張 影,周 月,嚴尚學,魏 偉
研究報告
類風濕關節炎復合高血壓疾病模型的建立及評價
張 影,周 月,嚴尚學*,魏 偉
類風濕關節炎(rheumatiod arthritis, RA)是一種常見的系統性自身免疫病,以對稱性關節腫脹、疼痛、炎癥細胞浸潤、滑膜襯里層細胞增生為主要病理特征,多數患者伴有骨與軟骨破壞,并最終導致殘疾[1]。中國每年發病人數高達500萬,發病率約為0.32%~ 0.36%,有200余萬人致殘[2]。
研究表明,RA患者的血管內皮功能異常、動脈硬化程度和動脈粥樣硬化斑塊數量明顯增加[3,4],其高血壓(hypertension, HT)發生率比一般人群高達30%[5];RA伴發高血壓患者的心血管器官損傷(如左心室異常、舒張功能不全、系統性動脈順應性降低)發生率也比非高血壓RA患者的發生率顯著升高[6,7],這些研究提示了RA既可導致心血管疾病的發生發展,同時,高血壓也成為增加RA患者心血管疾病發生率與死亡率的主要風險因素。HT與RA相互交叉影響,探索其防治措施及其病理機制成為目前的研究熱點。
佐劑性關節炎(adjuvant arthritis, AA)模型動物在臨床表現、病理學、免疫學改變等方面與人RA有許多相似特征,是研究RA病理機制和篩選評價治療RA藥物的理想動物模型[8]。兩腎一夾(two kidney one clip, 2K1C)高血壓模型是一種模擬人類腎性高血壓的經典動物模型[9]。在本研究中,我們首次將這兩個動物模型建成類風濕關節炎復合高血壓疾病(arthritis-hypertension disease, AHD)模型,并探索AHD模型的病理特點,以期更好地研究RA與HT之間的相互影響及病理機制。
1.1 實驗動物及分組
SPF級雄性SD大鼠,40只,體重(160±10)g,5~6周齡,購置并飼養于安徽醫科大學實驗動物中心[SCXK(皖)2011-002][SYXK(皖)2011-007]。40只SD大鼠隨機分為正常組8只、AA組10只、高血壓(HT)組10只、AHD組12只。本實驗符合動物倫理和福利要求,實驗方案按照“3R”原則得到本單位實驗動物倫理委員會批準。
1.2 主要試劑與儀器
卡介苗,購自成都生物制品研究所有限公司;YLS-7B型足趾容積測量儀,創博環球生物科技有限公司產品;ALC-NIBP型無創血壓測量分析系統,上海奧爾科特生物科技有限公司產品。
1.3 實驗方法
1.3.1 AA大鼠模型的建立[10]
卡介苗80℃水浴恒溫滅活1 h,與滅菌的液體石蠟充分研磨成濃度為10 mg/mL完全弗氏佐劑,于大鼠左后足跖注射0.1 mL致炎。
1.3.2 高血壓大鼠模型的建立[11]
采用手術法建立2K1C高血壓大鼠模型。大鼠術前禁食過夜,自由飲水。3%戊巴比妥鈉溶液按0.2 mL/100 g體重腹腔注射麻醉大鼠,外科手術暴露出左腎動脈,用內徑為0.25 mm銀夾將左腎動脈縮窄,縫合皮膚,術后肌肉注射青霉素抗感染治療3 d。
1.3.3 AHD模型的建立
在建立2K1C高血壓大鼠模型的基礎上,同時于大鼠左后足跖注射0.1 mL完全弗氏佐劑致炎建立模型。
1.3.4 炎癥指標測定、關節炎指數、致炎率的測定
關節腫脹度測定:致炎前用足爪容積測量儀測量大鼠足爪(非致炎側)容積,炎癥出現后,每隔3 d測一次足爪容積,關節腫脹度(mL)=|致炎后足爪容積-致炎前足爪容積|[12]。
關節炎指數評分:炎癥出現后,每隔3 d進行關節炎指數評分,觀察每組大鼠的繼發病變。關節炎指數評分標準:0=正常;1=踝關節出現紅斑和輕微腫脹;2=踝關節到跖關節或掌關節紅斑和輕微腫脹;3=踝關節到跖趾關節或掌關節出現紅斑和中度腫脹;4=踝關節到趾關節出現紅斑和重度腫脹。每只大鼠最多評16分[12]。
致炎率計算:每組大鼠非致炎側出現紅腫的百分率,致炎率(%)=每組炎癥大鼠數量 / 每組動物總數量×100%。
1.3.5 高血壓判定標準
造模前用血壓測量儀測量尾動脈壓6次,取平均值作為基線壓,造模后每周測量一次。血壓高于基線20 mmHg且高于140 mmHg被認為2K1C高血壓模型成功[11]。
1.3.6 病理學檢查
第35天處死大鼠,取大鼠胸主動脈、踝關節和脾臟組織,10%福爾馬林固定、HE染色鏡檢。在鏡下用cellSens Entry軟件測量胸主動脈的中膜厚度、橫切面積和管腔直徑[13];觀察大鼠踝關節中滑膜細胞增殖、細胞浸潤、血管翳生成及骨與軟骨破壞等病理變化;以及脾臟生發中心數量、淋巴細胞浸潤、白髓增生、紅髓浸潤的病理改變[14]。
1.4 統計學方法
2.1 AHD模型關節腫脹度、關節炎指數、致炎率和血壓值的變化情況
AA、AHD組大鼠免疫后第11天,右后足趾開始腫脹,隨著病程延長,關節腫脹度和關節炎指數逐漸升高,第20~23天關節炎指數處于較高水平,第27天后,關節炎指數開始降低,但關節腫脹仍維持較高水平。與AA組比較,AHD模型大鼠關節腫脹度、關節炎指數明顯升高(詳見圖1A、B)。與AA組相比,AHD模型大鼠炎癥發病率有升高趨勢(詳見圖1C)。手術法造模后第2周,HT模型及AHD模型大鼠血壓開始升高,隨著病程延長,血壓值逐漸升高且第4周達到平穩值,與HT組相比,AHD模型大鼠血壓值明顯升高(詳見圖1D)。篩選成模大鼠后各組只數:正常組8只,AA組7只,HT組9只,AHD組10只。
2.2 AHD模型大鼠胸主動脈結構變化情況
如圖2所示,與正常組相比,HT、AHD模型大鼠血管中膜厚度、橫截面積明顯增加,管腔直徑明顯降低;與HT組大鼠相比,AHD模型大鼠血管中膜厚度、橫截面積明顯增加,管腔直徑明顯降低,提示HT、AHD模型大鼠出現胸主動脈血管重構,AA炎癥可加重2K1C引起的高血壓大鼠血管損傷。

注:與正常組比較,*P < 0.05,**P < 0.01;與AA組比較,#P < 0.05,##P < 0.01;與HT組比較,&P < 0.05。圖1 AHD模型足爪腫脹、關節炎指數、致炎率和血壓值的變化情況Note.Compared with the normal group,*P < 0.05,**P < 0.01; Compared with the AA group,#P < 0.05,##P < 0.01; Compared with the HT group,&P < 0.05.Fig.1 Changes of paw swelling, arthritis index, the incidence of inflammation and blood pressure of AHD model rats

注:A:正常組;B:AA組;C:HT組;D:AHD組。與正常組比較,**P < 0.01;與HT組比較,&P < 0.05。圖2 AHD模型大鼠胸主動脈結構變化情況Note.A:Normal group; B:AA group; C:HT group; D: AHD group. Compared with the normal group,**P< 0.01; Compared with the HT group,&P< 0.05.Fig.2 Structural changes of thoracic aorta in the AHD model rats

注:A:正常組;B:AA組;C:HT組;D:AHD組。A、C:箭頭指正常關節腔及正常軟骨表面;B:箭頭指軟骨被嚴重破壞,關節腔大量炎癥細胞增生、浸潤;D:箭頭指關節腔有大量細胞浸潤、血管翳生成、骨與軟骨被破壞;與正常組比較,**P < 0.01;與AA組相比,#P < 0.05。圖3 AHD模型大鼠關節病理變化情況Note.A:Normal group; B:AA group; C:HT group; D: AHD group. A, C: Arrows point to normal articular and normal cartilage surfaces; B: Arrows point to the cartilage was severely damaged, a large number of inflammatory cell were present, infiltrating the joint cavity; D:Arrows point to the joint cavity showing a large number of cell infiltration, pannus formation, and bone and cartilage destruction. Compared with the normal group,**P < 0.01; Compared with the AA group,#P < 0.05.Fig.3 Pathological changes of the joints in AHD model rats

注:A:正常組;B:AA組;C:HT組;D:AHD組。W:白髓;R:紅髓;L:淋巴濾泡;GC:生發中心。與正常組相比,**P < 0.01;與AA組相比,#P < 0.05。圖4 AHD模型大鼠脾臟病理變化情況Note.A:Normal group; B:AA group; C:HT group; D: AHD group. W:White pulp; R:Red pulp; L:Lymphoid follicles; GC: Germinal centers. Compared with the normal group,**P < 0.01; Compared with the AA group,#P < 0.05.Fig.4 Pathological changes of spleen in the AHD model rats
2.3 AHD模型大鼠關節病理變化情況
關節病理檢查結果表明(圖3),與正常組相比,AA、AHD大鼠關節明顯腫脹,關節腔大量滑膜細胞增生、炎癥細胞浸潤、血管翳生成、骨與軟骨被破壞。與AA大鼠相比,AHD模型大鼠關節病理評分明顯升高。正常組和HT組大鼠關節組織無明顯病理改變。提示,AA、AHD大鼠出現了明顯的關節炎癥,且2K1C引起的高血壓可加重關節炎癥病理改變。
2.4 AHD模型大鼠脾臟病理變化情況
脾臟組織病理檢查結果顯示(圖4),與正常組相比,AA、AHD大鼠脾臟組織生發中心數量增加、大量淋巴細胞浸潤、白髓彌漫性增生、紅髓浸潤。與AA組相比,AHD模型大鼠脾臟組織病理評分明顯升高。正常組和HT組動物脾臟組織無明顯病理改變。提示,AA、AHD大鼠具有明顯的脾臟病理變化,2K1C引起的高血壓可加重AA大鼠的脾臟病理改變。
大量臨床研究表明[6,7,15-17],RA患者的心血管功能發生了異常改變,而高血壓等心血管疾病則是導致RA患者死亡的最重要因素之一,RA與HT二者互相影響加重了病情發展,建立AHD疾病模型對研究二類疾病關聯的發病機制以及篩選和研究治療藥物作用具有重要意義。有報道闡述了RA與HT二類疾病之間的相互作用機制,表明炎癥條件下升高的C-反應蛋白(CRP)水平減少內皮細胞一氧化氮(NO)、增加內皮素-1的產生,引起血管收縮、血壓升高;而升高的血壓導致粘附分子、促炎因子的表達并進入循環系統,升高CRP的水平,誘發炎癥反應[18]。
在本研究中,AHD模型大鼠血壓明顯升高,關節腫脹,關節腫脹指數、關節病理、主動脈血管損傷、脾臟病理變化明顯,且模型大鼠的血清中血管緊張素Ⅱ、腫瘤壞死因子α等炎癥介質水平顯著升高(結果未附),具有RA和高血壓動物模型的典型特征,提示AHD模型成功建立。
AA模型是經典的RA動物模型[10,19],造模第11天右后非致炎側足爪開始腫脹,第20天關節炎指數處于較高水平,第23天關節腫脹處于較高水平,第27天后關節腫脹開始緩解但仍維持較高水平,關節炎指數開始降低。手術法誘導的2K1C高血壓模型大鼠[20,21]在造模第2周血壓開始升高,第4~5周血壓可達穩定值,第7~8周后血壓逐漸下降。因此,AHD大鼠的模型癥狀評價以造模第27~35天為宜。
本研究還初步觀察了RA和HT對各自疾病模型的影響。實驗結果表明,與AA大鼠相比,AHD模型大鼠足爪腫脹度、關節腫脹指數明顯升高且關節炎發病病程早、發病率高,脾臟病理評分也明顯升高,提示高血壓可能加速了RA的炎癥進程;與HT組大鼠相比,AHD模型大鼠血壓值明顯升高,胸主動脈的中膜厚度、橫截面積明顯增加,管腔直徑明顯降低,提示RA的炎癥過程加重了HT模型大鼠的血管損傷,導致血壓進一步升高。
綜上,AHD模型癥狀明顯,操作簡單,是研究RA與高血壓的疾病病理機制、篩選治療藥物的理想動物模型。
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(安徽醫科大學臨床藥理研究所,抗炎免疫藥物教育部重點實驗室,安徽省抗炎免疫藥物協同創新中心,合肥 230032)
目的 建立類風濕關節炎復合高血壓疾病(arthritis-hypertension disease, AHD)大鼠模型,并對該模型的特點進行評價。方法 實施外科手術用0.25 mm銀夾縮窄大鼠左腎動脈建立高血壓(hypertension, HT)模型,同時于大鼠左后足跖注射0.1 mL完全弗氏佐劑致炎建立AHD模型。無創血壓測量分析系統測量尾動脈壓。足爪容積測量儀測量大鼠非致炎側關節腫脹度,并分析關節炎指數與炎癥發生率。第35天處死大鼠,收集胸主動脈、踝關節及脾臟組織HE染色并進行病理學檢查。結果 AHD模型大鼠關節明顯腫脹,關節腔大量滑膜細胞增生、炎癥細胞浸潤、血管翳形成,脾臟生發中心數量增加、大量淋巴細胞浸潤、白髓彌漫性增生、紅髓浸潤。關節炎指數、炎癥發生率以及關節、脾臟組織病理評分較佐劑性關節炎(adjuvant arthritis, AA)大鼠明顯升高;同時,AHD模型大鼠血壓顯著升高,胸主動脈中膜厚度、橫截面積明顯增加,管腔直徑明顯降低,且其血壓值和血管損傷程度較HT大鼠明顯升高或加重。結論 用完全弗氏佐劑足跖皮內注射法合并外科手術縮窄左腎動脈法可成功建立大鼠AHD模型。
類風濕關節炎復合高血壓;佐劑性關節炎;高血壓
Establishment and evaluation of a rat model of arthritis-hypertension disease
ZHANG Ying, ZHOU Yue, YAN Shang-xue*, WEI Wei
(Institute of Clinical Pharmacology, Anhui Medical University, Key Laboratory of Anti- inflammatory and Immune Medicine, Ministry of Education, Anhui Collaborative Innovation Center ofAnti-inflammatory and Immune Medicine, Hefei 230032, China)
Objective To establish and evaluate a rat model presenting symptoms of arthritis-hypertension disease (AHD). Methods A total of forty healthy 5-6 week-old male SD rats were used in this study. Hypertension was induced by constriction of the left renal artery by two kidney one clip (2K1C) with a 0.25 mm silver clamp, and AHD model was established by injecting 0.1 mL complete Freund adjuvant to the left hind paw. Tail artery pressure was measured with a non-invasive blood pressure measurement system. The degree of swelling in the non-inflammatory joint of rats was measured with a paw volume measuring instrument, the arthritis index and incidence of inflammation were evaluated. The rats were sacrificed on the 35thday. The thoracic aorta, ankle joint and spleen tissues were examined by pathology using HE staining. Results The joint of AHD model rat was significantly swollen, extensive synovial cell hyperplasia, inflammatory cell infiltration, vascular pannus formation, and bone and cartilage destruction. The number of germinal centers in spleen was increased, and a large number of lymphocyte infiltration, diffuse proliferation of white pulp, and red pulp infiltration were present. The arthritis index, incidence of inflammation and histopathological scores of the joint and spleen were significantly higher than adjuvant arthritis (AA) rats; meanwhile, the blood pressure of AHD model rat was significantly increased, the thickness and cross-sectional area of thoracic aorta were significantly increased, while the lumen diameter was significantly reduced. The blood pressure and vascular injury were significantly increased or aggravated compared with the HT rats. Conclusions A rat model of arthritis-hypertension disease is successfully established by using complete Freund adjuvant intradermal injection to the footpad and surgery to narrow the left renal artery.
Arthritis hypertension disease; Adjuvant arthritis; Hypertension
國家自然科學基金(81330081,81302784,81673444);安徽省自然科學基金(1508085MH182);安徽醫科大學博士科研資助基金(XJ201534)。
張影(1991-),女,碩士,研究方向:抗炎免疫藥理學。E-mail:1374393895@qq.com
嚴尚學(1973-),男,副研究員,碩士生導師,研究方向:抗炎免疫藥理學。E-mail:yan-shx@163.com
R-33
A
1671-7856(2017) 08-0034-06
10.3969.j.issn.1671-7856. 2017.08.007
2016-12-08