Graphical abstract

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an infectious disease that has spread worldwide. Current treatments are limited in both availability and efficacy, such that improving our understanding of the factors that facilitate infection is urgently needed to more effectively treat infected individuals and to curb the pandemic. We and others have previously demonstrated the significance of interactions between the SARS-CoV-2 spike protein, integrin α5β1, and human ACE2 to facilitate viral entry into host cells in vitro. We previously found that inhibition of integrin α5β1 by the clinically validated small peptide ATN-161 inhibits these spike protein interactions and cell infection in vitro. In continuation with our previous findings, here we have further evaluated the therapeutic potential of ATN-161 on SARS-CoV-2 infection in k18-hACE2 transgenic (SARS-CoV-2 susceptible) mice in vivo. We discovered that treatment with single- or repeated intravenous doses of ATN-161 (1 mg/kg) within 48 h after intranasal inoculation with SARS-CoV-2 lead to a reduction of lung viral load, viral immunofluorescence, and improved lung histology in a majority of mice 72 h post-infection. Furthermore, ATN-161 reduced SARS-CoV-2-induced increased expression of lung integrin α5 and αv (an α5-related integrin that has also been implicated in SARS-CoV-2 interactions) as well as the C–X–C motif chemokine ligand 10 ( Cxcl10 ), further supporting the potential involvement of these integrins, and the anti-inflammatory potential of ATN-161, respectively, in SARS-CoV-2 infection. To the best of our knowledge, this is the first study demonstrating the potential therapeutic efficacy of targeting integrin α5β1 in SARS-CoV-2 infection in vivo and supports the development of ATN-161 as a novel SARS-CoV-2 therapy.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an infectious disease that has spread worldwide. Current treatments are limited in both availability and efficacy, such that improving our understanding of the factors that facilitate infection is urgently needed to more effectively treat infected individuals and to curb the pandemic. We and others have previously demonstrated the significance of interactions between the SARS-CoV-2 spike protein, integrin alpha5beta1 and human ACE2 to facilitate viral entry into host cells in vitro. We previously found that inhibition of integrin alpha5beta1 by the clinically validated small peptide ATN-161 inhibits these spike protein interactions and cell infection in vitro. In continuation with our previous findings, here we have further evaluated the therapeutic potential of ATN-161 on SARS-CoV-2 infection in k18-hACE2 transgenic (SARS-CoV-2 susceptible) mice in vivo. We discovered that treatment with single- or repeated intravenous doses of ATN-161 (1 mg/kg) within 48 hours after intranasal inoculation with SARS-CoV-2 lead to a reduction of lung viral load, viral immunofluorescence and improved lung histology in a majority of mice 72 hours post-infection. Furthermore, ATN-161 reduced SARS-CoV-2-induced increased expression of lung integrin alpha 5 and alpha v (an alpha 5-related integrin that has also been implicated in SARS-CoV-2 interactions) as well as the C-X-C motif chemokine ligand 10 (Cxcl10), further supporting the potential involvement of these integrins, and the anti-inflammatory potential of ATN-161, respectively, in SARS-CoV-2 infection. To the best of our knowledge, this is the first study demonstrating the potential therapeutic efficacy of targeting integrin alpha5beta1 in SARS-CoV-2 infection in vivo and supports the development of ATN-161 as a novel SARS-CoV-2 therapy.

Major depression is a significant medical issue impacting millions of individuals worldwide. Identifying factors contributing to its manifestation has been a subject of intense investigation for decades and several targets have emerged including sex hormones and the immune system. Indeed, an extensive body of literature has demonstrated that sex hormones play a critical role in modulating brain function and impacting mental health, especially among female organisms. Emerging findings also indicate an inflammatory etiology of major depression, revealing new opportunities to supplement, or even supersede, currently available pharmacological interventions in some patient populations. Given the established sex differences in immunity and the profound impact of fluctuations of sex hormone levels on the immune system within the female, interrogating how the endocrine, nervous, and immune systems converge to impact women’s mental health is warranted. Here, we review the impacts of endogenous estrogens as well as exogenously administered estrogen-containing therapies on affect and immunity and discuss these observations in the context of distinct reproductive milestones across the female lifespan. A theoretical framework and important considerations for additional study in regards to mental health and major depression are provided.

Perlecan is a 500 kDa proteoglycan residing in the extracellular matrix of endothelial basement membranes with five distinct protein domains and three heparan sulfate chains. The complex structure of perlecan and the interaction it has with its local environment accounts for its various cellular and tissue-related effects, to include cartilage, bone, neural and cardiac development, angiogenesis, and blood brain barrier stability. As perlecan is a key contributor to extracellular matrix health involved in many tissues and processes throughout the body, dysregulation of perlecan has the potential to contribute to various neurological and musculoskeletal diseases. Here we review key findings associated with perlecan dysregulation in the context of disease. This is a narrative review article examining perlecan’s role in diseases of neural and musucloskeletal pathology and its potential as a therapeutic index. Literature searches were conducted on the PubMed database, and were focused on perlecan’s impact in neurological disease, to include ischemic stroke, Alzheimer’s Disease (AD) and brain arteriovenous malformation (BAVM), as well as musculoskeletal pathology, including Dyssegmental Dysplasia Silverman-Handmaker type (DDSH), Schwartz-Jampel syndrome (SJS), sarcopenia, and osteoarthritis (OA). PRISMA guidelines were utilized in the search and final selection of articles.Increased perlecan levels were associated with sarcopenia, OA, and BAVM, while decreased perlecan was associated with DDSH, and SJS. We also examined the therapeutic potential of perlecan signaling in ischemic stroke, AD, and osteoarthritic animal models. Perlecan experimentally improved outcomes in such models of ischemic stroke and AD, and we found that it may be a promising component of future therapeutics for such pathology. In treating the pathophysiology of sarcopenia, OA, and BAVM, inhibiting the effect of perlecan may be beneficial. As perlecan binds to both α-5 integrin and VEGFR2 receptors, tissue specific inhibitors of these proteins warrant further study. In addition, analysis of experimental data revealed promising insight into the potential uses of perlecan domain V as a broad treatment for ischemic stroke and AD. As these diseases have limited therapeutic options, further study into perlecan or its derivatives and its potential to be used as novel therapeutic for these and other diseases should be seriously considered.