Biology subjects

Smeenk, H.

Publications and source records attributed to Smeenk, H..

4 recordsLinked to original sources

bioRxiv2025

Influenza A Virus Infection Impairs Neuronal Activity in Human iPSC-Derived NGN2 Neural Co-Cultures

Influenza A virus (IAV) infection is associated with a wide variety of neurological complications, of which mild complications like impaired cognitive functioning are most prominent. Even though several studies have shown that many influenza viruses can enter the CNS, the neuropathogenesis of seasonal (H3N2 and H1N1) and pandemic (pH1N1 2009) IAV infections is poorly understood. Therefore, we aimed to investigate the cellular tropism, replication efficiency and associated functional consequences using a human stem cell-derived neural co-culture model of neurons and astrocytes. All viruses were able to infect neurons in the co-culture model, although this infection did not result in efficient replication and release of progeny virus. In addition, infection did not result in visible cell death or apoptosis. However, functional analyses revealed that IAV inoculation resulted in a reduction of spontaneous neural activity and a partial reduction of neural excitability. This study shows that seasonal and pandemic IAVs can disrupt neural homeostasis, without efficient virus replication or the induction of cell death. However, these functional changes in neural activity can contribute to cognitive problems during IAV infections in the acute and potentially post-acute phase of the infection.

microbiology↗

bioRxiv2024

Neuronal autophagosomes are transported to astrocytes for degradation

Autophagy is a vital catabolic process responsible for the degradation of cytosolic components, playing a key role in cellular homeostasis and survival. At synapses, autophagy is crucial for regulating neuronal activity and utilizes a specialized machinery. While considerable progress has been made in understanding the initiation of autophagy and autophagosome formation, the mechanisms governing the clearance of autophagosomes from synaptic sites remain poorly understood. Here, we identify a novel pathway in which astrocytes actively participate in the clearance of pre-synaptic autophagosomes. Using neurons derived from human induced pluripotent stem cell (hiPSC) lines expressing fluorescent autophagy markers and chimeric mouse models, we demonstrate that neuronal autophagosomal vesicles are physically transferred to astrocytes, a process that is enhanced when synaptic activity is suppressed. Autophagosome transfer does not require direct physical cellular contact, but it does require Dynamin and cholesterol-dependent endocytosis for the internalized neuronal autophagosomes to ultimately fuse with astrocytic lysosomes. Our findings reveal a previously unrecognized mechanism of neuronal autophagosome clearance that does not require slow axonal retrograde transport but their transfer to nearby astrocytes.

neuroscience↗

bioRxiv2024

Human adherent cortical organoids in a multiwell format

In the growing diversity of human iPSC-derived models of brain development, we present here a novel method that exhibits 3D cortical layer formation in a highly reproducible topography of minimal dimensions. The resulting adherent cortical organoids develop by self-organization after seeding frontal cortex patterned iPSC-derived neural progenitor cells in 384-well plates during eight weeks of differentiation. The organoids have stereotypical dimensions of 3 x 3 x 0.2 mm, contain multiple subtypes of neurons, astrocytes and oligodendrocyte lineage cells, and are amenable to extended culture for at least 10 months. Longitudinal imaging revealed morphologically mature dendritic spines, axonal myelination, and robust neuronal activity. Moreover, adherent cortical organoids compare favorably to existing free-floating brain organoid models on the basis of robust reproducibility in obtaining topographically-standardized radial cortical structures and circumventing internal necrosis. Adherent human cortical organoids hold considerable potential for high-throughput drug discovery applications, neurotoxicological screening, and mechanistic pathophysiological studies of brain disorders.

neuroscience↗

bioRxiv2023

Dissecting the neurotropism and neurovirulence of MPXV using human stem cell-based models

Mpox is a zoonotic illness of international concern that can lead to severe disease including neurological sequelae. However, the neurotropism of monkeypox virus (MPXV) and the mechanisms regulating cell-intrinsic antiviral immunity within the central nervous system (CNS) remain poorly understood. Here, we investigated the neurotropism of MPXV using astrocytes, cortical neurons, and microglia derived from human pluripotent stem cells (hPSCs) and ex vivo human brain tissue to demonstrate that MPXV infects and replicates more efficiently in astrocytes and microglia compared to cortical neurons. Upon MPXV exposure, glial cells, in contrast to cortical neurons, inhibit type I IFN antiviral programs potentially conferring differential susceptibility to MPXV. Furthermore, we demonstrate that treatment using either IFN-beta or tecovirimat inhibits MPXV infection. Together, our results suggest that MPXV has a broad tropism within the CNS and that differential type I IFN signaling underpins cell type-specific susceptibility to MPXV infection.

microbiology↗