sdf1趨化因子在缺血性中風(fēng)患者的周梗塞區(qū)誘導(dǎo)

1、SDF-1/CXCR7 Chemokine Signaling is Induced in the Peri-Infarct Regions in Patients with Ischemic Stroke,SDF-1/CXCR7趨化因子在缺血性中風(fēng)患者的周梗塞區(qū)域誘導(dǎo),綱要,AbstractImage and ResultDiscussion Acknowledgments,,,1,Abstract,Abstract,Str

2、omal-derived factor-1 (SDF-1, also known as CXCL12) and its receptors CXCR4 and CXCR7 play important roles in brain repair after ischemic stroke, as SDF-1/ CXCR4/CXCR7 chemokine signaling is critical for recruiting stem

3、cells to sites of ischemic injury. Upregulation of SDF-1/CXCR4/CXCR7 chemokine signaling in the ischemic regions has been well-documented in the animal models of ischemic stroke, but not in human ischemic brain.由間質(zhì)衍生的fa

4、c-1（SDF-1，也稱為CXCL12）和它的受體CXCR4和CXCR7在缺血性中風(fēng)后在大腦修復(fù)中扮演著重要的角色，因為SDF-1/CXCR4/CXCR7趨化因子對于在缺血性損傷的部位招募干細胞是至關(guān)重要的。在缺血性中風(fēng)的動物模型中，在缺血性中風(fēng)的動物模型中已經(jīng)記錄了SDF-1/CXCR4/CXCR7的趨化因子，但在缺血性腦內(nèi)卻沒有。,Abstract,Here, we found that protein expression of

5、SDF-1 and CXCR7, but not CXCR4, were significantly increased in the cortical peri-infarct regions (penumbra) after ischemic stroke in human, compared with adjacent normal tissues and control subjects.Double-label fluores

6、cence immunohistochemistry shows that SDF-1 and CXCR4 proteins were expressed in neuronal cells and astrocytes in the normal brain tissue and peri-infarct regions. 在這里，我們發(fā)現(xiàn)，與鄰近的正常組織和對照組相比，在人類缺血性中風(fēng)后的皮質(zhì)周梗塞區(qū)域（半影）中，SDF-1和CX

7、CR7的蛋白質(zhì)表達，而不是CXCR4，顯著增加。雙標(biāo)簽熒光免疫組織化學(xué)顯示，SDF-1和CXCR4蛋白質(zhì)表達在正常腦組織和周圍梗塞區(qū)域的神經(jīng)元細胞和星形膠質(zhì)細胞中。,Abstract,CXCR7 protein was also observed in neuronal cells and astrocytes in the normal cortical regions, but predominantly in astrocytes

8、 in the penumbra of ischemic brain. Our data suggest that ischemic stroke in human leads to an increase in the expression of SDF-1 and CXCR7, but not CXCR4, in the peri-infarct cerebral cortex. Our findings suggest that

9、chemokine SFD-1 is expressed not only in animal models of stroke, but also in the human brain after an ischemic injury. In addition, unlike animals, CXCR7 may be the primary receptor of SDF-1 in human stroke brain.在正常的皮

10、質(zhì)區(qū)域，也觀察到CXCR7蛋白質(zhì)，但主要是在缺血性大腦的半影膜中的星形膠質(zhì)細胞中。我們的數(shù)據(jù)表明，人類的缺血性中風(fēng)導(dǎo)致了SDF-1和CXCR7的表達，而不是CXCR4，在梗塞的腦皮質(zhì)中。我們的研究結(jié)果表明，趨化因子SFD-1不僅表現(xiàn)在中風(fēng)的動物模型中，而且在缺血性損傷后的人類大腦中也表現(xiàn)出來。此外，與動物不同的是，CXCR7可能是人類中風(fēng)大腦中SDF-1的主要受體。,,,Image and Result,2,Image 1,Expre

11、ssion pattern of SDF-1/CXCR4/CXCR7 in post-stroke human brain. A) Representative images show that SDF-1 expression in cerebral cortex of infarcted brain. Top panel: low magnification; Bottom panel: high magnification. B)

12、 CXCR7 immunocytochemistry in the peri-infarct region (penumbra) and adjacent normal tissue. C) CXCR4 immunocytochemistry in the cortical penumbra and adjacent normal tissue.中風(fēng)后人類大腦的SDF-1/CXCR4/CXCR7的表達模式。A）代表性的圖像顯示，在梗塞

13、的大腦皮層中，SDF-1表達。前面板:低放大;底板:高放大。B）在梗塞部位（半乳）和鄰近的正常組織中，CXCR7免疫細胞化學(xué)。C）在皮質(zhì)的半影和鄰近的正常組織中，CXCR4免疫細胞化學(xué)。,Image 2,Phenotypes of SDF-1-positive cells in the human ischemic brain. A-B) Confocal image of representative immunofluorescen

14、t staining for NeuN (A) or GFAP (B) (Alexa Fluor 594, red), SDF-1 (Alexa Fluor 488, green), nuclei (DAPI, blue), and merged image from adjacent normal regions of human ischemic stroke brain. C) Merged confocal images of

15、double-label immunohistochemistry in the peri-infarct region (penumbra) of the human ischemic brain section using anti-GFAP (green) and anti-SDF-1 (red). D) Merged confocal images of double-label immunohistochemistry in

16、the penumbra on the human ischemic brain using anti-NeuN (red) and anti-SDF-1 (green). DAPI (blue) was used for nuclei counterstains.,Image 3,Phenotypes of CXCR7-positive cells in the human ischemic brain. A) Merged conf

17、ocal image of double-label immunohistochemistry on the normal region of the human ischemic brain section using anti-NeuN (red) and anti- CXCR7 (green). B) Merged confocal image of double-label immunohistochemistry on the

18、 normal region of the human ischemic brain section using anti-GFAP (red) and anti- CXCR7 (green). C) Double immunocytochemistry was performed on the ischemic brain sections in the penumbra using anti-GFAP (red) and anti-

19、CXCR7 (green). The images were recorded using a 2-photon confocal microscope. D) Higher magnification view of merged confocal image in panel C. DAPI (blue) was used for nuclei counterstains.,Image 4,人類缺血性腦中的cxcr4表達細胞的表型。

20、在缺血的腦區(qū)進行了雙重免疫細胞化學(xué)反應(yīng)，并用2光子共焦顯微鏡記錄了這些圖像。代表性的圖像顯示，CXCR4（綠色）在正常區(qū)域（A）和半影（C），以及在正常區(qū)域（B）和半影（D）的人類缺血性大腦中，在正常區(qū)域（紅色）中表達的是星形膠質(zhì)細胞（紅色）。DAPI（藍色）用于核反染色。,RESULTS,To determine the expression pattern of SDF-1 protein, immunocytochemistry

21、was performed on the ischemic brain sections from patients with ischemic stroke using anti-SDF-1 antibody. As shown in Fig. 1A, SDF-1-immunopositive cells were predominantly localized in the cortical peri-infarct re

22、gion (penumbra) and infarct area, but a little in the adjacent normal region in brain specimens of stroke patients, suggesting that SDF-1 protein is induced in the ischemic regions after ischemic stroke. Next, we examine

23、d the expression patterns of second SDF-1 receptor CXCR7, Like SDF-1, CXCR7 protein expression was significantly increased in the penumbra of human ischemic brain, compared with the adjacent normal regions. However, the

24、expression of CXCR7 was low in the infarct core (Fig. 1B). Interestingly, the expression of CXCR4 protein in the cortical penumbra was not significantly increased, compared with the adjacent normal region, and essentiall

25、y absent from the infarct core (Fig. 1C). These findings suggest that CXCR7, rather than CXCR4, is the primary receptor for SDF1 in the ischemic brain in human.,為了確定SDF-1蛋白質(zhì)的表達模式，免疫細胞化學(xué)是用抗SDF-1抗體對缺血性中風(fēng)患者的缺血性腦區(qū)進行的。如無花果所示。

26、1-1-1-免疫反應(yīng)細胞主要集中在皮質(zhì)周梗塞區(qū)域（半乳）和梗塞區(qū)域，但在卒中患者的腦標(biāo)本的鄰近正常區(qū)域有一小部分，這表明SDF-1蛋白在缺血性中風(fēng)后在缺血區(qū)域被誘導(dǎo)。接下來，我們研究了第二SDF-1受體CXCR7的表達模式，如SDF-1，CXCR7蛋白質(zhì)表達在人類缺血大腦的半影中顯著增加，與鄰近的正常區(qū)域相比。然而，CXCR7的表達在梗塞灶的核心（圖1B）中很低。有趣的是，與鄰近的正常區(qū)域相比，皮質(zhì)半乳中的CXCR4蛋白質(zhì)的表達并沒有顯

27、著增加，而且基本上沒有出現(xiàn)在梗塞部位（圖1 C）。這些發(fā)現(xiàn)表明，CXCR7，而不是CXCR4，是人類缺血性大腦中SDF1的主要受體。,RESULTS,,,3,Discussion,Discussion,The major finding of this study is that ischemic stroke in human leads to an increase in the expression of SDF-1 and CX

28、CR7, but not CXCR4, in the peri-infarct cerebral cortex compared with the adjacent normal brain and ischemic core.這項研究的主要發(fā)現(xiàn)是，人類的缺血性中風(fēng)導(dǎo)致了SDF-1和CXCR7的表達增加，而不是CXCR4，與鄰近的正常大腦和缺血性核心相比。,Discussion,Stem cells are a source of p

29、aracrine and structural regeneration for brain damaged by acute ischemic stroke. Therefore, proper homing of stem cells, including HSCs, BMSCs, EPCs and NSCs, to ischemic brain, is critical for the restoration of the inj

30、ured neural tissues and improved functional outcomes. 干細胞是急性缺血性中風(fēng)腦損傷的一種旁分泌和結(jié)構(gòu)再生的來源。因此，適當(dāng)?shù)母杉毎?，包括HSCs、BMSCs、EPCs和NSCs，對缺血性大腦來說，對于恢復(fù)受傷的神經(jīng)組織和改善功能結(jié)果是至關(guān)重要的。,Discussion,Although the mechanism underlying stem cell homing to isc

31、hemic regions is unclear, the overexpression and secretion of SDF-1 by ischemic tissues could develop a gradient in circulation and guides CXCR4-postive stem cell recruitment from bone marrow and neurogenic niches in the

32、 brain to the injured site [24]. 雖然目前尚不清楚干細胞歸巢的機理，但缺血性組織的SDF-1的過度表達和分泌可能會在血液循環(huán)中形成一個梯度，并引導(dǎo)cxcr4-陽性干細胞從骨髓和神經(jīng)原性的小生境到受傷的部位24。,Discussion,Indeed, study has shown that deficiency of CXCR-4 significantly decrease the migration

33、 of BMSCs toward the ischemic region, indicating the SDF-1/CXCR-4 play an important role in regulating the homing of BMSCs [9, 18, 25-28]. 事實上，研究表明，CXCR-4的不足顯著地減少了BMSCs向缺血性區(qū)域的遷移，表明SDF-1/CXCR-4在調(diào)節(jié)BMSCs 9、18、25-

34、28的引導(dǎo)方面起著重要的作用。,Discussion,In addition, SDF-1/CXCR4 increased the radial migration of NSCs from the subventricular zone (SVZ) toward the infarct areas in a dose-dependent manner [29]. Blockade of the CXCR4 or CXCR7 could

35、 disrupt the migration of NSCs, leading to a failure of the newborn neurons to migrate to the ischemic tissue in animal models of stroke [30]. 此外，SDF-1/CXCR4增加了NSCs從次室區(qū)（SVZ）向梗塞區(qū)域的徑向遷移，以劑量依賴性的方式29。對CXCR4或CXCR7的封鎖可能會破壞N

36、SCs的遷移，導(dǎo)致新生神經(jīng)元在中風(fēng)30的動物模型中轉(zhuǎn)移到缺血組織。,Discussion,In human, higher increase in CXCR4-positive stem cell number and lower increase in CXCR4-positive cells in peripheral blood in acute stroke patients correlated with initially

37、worse neurological status. However, increased CXCR4-positive cell induction in peripheral blood of acute stroke patients correlated with better functional/neurological status after the 6-month follow-up [31]. 在人類中，在急性中風(fēng)

38、患者的周圍血液中，cxcr4陽性的干細胞數(shù)量增加，cxcr4陽性細胞的增加，與最初的神經(jīng)狀況較差有關(guān)。然而，在6個月的隨訪31之后，急性中風(fēng)患者周圍血液中增加的cxcr4陽性細胞誘導(dǎo)與更好的功能/神經(jīng)狀況相關(guān)。,Discussion,Similar to the findings in animals, our data show that SDF-1 is increased in the penumbra of patients w

39、ith ischemic stroke, indicating that the function of up-regulated SDF-1 could recruit different types of stem cells at different locations to ischemic regions. Majority of cells that expressed SDF-1 are neurons, astrocyt

40、e and endothelial cells, suggest that SDF-1 may be released from these cells after ischemic stroke, but primarily secreted by astrocytes and endothelial cells in animal models of ischemic stroke [9].與動物的發(fā)現(xiàn)類似，我們的數(shù)據(jù)顯示，SDF

41、-1在缺血性中風(fēng)患者的半影中增加，這表明，上調(diào)節(jié)的SDF-1的功能可以在不同的位置為缺血性區(qū)域招募不同類型的干細胞。大多數(shù)表達SDF-1的細胞是神經(jīng)元、星形膠質(zhì)細胞和內(nèi)皮細胞，這表明SDF-1可能在缺血性中風(fēng)后從這些細胞中釋放出來，但主要是由星形膠質(zhì)細胞和內(nèi)皮細胞在缺血性中風(fēng)的動物模型中分泌。,Discussion,Interestingly, our data also showed that CXCR7, but not CXCR4

42、, was significantly increased in the peri-infarcted regions in human stroke brain. Specifically, we found that these CXCR7-positive cells in the peri-infarcted regions are predominantly astrocytes in human. Consistently,

43、 previous studies have documented that, astrocytes show the rare expression of CXCR4 in the developing and injured brain, whereas throughout the brain a much larger subset of astrocytes seem to express CXCR7 [10, 32

44、, 33]. The origin of the CXCR7-psotive astrocytes in the cortical penumbra is unknown. It is possible that these CXCR7-positive mature cells are derived from stem cells migrated from other regions.,However, CXCR7-po

45、sitive astrocytes most likely are resident cells. Therefore, it is consequently feasible to assume that the predominant role of CXCR7 in astrocytic SDF-1 signaling could be different from stem cell homing. Supported evid

46、ence includes that RNAi-mediated depletion of CXCR7 silenced SDF-1 signaling in astrocytes [34], and that SDF-1 in vitro acts as a growth factor for astrocytes by stimulating their proliferation [35], a phenome

47、non that could represent the basis of pathological conditions such as gliosis or reactive astrogliosis [36].,Discussion,Peri-infarct astrocytes undergo reactive astrogliosis after ischemic stroke, which plays key roles i

48、n modulating the adaptive responses in neurons. Our data suggest that SDF-1/CXCR7 signaling is likely to be related to glial proliferation in the peri-infarcted regions after ischemic stroke. Further study should be perf

49、ormed to determine whether SDF-1/CXCR7 signaling is truly involved in astrogliosis or glial scar formation in patients with ischemic stroke.,Discussion,,,4,Acknowledgments,This work was supported by National Institute of

50、 Health (NIH) grants R21NS094859 and AG21980 (J.K), National Natural Science Foundation of China (81371396, 81778262; Q. Z.G), and Key research project of Science Technology Department of Zhejiang Province (NO2017C03027;

51、 Q.Z.G), and Wenzhou public welfare science and technology project (Y20170089; Y.Z). Some human tissues were obtained from the NICHD Brain and Tissue Bank for Developmental Disorders at the University of Maryland, Baltim

52、ore, MD. The role of the NICHD Brain and Tissue Bank is to distribute tissue and, therefore, cannot endorse the studies performed or the interpretation of results.這項工作得到了國家衛(wèi)生研究院（NIH）的資助，該機構(gòu)為中國國家自然科學(xué)基金（81371396，81778262）