日本研究人員日前報(bào)告說(shuō)，一種變異鏈球菌會(huì)使腦出血的風(fēng)險(xiǎn)增高約3倍,。這一發(fā)現(xiàn)將有助于開(kāi)發(fā)預(yù)防和治療腦出血的藥物,。
（圖片來(lái)自文章）
日本大阪大學(xué)等機(jī)構(gòu)的研究人員在新一期英國(guó)《自然—通訊》雜志上報(bào)告說(shuō),，生活在口腔中的變異鏈球菌會(huì)導(dǎo)致蛀牙,，60%至70%的日本人都攜帶這種細(xì)菌,。研究人員還發(fā)現(xiàn),，約有8%的日本人攜帶一種含膠原蛋白的特殊變異鏈球菌,。但在腦出血患者中,，約有30%的人攜帶這種變異鏈球菌,。由此推算,，攜帶這種變異鏈球菌的人,，其腦出血發(fā)病風(fēng)險(xiǎn)比其他人高出約3倍。
在動(dòng)物實(shí)驗(yàn)中,，研究人員用一種特殊設(shè)備破壞實(shí)驗(yàn)鼠的腦血管使其出血,，并從人類(lèi)腦出血患者唾液中采集這種變異鏈球菌投放到這些實(shí)驗(yàn)鼠的血管中,。結(jié)果發(fā)現(xiàn),，投放變異鏈球菌的實(shí)驗(yàn)鼠的腦血管出血量比對(duì)照組實(shí)驗(yàn)鼠多五六倍。研究人員發(fā)現(xiàn),，這種變異鏈球菌的膠原蛋白會(huì)富集到血管破損處,，妨礙血管修復(fù),，從而導(dǎo)致出血增加。
研究人員說(shuō),，健康人攜帶此類(lèi)變異鏈球菌并無(wú)太大問(wèn)題,，但對(duì)于高血壓患者,、吸煙者等血管較脆弱的人群，就容易引發(fā)腦出血,。研究人員提醒這些“脆弱”人群更加注意養(yǎng)成健康生活習(xí)慣，警惕腦出血的發(fā)生。（生物谷 Bioon.com）
doi:10.1038/ncomms1491
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The collagen-binding protein of Streptococcus mutans is involved in haemorrhagic stroke
Kazuhiko Nakano; Kazuya Hokamura; Naho Taniguchi; Koichiro Wada; Chiho Kudo; Ryota Nomura; Ayuchi Kojima; Shuhei Naka; Yoshinori Muranaka; Min Thura; Atsushi Nakajima; Katsuhiko Masuda; Ichiro Nakagawa; Pietro Speziale; Nobumitsu Shimada; Atsuo Amano; Yoshinori Kamisaki; Tokutaro Tanaka; Kazuo Umemura; Takashi Ooshima
Although several risk factors for stroke have been identified, one-third remain unexplained. Here we show that infection with Streptococcus mutans expressing collagen-binding protein (CBP) is a potential risk factor for haemorrhagic stroke. Infection with serotype k S. mutans, but not a standard strain, aggravates cerebral haemorrhage in mice. Serotype k S. mutans accumulates in the damaged, but not the contralateral hemisphere, indicating an interaction of bacteria with injured blood vessels. The most important factor for high-virulence is expression of CBP, which is a common property of most serotype k strains. The detection frequency of CBP-expressing S. mutans in haemorrhagic stroke patients is significantly higher than in control subjects. Strains isolated from haemorrhagic stroke patients aggravate haemorrhage in a mouse model, indicating that they are haemorrhagic stroke-associated. Administration of recombinant CBP causes aggravation of haemorrhage. Our data suggest that CBP of S. mutans is directly involved in haemorrhagic stroke.
