Lhx2 promotes axon regeneration of adult retinal ganglion cells and rescues neurodegeneration in mouse models of glaucoma.

The axons of retinal ganglion cells (RGCs) form the optic nerve, transmitting visual information from the eye to the brain. Damage or loss of RGCs and their axons is the leading cause of visual functional defects in traumatic injury and degenerative diseases such as glaucoma. However, there are no effective clinical treatments for nerve damage in these neurodegenerative diseases. Here, we report that LIM homeodomain transcription factor Lhx2 promotes RGC survival and axon regeneration in multiple animal models mimicking glaucoma disease. Furthermore, following N-methyl-D-aspartate (NMDA)-induced excitotoxicity damage of RGCs, Lhx2 mitigates the loss of visual signal transduction. Mechanistic analysis revealed that overexpression of Lhx2 supports axon regeneration by systematically regulating the transcription of regeneration-related genes and inhibiting transcription of Semaphorin 3C (Sema3C). Collectively, our studies identify a critical role of Lhx2 in promoting RGC survival and axon regeneration, providing a promising neural repair strategy for glaucomatous neurodegeneration.

Identification of a small-molecule Tim-3 inhibitor to potentiate T cell-mediated antitumor immunotherapy in preclinical mouse models.

T cell immunoglobulin and mucin-containing molecule 3 (Tim-3), expressed in dysfunctional and exhausted T cells, has been widely acknowledged as a promising immune checkpoint target for tumor immunotherapy. Here, using a strategy combining virtual and functional screening, we identified a compound named ML-T7 that targets the FG-CC' cleft of Tim-3, a highly conserved binding site of phosphatidylserine (PtdSer) and carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1). ML-T7 enhanced the survival and antitumor activity of primary CD8+ cytotoxic T lymphocytes (CTLs) and human chimeric antigen receptor (CAR) T cells and reduced their exhaustion in vitro and in vivo. In addition, ML-T7 promoted NK cells' killing activity and DC antigen-presenting capacity, consistent with the reported activity of Tim-3. ML-T7 strengthened DCs' functions through both Tim-3 and Tim-4, which is consistent with the fact that Tim-4 contains a similar FG-CC' loop. Intraperitoneal dosing of ML-T7 showed comparable tumor inhibitory effects to the Tim-3 blocking antibody. ML-T7 reduced syngeneic tumor progression in both wild-type and Tim-3 humanized mice and alleviated the immunosuppressive microenvironment. Furthermore, combined ML-T7 and anti-PD-1 therapy had greater therapeutic efficacy than monotherapy in mice, supporting further development of ML-T7 for tumor immunotherapy. Our study demonstrates a potential small molecule for selectively blocking Tim-3 and warrants further study.

Transcription factor Zhx2 is a checkpoint that programs macrophage polarization and antitumor response.

Macrophages are usually educated to tumor-associated macrophages (TAMs) in cancer with pro-tumor functions by tumor microenvironment (TME) and TAM reprogramming has been proposed as a potential tumor immunotherapy strategy. We recently demonstrated the critical role of Zinc-fingers and homeoboxes 2 (Zhx2) in macrophages' metabolic programming. However, whether Zhx2 is responsible for macrophage polarization and TAMs reprogramming is largely unknown. Here, we show that Zhx2 controls macrophage polarization under the inflammatory stimulus and TME. Myeloid-specific deletion of Zhx2 suppresses LPS-induced proinflammatory polarization but promotes IL-4 and TME-induced anti-inflammatory and pro-tumoral phenotypes in murine liver tumor models. Factors in TME, especially lactate, markedly decrease the expression of Zhx2 in TAMs, leading to the switch of TAMs to pro-tumor phenotype and consequent cancer progression. Notably, reduced ZHX2 expression in TAM correlates with poor survival of HCC patients. Mechanistic studies reveal that Zhx2 associates with NF-κB p65 and binds to the Irf1 promoter, leading to transcriptional activation of Irf1 in macrophages. Zhx2 functions in maintaining macrophage polarization by regulating Irf1 transcription, which may be a potential target for macrophage-based cancer immunotherapy.

Enhanced Delivery of TLR7/8 Agonists by Metal-Organic Frameworks for Hepatitis B Virus Cure.

Hepatitis B virus (HBV) infection remains a major challenge to global health due to unsatisfactory treatment efficacy, side effects of current therapies, and immune tolerance. Toll-like receptors 7/8 (TLR7/8) agonists have shown great potential in chronic hepatitis B (CHB) cure, but systemic administration often induces severe side effects due to rapid dispersion into the microvasculature. Herein, we encapsulate an imidazoquinoline-based TLR7/8 agonist (IMDQ) into zeolitic imidazolate framework 8 nanoparticles (IMDQ@ZIF-8 NPs) for HBV immunotherapy. Compared with free IMDQ, IMDQ@ZIF-8 NPs efficiently accumulate in the liver and are selectively taken up by antigen-presenting cells (APCs), leading to enhanced APC activation and efficient viral elimination in HBV-infected models. Strikingly, MDQ@ZIF-8 NP treatment results in the obvious production of anti-HBs antibody and seroconversion in HBV-infected mice. Overall, this study on the convergence of a facile assembly approach and efficient therapeutic effects represents a promising strategy for HBV treatment.

Hepatitis B virus evades immune recognition via RNA adenosine deaminase ADAR1-mediated viral RNA editing in hepatocytes.

HBV is considered as a "stealth" virus that does not invoke interferon (IFN) responses; however, the mechanisms by which HBV bypasses innate immune recognition are poorly understood. In this study, we identified adenosine deaminases acting on RNA 1 (ADAR1), which is a key factor in HBV evasion from IFN responses in hepatocytes. Mechanically, ADAR1 interacted with HBV RNAs and deaminated adenosine (A) to generate inosine (I), which disrupted host immune recognition and thus promoted HBV replication. Loss of ADAR1 or its deficient deaminase activity promoted IFN responses and inhibited HBV replication in hepatocytes, and blocking the IFN signaling pathways released the inhibition of HBV replication caused by ADAR1 deficiency. Notably, the HBV X protein (HBx) transcriptionally promoted ADAR1 expression to increase the threshold required to trigger intrinsic immune activation, which in turn enhanced HBV escape from immune recognition, leading to persistent infection. Supplementation with 8-azaadenosine, an ADAR1 inhibitor, efficiently enhanced liver immune activation to promote HBV clearance in vivo and in vitro. Taken together, our results delineate a molecular mechanism by which HBx promotes ADAR1-derived HBV immune escape and suggest a targeted therapeutic intervention for HBV infection.

Loss of Arid1a Promotes Neuronal Survival Following Optic Nerve Injury.

Trauma or neurodegenerative diseases trigger the retrograde death of retinal ganglion cells (RGCs), causing an irreversible functional loss. AT-rich interaction domain 1A (ARID1A), a subunit of the SWItch/Sucrose Non-Fermentable (SWI/SNF) chromatin remodeling complex, has been shown to play crucial roles in cell homeostasis and tissue regeneration. However, its function in adult RGC regeneration remains elusive. Here, we show that optic nerve injury induces dynamic changes of Arid1a expression. Importantly, deleting Arid1a in mice dramatically promotes RGC survival, but insignificantly impacts axon regeneration after optic nerve injury. Next, joint profiling of transcripts and accessible chromatin in mature RGCs reveals that Arid1a regulates several genes involved in apoptosis and JAK/STAT signaling pathway. Thus, our findings suggest modulation of Arid1a as a potential therapeutic strategy to promote RGC neuroprotection after damage.

Strategies to Promote Long-Distance Optic Nerve Regeneration.

Mammalian retinal ganglion cells (RGCs) in the central nervous system (CNS) often die after optic nerve injury and surviving RGCs fail to regenerate their axons, eventually resulting in irreversible vision loss. Manipulation of a diverse group of genes can significantly boost optic nerve regeneration of mature RGCs by reactivating developmental-like growth programs or suppressing growth inhibitory pathways. By injury of the vision pathway near their brain targets, a few studies have shown that regenerated RGC axons could form functional synapses with targeted neurons but exhibited poor neural conduction or partial functional recovery. Therefore, the functional restoration of eye-to-brain pathways remains a greatly challenging issue. Here, we review recent advances in long-distance optic nerve regeneration and the subsequent reconnecting to central targets. By summarizing our current strategies for promoting functional recovery, we hope to provide potential insights into future exploration in vision reformation after neural injuries.

Epigenome-wide study for the offspring exposed to maternal HBV infection during pregnancy, a pilot study.

BACKGROUND & AIM: Hepatitis B virus (HBV) can be transmitted to infants, and is related to infants' later disease risk. Epigenetic change (such as DNA methylation) may be mechanism underlying the relationship. In this study, we aimed to investigate whether prenatal HBV infection could alter DNA methylation status in newborns. METHOD: We selected 12 neonates with intrauterine HBV infection whose mothers were HBsAg-positive during pregnancy, relative to 12 HBV-free neonates with HBsAg-negative mothers. The pattern of genome-wide DNA methylation in the umbilical cord blood was investigated by Illumina Infinium Human Methylation 450K BeadChip. RESULT: The average level of global methylation in infected neonates exposed to maternal HBV infection was not significantly different from controls. However, after adjusting for multiple comparisons, we found differential significance in the cases group compared to the controls for 663 CpG sites, associated with 534 genes. Among these sites, 53.85% (357/663) had decreased methylation (ΔM < 0) and 46.15% (306/663) had increased methylation (ΔM > 0). The average percentage change (Δß) in methylation ranged from -46% to 36%. Validated by pyrosequencing, we identified 4 significantly differentially methylated CpG sites in the KLHL35 gene and additional CpGs for the CPT1B gene. These genes play a role in the development of hepatocellular and colorectal carcinoma and fatty acid oxidation, suggesting the candidature of these genes in HBV related disease. CONCLUSION: Prenatal HBV exposure, even without malformation or preterm birth, may alter the epigenome profile in newborns. We identified a set of genes with differentially methylated CpG sites presented in the cord blood of HBV-infected newborns with HBsAg-positive mothers, demonstrating that DNA methylation status at birth can be used as a biomarker of prenatal exposure. These DNA methylation differences suggest a possible role for epigenetic processes in neonatal development in response to prenatal HBV exposure.