Effects of PerClot® on the healing of full-thickness skin wounds in rats

PerClot^® is a hemostatic material made of polysaccharide from modified starch and has been shown to assist in topical hemostasis. The principal goal in treating surgical and non-surgical wounds is the need for rapid closure of the lesion. This study investigated whether topical application of PerClot^® could improve impaired wound healing in Sprague-Dawley (SD) rats. Full-thickness skin wounds were created on the back of the rats. Immediately, PerClot^® was introduced into the wound bed, while wounds receiving starch or nothing served as controls. Wound closure was monitored using well-recognized wound-healing parameters: histological examination for inflammatory cells and fibroblast infiltration, newly formed capillaries, and collagen deposition. Meanwhile, transforming growth factor (TGF-β1) was measured by immunochemistry. Wound closure was significantly accelerated by local application of PerClot^®. Furthermore, PerClot^®-treated wounds showed significantly increased fibroblast numbers at 5 days post-wounding, and newly formed capillaries at 7 days post-wounding, and collagen regeneration at 7 and 14 days post-wounding. The number of infiltrating fibroblasts expressing TGF-β1 was significantly higher than that in the controls at 7 and 14 days post-wounding. PerClot^® can improve the wound healing and this effect might involve an increase in the activity of fibroblasts and increased release of TGF-β1.     

TGF-βS and TGF-β type II receptor in human epidermis: Differential expression in acute and chronic skin wounds

Exogenously applied transforming growth factor-beta (TGF-β) isoforms enhance wound healing processes in animal models;¹ however, little is known about the expression of endogenous TGF-β_s and TGF-β receptors in intact human skin or during wound healing. The present study has revealed several unexpected findings by means of in situ hybridization and immunohistology techniques. In humans, TGF-β₃ is constitutively expressed in the epidermis of intact skin and in that of acute and chronic wounds—a pattern of expression closely mirrored by the TGF-β type II receptor. Although not detected in intact skin, TGF-β mRNA expression was observed in the regenerating epidermis of acute (thermal) wounds but was not found in chronic decubital (pressure) wounds. TGF-β₂ mRNA expression was not detected in the epidermis of any human skin or wound biopsies. From these findings we suggest that constitutive expression of TGF-β₃ is important for maintenance of epidermal differentiation and that an induction of TGF-β₁ expression is essential for re-epithelialization of human skin wounds. Lack of TGF-β₁ expression in chronic pressure wounds may be associated with their protracted healing tendencies.     

The effects of inflammatory response associated with traumatic spinal cord injury in cutaneous wound healing and on expression of transforming growth factor-beta1 (TGF-β1) and platelet-derived growth factor (PDGF)-A at the wound site in rats

At the cellular level, spinal cord injury (SCI) provokes an inflammatory response that generates substantial secondary damage within the cord, but also may contribute to its repair. The aim of this study was to investigate the effects of inflammatory response associated with SCI in cutaneous wound healing and on expression of transforming growth factor-beta1 (TGF-β₁) and platelet-derived growth factor (PDGF)-A at the wound site in rats. At the 14th day analysis, the mean TGF-β₁ score in trauma group (I) was significantly lower than that in control group (C) (2.60 ± 0.90 vs. 3.64 ± 0.37, respectively; p < 0.05). The mean score for PDGF-A expression in group I was similar to the corresponding value in group C (2.42 ± 0.74 vs. 2.94 ± 0.72, respectively). Compared to group C, group I had significantly lower mean scores for epidermal and dermal regeneration, but higher mean scores for granulation tissue thickness and similar scores for angiogenesis. The dermal layer contains diffuse deposition of collagen fibers that are not organised as in control rat skin, and intraepidermal and subepidermal vasocongestion is distinct. Based on the results on the parameters evaluated in the study, experimental SCI in rats results in delay in wound healing and low intensity of TGF-β₁ in the dorsal wound-tissue specimens.     

Accelerated Healing of Ulcer Wounds in the Rabbit Ear by Recombinant Human Transforming Growth Factor-β1

Abstract

A dermal ulcer wound-healing model was established in rabbit ear to examine the effects of recombinant human transforming growth factor-β1 (rhTGF-β 1) in wound healing. Histo-morphometric examination of the wounds indicate a biphasic healing response 7 days after a single application of rhTGF-β l at the time of wounding. Statistically significant healing occurred at 5-100 ng but not at higher doses of 500 or 1000 ng rhTGF-β l/wound. Enhanced collagen synthesis as determined by [³H] proline incorporation occurred at 15 and 25 ng and was significantly depressed at 500 ng rhTGF-β1wound. Multiple doses of 100 ng rhTGF-/3l applied to the wound at the time of wounding and for 3 days after wounding provided results comparable to the single application of growth factor. Delaying treatment 24 hr after wounding did not enhance wound healing compared with vehicle. Our findings suggest that rhTGF-β l can be a valuable growth factor to improve the healing of ulcer wounds.     

负压伤口疗法对糖尿病足轻、中度缺血创面肉芽组织转化生长因子-β1表达的影响

目的探讨负压伤口疗法(NPWT)对糖尿病足轻、中度缺血创面肉芽组织转化生长因子-β1(TGF-β1)表达的影响。 方法选取2014年1月至2018年2月在解放军白求恩国际和平医院接受NPWT治疗的43例糖尿病足患者,据踝肱指数(ABI)分为中度缺血组23例(0.5≤ABI<0.7)和轻度缺血组20例(0.7≤ABI<0.9)。于治疗前及治疗14 d后分别取创面肉芽组织,标本分成3份,1份于4%多聚甲醛溶液中固定,4 ℃保存,标本收齐后行免疫组织化学染色,分析TGF-β1平均光密度;另外2份于液氮中转送至-80 ℃冰箱中保存,其中1份行Western blotting法,分析TGF-β1蛋白表达情况,另1份行Real-time PCR,分析TGF-β1 mRNA表达情况。2组间数据比较采用独立样本t检验。 结果经免疫组织化学染色分析TGF-β1表达,中度缺血组和轻度缺血组经14 d治疗后TGF-β1平均光密度均高于治疗前,差异有统计学意义(P值均小于0.05),且相较于中度缺血组变化幅度[(38.71±12.78)%],轻度缺血组[(63.09±10.96)%]升高幅度显著,差异均有统计学意义(t＝－6.66,P<0.05);经Western blotting法分析TGF-β1蛋白表达水平,中度缺血组和轻度缺血组经14 d治疗后TGF-β1蛋白表达均高于治疗前,差异均有统计学意义(P值均小于0.05),且相较于中度缺血组变化幅度[(50.31±25.64)%],轻度缺血组变化幅度[(85.44±27.78)%]升高幅度显著,差异有统计学意义(t＝－4.31,P<0.05);经Real-time PCR法分析TGF-β1 mRNA表达水平,中度缺血组和轻度缺血组经14 d治疗后TGF-β1 mRNA表达均高于治疗前,差异均有统计学意义(P值均小于0.05),且相较于中度缺血组变化幅度[(73.85±41.22)%],轻度缺血组[(129.78±36.71)%]升高幅度显著,差异有统计学意义(t＝－4.67,P<0.05)。 结论NPWT能促进糖尿病足轻、中度缺血创面肉芽组织TGF-β1的表达,且对糖尿病足轻度缺血创面肉芽组织TGF-β1表达的促进作用优于糖尿病足中度缺血创面。     

Macroscopic aspects of wound healing (contraction and epithelialisation) after topical administration of allicin in dogs

Macroscopical aspects of second-intention healing of full-thickness excisional wounds were studied in five normal male mixed-breed dogs. Test wounds were treated topically with allicin 0.5% in methyl cellulose gel, and control wounds were treated with methyl cellulose gel only. Wound treatment started 24 h after wounding. The wounds were evaluated over a 4-week period. At days 0, 3, 7, 10, 14, 17, 21, 24 and 28, digital photographs were taken of all wounds. Rulers were held vertically and horizontally close to the wound as a reference. The area of epithelialisation and granulation tissue were measured for each wound using Scion Image software. Percentage wound contraction, epithelialisation and healing were calculated for each wound. Initially, all wound areas increased in size. After the initial enlargement, wound areas decreased rapidly in size between days 7 and 17 in both the test and control groups. Epithelialisation was first noticed at day 3 in control and day 5 in the test wounds. No significant differences were observed in the percentage of wound contraction, epithelialisation and healing between the test and control wounds (P> 0.05).     

Effects of systemic and topical estrogen application on the healing of full-thickness skin wounds in diabetic rats

In this research, the possible effects of systemic and topical estrogen were investigated on wound healing in normal and diabetic male rats. One hundred and ten male Wistar rats were divided into two groups (normal and diabetic). After induction of diabetes by streptozotocin in rats, each group was divided into three subgroups (control, sham, and test). A round full-thickness skin excision with 1.5-cm diameter was performed on the dorsum of each rat. In systemic use, 10?μG/SC of estradiol benzoate was administered daily to test subgroups for 28?days. In topical use, the wounds in the test subgroup rats were treated with a daily topical dose of 0.5?mg estrogen. Sham subgroup was injected with placebo and the control subgroup received nothing. The area of the wounds was measured by using scion image software at 3, 5, 7, 14, 21, 28?days. Histopathologic evaluation was assessed semi-quantitatively for different parameters including re-epithelization, neoangiogenesis, and granulation tissue formation. In macroscopic study, estradiol subgroups (systemic and topical application) wound healing had considerable changes in day?7 (p?<?0.05). Histopathologic evaluation was revealed increased vascularization, re-epithelialization in estradiol subgroups. So, this research expressed that systemic and topical estrogen can improve the impaired healing of diabetic wounds.     

Effectiveness of topical application of ostrich oil on the healing of Staphylococcus aureus- and Pseudomonas aeruginosa-infected wounds

Background/aims: Management of infected wounds is one of the major challenges that surgeons and nurses face. Several antimicrobial agents have been used, but the toxicity, drug resistance, and their effect on the healing process remain a matter of concern. The present study was designed to analyze the accelerative impact of topical application of ostrich oil on infected wounds in a mouse model. Materials and methods: 72 BALB/c mice were divided into four main groups of control-sham, mupirocin, and two treatment groups receiving 2% and 4% (w/w) concentrations of ostrich oil, topically. The mice were routinely anesthetized and wounds were created by excising the skin with a 5-mm biopsy punch. Immediately after wounding, an aliquot of 25 × 10⁷ Staphylococcus aureus and Pseudomonas aeruginosa was suspended in 50-μL phosphate-buffered saline and applied on the wound and the wound was left open. The healing rate in the infected wound was assessed using wound area, histopathological characteristics, and expression of growth factors including vascular endothelial growth factor (VEGF), transforming growth factor beta 1 (TGF-β1), and fibroblast growth factor 2 (FGF-2). Results: The wound area significantly decreased (p < 0.05) in the treated animals. There was a significant increase (p < 0.05) in new vessels, fibroblasts count, and collagen deposition in the ostrich oil-treated animals. Expression of VEGF, TGF-β1, and FGF-2 revealed the immunomodulation and angiogenesis effects of the ostrich oil on wound healing. Conclusions: Our study demonstrated that ostrich oil may be a useful treatment in infected cutaneous wounds.     

Platelet-rich plasma gel promotes differentiation and regeneration during equine wound healing

Nonhealing wounds of the lower equine limb represent a challenging model. The platelet is a natural source of a myriad of growth factors and cytokines that promote wound healing. This study evaluates the potential of platelet derived factors to enhance wound healing in the lower equine limb. Platelets were isolated from horse blood and activated with thrombin, a process known to induce growth factor release. This produced a platelet gel composed of platelet-rich plasma (PRP). To test this all-natural wound healant, 2.5-cm(2) full thickness cutaneous wounds were created below the knee and hock of a thoroughbred horse. Wounds were treated with PRP gel or left untreated. Sequential wound biopsies collected at Days 7, 36, and 79 postwounding permitted comparison of the temporal expression of differentiation markers and wound repair. To test the hypothesis that wounds treated with PRP gel exhibit more rapid epithelial differentiation and enhanced organization of dermal collagen compared to controls, tissues were stained for cytokeratin 10, a suprabasal differentiation marker, and the reestablishment of collagen was evaluated by trichrome staining. PRP gel-treated wounds at Day 7 expressed intense cytokeratin 10 staining near the wound junction in suprabasal epidermal layers, while staining in control tissues was less intense and restricted to apical epidermal layers distal to the wound junction. By Day 79, the staining was equal in both groups. However, PRP gel-treated wounds at Day 79 contained abundant, dense collagen bundles oriented parallel to each other and to the overlying epithelium, whereas control tissues contained fewer collagen fibers that were oriented randomly. Thus, treatment of wounds with PRP gel induced accelerated epithelial differentiation and produced tissue with organized, interlocking collagen bundles. This study reveals that this novel all-natural wound healant induced wound repair in injuries previously deemed untreatable.     

TGF-β3基因转染成纤维细胞促进大鼠深Ⅱ度烫伤创面愈合的实验研究

目的观察TGF-β3基因转染的成纤维细胞对深Ⅱ度大鼠烫伤模型创面愈合的影响。方法将90只Wistar成年大鼠随机分为模型对照组(C组)、表皮转化生长因子组(EGF组)和TGF-β3转基因成纤维细胞组(TGF-β3组),制作10% TBSA烫伤模型,各组给予对应治疗,检测各组大鼠的创面愈合率,HE染色观察烫伤创面组织变化,SP法观察烫伤皮肤组织中TGF-β3蛋白表达情况。结果烫伤后14d、21d,创面愈合率TGF-β3组最高,与EGF组及C组之间的差异有统计学意义(分别为P0.05,P0.01);烫伤后14d及21d,C组、EGF组与TGF-β3组之间TGF-β1及TGF-β2蛋白表达差异有统计学意义(分别为P0.05,P0.01);烫伤后1d到21d,TGF-β3组与C及EGF组之间的TGF-β3蛋白表达的差异均有统计学意义(P0.01)。结论 TGF-β3转基因转染成纤维细胞可能通过在创面上持续分泌TGF-β3蛋白,降低TGF-β1及TGF-β2的水平,从而促进创面的愈合。     

rbbFGF凝胶联合高锰酸钾水疗治疗难愈性创面的临床研究

目的 探讨重组牛碱性成纤维细胞生长因子（rbbFGF）凝胶联合高锰酸钾水疗治疗难愈性创面的临床疗效。方法 选取2017年1月~2018年5月我院收治的难愈性创面患者40例,随机分为观察组和对照组,各20例。对照组创面清创后予以外用生理盐水冲洗,碘伏消毒,磺胺嘧啶银乳膏纱布覆盖,无菌敷料包扎。观察组清创后给予1∶5000高锰酸钾溶液（35℃）浸泡水疗30 min联合rbbFGF凝胶局部外用治疗,余操作同对照组一致。比较两组患者临床疗效、创面愈合时间、住院时间及不良反应情况。结果 治疗后,观察组愈合时间为（30.52±8.72）d,短于对照组的（40.42±15.81）d,差异有统计学意义（P＜0.05）;观察组创面缩小和肉芽生长结果均优于对照组,差异有统计学意义（P＜0.05）;观察组创面细菌转阴率为85.00%,高于对照组的50.00%,差异有统计学意义（P＜0.05）。两组不良反应比较,差异无统计学意义（P＞0.05）。结论 rbbFGF凝胶联合高锰酸钾水疗治疗难愈性创面能够促进创面缩小,加速创面肉芽增长,有明显的抗感染的作用,缩短创面愈合时间,具有较高的临床价值。     

血管紧张素Ⅱ2型受体阻滞剂对小鼠全层皮肤缺损创面愈合的影响

 目的： 观察阻断血管紧张素II （Ang II）及其2型受体（AT2R）对创面愈合过程的创面愈合率、上皮爬行、肉芽组织形成以及创伤局部生长因子表达的影响,探讨Ang II及AT2R影响创伤愈合的机制。方法：建立小鼠背部全层皮肤缺损创面模型,直径6 mm,在创面模型建立同时腹腔注射给予特异性AT2R阻断剂PD123319（每天10 mg/kg）,于创面形成后第3、5、7、9、11、13和15天切取创面组织标本,采用HE染色观察PD123319对创面愈合过程中创面愈合率、上皮爬行和肉芽组织生长的影响;采用ELISA法检测PD123319对创面内与创伤愈合密切相关的表皮生长因子（EGF）、血管内皮生长因子（VEGF）和碱性成纤维细胞生长因子（bFGF）表达的影响。结果：对照组在创面形成后第5天和第7天的愈合率分别为(63.55±2.57)%和(80.78±4.65)%。PD123319处理组在创面形成后第5天和第7天分别为(79.89±4.56)%和(88.98±3.83)%,两组差异有统计学意义（P＜0.05）。在伤后第5天和第7天, 对照组创面上皮爬行距离分别为(1.22±0.15)mm和(1.93±0.17)mm,PD123319处理组创面上皮爬行距离分别为(1.65±0.12)mm和(2.36±0.18) mm,两组差异有统计学意义（P＜0.05）。在伤后第5天和第7天对照组创面肉芽组织的面积分别为(9.37±0.53)mm2和(7.15±0.42)mm2,PD123319处理组创面肉芽组织面积分别为(11.51±0.98) mm2和(9.32±0.67) mm2,两组差异有统计学意义（P＜0.05）。在伤后第5天和第7天,PD123319处理组创面局部EGF、 VEGF和bFGF的含量明显高于对照组,差异有统计学意义（P＜0.05）。结论：AT2R阻滞剂PD123319能够促进创面愈合。PD123319促进创面愈合可能与其促进创面内上皮爬行、肉芽组织形成及EGF、VEGF、bFGF等生长因子的表达有关。     

Recombinant Hepatocyte Growth Factor Accelerates Cutaneous Wound Healing in a Diabetic Mouse Model

We examined effects of recombinant hepatocyte growth factor (HGF) on cutaneous wound healing, using a full-thickness cutaneous excision model in diabetic mice. Topical administration of HGF, as well as basic fibroblast growth factor (bFGF), promoted the rate of wound closure and re-epithelialization. Both HGF and bFGF enhanced expansion of the granulation tissue and stimulated neovascularization on day 7 postwounding, wherein the increase in microvessel density in HGF-treated wounds was higher than that in bFGF-treated wounds. Matrix metalloproteinases (MMP-2 and MMP-9) activities involved in cell migration, angiogenesis, and extracellular matrix (ECM) remodeling, were enhanced by HGF-treatment on day 7. On day 28 postwounding (later stages of wound healing), granulation tissue in bFGF-treated wounds remained to a greater extent than that seen in saline- and HGF-treated wounds. Likewise, bFGF- but not HGF-treatment stimulated DNA synthesis of fibroblasts in granulation tissue, suggesting that HGF stimulates wound healing with lesser degree of susceptibility to cutaneous scarring. We propose that supplement of HGF may be a potential therapeutic approach for treatment of cutaneous ulcer.     

TGF-beta 1 accelerates wound healing: reversal of steroid-impaired healing in rats and rabbits.

TGF-beta modulates events of normal wound healing through multiple pathways that influence cell infiltration, proliferation, angiogenesis, extracellular matrix synthesis and remodeling. The effects of topically applied TGF-beta 1 on wound healing in two models of healing were evaluated when the healing response was impaired by the administration of methylprednisolone to rats or rabbits. TGF-beta 1 increased the healing of linear incision wounds on rats, as measured by breaking strength, to that of normal rats. Full thickness open wounds were also created on the inner ears of rabbits to simulate a non-contracting wound with limited blood supply. Healing was further impaired by the administration of methylprednisolone. The single application of TGF-beta 1 improved the healing of open wounds. TGF-beta 1 stimulated increased granulation tissue formation, as well as reepithelialization. The amount of granulation tissue and epithelialization were similar to wounds from normal-healing control rabbits. The delayed healing caused by methylprednisolone permitted the evaluation of multiple applications of TGF-beta 1 to wounds. Two applications of TGF-beta 1 spaced 7 days apart further improved the healing response when compared to a single application. Thus, single or multiple topical applications of TGF-beta 1 reversed impaired healing conditions secondary to methylprednisolone when used on incisional or open wounds. These observations support the hypothesis that growth factors, such as TGF-beta 1, may be useful as accelerators of wound repair in patients with impaired healing conditions.     

Basic fibroblast growth factor promotes apoptosis and suppresses granulation tissue formation in acute incisional wounds

Cytokines are thought to play an important role in cellular loss and apoptosis during the repair of granulation tissue. In order to investigate the role of apoptosis following the administration of basic fibroblast growth factor (bFGF) to a wound, the present study examined the relationship between the degree of granulation tissue formation and the level of apoptosis in rat skin incisional wounds, following treatment with an intradermal injection of bFGF (0.1 microg and 1 microg per cm of wound). Histological assessment of the width of the wound tissue showed that the degree of granulation tissue in the 1 microg-bFGF-treated group had increased by day 7, but then subsequently diminished by days 14 and 28. The TUNEL index increased rapidly from day 1, peaking on day 7, with the index being higher in the 1 microg-bFGF-treated group on days 4, 7, and 14, when compared with a control group. In parallel with a marked increase in the TUNEL index over the first 14 days, the number of cells positive for vimentin and CD3 in the 1 microg-bFGF-treated wounds had decreased by day 14. The number of PCNA-positive cells, an indicator of cell proliferation, peaked on day 4 in the bFGF-treated wounds and then declined rapidly. On the basis of these results, it is suggested that the suppression of granulation tissue formation in bFGF-treated wounds is mainly due to an early and persistent increase in apoptosis in the granulation tissue cells. The expression of both transforming growth factor (TGF)-beta1 and bFGF was also elevated in the bFGF-treated wounds on days 4 and 7, suggesting that fibroblast apoptosis was induced by bFGF treatment. Unexpectedly, on day 28, the wound breaking strength was not reduced in the bFGF-treated wounds. These results indicate that apoptosis regulation following bFGF administration to an incisional wound may lead effectively to granulation tissue formation and promote a scar-less repair process.     

Effect of collagen cross-linking inhibition by local application of beta-aminopropionitrile fumarate on wound contraction and healing (macroscopic study)

Wound contraction is a major component of second-intention wound healing. The mechanism of this process is not completely understood. Two theories have been described for the mechanism of the wound contraction. To evaluate the collagen cross-linking inhibition on wound contraction, the present study was carried out. Macroscopical aspects of second-intention healing of full-thickness, excisional wounds were studied in five normal male mixed-breed dogs. Under general anesthesia, two full-thickness skin wounds (20 × 20 mm) were created on the back of each dog symmetrically. Left-side wounds (test group) and right-side wounds (control group) were treated topically with beta-aminopropionitrile fumarate 5 mg/ml in methyl cellulose gel and methyl cellulose gel, respectively. Wounds were treated starting at 24 h after wounding and continued for ten successive days. The wounds were evaluated over a 4-week period. At the days 0, 3, 7, 10, 14, 17, 21, 24, and 28, digital photographs were taken of all wounds. Rulers were held vertically and horizontally close to the wound as a reference. The area of the epithelialization and granulation tissue were measured for each wound using Scion Image software. Percent of the wound contraction, epithelialization, and healing were calculated for each wounds. Wound contraction, epithelialization, and healing were significantly decreased in the wounds treated by beta-aminopropionitrile fumarate (P < 0.05). Our data demonstrated that the collagen and collagen cross-linking play a key role in the wound contraction and healing during the first 10 days of the wound healing.     

黄芪注射液联合葛根素注射液对2型糖尿病KKAy小鼠肾脏TGF-β1和BMP-7表达的影响

目的: 观察黄芪注射液联用葛根素注射液对2型糖尿病KKA^y小鼠肾脏转化生长因子β₁(TGF-β₁)和骨形态发生蛋白7(BMP-7)表达的影响。方法: 雄性KKA^y小鼠饲养至14周龄时随机分成模型组和黄芪注射液联合葛根素注射液治疗组,同龄雄性C57BL/6J小鼠作为正常组。观察各组小鼠一般状态并测量体重;检测20周龄、24周龄及28周龄小鼠空腹血糖(BG)、血清甘油三酯(TG)、胆固醇 (TC) 和血清肌酐(SCr);免疫组化法测定肾脏组织TGF-β₁蛋白表达情况,RT-PCR法检测肾脏组织BMP-7和TGF-β₁ 的mRNA表达情况。结果: 与正常组相比,模型组小鼠的体重、BG、TG、TC和SCr均有较明显增高;肾组织TGF-β₁蛋白和mRNA表达明显升高,BMP-7 mRNA表达下降。与模型组比较,黄芪注射液联合葛根素注射液治疗组小鼠的体重、BG、TG 、TC 及SCr均有不同程度下降;肾组织BMP-7 mRNA表达升高,而TGF-β₁蛋白及mRNA表达明显下调。结论: 黄芪注射液联合葛根素注射液对2型糖尿病KKA^y小鼠肾脏有保护作用,其机制可能与恢复肾组织BMP-7表达,降低肾组织TGF-β₁过度表达有关。     

TGF-β1/Smads和ERK表达异常在高盐饮食诱导的大鼠血管重构中的作用

目的: 研究转化生长因子β₁(TGF-β₁)/Smads和细胞外信号调节激酶(ERK)表达在高盐饮食诱导的大鼠血管重构中的作用及替米沙坦的干预效应。方法: 雄性 Wistar大鼠随机分为正常盐对照组(C组),8%高盐模型组和8%高盐+替米沙坦干预组(T组),每2周测量尾动脉压1次,根据尾动脉压又将8%高盐模型组分为模型高血压组(MH组)和模型正常血压组(MN组),喂养共24周。HE染色和Masson染色观察主动脉和肠系膜动脉重构。通过 real-time PCR测定主动脉中膜TGF-β₁、Smad2和Smad3和Smad7 mRNA表达,同时免疫组化法检测主动脉和肠系膜动脉中膜增殖细胞核抗原(PCNA)、TGF-β₁、磷酸化Smad2/3(p-Smad2/3)、磷酸化ERK1/2(p-ERK1/2)及Smad7的蛋白表达和分布。结果: 与C组相比,MH组大鼠血压升高(P<0.05), MH组和MN组主动脉和肠系膜动脉中膜胶原容积分数(CVF)和中膜厚度(MT)显著增加(P<0.01),主动脉TGF-β₁、Smad2 和Smad7 mRNA表达增高(P<0.05),主动脉和肠系膜动脉中膜PCNA、TGF-β₁、p-Smad2/3和p-ERK1/2蛋白表达显著升高(P<0.05),Smad7表达明显降低(P<0.05);经替米沙坦干预后,主动脉和肠系膜动脉中膜CVF和MT减小(P<0.01),PCNA、TGF-β₁、p-Smad2/3和p-ERK1/2表达减少(P<0.05),Smad7 表达上升(P<0.05)。结论: TGF-β₁/Smads 和ERK表达异常共同参与高盐饮食致主动脉和肠系膜动脉重构的机制;替米沙坦抗动脉重构的作用可能部分是通过阻断血管紧张素Ⅱ1型(AT₁)受体影响TGF-β₁ /Smads 和ERK表达实现的。