EMBO Molecular Medicine最新文献

The lack of regeneration in the human central nervous system (CNS) has major health implications. To address this, we previously used transgenic mouse models to show that neurogenesis can be stimulated in the adult mammalian retina by driving regeneration programs that other species activate following injury. Expression of specific proneural factors in adult Müller glia causes them to re-enter the cell cycle and give rise to new neurons following retinal injury. To bring this strategy closer to clinical application, we now show that neurogenesis can also be stimulated when delivering these transcription factors to Müller glia using adeno-associated viral (AAV) vectors. AAV-mediated neurogenesis phenocopies the neurogenesis we observed from transgenic animals, with different proneural factor combinations giving rise to distinct neuronal subtypes in vivo. Vector-borne neurons are morphologically, transcriptomically and physiologically similar to bipolar and amacrine/ganglion-like neurons. These results represent a key step forward in developing a cellular reprogramming approach for regenerative medicine in the CNS.

Mycobacterial infections pose a significant global health concern, requiring precise identification for effective treatment. However, diagnosing them is challenging due to inaccurate identifications and prolonged times. In this study, we aimed to develop a novel peptidome-based method using mycobacterial growth indicator tube (MGIT) cultures for faster and more accurate identification. We created the PEPtide Taxonomy/ORganism CHecking (PEP-TORCH), an algorithm that analyzes tryptic peptides identified by mass spectrometry to diagnose species and subspecies with predominance scores. PEP-TORCH demonstrated 100% accuracy in identifying mycobacterial species, subspecies, and co-infections in 81 individuals suspected of mycobacterial infections, eliminating the need for a sub-solid culture procedure, the gold standard in clinical practice. A notable strength of PEP-TORCH is its ability to provide information on species and subspecies simultaneously, a process conventionally achieved sequentially. This capability significantly expedites pathogen identification. Furthermore, a targeted proteomics method was validated in 63 clinical samples using the taxa-specific peptides selected by PEP-TORCH, making them suitable as biomarkers in more clinically friendly settings. This comprehensive identification approach holds promise for streamlining treatment strategies in clinical practice.

As a common and severe cerebrovascular disease, ischemic stroke casts a significant shadow over global health. Unfortunately, the mechanisms regulating neuronal death in the affected areas remain largely unclear. Here, we found that deletion of the deubiquitinating enzyme Otubain-2 (OTUB2) significantly alleviated ischemia-induced cerebral infarction and neurological deficits, accompanied by a reduction in neuronal loss, glial activation, and neuroinflammation. OTUB2 was predominantly expressed in neurons and its deletion decreased receptor-interacting protein kinase 3 (RIPK3)-mediated neuronal necroptosis. Moreover, OTUB2 increased RIPK3 protein abundance by inhibiting the proteasomal degradation of RIPK3. Mechanistically, OTUB2 removed K48-linked polyubiquitin chains from RIPK3 through its active site C51. Importantly, pharmacological inhibition of OTUB2 alleviated ischemic brain injury in mice and reduced oxygen-glucose deprivation-induced neuronal death in human brain organoids. These results demonstrate that OTUB2 critically regulates ischemic stroke injury by potentiating neuronal necroptosis, suggesting that OTUB2 inhibition may become a potential therapeutic approach for treating ischemic stroke.

X-linked myopathy with excessive autophagy (XMEA), a rare childhood-onset autophagic vacuolar myopathy caused by mutations in VMA21, is characterized by proximal muscle weakness and progressive vacuolation. VMA21 encodes a protein chaperone of the vacuolar hydrogen ion ATPase, the loss of which leads to lysosomal neutralization and impaired function. At present, there is an incomplete understanding of XMEA, its mechanisms, consequences on other systems, and therapeutic strategies. A significant barrier to advancing knowledge and treatments is the lack of XMEA animal models. Therefore, we used CRISPR-Cas9 editing to engineer a loss-of-function mutation in zebrafish vma21. The vma21 mutant zebrafish phenocopy the human disease with impaired motor function and survival, liver dysfunction, and dysregulated autophagy indicated by lysosomal de-acidification, the presence of characteristic autophagic vacuoles in muscle fibers, altered autophagic flux, and reduced lysosomal marker staining. As proof-of-concept, we found that two drugs, edaravone and LY294002, improve swim behavior and survival. In total, we generated and characterized a novel preclinical zebrafish XMEA model and demonstrated its suitability for studying disease pathomechanisms and identifying potential therapeutic targets.

After the Covid-19 pandemic, pertussis has made a spectacular comeback in Europe and many other parts of the world, while during the pandemic it had essentially disappeared because of the social distancing requirements. However, even before the Covid-19 pandemic, the disease was on the rise in many countries, especially those that have replaced whole-cell pertussis vaccines by acellular pertussis vaccines. Several reasons may account for this upsurge, including strain adaptation to escape vaccine-induced immunity, rapid waning of immunity after vaccination and the failure of current vaccines to prevent infection by and transmission of the causative agent Bordetella pertussis. Various strategies have been deployed to control the disease, the most effective of which is maternal vaccination during pregnancy to protect the newborn against the most severe and deadly forms of the disease. However, ultimate control of pertussis likely requires novel vaccines, which prevent infection and transmission, not only disease. One of them is the live attenuated BPZE1 vaccine, which has shown promise in pre-clinical and clinical studies and may therefore perhaps become a gamechanger.

Regulatory T cells (Tregs) play critical roles in inhibiting antitumor immunity, which is dependent on FOXP3-mediated transcriptional activity. However, no Treg-specific therapeutics has been approved for clinical use. We performed a high-throughput screen of FDA-approved drugs for potential inhibitors of FOXP3 transcriptional activity. These efforts identified Lanatoside C (Lac), which potently inhibits FOXP3 activity by causing degradation of RUNX1, a FOXP3-associated component required for its transcriptional activity. Lac directly binds the E3 ligase STUB1, leading to increased polyubiquitination and proteasomal degradation of RUNX1. Lac inhibits Tregs activity and promotes antitumor immunity in a mouse primary lung cancer model. In addition, Lac synergizes with PD-1 inhibitor to shrink lung cancers driven by mutant KRAS in a mouse model. Our findings suggested that the FDA-approved Lac is a Tregs inhibitor and serves as a candidate drug for cancer patients by its own or in combination with existing therapeutics such as PD-1 inhibitors.

Glioblastomas (GBM) are routinely treated with high doses of ionizing radiation (IR), yet these tumors recur quickly, and the recurrent tumors are highly therapy resistant. Here, we report that IR-induced senescence of tumor cells counterintuitively spurs GBM recurrence, driven by the senescence-associated secretory phenotype (SASP). We find that irradiated GBM cell lines and patient derived xenograft (PDX) cultures senesce rapidly in a p21-dependent manner. Senescent glioma cells upregulate SASP genes and secrete a panoply of SASP factors, prominently interleukin IL-6, an activator of the JAK-STAT3 pathway. These SASP factors collectively activate the JAK-STAT3 and NF-κB pathways in non-senescent GBM cells, thereby promoting tumor cell proliferation and SASP spreading. Transcriptomic analyses of irradiated GBM cells and the TCGA database reveal that the cellular inhibitor of apoptosis protein 2 (cIAP2), encoded by the BIRC3 gene, is a potential survival factor for senescent glioma cells. Senescent GBM cells not only upregulate BIRC3 but also induce BIRC3 expression and promote radioresistance in non-senescent tumor cells. We find that second mitochondria-derived activator of caspases (SMAC) mimetics targeting cIAP2 act as novel senolytics that trigger apoptosis of senescent GBM cells with minimal toxicity towards normal brain cells. Finally, using both PDX and immunocompetent mouse models of GBM, we show that the SMAC mimetic birinapant, administered as an adjuvant after radiotherapy, can eliminate senescent GBM cells and prevent the emergence of recurrent tumors. Taken together, our results clearly indicate that significant improvement in GBM patient survival may become possible in the clinic by eliminating senescent cells arising after radiotherapy.

The adipokine apelin has been directly implicated in various physiological processes during embryogenesis and human cancers. Nevertheless, the importance of the conversion of its precursor proapelin to mature apelin in tumorigenesis remains unknown. In this study, we identify Furin as the cellular proprotein convertase responsible for proapelin cleavage. We explore the therapeutic potential of targeting proapelin cleavage sites in metastatic colorectal cancer by introducing apelin-dm, a modified variant resulting from alteration in proapelin cleavage sites. Apelin-dm demonstrates efficacy in inhibiting tumor growth, promoting cell death, suppressing angiogenesis, and early colorectal liver metastasis events. Proteomic analysis reveals reciprocal regulation between apelin and apelin-dm on proteins associated with clinical outcomes in colon cancer patients. Apelin-dm emerges as a modulator of apelin receptor dynamics, influencing affinity, internalization, and repression of apelin signaling linked to various protein kinases. Pharmacokinetic and toxicity assessments confirm the specificity, safety, and stability of apelin-dm, as well as its facile hepatic metabolism. These findings position targeting proapelin cleavage as a promising therapeutic strategy against metastatic colorectal cancer, paving the way for further clinical exploration.

Colorectal cancer (CRC) is a major health problem, with an alarming increase of early-onset CRC (EO-CRC) cases among individuals under 50 years of age. This trend shows the urgent need for understanding the underlying mechanisms leading to EO-CRC development and progression. There is significant evidence that the gut microbiome acts as a key player in CRC by triggering molecular changes in the colon epithelium, leading to tumorigenesis. However, a comprehensive collection and comparison of methods to study such tumor-microbiome interactions in the context of EO-CRC is sparse. This review provides an overview of the available in vivo, ex vivo as well as in vitro approaches to model EO-CRC and assess the effect of gut microbes on tumor development and growth. By comparing the advantages and limitations of each model system, it highlights that, while no single model is perfect, each is suitable for studying specific aspects of microbiome-induced tumorigenesis. Taken together, multifaceted approaches can simulate the human body's complexity, aiding in the development of effective treatment and prevention strategies for EO-CRC.