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Biology subjects

Zhao, Y.-Y.

Publications and source records attributed to Zhao, Y.-Y..

7 recordsLinked to original sources

Pharmacologic Targeting of ZNF281 Suppresses Metastatic Prostate Cancer Beyond Androgen Receptor Dependence

Metastatic prostate cancer remains a lethal disease, with most treatments focusing on the androgen receptor (AR) axis. We identified the zinc finger protein 281 (ZNF281) as a previously unrecognized driver of metastatic prostate cancer that promotes both AR-related transcriptional output and distinct AR-independent tumor-promoting pathways. It increases AR expression and acts as a coactivator to promote AR transcriptional activity. Independent of AR, ZNF281 promotes prostate cancer by upregulating SMURF1 to sustain tumor growth and by promoting SNAIL-mediated metastasis. We developed an orally bioavailable, ZNF281 Interfering Molecule (Oral ZIM) that disrupts its DNA binding and AR protein interaction. Knockout of ZNF281 as well as treatment with oral ZIM potently inhibited prostate cancer growth and metastasis in orthotopic xenograft models of castration-sensitive and castration-resistant prostate cancers (without detectable systemic toxicity), and ZIM outperformed enzalutamide treatment in patient-derived prostate cancer organoids.

cancer biology↗

An inducer of snail hibernation causes quiescence and hibernation-like cardioprotection, through metabolic rewiring and autophagy, in mice hearts

Cells of hibernators achieve dormancy, resembling cellular quiescence, through molecular rewiring, metabolic remodelling and autophagy, resisting ischemic and ischemia-reperfusion (IR) injury, while non-hibernators are vulnerable to both. We discovered a circulating dormancy-inducing factor in hibernating snails, synthesized it chemically and because it activates PHLPP1 (a phosphatase regulating the mTOR mediators p-AKT and p-S6K1), named it SNail Activator of PHLPP1 (SNAP). During IR, plasma membrane PHLPP1 and p-AKT translocate to the cytoplasm and mitochondria. SNAP dephosphorylates mitochondrial p-AKT, p-S6K1 and induces dormancy in snails and quiescence (autophagy, reversible cell-cycle exit, proteostasis, apoptosis-resistance) in ischemic mouse fibroblasts. In IR models of cardiomyocytes and perfused hearts, SNAP is cardioprotective by preserving Pyruvate Dehydrogenase (PDH) activity, preventing mitochondrial depolarization, apoptosis and ROS-induced ER stress. SNAPs cardioprotective and mitochondrial effects are absent in hearts with a cardiomyocyte-specific PDH knockout. SNAP reveals fundamental mechanisms of quiescence under stress; while its cardioprotection may be beneficial in the IR injury of normal hearts offered for transplantation, a major challenge in transplant medicine.

cell biology↗

A critical contribution of cardiac myofibroblasts in right ventricular failure and the role of UCP2 SNPs in the predisposition to RV decompensation in pulmonary arterial hypertension

The mechanism of transition from compensated (cRV) to decompensated right ventricle (dRV) in pulmonary arterial hypertension (PAH) is unknown. We explored the role of RV cardiac myofibroblasts (cMFB) on this transition utilizing a rat model and 3 cohorts of 81 patients which included clinical data, RV tissues and blood. We hypothesized that the loss of UCP2, critical for mitochondrial calcium (mCa++) regulation and cardiac fibroblasts (cFB) differentiation, is associated with dRV in rats and humans; and that a loss-of-function UCP2 SNP (rs659366) may predict dRV in human PAH. We separated rat cRV from dRV based on catheterization and echocardiographic criteria and found a significant increase in cMFB in dRV. In isolated hearts, RV contractility was lower in dRV but not in isolated cardiomyocyte (CM), pointing to a non-CM cause. Mitochondrial respiration was lower in dRV cMFB than in control and cRV cFB. mCa++ was progressively decreased from normal to cRV to dRV c(M)FB, and the same was true for c(M)FB (but not CM) UCP2 levels. Human PAH, but not secondary pulmonary hypertension, dRVs had more cMFB and less UCP2 than control and cRVs. Decreased UCP2 (protein and mRNA) levels and the presence of heterozygous/homozygous UCP2 SNP were associated with worse RV performance (TAPSE, cardiac index), even among patients with similar mean pulmonary arterial pressure. Our data point to a change of cell identity (cFB to cMFB) in the RV as a driver of RV decompensation. UCP2 SNPs are promising biomarkers for early cRV transition to dRV in PAH.

molecular biology↗

Hyperacute Response Proteins (HARPs) synthesized on γ-tubulin-FTO-MARK4 translation microdomains upon exposure to stress, regulate stressresponse in cancer.

Compared to normal, cancer cells are particularly resistant to stress, and their immediate response to stress is critical for their subsequent multilayered adaptation programs which pose a major clinical challenge. With unbiased proteomics and transcriptomics analysis, we identified a list of HARPs synthesized from pre-existing mRNAs within 20 min of diverse stresses in A549 cancer cells, despite the known suppressed global translation in stress. HARP mRNAs were translated on microtubule-associated translation microdomains (MATMs) located on {gamma}-tubulin, that host FTO and specialized cytoskeletal ribosomes, structurally and functionally distinct from ER and cytosolic ribosomes. FTO exited the nucleus immediately after stress and was activated by the microtubule-associated stress kinase MARK4 via T6 phosphorylation. Activated FTO demethylated a translation-inhibiting mRNA methylation (m6A) signature, facilitating compartmentalized HARP translation on MATMs, while non-HARP mRNA remained inhibited. FTO or MARK4 inhibition suppressed HARP synthesis and increased apoptosis post various stresses, including chemotherapy. These data were confirmed in 4 additional cancer cell lines and normal fibroblasts. Using the Protein Atlas database, we found that high levels of our identified HARPs had on average a 35% decrease on patient 5-year survival in prevalent and resistant cancers (breast, lung, liver, pancreas). {gamma}-tubulin, FTO and MARK4 are therapeutic targets for many cancers, through their ability to comprehensively promote HARPs translation, a potential Achilles heel for cancers resistance to physiologic or therapeutic stress, offering a new window in stress biology.

cancer biology↗

The Unexpected Role of GCN2 Kinase Activation in Mediating Pulmonary Vascular Remodeling and Pulmonary Arterial Hypertension

BackgroundPulmonary arterial hypertension (PAH) is characterized by progressive increase of pulmonary vascular resistance and remodeling that result in right heart hypertrophy and failure. Published studies show that recessive mutations of EIF2AK4 gene (encoding GCN2, General control nonderepressibe 2 kinase) are linked to heritable pulmonary veno-occlusive disease (PVOD) in patients and EIF2AK4 mutations were also found in PAH patients although very rare. However, the role of GCN2 kinase in the pathogenesis of PAH remains unclear. MethodsEif2ak4-/- mice with genetic disruption of the kinase domain and GCN2 kinase inhibitor A-92 were employed in animal models of PH including chronic hypoxia-exposed mice and monocrotaline-challenged rats. Human lung endothelial cells (HLMVECs) were used for mechanistic studies. Endothelium-targeted nanoparticles were employed to deliver plasmid DNA to adult mice to knockout Eif2ak4 or overexpress Endothelin-1 (Edn1) selectively in ECs. ResultsHere we show that loss of GCN2 induced neither spontaneous PVOD nor PH in Eif2ak4-/- mice but inhibited hypoxia-induced PH evident by reduced right ventricular systolic pressure, right ventricle hypertrophy and pulmonary vascular remodeling. RNA sequencing analysis suggested Edn1 as the downstream target of GCN2. In cultured HLMVECs, GCN2 was phosphorylated and activated in response to hypoxia, mediating hypoxia-induced Edn1 expression via HIF-2. Restored Edn1 expression in ECs in Gcn2-deficient mice reversed the reduced phenotype of hypoxia-induced PH. Furthermore, loss of endothelial Eif2ak4 in mice attenuated hypoxia-induced PH. Monocrotaline-induced PH and pulmonary vascular remodeling in rats were inhibited by GCN2 inhibitor A-92 treatment. The clinical relevance of the observation was validated by GCN2 hyperphosphorylation indicative of activation in ECs of pulmonary vascular lesions of PAH patients. ConclusionThese studies demonstrate that GCN2 activation by hypoxia mediates pulmonary vascular remodeling and PAH through Edn1. Thus, targeting GCN2 signaling is a promising therapeutic strategy for treatment of PAH in patients without EIF2AK4 loss of function mutations.

physiology↗

Born with intronless ERF transcriptional factors: C4 photosynthesis inherits a legacy dating back 450 million years

The genus Flaveria, containing species at different evolutionary stages of the progression from C3 to C4 photosynthesis, is used as a model system to study the evolution of C4 photosynthesis. Here, we report chromosome-scale genome sequences for five Flaveria species, including C3, C4, and intermediate species. Our analyses revealed that both acquiring additional gene copies and recruiting ethylene responsive factor (ERF) cis-regulatory elements (CREs) contributed to the emergence of C4 photosynthesis. ERF transcriptional factors (TFs), especially intronless ERF TFs, were co-opted in dicotyledonous C4 species and monocotyledonous C4 species in parallel. These C4 species co-opted intronless ERF TFs originated from the Late Ordovician mass extinction that occurred [~]450 million years ago in coping with environmental stress. Therefore, this study demonstrated that intronless ERF TFs were acquired during the early evolution of plants and provided the molecular toolbox facilitating multiple subsequent independent evolutions of C4 photosynthesis.

evolutionary biology↗

Decitabine Reactivation of FoxM1-Dependent Endothelial Regeneration and Vascular Repair for Potential Treatment of Elderly ARDS and COVID-19 Patients

Aging is a major risk factor of high incidence and increased mortality of acute respiratory distress syndrome (ARDS) and COVID-19. We repot that aging impairs the intrinsic FoxM1-dependent endothelial regeneration and vascular repair program and causes persistent lung injury and high mortality following sepsis. Therapeutic gene transduction of FOXM1 in vascular endothelium or treatment with FDA-approved drug Decitabine was sufficient to reactivate FoxM1-dependent lung endothelial regeneration in aged mice, reverse aging-impaired resolution of inflammatory injury, and promote survival. In COVID-19 lung autopsy samples, FOXM1 expression was not induced in vascular endothelial cells of elderly patients in contrast to mid-age patients. Thus, Decitabine reactivation of FoxM1-dependent vascular repair represents a potential effective therapy for elderly COVID-19 and non-COVID-19 ARDS patients.

molecular biology↗