bioRxiv Science⌕ Search

Biology subjects

Tai, W.

Publications and source records attributed to Tai, W..

7 recordsLinked to original sources

in vivo Reprogramming of NG2 Glia Improves Bladder Function After Spinal Cord Injury

Neurogenic bladder is a debilitating consequence of spinal cord injury (SCI), with few treatment options that restore voluntary voiding. Here, we show that SOX2-mediated in vivo reprogramming of NG2 glia improves bladder function in a clinically relevant mouse model of contusive SCI. NG2 glia reprogramming induces adult neurogenesis, reduces glial scarring, and significantly improves urinary performance, as measured by voiding assays and conscious cystometry. Functional recovery correlates positively with neurogenesis and negatively with glial scarring. These findings demonstrate that SOX2-mediated glial reprogramming promotes autonomic repair and offers a regenerative strategy for neurogenic bladder after SCI.

neuroscience↗

An Efficient and Safe Trans-complementation System of Mpox Virus Reproduces Authentic Viral Architecture and Infection

Since the Mpox virus (MPXV) outbreak in 2022, there have been 97,745 cases and 203 fatalities. This outbreak features increased transmission efficiency and a higher infection rate in the MSM population, with the underlying causes remaining unknown. The requirement of BSL-3 laboratories poses a barrier to MPXV research and antiviral development. Here, we report an efficient and safe trans-complementary system that produces a single-round infectious MPXV, preserving the viruss authentic architecture and enabling it to complete its life cycle in complementing cells. This deficient MPXV genome, lacking two essential genes crucial for late gene transcription and viral assembly, is restricted to a single-round infection in non-complementing cell lines. Notably, SCID mice inoculated with this deficient MPXV exhibited no detectable disease or viral load. This deficient MPXV platform has demonstrated its capacity to study innate immunity and cell death during infection in complementing cells. It can also be used for antibody neutralization assays and anti-MPXV drug evaluation. This trans-complementation platform, safe for use in low-biosafety laboratories, offers a valuable resource for MPXV research and countermeasure development.

microbiology↗

NG2 Glia Reprogramming Induces Robust Axonal Regeneration After Spinal Cord Injury

Spinal cord injury (SCI) often leads to neuronal loss, axonal degeneration and behavioral dysfunction. We recently show that in vivo reprogramming of NG2 glia produces new neurons, reduces glial scaring, and ultimately leads to improved function after SCI. By examining endogenous neurons, we here unexpectedly uncover that NG2 glia reprogramming also induces robust axonal regeneration of the corticospinal tract and serotonergic neurons. Such reprogramming-induced axonal regeneration may contribute to the reconstruction of neural networks essential for behavioral recovery.

neuroscience↗

Chemical screens in aging-relevant human motor neurons identify MAP4Ks as therapeutic targets for amyotrophic lateral sclerosis

Effective therapeutics is much needed for amyotrophic lateral sclerosis (ALS), an adult-onset neurodegenerative disease mainly affecting motor neurons. By screening chemical compounds in human patient-derived and aging-relevant motor neurons, we identify a neuroprotective compound and show that MAP4Ks may serve as therapeutic targets for treating ALS. The lead compound broadly improves survival and function of motor neurons directly converted from human ALS patients. Mechanistically, it works as an inhibitor of MAP4Ks, regulates the MAP4Ks-HDAC6-TUBA4A-RANGAP1 pathway, and normalizes subcellular distribution of RANGAP1 and TDP-43. Finally, in an ALS mouse model we show that inhibiting MAP4Ks preserves motor neurons and significantly extends animal lifespan.

neuroscience↗

Development of a ferritin-based nanoparticle vaccine against the SARS-CoV-2 Omicron variant

A new SARS-CoV-2 variant named Omicron (B.1.1.529) discovered initially in South Africa has recently been proposed as a variant of concern (VOC) by the World Health Organization, because of its high transmissibility and resistance to current vaccines and therapeutic antibodies. Therefore, rapid development of vaccines against prevalent variants including Omicron is urgently needed for COVID-19 prevention. Here, we designed a self-assembling ferritin-based nanoparticle (FNP) vaccine against the SARS-CoV-2 Omicron variant. The purified Fc-RBDOmicron automatically formed a dimer depending on the nature of the Fc tag, thus assembling onto the nanoparticles by the Fc-protein A tag interaction (FNP-Fc-RBDOmicron). The results of hACE2-transgenic mice immunization showed that SARS-CoV-2 Omicron RBD-specific IgG titer induced by FNP-Fc-RBDOmicron was much higher than that by Fc-RBDOmicron. Consistently, the sera showed a higher neutralizing activity against SARS-CoV-2 Omicron BA.1 and BA.2 in the FNP-Fc-RBDOmicron immunized mice, indicating that immunization of a self-assembling ferritin-based nanoparticle vaccine offers a robust humoral immune response against Omicron variants. This study offers a great potential for the quick response of the emerging SARS-CoV-2 variants and affords versatility to develop universal vaccines against other emerging and reemerging coronaviruses in the future.

microbiology↗

The Development of a Novel Nanobody Therapeutic for SARS-CoV-2

Combating the COVID-19 pandemic requires potent and low-cost therapeutics. We identified a novel series of single-domain antibodies (i.e., nanobody), Nanosota-1, from a camelid nanobody phage display library. Structural data showed that Nanosota-1 bound to the oft-hidden receptor-binding domain (RBD) of SARS-CoV-2 spike protein, blocking out viral receptor ACE2. The lead drug possessing an Fc tag (Nanosota-1C-Fc) bound to SARS-CoV-2 RBD with a Kd of 15.7picomolar ([~]3000 times more tightly than ACE2 did) and inhibited SARS-CoV-2 infection with an ND50 of 0.16microgram/milliliter ([~]6000 times more potently than ACE2 did). Administered at a single dose, Nanosota-1C-Fc demonstrated preventive and therapeutic efficacy in hamsters subjected to SARS-CoV-2 infection. Unlike conventional antibody drugs, Nanosota-1C-Fc was produced at high yields in bacteria and had exceptional thermostability. Pharmacokinetic analysis of Nanosota-1C-Fc documented a greater than 10-day in vivo half-life efficacy and high tissue bioavailability. Nanosota-1C-Fc is a potentially effective and realistic solution to the COVID-19 pandemic. Impact statementPotent and low-cost Nanosota-1 drugs block SARS-CoV-2 infections both in vitro and in vivo and act both preventively and therapeutically.

microbiology↗

Biomechanical Characterization of SARS-CoV-2 Spike RBD and Human ACE2 Protein-Protein Interaction

The current COVID-19 pandemic has led to a devastating impact across the world. SARS-CoV-2 (the virus causing COVID-19) is known to use receptor-binding domain (RBD) at viral surface spike (S) protein to interact with the angiotensin-converting enzyme 2 (ACE2) receptor expressed on many human cell types. The RBD-ACE2 interaction is a crucial step to mediate the host cell entry of SARS-CoV-2. Recent studies indicate that the ACE2 interaction with the SARS-CoV-2 S protein has higher affinity than its binding with the structurally identical S protein of SARS-CoV-1, the virus causing the 2002-2004 SARS outbreak. However, the biophysical mechanism behind such binding affinity difference is unclear. This study utilizes a combined single-molecule force spectroscopy and steered molecular dynamics (SMD) simulation approach to quantify the specific interactions between CoV-2 or CoV-1 RBD and ACE2. Depending on the loading rates, the unbinding forces between CoV-2 RBD and ACE2 range from 70 to 110 pN, and are 30-50% higher than those of CoV-1 RBD and ACE2 under similar loading rates. SMD results indicate that CoV-2 RBD interacts with the N-linked glycan on Asn90 of ACE2. This interaction is mostly absent in the CoV-1 RBD-ACE2 complex. During the SMD simulations, the extra RBD-N-glycan interaction contributes to a greater force and prolonged interaction lifetime. The observation is confirmed by our experimental force spectroscopy study. After the removal of N-linked glycans on ACE2, its mechanical binding strength with CoV-2 RBD decreases to a similar level of the CoV-1 RBD-ACE2 interaction. Together, the study uncovers the mechanism behind the difference in ACE2 binding between SARS-CoV-2 and SARS-CoV-1, and could aid in the development of new strategies to block SARS-CoV-2 entry. STATEMENT OF SIGNIFICANCEThis study utilizes a combined single-molecule force spectroscopy and steered molecular dynamics simulation approach to quantify the specific interactions between SARS-CoV-2 or SARS-CoV-1 receptor-binding domain and human ACE2. The study reveals the mechanism behind the difference in ACE2 binding between SARS-CoV-2 and SARS-CoV-1, and could aid in the development of new strategies to block SARS-CoV-2 entry.

biophysics↗