ、MMP-3阳性表达率及平均灰度值差异具有统计学意义(P<0.05)。POP组Ⅲ期和Ⅳ期患者TGF-β1、CollagenⅢ、MMP-3阳性表达率及平均灰度值差异具有统计学意义(P<0.05)。POP患者TGF-β1、CollagenⅢ与MMP-3呈负相关(r=-0.563,-0.677,P<0.05),TGF-β1与CollagenⅢ呈正相关(r=0.441,P<0.05)。结论POP患者子宫主韧带组织中MMP-3呈高表达,而TGF-β1与CollagenⅢ呈低表达,与绝经状况及病情程度可能有一定关系,且3者间表达有相关性。

大蒜素对SD大鼠膝骨关节炎关节软骨中MMP-13、TIMP1和Collagen Ⅱ表达的影响

目的探讨大蒜素对SD大鼠膝骨关节炎关节软骨中基质金属蛋白酶-13(MMP-13)、基质金属蛋白酶组织抑制因子1(TIMP1)和胶原蛋白酶Ⅱ(CollagenⅡ)的影响,明确大蒜素对SD大鼠膝骨关节炎关节软骨的保护作用及机制。方法 90只SD大鼠随机分为5组:空白对照组、手术对照组、手术组+5 mg大蒜素、手术组+10 mg大蒜素、手术组+20 mg大蒜素。手术对照组和手术组均行改良Hulth法复制OA模型,于术后第2日开始分组腹腔注射给药:空白对照组和手术对照组给予等量生理盐水腹腔注射,另外3组分别给予大蒜素5、10、20 mg/(kg·d)腹腔注射。用药干预12周后处死,取软骨组织,运用Western blot和免疫组化实验检测MMP-13、TIMP1和CollagenⅡ表达。结果Western blot检测发现大蒜素10和20 mg/(kg·d)给药12周后能够下调MMP-13的表达,上调TIMP1的表达,同时2组中CollagenⅡ的表达较手术对照组及手术+5 mg大蒜素组多;免疫组化染色结果进一步明确MMP-13、TIMP1和CollagenⅡ在软骨组织中的表达,变化趋势与Western blot一致。结论大蒜素通过下调关节软骨中MMP-13的表达,上调关节软骨中TIMP1及CollagenⅡ的表达,减少细胞外基质的降解,对SD大鼠骨性关节炎中关节软骨具有积极保护作用。

Changes in extracellular matrix in different stages of colorectal cancer and their effects on proliferation of cancer cells

BACKGROUND The extracellular matrix is the main component of the tumor microenvironment.Extracellular matrix remodels with the oncogenesis and development of tumors.Previous studies usually focused on the changes of proteins in normal colorectal tissues and colorectal cancers.Little is known about the changes in the extracellular matrix in different stages of colorectal cancer and the effects of these changes on the development of this cancer.AIM To test the changes of type I collagen,type IV collagen,matrix metalloproteinase-2(MMP-2),matrix metalloproteinase-9(MMP-9),and tissue inhibitor of metalloproteinase-3(TIMP-3)in different stages of colorectal cancer and the effects of these changes on the proliferation of cancer cells.METHODS The extracellular matrix from various stages of colorectal cancer and normal colon tissue was obtained by using acellular technology.We used proteomics to detect the differential expression of proteins between normal colon tissues and colorectal cancer tissues,and then we used Western blot to observe their expression in each stage of colorectal cancer and in normal colon tissue.By coculturing the extracellular matrix and HT29 colon cancer cells in vivo and in vitro,we tested the cancer cell proliferation rate in vitro by methyl thiazolyl tetrazolium(MTT)assay and in vivo by measuring the tumor volume.RESULTS The expression of type I collagen and MMP-2 increased with increased tumor stage.The expression of MMP-9 was higher in colorectal cancer tissues and was highest in stage III cancer.The expression of type IV collagen and TIMP-3 decreased with increased tumor stage.The proliferation rate of cancer cells in the extracellular matrix of colorectal cancer was higher than that in the extracellular matrix of the normal colon.CONCLUSION These data suggest that the extracellular matrix structure and composition become disorganized during the development of tumors,which is more conducive for the growth of cancer cells.

Distribution of pericellular matrix molecules in the temporomandibular joint and their chondroprotective effects against inflammation

The objectives of this study were to （1） determine the distribution and synthesis of pericellular matrix （PCM） molecules （collagen VI, collagen IV and laminin） in rat temporomandibular joint （TMJ） and （2） investigate the effects of PCM molecules on chondrocytes against inflammation in osteoarthritis. Four zones （fibrous, proliferating, mature and hypertrophic） of condylar cartilage and three bands （anterior, intermediate and posterior） of disc were analysed by immunohistochemistry for the presence of PCM molecules in rat TMJs. Isolated chondrocytes were pre-treated with PCM molecules before being subjected to interleukin （IL）-II~ treatment to stimulate inflammation. The responses of the chondrocytes were analysed using gene expression, nitric oxide release and matrix metalloproteinase （MMP）-13 production measures. Histomorphometric analyses revealed that the highest areal deposition of collagen VI （67.4%）, collagen IV （45.7%） and laminin （52.4%） was in the proliferating zone of TMJ condylar cartilage. No significant difference in the distribution of PCM molecules was noted among the three bands of the TMJ disc. All three PCM molecules were expressed intracellularly by chondrocytes cultured in the monolayer. Among the PCM molecules, pre-treatment with collagen VI enhanced cellular proliferation, ameliorated IL-lp-induced MMP-3, MMP-9, MMP-13 and inducible nitric oxide synthase gene expression, and attenuated the downregulation of cartilage matrix genes, including collagen I, aggrecan and cartilage oligomeric matrix protein （COMP）. Concurrently, collagen VI pretreatment inhibited nitric oxide and MMP-13 production. Our study demonstrates for the first time the distribution and role of PCM molecules, particularly collagen VI, in the protection of chondrocytes against inflammation.

Inhibition of elastin and collagen networks degradation in human skin by gingival fibroblast. In vitro, ex vivo and in vivo studies.

Skin aging shows an imbalance between synthesis and degradation of the extracellular matrix. The overproduction of degradative enzymes (MMPs) during the chronology- and photo-induced aging leads to a degradation of the elastic and collagen networks. In a model of collagen and elastin destruction, we showed that the gingival fibroblast was able to preserve these macromolecules by inhibiting the overproduction of metalloproteinases by overproduction of TIMP-1 and modulation of the inflammatory cytokines activity. The objective of this study is to evaluate the effect of the gingival fibroblasts on human skin. The results in vitro and ex vivo show that the gingival fibroblast protects the skin collagen and elastic network by the inhibition of MMPs which leads to an overproduction of the TIMP-1. Moreover, the gingival fibroblast modulates the activity of some enzymes responsible for the inflammation;they inhibit the IL-1β and stimulate the production of TGF-β1. In vivo studies with a duration of six months and 50 women with pronounced wrinkles show that the culture supernatant of gingival fibroblasts diluted to 5% leads to a statistically significant decrease in the number and length of wrinkles.

盆腔脏器脱垂患者阴道壁组织MMP-1、TIMP-1和Collagen I表达的研究

目的:探讨盆腔脏器脱垂(POP)患者盆底支持结构胶原代谢与疾病发生发展的关系。方法:选择无压力性尿失禁(SUI)POP手术治疗患者30例为POP组,以同期无SUI和POP,因子宫良性病变行阴式全子宫切除术患者30例为对照组。采用免疫组化三步法检测阴道壁组织基质金属蛋白酶-1(MMP-1)、组织金属蛋白酶抑制剂-1(TIMP-1)和Ⅰ型胶原(CollagenⅠ)的表达情况。结果:POP组阴道前壁组织中MMP-1表达显著高于对照组(P<0.05),TIMP-1的表达显著低于对照组(P<0.05),CollagenⅠ的表达显著低于对照组(P<0.05)。3者之间存在相关关系,其中CollagenⅠ与MMP-1呈负相关(r=-0.961,P<0.05),CollagenⅠ与TIMP-1呈正相关(r=0.982,P<0.05),MMP-1与TIMP-1呈负相关(r=-0.977,P<0.05)。结论:POP患者阴道壁组织中MMP-1表达增强而其抑制剂TIMP-1表达降低,导致CollagenⅠ分解增加可能是POP的发病机制之一。

芡实对糖尿病肾病大鼠肾组织MMP-9、TIMP-1及Collagen Ⅳ表达的影响

目的:探讨芡实对糖尿病肾病大鼠肾组织MMP-9、TIMP-1及CollagenⅣ表达的影响。方法:健康雄性Wistar大鼠65只,随机选取10只为正常对照组(N组);其余一次性腹腔注射链脲佐菌素(STZ)制作DN模型,造模成功后,随机分为DN组、芡实低、中、高剂量组及氯沙坦钾组,均采用灌胃给药,N组和DN组给予等体积蒸馏水。12周后检测大鼠生化指标;HE、Masson、PAS染色观察肾脏病理变化;免疫组化法测定MMP-9、TIMP-1及CollagenⅣ在肾组织表达情况;采用实时荧光定量PCR技术检测肾组织中MMP-9、TIMP-1及CollagenⅣ基因的表达。结果:实验12周末,与N组比较,DN组大鼠肾小球肥大,细胞外基质积聚,血糖、24 h尿蛋白定量、血尿素氮(BUN)、肌酐(Scr)、尿白蛋白排泄率(UAER)、尿蛋白/尿肌酐(Up/Ucr)比值显著升高(P<0.05),肾组织MMP-9蛋白和mRNA表达降低(P<0.05),TIMP-1、CollagenⅣ蛋白和mRNA表达升高(P<0.05);与DN组比较,EM组、EH组及LP组大鼠病理改变减轻,24 h尿蛋白定量、Scr、BUN、UAER、Up/Ucr显著降低(P<0.05),肾组织MMP-9蛋白和mRNA表达显著升高(P<0.05),TIMP-1、CollagenⅣ蛋白和mRNA表达显著减少(P<0.05)。结论:芡实可能通过调节DN大鼠肾脏MMP-9、TIMP-1的表达,减少细胞外基质积聚,从而减轻肾小球硬化,减少蛋白尿,保护肾功能,延缓DN病变的进展。

The Influence of <i>Morinda citrifolia</i>(Noni) Fruit Juice on Collagen Deposition in the Skin: A Minireview

The fruit of Morinda citrifolia, commonly known as noni, has an extensive history of use as a food and medicine throughout the tropics. Among its many uses, noni was believed to promote skin health. In vivo wound healing studies reveal that noni fruit juice ingestion increases collagen production and deposition via increased expression of extracellular matrix protein genes. Noni juice also appears to promote fibroblast proliferation. In vitro studies indicate that noni juice also protects fibroblasts via activation of the transcription factor Nrf2 and protects extracellular matrix collagen by inhibiting matrix metalloproteinases. In vitro and in vivo study findings are corroborated by a clinical trial where hospitalization times were reduced, and wound granulation quality was improved in pediatric burn patients. The findings of other human studies also indicate that noni juice has the potential to protect skin collagen. These include reduced plasma reactive oxygen species in cigarette smokers, lowered skin glycation levels in overweight and obese adults, as well as reduced skin glycation levels among noni juice consumers within the general population. These in vitro, in vivo and human studies reveal that there are multiple mechanisms of action through which noni juice promotes collagen synthesis and inhibits collagen degradation. The procollagen properties of noni juice aid wound healing, increase skin elasticity, and improve the overall appearance of the skin.

Active Peptides and Motifs within Collagen and Other ECM Proteins

Collagens are the most abundant proteins in mammals and form an extracellular matrix (ECM) with other components as the structural support of muscle, skin, corneas and blood vessels etc. Other than providing structural support, the ECM exhibits active communication with cells and influences many cellular processes including migration, wound healing, differentiation and cancer metastasis. Though collagen proteins contain highly repetitive primary sequences and defined tertiary structures, more and more studies have shown that many short peptides/motifs within collagen proteins play key roles in various biological processes. These short sequences are effective within triple helical structures or independently as stand-alone molecules resulting from proteolytic degradation. Besides endogenous ECM-derived peptides, many more functional peptides have been produced by tissue processing, chemical synthesis, and recombinant protein production. In this review, we summarize different peptides/motifs identified in collagen and other ECM proteins and discuss their potential for medical, personal care, and cosmetics applications.

High matrix metalloproteinase-9 expression induces angiogenesis and basement membrane degradation in stroke-prone spontaneously hypertensive rats after cerebral infarction

Basement membrane degradation and blood-brain barrier damage appear after cerebral infarc- tion, severely impacting neuronal and brain functioning; however, the underlying pathogenetic mechanisms remain poorly understood. In this study, we induced cerebral infarction in stroke- prone spontaneously hypertensive rats by intragastric administration of high-sodium water （1.3% NaC1） for 7 consecutive weeks. Immunohistochemical and immunofluorescence assays demonstrated that, compared with the non-infarcted contralateral hemisphere, stroke-prone spontaneously hypertensive rats on normal sodium intake and Wistar-Kyoto rats, matrix metalloproteinase-9 expression, the number of blood vessels with discontinuous collagen IV expression and microvessel density were significantly higher, and the number of continuous collagen IV-positive blood vessels was lower in the infarct border zones of stroke-prone sponta- neously hypertensive rats given high-sodium water. Linear correlation analysis showed matrix metalloproteinase-9 expression was positively correlated with the number of discontinuously collagen IV-labeled blood vessels and microvessel density in cerebral infarcts of stroke-prone spontaneously hypertensive rats. These results suggest that matrix metalloproteinase-9 upregula- tion is associated with increased regional angiogenesis and degradation of collagen IV, the major component of the basal lamina, in stroke-prone spontaneously hypertensive rats with high-sodi- um water-induced focal cerebral infarction.

Specific shRNA targeting of FAK influenced collagen metabolism in rat hepatic stellate cells

AIM:To investigate the effects and mechanism of disruption of focal adhesion kinase(FAK) expression on collagen metabolism in rat hepatic stellate cells(HSC).METHODS:The plasmids expressing FAK short hairpin RNA(shRNA) were transfected into HSC-T6 cells,and the level of FAK expression was determined by both real-time quantitative polymerase chain reaction(QPCR) and Western blotting analysis.The production of type collagen and type collagen in FAK-disrupted cells was analyzed by real-time Q-PCR.The level of collagen metabolism proteins,including matrix metalloproteinases-13(MMP-13) and tissue inhibitors of metalloproteinases-1(TIMP-1) was also determined by both real-time Q-PCR and Western blotting analysis.RESULTS:The transfection of FAK shRNA plasmids into HSC resulted in disrupted FAK expression.Compared with the HK group,the levels of type collagen and type collagen mRNA transcripts in FAK shRNA plas-mid group were signif icantly decreased(0.69 ± 0.03 vs 1.96 ± 0.15,P = 0.000;0.59 ± 0.07 vs 1.62 ± 0.12,P = 0.020).The production of TIMP-1 in this cell type was also signif icantly reduced at both mRNA and protein levels(0.49 ± 0.02 vs 1.72 ± 0.10,P = 0.005;0.76 ± 0.08 vs 2.31 ± 0.24,P = 0.000).However,the expression of MMP-13 mRNA could be significantly up-regulated by the transfection of FAK shRNA plasmids into HSC(1.74 ± 0.20 vs 1.09 ± 0.09,P = 0.000).CONCLUSION:These data support the hypothesis that shRNA-mediated disruption of FAK expression could attenuate extracellular matrix(ECM) synthesis and promote ECM degradation,making FAK a potential target for novel anti-f ibrosis therapies.

Effects of AT1 Antagonist on MMP2, MMP9 Expression and Collagen Remodeling in Left Ventricle of Rabbit Undergoing Chronic Pressure Overload

Objectives To study the effects of AT1 antagonist on MMP2, MMP9 expression and collagen remodeling in left ventricle of rabbit undergoing chronic pressure overload. Methods 30 rabbits were randomly divided into 3 groups ( n = 10, each group), including sham operation group, abdominal aorta banded group (banded group), abdominal aorta banded +valsartan group (valsartan group). Twelve weeks after operation, hemodynamic parameters were acquired, then collagen volume fraction (CVF) and MMP2, MMP9 expression of left ventricle were measured by using VG and immunohistochemical stain. Results Compared with sham operation group, both MMP2 and MMP9 expression were enhanced in banded group; meanwhile, LVW/BW, LVEDP and CVF increased significantly. Compared with banded group, both MMP2 and MMP9 expression were weakened in valarstan group; simultaneously, LVW/BW, LVEDP and CVF decreased significantly. Conclusions Expression of MMP2 and MMP9 was enhanced in left ventricle of rabbit undergoing chronic pressure overload, which may be associated with collagen proliferation, ventricule remodeling and impaired heart function; Valsartan could inhibit collagen proliferation, prevent ventricule remodeling and preserve heart function by inhibiting abnormal expression of MMP2 and MMP9.

Neurotrophins differentially stimulate the growth of cochlear neurites on collagen surfaces and in gels

The electrodes of a cochlear implant are located far from the surviving neurons of the spiral ganglion, which results in decreased precision of neural activation compared to the normal ear. If the neurons could be induced to extend neurites toward the implant, it might be possible to stimulate more discrete subpopulations of neurons, and to increase the resolution of the device. However, a major barrier to neurite growth toward a cochlear implant is the fluid filling the scala tympani, which separates the neurons from the electrodes. The goal of this study was to evaluate the growth of cochlear neurites in three-dimensional extracellular matrix molecule gels, and to increase biocompatibility by using fibroblasts stably transfected to produce neurotrophin-3 and brain-derived neurotrophic factor. Spiral ganglion explants from neonatal rats were evaluated in cultures. They were exposed to soluble neurotrophins, cells transfected to secrete neurotrophins, and/or collagen gels. We found that cochlear neurites grew readily on collagen surfaces and in three-dimensional collagen gels. Co-culture with cells producing neurotrophin-3 resulted in increased numbers of neurites, and neurites that were longer than when explants were cultured with control fibroblasts stably transfected with green fluorescent protein. Brain-derived neurotrophic factor-producing cells resulted in a more dramatic increase in the number of neurites, but there was no significant effect on neurite length. It is suggested that extracellular matrix molecule gels and cells transfected to produce neurotrophins offer an opportunity to attract spiral ganglion neurites toward a cochlear implant.

手术切除联合角膜缘干细胞移植治疗翼状胬肉的疗效观察

目的 观察手术切除联合角膜缘干细胞移植治疗翼状胬肉的疗效。方法 招募2020年1月至2022年12月启东市中医院收治的翼状胬肉患者180例,采用随机数字表法将其分为Ologen胶原基质植入组(接受手术切除联合Ologen胶原基质植入治疗,90例145眼)和角膜缘干细胞移植组(接受手术切除联合角膜缘干细胞移植治疗,90例147眼)。比较两组治疗后屈光状态、泪膜功能、舒适度情况、创面愈合时间、临床疗效及复发情况。结果 两组术后裸眼视力(UCVA)、泪膜破裂时间(BUT)呈上升趋势,角膜散光度(CA)呈下降趋势,两组变化幅度差异有统计学意义(P<0.05)。在术后6个月,Ologen胶原基质植入组UCVA、BUT低于角膜缘干细胞移植组,CA高于角膜缘干细胞移植组,差异有统计学意义(P<0.05)。术后6个月,在畏光流泪、异物感、眼痛、球结膜充血4个维度,角膜缘干细胞移植组的舒适度评分显著优于Ologen胶原基质植入组(P<0.05)。角膜缘干细胞移植组的创面愈合时间显著快于Ologen胶原基质植入组[(2.85±1.06)d vs (3.04±0.31)d;t=2.073,P=0.039]。角膜缘干细胞移植组的临床有效率显著高于Ologen胶原基质植入组(98.64%vs 93.10%;χ^(2)=5.678,P=0.017),术后6个月的复发率更低(0.00%vs 4.14%;χ^(2)=4.325,P=0.038)。结论 手术切除联合角膜缘干细胞移植治疗翼状胬肉的疗效优于手术切除联合Ologen胶原基质植入治疗,值得推荐。

Effects of Calcium Dobesilate on Glomerulus TIMP1 and Collagen Ⅳ of Diabetic Rats

Summary ： To observe the effects of calcium dobesilate on the expression of glomerular tissue inhibitor of metalloproteinase 1 （TIMP1）, collagen Ⅳ , and ultrastrueture of glomerular basement mem- brane in diabetic rats, rats model of diabetes was established by unilateral nephreetomy and intraperitoneal injection of 1% STZ （55 mg/kg）, and rats were administered calcium dobesilate 100 mg/ kg （DD group） or distilled water （DM group） respectively. 12 weeks later, the changes in the renal uhrastrueture and ereatinine clearance rate （Cer） were examined in each group. The expression of glomerular TIMP1 and collagen Ⅳ were studied by immunohistoehemieal staining. Our results showed that after 12 weeks, the Cer in DD group increased and was significantly higher than that in DM group. Electron microscopy showed that thickness of glomerular capillary basement membrane （GBM） in Group DD was less than that of DM group. No hyperplasia of collagen fibers was found, and the distance betweeh the holes of endothelial cells in DD group was not as even as that in the normal group, but more even than that of DM group, and podocyte processes was still in order. Immunohistochemical staining of glomeruli showed that expression of TIMP1 and collagen Ⅳ in DD group were significantly less than those of DM group DM. It is concluded that calcium dobesilate can improve diabetic nephropathy by inhibiting the overaccumulation of collagen Ⅳ and calcium dobesilate may also contribute to diabetes by inhibiting the expression of TIMP1.