Investigating the role and therapeutic potential of the alpha5beta1 integrin in risk factors for COVID-19-associated cognitive impairment

摘要 迅速涌现的证据表明，血管性痴呆(Vad)和高血压之间存在联系。 新冠肺炎的发病率、发病率和COVID后认知功能下降。我们将脑血管病理推论为 VAD和其他病理生理特征，如血脑屏障(BBB)破坏和脑减少 血流可能对VaD和新冠肺炎均有直接作用。有几条证据支持这一假设。 首先，我们已经证明了SARS-CoV-2与血管整合素α5β1受体结合来感染细胞， 在脑缺血(中风)模型和慢性双侧脑缺血模型中，同样的受体也与血脑屏障紊乱有关 颈动脉狭窄(BCAS)，模拟VaD的病理生理方面，如脑血流减少 血流、血脑屏障紊乱、神经炎症、脑白质损伤和认知能力下降。第二，整合素α5β1是 中风和中风后脑血管系统中显著上调的年龄依赖方式(年老和年轻) 以及临床验证的整合素α5β1五肽抑制剂ATN161对该受体的抑制作用 减轻这些模型中的血脑屏障紊乱和认知障碍。第三，SARS-CoV-2感染也增加 整合素α5β1在体内的表达，并破坏血脑屏障。第四，初步结果表明，SARS-CoV-2 BCAS后感染与BCAS或单独感染相比进一步增加发病率，并加速脑血管 整合素α5β1表达上调。第五，ATN-161在体内外抑制SARS-CoV-2感染，预防SARS-CoV-2感染。 冠状病毒2诱导α5β1整合素表达增加。最后，尽管血管紧张素转换酶2 (ACE2)是病毒进入宿主细胞(内化和融合)的典型受体，其胞外结构域结合 病毒表面的尖峰蛋白(S蛋白)通过促进病毒附着和进入宿主细胞 使用RGD基序的受体介导的内吞作用。由于许多细胞表面整合素也与RGD结合，我们和 其他研究人员提供了令人信服的证据，证明整合素是病毒的辅助受体。此外，我们还有 结果表明，SARS-CoV-2的感染性需要Talin依赖的整合素激活。与我们的结果一致， 以前的研究表明，α5、β1和ACE2参与的信号串扰可能是由相互驱动的 它们在细胞质尾部的相互作用。基于这些发现，我们假设(I)整合素α5β1发挥作用 年龄相关致病因子在SARS-CoV-2感染与VaD关系中的重要作用 (Ii)在新冠肺炎感染之前、期间或之后接受ATN-161治疗 将稳定血脑屏障完整性，以改善新冠肺炎在原有血管背景下的神经认知结果 整合素α5β1信号调节感染性，其上调加强了对 BBB。为了研究这些假设，我们建议1)。证明实验性的VAD恶化 新冠肺炎患病率与随后的认知功能减退。确定整合素α5β1的治疗潜力 抑制治疗可改善VAD患者COVID后的发病率和认知功能减退。确定信令机制 整合素α5β1是SARS-CoV-2产生性感染和细胞屏障功能失调所必需的。

ABSTRACT Rapidly emerging evidence has characterized the association between vascular dementia (VaD) and increased COVID-19 incidence, morbidity, and post-COVID cognitive decline. We theorize that brain vascular pathology in VaD and additional pathophysiologic features such as blood-brain barrier (BBB) disruption and reduced cerebral blood flow may directly contribute to both VaD and COVID-19. Several lines of evidence support this hypothesis. First, we have demonstrated that SARS-CoV-2 binds to the vascular integrin α5β1 receptor to infect cells, the same receptor we have also linked to BBB disruption in brain ischemia (stroke) models and chronic bilateral carotid artery stenosis (BCAS), which models pathophysiological aspects of VaD such as reduced cerebral blood flow, BBB disruption, neuroinflammation, white matter damage, and cognitive decline. Second, integrin α5β1 is substantially upregulated in an age-dependent fashion (aged>young) in the brain vasculature after stroke and BCAS, and inhibition of this receptor with the clinically-validated integrin α5β1 pentapeptide inhibitor ATN-161 lessens BBB disruption and cognitive impairment in these models. Third, SARS-CoV-2 infection also increases integrin α5β1 expression in vivo and disrupts the BBB. Forth, preliminary results suggest that SARS-CoV-2 infection after BCAS further increases morbidity vs. BCAS or infection alone and accelerates brain vascular integrin α5β1 upregulation. Fifth, ATN-161 inhibits SARS-CoV-2 infection in vitro and in vivo and prevents SARS- CoV-2-induced increased expression of α5β1 integrin. Finally, although angiotensin-converting enzyme 2 (ACE2) is the canonical receptor for viral entry (internalization and fusion) into host cells, its ectodomain binds the viral spike protein (S-protein) on the surface to facilitate virus attachment and access into host cells through receptor-mediated endocytosis using an RGD motif. As many cell-surface integrins also bind RGD, we and others have provided compelling evidence that integrins are co-receptors of the virus. Additionally, we have shown that talin-dependent integrin activation is required for SARS-CoV-2 infectivity. Consistent with our results, previous studies have shown that α5β1 and ACE2 engage in signaling crosstalk likely driven by mutual interaction at their cytoplasmic tails. Building on these findings, we hypothesize that (i) integrin α5β1 plays an important age-dependent pathogenic role in the association between SARS-CoV-2 infection and VaD by worsening pre-existing VaD after COVID-19, (ii) ATN-161 treatment before, during, or after COVID-19 infection will stabilize BBB integrity to improve COVID-19 neurocognitive outcomes in the context of pre-existing vascular dementia, and (iii) integrin α5β1 signaling regulates infectivity, and its upregulation potentiates dysregulation of the BBB. To investigate these hypotheses, we propose to 1). Demonstrate that experimental VaD worsens COVID-19 morbidity and subsequent cognitive decline, 2). Determine the therapeutic potential of integrin α5β1 inhibition in improving VaD post-COVID morbidity and cognitive decline, 3). Determine the signaling mechanism of integrin α5β1 required for SARS-CoV-2 productive infection and dysregulation of cell barrier function.