Biology subjects

Leng, H.

Publications and source records attributed to Leng, H..

6 recordsLinked to original sources

bioRxiv2025

Systematic Discovery of Pathogen Effector Functions across Human Pathogens and Pathways

Pathogens deploy effector proteins to exploit host cell biology, and most pathogen open reading frames (ORFs) are rapidly evolving and lack functional annotation. We developed the eORFeome, a scalable functional genomics platform encompassing 3,835 effector ORFs from diverse viruses, bacteria, and parasites. High-throughput barcoded screens across NF{kappa}B, apoptosis, p53, cGAS-STING and MHC-I pathways revealed functions for hundreds of uncharacterized eORFs, unexpected new activities for known effectors, and distinct pathway-specific functions encoded by single ORFs. Illustrating the power of the approach, we identify HHV6A U14 as a p53 antagonist, HHV7 U21 as a dual-function STING antagonist and MHC-I antigen display inhibitor, and adenoviral 13.6K/i-leader protein as a de novo evolved TAP inhibitor that suppresses MHC-I display. These results establish a general framework for systematic effector annotation, uncover new mechanisms of host-pathogen interaction across kingdoms, and highlight pathogen effectors as a versatile toolkit for rewiring and probing human cellular pathways.

systems biology↗

bioRxiv2025

Mitochondrial heterogeneity disrupts osteoclast differentiation and bone resorption by impairing respiratory complex I

Mitochondrial heteroplasmy, the co-existence of different mitochondrial genomes within a cell, is linked to aging and disease. Patients with heteroplasmy due to mitochondrial mutations experience multiple organ complications, particularly poor bone health and bone structure defects. However, the mechanisms involved are generally unknown, due largely to the difficulty of manipulating mtDNA in vivo. To overcome this, we leveraged a heteroplasmic mouse model and discovered that mitochondrial heteroplasmy affects a fundamental developmental process. Specifically, the differentiation of osteoclasts, which resorb bone tissue and maintain bone homeostasis. Mechanistically, there was a reduced localization of specifically respiratory complex I subunits in mitochondria in heteroplasmic mice, disrupting ATP production and osteoclast differentiation. In addition, autophagic flux is exhausted, and the autophagy inducer spermidine restores mitochondrial health and rescues osteoclast activity, both in mice and in cells from patients with primary mitochondrial disease. Together, we identify the mechanisms by which mitochondrial heteroplasmy impacts osteoclastogenesis and discover spermidine as a modulator of this process, which presents a potential treatment for human heteroplasmic conditions such as mitochondrial diseases, which are largely untreatable. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=152 SRC="FIGDIR/small/651799v4_ufig1.gif" ALT="Figure 1"> View larger version (94K): org.highwire.dtl.DTLVardef@131d3f6org.highwire.dtl.DTLVardef@52bf2aorg.highwire.dtl.DTLVardef@848bb3org.highwire.dtl.DTLVardef@1efa572_HPS_FORMAT_FIGEXP M_FIG C_FIG

cell biology↗

bioRxiv2024

Exploiting the Achilles' Heel of Viral RNA Processing to Develop Novel Antivirals

Viruses continue to pose a significant health burden to the human population, and recent history has shown a concerning surge in viral threats. Treatment options for viral infections are limited, and viruses have proven adept at evolving resistance to many existing therapies, highlighting a significant vulnerability in our defenses. In response to this challenge, we explored the modulation of cellular RNA metabolic processes as an alternative paradigm to antiviral development. Many viruses depend on the host cells RNA splicing machinery, and small alterations to this host process results in catastrophic changes in viral protein production, ultimately inhibiting virus replication. Previously, the small molecule 5342191 was identified as a potent inhibitor of HIV-1 replication by altering viral RNA accumulation at doses that minimally affect host gene expression. In this report, we document 5342191 as a potent inhibitor of adenovirus, coronavirus, and influenza replication. In each case, 5342191-mediated reduction in virus replication was associated with altered viral RNA accumulation and loss of viral structural protein expression. Interestingly, while resistant viruses were rapidly isolated for compounds targeting either virus-encoded proteases or polymerases, we have not yet isolated 534219-resistant variants of coronavirus or influenza. As with HIV-1, 5342191s inhibition of coronaviruses and influenza is mediated through the activation of specific cell signaling networks, including GPCR and/or MAPK signaling pathways that ultimately affect SR kinase expression. Together, these studies highlight the therapeutic potential of compounds that target cellular processes essential for the replication of multiple viruses. Not only do these compounds hold promise as broad-spectrum antivirals, but they also offer the potential of greater resilience in combating viral infections.

microbiology↗

bioRxiv2022

An expanded deep-branching thermophilic bacterial clade sheds light on the early evolution of bacteria

The origin of thermophilic bacteria is essential to our understanding of the early evolution of life. However, due to the lack of deep-branching culturable lineages, many controversies remain. Here, we report a novel deep-branching, sulfur-reducing, thermophilic bacterium that was isolated from a deep-sea hydrothermal vent using a newly developed cultivation strategy ("Subtraction-Suboptimal", StS). This bacterial lineage clusters together with other major thermophilic bacterial groups on phylogenomic trees and forms a robust superphylum-level clade that represents a major, early-diverging bacterial lineage. Ancestral analyses and metabolic modeling reveal the ancestor of this lineage might be a thermophilic and mixotrophic bacteria with a preference for amino acids utilization. These findings provide evolutionary insights into the early divergence of thermophilic bacteria and their adaptive strategies on early Earth.

microbiology↗

bioRxiv2021

The glycosphingolipid inhibitor eliglustat inhibits autophagy in osteoclasts to increase bone mass and reduce myeloma bone disease

Multiple myeloma (MM) is a fatal hematological malignancy, where the majority of patients are diagnosed with, or develop, destructive and debilitating osteolytic bone lesions. Current treatments for MM bone disease such as the bisphosphonate zoledronic acid can result in deleterious side effects at high doses. In this study, eliglustat, an FDA approved glycosphingolipid inhibitor, was shown to reduce MM bone disease in preclinical models of MM. Mechanistically, eliglustat alters the lipid composition and plasma membrane fluidity and acts as an autophagy flux inhibitor in bone-resorbing osteoclasts (OC). Autophagic degradation of the signaling molecule TRAF3 is key step in OC differentiation; this was prevented by eliglustat in OC precursors. In addition, eliglustat works depend on TRAF3 in vivo. Furthermore, the combination of eliglustat and zoledronic acid was found to have an additive effect to reduce MM bone disease, suggesting the potential for combination therapies that would allow for drug dose reductions. Taken together, this project identifies a novel mechanism in which glycosphingolipid inhibition reduces osteoclastogenesis via autophagy and highlights the translational potential of eliglustat for the treatment of bone loss disorders such as MM. One Sentence SummaryTranslational use of eliglustat as an autophagy inhibitor to limit bone lesions in multiple myeloma.

cell biology↗

bioRxiv2019

Effects of 7,8-dihydroxycoumarin on the Myelin Morphological Changes and PSD-95 Protein Expression in Balb/c Mice after Sciatic Nerve Injury

To investigate the effects of 7,8-dihydroxycoumarin on the myelin morphological changes and PSD-95 protein expression in mice with sciatic nerve injury, and to explore the relationship between PSD-95 protein and myelin regeneration after nerve myelin injury. 127 male adult Balb/c mice were selected and randomly divided into high, medium and low 7,8-dihydroxycoumarin dose groups and blank control group. Anastomosis was then carried out for the amputated right sciatic nerve, and intraperitoneal injection of 7,8-dihydroxycoumarin was applied postoperatively. At weeks 1, 2, 4 and 8 after surgery, nervous tissues from the injury side were taken for immunohistochemical Luxol Fast Blue (LFB) staining, so as to observe the morphological changes of the locally injured nerve myelin. Meanwhile, PSD-95 mRNA and protein expression were determined using real-time PCR and western blotting. The nerve myelin recovery in injury side of mice at all time points showed a definite dose-effect relationship with the dose of 7,8-dihydroxycoumarin. Moreover, 7,8-dihydroxycoumarin could inhibit the PSD-95 mRNA level and protein expression. At the same time, there was a dose-effect of the inhibition. 7,8-dihydroxycoumarin can affect nerve recovery in mice with sciatic nerve injury, which shows a definite dose-effect relationship with its dose. Besides, PSD-95 protein expression can suppress the regeneration of the injured nerve myelin.

neuroscience↗