Copper regulation disturbance linked to oxidative stress and cell death during Zika virus infection in human astrocytes.

The Zika virus (ZIKV) caused neurological abnormalities in more than 3500 Brazilian newborns between 2015 and 2020. Data have pointed to oxidative stress in astrocytes as well as to dysregulations in neural cell proliferation and cell cycle as important events accounting for the cell death and neurological complications observed in Congenital Zika Syndrome. Copper imbalance has been shown to induce similar alterations in other pathologies, and disturbances in copper homeostasis have already been described in viral infections. Here, we investigated copper homeostasis imbalance as a factor that could contribute to the cytotoxic effects of ZIKV infection in astrocytes. Human induced pluripotent stem cell-derived astrocytes were infected with ZIKV; changes in the gene expression of copper homeostasis proteins were analyzed. The effect of the administration of CuCl2 or a copper chelator on oxidative stress, cell viability and percentage of infection were also studied. ZIKV infection leads to a downregulation of one of the transporters mediating copper release, ATP7B protein. We also observed the activation of mechanisms that counteract high copper levels, including the synthesis of copper chaperones and the reduction of the copper importer protein CTR1. Finally, we show that chelator-mediated copper sequestration in ZIKV-infected astrocytes reduces the levels of reactive oxygen species and improves cell viability, but does not change the overall percentage of infected cells. In summary, our results show that copper homeostasis imbalance plays a role in the pathology of ZIKV in astrocytes, indicating that it may also be a factor accounting for the developmental abnormalities in the central nervous system following viral infection. Evaluating micronutrient levels and the use of copper chelators in pregnant women susceptible to ZIKV infection may be promising strategies to manage novel cases of congenital ZIKV syndrome.

Oligomeric α-Synuclein induces skin degeneration in reconstructed human epidermis.

Aged and photoaged skin exhibit fine wrinkles that are signs of epidermal inflammation and degeneration. It has been shown that healthy elderly skin expresses amyloidogenic proteins, including α-Synuclein, which are known to oligomerize and trigger inflammation and neurodegeneration. However, little is known about their putative role in skin physiology and sensitivity. To unravel this possible role, we investigated the impact of oligomeric α-Synuclein (Oα-Syn) in 2D and 3D keratinocyte human models. Exogenous Oα-Syn caused degeneration of reconstructed human epidermis (RHE) by diminishing proliferation and thickness of the stratum basale. Oα-Syn also increased NF-kB nuclear translocation in keratinocytes and triggered inflammation in the RHE, by increasing expression of interleukin-1ß and tumor necrosis factor-alpha, and the release of tumor necrosis factor-alpha in a time-dependent manner. Dexamethasone and an IL-1ß inhibitor partially diminished RHE degeneration caused by Oα-Syn. These findings suggest that Oα-Syn induces epidermal inflammation and decreases keratinocyte proliferation, and therefore might contribute to epidermal degeneration observed in human skin aging.

SARS-CoV-2 infection of the central nervous system in a 14-month-old child: A case report of a complete autopsy.

BACKGROUND: Neurological and other systemic complications occur in adults with severe COVID-19. Here we describe SARS-CoV-2 infection complicated by neuroinvasion in the post-mortem tissues of a child. METHODS: We performed a complete autopsy of a 14-month-old child who died of COVID-19 pneumonitis. Histological sections of multiple organs were stained with haematoxylin and eosin. Luxol fast blue staining for myelin and immunohistochemistry were performed in selected areas of the brain. The presence of SARS-CoV-2 was investigated by immunostaining with anti-spike protein antibody and by RT-qPCR. FINDINGS: Lesions included microthrombosis, pulmonary congestion, interstitial oedema, lymphocytic infiltrates, bronchiolar injury, collapsed alveolar spaces, cortical atrophy, and severe neuronal loss. SARS-CoV-2 staining was observed along the apical region of the choroid plexus (ChP) epithelium and in ependymal cells of the lateral ventricle, but was restricted to ChP capillaries and vessels in some regions. SARS-CoV-2 infection of brain tissue was confirmed by RT-qPCR in fragments of the ChP, lateral ventricle, and cortex. INTERPRETATION: Our results show multisystemic histopathological alterations caused by SARS-CoV-2 infection and contribute to knowledge regarding the course of fatal COVID-19 in children. Furthermore, our findings of ChP infection and viral neurotropism suggest that SARS-CoV-2 may invade the central nervous system by blood-cerebrospinal fluid barrier disruption. FUNDING: Carlos Chagas Filho Foundation for Supporting Research in the State of Rio de Janeiro (FAPERJ); the National Council for Scientific and Technological Development (CNPq) and Coordination for the Improvement of Higher Education Personnel (CAPES), in addition to intramural grants from D'Or Institute for Research and Education. EDITOR'S NOTE: This translation in Portuguese was submitted by the authors and we reproduce it as supplied. It has not been peer reviewed. Our editorial processes have only been applied to the original abstract in English, which should serve as reference for this manuscript. RESUMO: Complicações sistêmicas e neurológicas foram descritas em adultos com COVID-19 grave. Neste trabalho, descrevemos a infecção por SARS-CoV-2, incluindo sua neuroinvasão, nos tecidos post-mortem de uma criança. MÉTODOS: Realizamos a autópsia completa de uma criança de 14 meses que morreu de pneumonite por COVID-19. Cortes histológicos de múltiplos órgãos foram corados com Hematoxilina e Eosina. A coloração de Luxol Fast Blue para mielina e imuno-histoquímica foram realizadas em áreas selecionadas do cérebro. A presença de SARS-CoV-2 foi investigada por imunomarcação com anticorpo anti-proteína spike e por RT-qPCR. ACHADOS: As lesões incluíram microtrombose, congestão pulmonar, edema intersticial, infiltrados linfocíticos, lesão bronquiolar, colapso dos espaços alveolares, atrofia cortical e perda neuronal grave. A presença de SARS-CoV-2 foi observada ao longo da região apical do epitélio do plexo coróide (PC) e nas células ependimárias do ventrículo lateral, mas ficou restrita aos capilares e vasos do PC em outras regiões. A infecção do tecido cerebral por SARS-CoV-2 foi confirmada por RT-qPCR em fragmentos do PC, ventrículo lateral e cortex cerebral. INTERPRETAÇÃO: Nossos resultados mostram alterações histopatológicas multissistêmicas causadas pela infecção por SARS-CoV-2 e contribuem para ampliar o conhecimento sobre a evolução da COVID-19 fatal em crianças. Além disso, nossos achados sobre a infecção no PC e neurotropismo viral sugerem que o SARS-CoV-2 pode invadir o sistema nervoso central pela ruptura da barreira sangue-líquido cefalorraquidiano. FINANCIAMENTO: Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPQ) e Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), além de financiamento intramural do Instituto D'Or de Pesquisa e Educação.

Non-permissive SARS-CoV-2 infection in human neurospheres.

Coronavirus disease 2019 (COVID-19) was initially described as a viral infection of the respiratory tract. It is now known, however, that several other organs are affected, including the brain. Neurological manifestations such as stroke, encephalitis, and psychiatric conditions have been reported in COVID-19 patients, but the neurotropic potential of the virus is still debated. Herein, we sought to investigate SARS-CoV-2 infection in human neural cells. We demonstrated that SARS-CoV-2 infection of neural tissue is non-permissive, however, it can elicit inflammatory response and cell damage. These findings add to the hypothesis that most of the neural damage caused by SARS-CoV-2 infection is due to a systemic inflammation leading to indirect harmful effects on the central nervous system despite the absence of local viral replication.

Non-permissive SARS-CoV-2 infection in human neurospheres.

Coronavirus disease 2019 (COVID-19) was initially described as a viral infection of the respiratory tract. It is now known, however, that several other organs are affected, including the brain. Neurological manifestations such as stroke, encephalitis, and psychiatric conditions have been reported in COVID-19 patients, but the neurotropic potential of the virus is still debated. Herein, we sought to investigate SARS-CoV-2 infection in human neural cells. We demonstrated that SARS-CoV-2 infection of neural tissue is non-permissive, however, it can elicit inflammatory response and cell damage. These findings add to the hypothesis that most of the neural damage caused by SARS-CoV-2 infection is due to a systemic inflammation leading to indirect harmful effects on the central nervous system despite the absence of local viral replication.

The cyanobacterial saxitoxin exacerbates neural cell death and brain malformations induced by Zika virus.

The northeast (NE) region of Brazil commonly goes through drought periods, which favor cyanobacterial blooms, capable of producing neurotoxins with implications for human and animal health. The most severe dry spell in the history of Brazil occurred between 2012 and 2016. Coincidently, the highest incidence of microcephaly associated with the Zika virus (ZIKV) outbreak took place in the NE region of Brazil during the same years. In this work, we tested the hypothesis that saxitoxin (STX), a neurotoxin produced in South America by the freshwater cyanobacteria Raphidiopsis raciborskii, could have contributed to the most severe Congenital Zika Syndrome (CZS) profile described worldwide. Quality surveillance showed higher cyanobacteria amounts and STX occurrence in human drinking water supplies of NE compared to other regions of Brazil. Experimentally, we described that STX doubled the quantity of ZIKV-induced neural cell death in progenitor areas of human brain organoids, while the chronic ingestion of water contaminated with STX before and during gestation caused brain abnormalities in offspring of ZIKV-infected immunocompetent C57BL/6J mice. Our data indicate that saxitoxin-producing cyanobacteria is overspread in water reservoirs of the NE and might have acted as a co-insult to ZIKV infection in Brazil. These results raise a public health concern regarding the consequences of arbovirus outbreaks happening in areas with droughts and/or frequent freshwater cyanobacterial blooms.

Isolation of human nasoseptal chondrogenic cells: a promise for cartilage engineering.

In cartilaginous tissues, perichondrium cambium layer may be the source of new cartilage. Human nasal septal perichondrium is considered to be a homogeneous structure in which some authors do not recognize the perichondrium internal zone or the cambium layer as a layer distinct from adjacent cartilage surface. In the present study, we isolated a chondrogenic cell population from human nasal septal cartilage surface zone. Nasoseptal chondrogenic cells were positive for surface markers described for mesenchymal stem cells, with exception of CD146, a perivascular cell marker, which is consistent with their avascular niche in cartilage. Although only Sox-9 was constitutively expressed, they also revealed osteogenic and chondrogenic, but not adipogenic, potentials in vitro, suggesting a more restricted lineage potential compared to mesenchymal stem cells. Interestingly, even in absence of chondrogenic growth factors in the pellet culture system, nasoseptal chondrogenic cells had a capacity to synthesize sulfated glycosaminoglycans, large amounts of collagen type II and to a lesser extent collagen type I. The spontaneous chondrogenic potential of this population of cells indicates that they may be a possible source for cartilage tissue engineering. Besides, the pellet culture system using nasoseptal chondrogenic cells may also be a model for studies of chondrogenesis.