Brain Organoids as a Model to Study Zika Virus and SARS-CoV-2 Infections

In recent years, we are living through different viral pandemics that result in neurological impairments. Given the human-specific nature of brain development, physiology, and pathology, it is imperative to use human models to investigate the neurological impact of viral infections, such as Zika virus and SARS-CoV-2. Brain organoids are powerful in vitro platforms for the analysis of the effects of viral infections on brain development and function, with prospective application to new emerging viral threats. Using brain organoids, it was possible to show that Zika virus infects neural stem cells, disrupting the cell cycle and neurogenesis, leading to microcephaly, a severe reduction of the brain. On the other hand, while it is still under investigation how SARS-CoV-2 might enter and alter the brain, organoid studies are helping to characterize its neurotropism and potential mechanisms of neurovirulence. Here, we describe a method for the infection of human brain organoid cultures with Zika and Sars-CoV-2 viruses that can be used to study neurodevelopmental phenotypes, alteration in neuronal functionality, host-pathogen interactions, as well as for drug testing. Copyright © 2023, Springer Science+Business Media, LLC, part of Springer Nature.

Zika virus ‘harms baby brain collagen development’

Speed read New study helps understand effects of Zika virus on foetal brain development Vaccine progress continues, despite COVID-19 challenge But Aedes aegypti is adapting to new environments Zika virus can hamper vital collagen development in the brains of babies whose mothers were infected with the disease while pregnant, new research reveals, as the search for a vaccine continues. The research shows that a vaccine that aims to neutralise mature Zika virus particles could be effective, says co-author Ted Pierson, chief of the Laboratory of Viral Diseases at the National Institute of Allergy and Infectious Diseases in the United States. The mosquito is moving faster than epidemiologists expected and there are smaller outbreaks occurring in southern parts of Brazil. “Since Zika is not an endemic disease in these regions, the population has no natural defences against it,” Spilki warns.

Zika a Vector Borne Disease Detected in Newer States of India Amidst the COVID-19 Pandemic.

Background: During the second wave of the COVID-19 pandemic, outbreaks of Zika were reported from Kerala, Uttar Pradesh, and Maharashtra, India in 2021. The Dengue and Chikungunya negative samples were retrospectively screened to determine the presence of the Zika virus from different geographical regions of India. Methods: During May to October 2021, the clinical samples of 1475 patients, across 13 states and a union territory of India were screened and re-tested for Dengue, Chikungunya and Zika by CDC Trioplex Real time RT-PCR. The Zika rRTPCR positive samples were further screened with anti-Zika IgM and Plaque Reduction Neutralization Test. Next generation sequencing was used for further molecular characterization. Results: The positivity was observed for Zika (67), Dengue (121), and Chikungunya (10) amongst screened cases. The co-infections of Dengue/Chikungunya, Dengue/Zika, and Dengue/Chikungunya/Zika were also observed. All Zika cases were symptomatic with fever (84%) and rash (78%) as major presenting symptoms. Of them, four patients had respiratory distress, one presented with seizures, and one with suspected microcephaly at birth. The Asian Lineage of Zika and all four serotypes of Dengue were found in circulation. Conclusion: Our study indicates the spread of the Zika virus to several states of India and an urgent need to strengthen its surveillance.

Clinicohaematological Patterns of Anemia and Correlation with Clinical Conditions in Children Aged 5 to 12 Years in Tertiary Care Centre

Objective: To classify the haematological pattern, severity of anemia in children 5-12 years age admitted and to find its correlation with the clinical conditions. Methods Crossectional study of 160 patients in two years was done. Patients satisfying the inclusion criteria were selected for study. Relevant clinical data were recorded in a structured proforma including detailed history was recorded with particular symptoms suggestive of anemia such as weakness and easily fatigability, breathlessness on exertion and pica. A thorough clinical examination of every child was done followed by routine investigations for anemia Results Patients between 7-8 year were found to be the most affected. Anemia was found to be more common in female children as compared to male children (F:M=1.13). Anemia is more common in undernourished child. Most common presenting symptoms were gastrointestinal including vomiting, diarrhea and pain abdomen. Most common sign was Pallor followed by other common signs included signs of dehydration associated with diarrhea, hepatosplenomegaly. microcytic hypochromic anemia was the most common morphological type of anemia and macrocytic anemia was the least common.Thalassemia cases were most common among hemolytic anemias. Iron Deficiency Anemia (Nutritional Anemia) was the most common etiology of anemia. Conclusion Dietary deficits affect children aged 5 to 12, creating financial, emotional, and psychological burden for patients and their families, as well as depleting critical national resources. As a result, screening for these illnesses, as well as early detection of anemia and related problems, is essential.

Congenital Zika Syndrome: Genetic Avenues for Diagnosis and Therapy, Possible Management and Long-Term Outcomes.

Zika virus (ZIKV) was discovered in Uganda in 1947 and was originally isolated only in Africa and Asia. After a spike of microcephaly cases in Brazil, research has closely focused on different aspects of congenital ZIKV infection. In this review, we evaluated many aspects of the disease in order to build its natural history, with a focus on the long-term clinical and neuro-radiological outcomes in children. The authors have conducted a wide-ranging search spanning the 2012-2021 period from databases PubMed, PubMed Central, Web of Science, Medline, Scopus. Different sections reflect different points of congenital ZIKV infection syndrome: pathogenesis, prenatal diagnosis, clinical signs, neuroimaging and long-term developmental outcomes. It emerged that pathogenesis has not been fully clarified and that the clinical signs are not only limited to microcephaly. Given the current absence of treatments, we proposed schemes to optimize diagnostic protocols in endemic countries. It is essential to know the key aspects of this disease to guarantee early diagnosis, even in less severe cases, and an adequate management of the main chronic problems. Considering the relatively recent discovery of this congenital infectious syndrome, further studies and updated long-term follow-up are needed to further improve management strategies for this disease.

Functional Genomics of PRUNE1 in Neurodevelopmental Disorders (NDDs) Tied to Medulloblastoma (MB) and Other Tumors.

We analyze the fundamental functions of Prune_1 in brain pathophysiology. We discuss the importance and maintenance of the function of Prune_1 and how its perturbation influences both brain pathological conditions, neurodevelopmental disorder with microcephaly, hypotonia, and variable brain anomalies (NMIHBA; OMIM: 617481), and tumorigenesis of medulloblastoma (MB) with functional correlations to other tumors. A therapeutic view underlying recent discoveries identified small molecules and cell penetrating peptides to impair the interaction of Prune_1 with protein partners (e.g., Nm23-H1), thus further impairing intracellular and extracellular signaling (i.e., canonical Wnt and TGF-ß pathways). Identifying the mechanism of action of Prune_1 as responsible for neurodevelopmental disorders (NDDs), we have recognized other genes which are found overexpressed in brain tumors (e.g., MB) with functional implications in neurodevelopmental processes, as mainly linked to changes in mitotic cell cycle processes. Thus, with Prune_1 being a significant target in NDDs, we discuss how its network of action can be dysregulated during brain development, thus generating cancer and metastatic dissemination.

The Neurobiology of Modern Viral Scourges: ZIKV and COVID-19.

The interactions of viruses with the nervous system were thought to be well understood until the recent outbreaks of Zika and SARS-CoV-2. In this review, we consider these emerging pathogens, the range and mechanisms of the neurological disease in humans, and how the biomedical research enterprise has pivoted to answer questions about viral pathogenesis, immune response, and the special vulnerability of the nervous system. ZIKV stands out as the only new virus in a generation, associating with congenital brain defects, neurological manifestations of microcephaly in newborns, and radiculopathy in adults. COVID-19, the disease caused by SARS-CoV-2, has swept the planet in an unprecedented manner and is feared worldwide for its effect on the respiratory system, but recent evidence points to important neurological sequelae. These can include anosmia, vasculopathy, paresthesias, and stroke. Evidence of ZIKV and SARS-CoV-2 genetic material from neural tissue, and evidence of infection of neural cells, raises questions about how these emerging viruses produce disease, and where new therapies might emerge.

The Zika virus: Lurking behind the COVID-19 pandemic?

WHAT IS KNOWN AND OBJECTIVE: The sudden and extensive outbreak of coronavirus (SARS-CoV-2) has overshadowed another developing viral threat: the Zika flavivirus. Of particular concern is that pregnant women can pass Zika virus to the foetus, and there is a strong implication of an association between Zika virus infection and foetal microcephaly. Currently, there is no vaccine, and there is no cure. METHODS: Published literature and Internet sources were searched for information related to Zika virus, its transmission, its clinical presentation and sequalae, prevention and implications (practice and regulatory) for healthcare providers. The identified English sources were reviewed, assessed and synthesized. Emphasis was placed on providing an overview of the problem, and identification of unmet needs and future directions. RESULTS AND DISCUSSION: Zika virus poses a major challenge for healthcare providers, particularly in areas unaccustomed to it, since it is transmitted to humans by the vector Aedes aegypti mosquito. The outbreak impacts every healthcare provider, because every provider is required to report cases of Zika infection to their state or local health agencies--whether the infection is confirmed or merely suspected. Since the virus has become a worldwide crisis, healthcare providers will need to work across national boundaries and medical disciplines in order to educate patients about Zika symptoms and the mosquito vector. Until further information is known, infected patients (male and female) are being advised to avoid conceiving a child. WHAT IS NEW AND CONCLUSION: Until a vaccine is developed or effective treatment for Zika virus is discovered, healthcare providers must be AVP (aware, vigilant and proactive) in order to lessen the spread and impact of the implicated devastating birth defects (microcephaly) and other neurological disorders (eg Guillain-Barré Syndrome) of this infection. Unfortunately, many knowledge gaps exist. There is an urgent need for a reliable, inexpensive diagnostic test, an effective treatment and an approved and readily available vaccine.