Biology subjects

Chuong, C.

Publications and source records attributed to Chuong, C..

5 recordsLinked to original sources

bioRxiv2026

Bioelectric state transitions enable de novo feather bud formation in developing skin

Tissue patterning is integral to development and regeneration, yet the factors that initiate morphogenetic patterning remain to be explored. Here, using embryonic chicken skin as a model, we show that perturbation of calcium signaling induces de novo feather bud formation in regions that normally do not form feather buds. This is achieved through coordinated changes in calcium dynamics, endogenous bioelectric currents, transcriptional regulation of calcium and potassium channel genes, and morphogen signaling. Different combinations of channel perturbations altered the number, distribution, size, and shape of induced feather buds. Live calcium imaging and extracellular electrophysiological recordings revealed homeostatic regulation, in which initially depressed calcium activity is followed by elevated calcium activity. Inward bioelectric currents emerge as de novo feather buds appear. Potassium channel blockade suppressed calcium dynamics, abolished endogenous currents, and inhibited new bud formation. Canonical feather morphogenesis pathways including Shh and {beta}-catenin are induced in these new buds. Our findings support a model in which developmental bioelectricity contributes to regulating the threshold of feather bud formation. These results identify developmental bioelectricity as an unrecognized regulatory layer of tissue patterning that warrants further study. Bullet points- Calcium signaling perturbation induces de novo feather bud formation in apteric skin - Ion channel perturbations regulate the formation, distribution and shape of new buds across a continuum, depending on channel type(s) and perturbation strength. - Elevated calcium activity and inward bioelectric currents accompany feather bud induction - Developmental bioelectricity represents an unrecognized regulatory layer for morphogenesis

Developmental Biology↗

bioRxiv2022

The E2 glycoprotein holds key residues for Mayaro virus adaptation to the urban Aedes aegypti mosquito

Adaptation to mosquito vectors suited for transmission in urban settings is a major driver in the emergence of arboviruses. To better anticipate future emergence events, it is crucial to assess their potential to adapt to new vector hosts. In this work, we used two different experimental evolution approaches to study the adaptation process of an emerging alphavirus, Mayaro virus (MAYV), to Aedes aegypti, an urban mosquito vector of many arboviruses. We identified E2-T179N as a key mutation increasing MAYV replication in insect cells and enhancing transmission by live Aedes aegypti. In contrast, this mutation decreased viral replication and binding in human fibroblasts, a primary cellular target of MAYV in humans. We also showed that MAYV E2-T179N was attenuated in vivo in a mouse model. We then used structural and experimental analyses to show that MAYV E2-T179N bound less efficiently to human cells, though the decrease in replication or binding was not mediated through interaction with one of the host receptors, Mxra8. When this mutation was introduced in the closely related chikungunya virus, which has caused major outbreaks globally in the past two decades, we observed increased replication in both human and insect cells, suggesting E2 position 179 is an important determinant of alphavirus host-adaptation, although in a virus-specific manner. Collectively, these results indicate that adaptation at the T179 residue in MAYV E2 may result in increased vector competence - but coming at the cost of optimal replication in humans - and may represent a first step towards a future emergence event. Author SummaryMosquito-borne viruses must replicate in both mosquito and vertebrate hosts to be maintained in nature successfully. When viruses that are typically transmitted by forest dwelling mosquitoes enter urban environments due to deforestation or travel, they must adapt to urban mosquito vectors to transmit effectively. For mosquito-borne viruses, the need to also replicate in a vertebrate host like humans constrains this adaptation process. Towards understanding how the emerging alphavirus, Mayaro virus, might adapt to transmission by the urban mosquito vector, Aedes aegypti, we used natural evolution approaches to identify several viral mutations that impacted replication in both mosquito and vertebrate hosts. We show that a single mutation in the receptor binding protein increased transmission by Aedes aegypti but simultaneously reduced replication and disease in a mouse model, suggesting that this mutation alone is unlikely to be maintained in a natural transmission cycle between mosquitoes and humans. Understanding the adaptive potential of emerging viruses is critical to preventing future pandemics.

microbiology↗

bioRxiv2021

Adenovirus transduction to express human ACE2 causes obesity-specific morbidity in mice, impeding studies on the effect of host nutritional status on SARS-CoV-2 pathogenesis.

The COVID-19 pandemic has paralyzed the global economy and resulted in millions of deaths globally. People with co-morbidities like obesity, diabetes and hypertension are at an increased risk for severe COVID-19 illness. This is of overwhelming concern because 42% of Americans are obese, 30% are pre-diabetic and 9.4% have clinical diabetes. Here, we investigated the effect of obesity on disease severity following SARS-CoV-2 infection using a well-established mouse model of diet-induced obesity. Diet-induced obese and lean control C57BL/6N mice, transduced for ACE2 expression using replication-defective adenovirus, were infected with SARS-CoV-2, and monitored for lung pathology, viral titers, and cytokine expression. No significant differences in tissue pathology, viral replication or cytokine expression were observed between lean and obese groups. Notably, significant weight loss was observed in obese mice treated with the adenovirus vector, independent of SARS-CoV-2 infection, suggesting an obesity-dependent morbidity induced by the vector. These data indicate that the adenovirus-transduced mouse model of SARS-CoV-2 infection is inadequate for performing nutrition studies, and caution should be used when interpreting resulting data.

pathology↗

bioRxiv2020

Development and characterization of infectious clones of two strains of Usutu virus

Usutu virus (USUV; genus Flavivirus; family Flaviviridae) is a mosquito-borne, positive-sense RNA virus that is currently causing significant die-offs in numerous bird species throughout Europe and has caused infections in humans. Currently, there are no molecular clones for USUV, hence, hindering studies on the pathogenesis and transmission of USUV. In this report, we demonstrate the development and characterization of infectious clones for two modern strains of USUV isolated from Europe and Africa. We show that the infectious clone-derived viruses replicated similarly to the parental strains in both mammalian and insect cells. Additionally, we observed similar levels of replication and pathogenesis in two mouse models. This reverse genetics system will aid the scientific community in studying and developing USUV infection, transmission, diagnostics, and vaccines.

molecular biology↗

bioRxiv2020

Rolling Circle Amplification is a high fidelity and efficient alternative to plasmid preparation for the rescue of infectious clones.

Alphaviruses (genus Alphavirus; family Togaviridae) are a medically relevant family of viruses that include chikungunya virus, Eastern equine encephalitis virus, and the emerging Mayaro virus. Infectious cDNA clones of these viruses are necessary molecular tools to understand viral biology and to create effective vaccines. The traditional approach to rescuing virus from an infectious cDNA clone requires propagating large amounts of plasmids in bacteria, which can result in unwanted mutations in the viral genome due to bacterial toxicity or recombination and requires specialized equipment and knowledge to propagate the bacteria. Here, we present an alternative to the bacterial-based plasmid platform that uses rolling circle amplification (RCA), an in vitro technology that amplifies plasmid DNA using only basic equipment. We demonstrate that the use of RCA to amplify plasmid DNA is comparable to the use of a midiprepped plasmid in terms of viral yield, albeit with a slight delay in virus recovery kinetics. RCA, however, has lower cost and time requirements and amplifies DNA with high fidelity and with no chance of unwanted mutations due to toxicity. We show that sequential RCA reactions do not introduce mutations into the viral genome and, thus, can replace the need for glycerol stocks or bacteria entirely. These results indicate that RCA is a viable alternative to traditional plasmid-based approaches to viral rescue. ImportanceThe development of infectious cDNA clones is critical to studying viral pathogenesis and for developing vaccines. The current method for propagating clones in bacteria is limited by the toxicity of the viral genome within the bacterial host, resulting in deleterious mutations in the viral genome, which can only be detected through whole-genome sequencing. These mutations can attenuate the virus, leading to lost time and resources and potentially confounding results. We have developed an alternative method of preparing large quantities of DNA that can be directly transfected to recover infectious virus without the need for bacteria by amplifying the infectious cDNA clone plasmid using rolling circle amplification (RCA). Our results indicate that viral rescue from an RCA product produces a viral yield equal to bacterial-derived plasmid DNA, albeit with a slight delay in replication kinetics. The RCA platform, however, is significantly more cost and time-efficient compared to traditional approaches. When the simplicity and costs of RCA are combined, we propose that a shift to an RCA platform will benefit the field of molecular virology and could have significant advantages for recombinant vaccine production.

molecular biology↗