SARS-CoV-2 replication in airway epithelia requires motile cilia and microvillar reprogramming.

How SARS-CoV-2 penetrates the airway barrier of mucus and periciliary mucins to infect nasal epithelium remains unclear. Using primary nasal epithelial organoid cultures, we found that the virus attaches to motile cilia via the ACE2 receptor. SARS-CoV-2 traverses the mucus layer, using motile cilia as tracks to access the cell body. Depleting cilia blocks infection for SARS-CoV-2 and other respiratory viruses. SARS-CoV-2 progeny attach to airway microvilli 24 h post-infection and trigger formation of apically extended and highly branched microvilli that organize viral egress from the microvilli back into the mucus layer, supporting a model of virus dispersion throughout airway tissue via mucociliary transport. Phosphoproteomics and kinase inhibition reveal that microvillar remodeling is regulated by p21-activated kinases (PAK). Importantly, Omicron variants bind with higher affinity to motile cilia and show accelerated viral entry. Our work suggests that motile cilia, microvilli, and mucociliary-dependent mucus flow are critical for efficient virus replication in nasal epithelia.

A defective viral genome strategy elicits broad protective immunity against respiratory viruses.

RNA viruses generate defective viral genomes (DVGs) that can interfere with replication of the parental wild-type virus. To examine their therapeutic potential, we created a DVG by deleting the capsid-coding region of poliovirus. Strikingly, intraperitoneal or intranasal administration of this genome, which we termed eTIP1, elicits an antiviral response, inhibits replication, and protects mice from several RNA viruses, including enteroviruses, influenza, and SARS-CoV-2. While eTIP1 replication following intranasal administration is limited to the nasal cavity, its antiviral action extends non-cell-autonomously to the lungs. eTIP1 broad-spectrum antiviral effects are mediated by both local and distal type I interferon responses. Importantly, while a single eTIP1 dose protects animals from SARS-CoV-2 infection, it also stimulates production of SARS-CoV-2 neutralizing antibodies that afford long-lasting protection from SARS-CoV-2 reinfection. Thus, eTIP1 is a safe and effective broad-spectrum antiviral generating short- and long-term protection against SARS-CoV-2 and other respiratory infections in animal models.

X-ray polarization evidence for a 200-year-old flare of Sgr A.

The centre of the Milky Way Galaxy hosts a black hole with a solar mass of about 4 million (Sagittarius A* (Sgr A)) that is very quiescent at present with a luminosity many orders of magnitude below those of active galactic nuclei1. Reflection of X-rays from Sgr A* by dense gas in the Galactic Centre region offers a means to study its past flaring activity on timescales of hundreds and thousands of years2. The shape of the X-ray continuum and the strong fluorescent iron line observed from giant molecular clouds in the vicinity of Sgr A* are consistent with the reflection scenario3-5. If this interpretation is correct, the reflected continuum emission should be polarized6. Here we report observations of polarized X-ray emission in the direction of the molecular clouds in the Galactic Centre using the Imaging X-ray Polarimetry Explorer. We measure a polarization degree of 31% ± 11%, and a polarization angle of -48° ± 11°. The polarization angle is consistent with Sgr A* being the primary source of the emission, and the polarization degree implies that some 200 years ago, the X-ray luminosity of Sgr A* was briefly comparable to that of a Seyfert galaxy.

Discovery of ciliary G protein-coupled receptors regulating pancreatic islet insulin and glucagon secretion.

Multiple G protein-coupled receptors (GPCRs) are expressed in pancreatic islet cells, but the majority have unknown functions. We observed specific GPCRs localized to primary cilia, a prominent signaling organelle, in pancreatic α and ß cells. Loss of cilia disrupts ß-cell endocrine function, but the molecular drivers are unknown. Using functional expression, we identified multiple GPCRs localized to cilia in mouse and human islet α and ß cells, including FFAR4, PTGER4, ADRB2, KISS1R, and P2RY14. Free fatty acid receptor 4 (FFAR4) and prostaglandin E receptor 4 (PTGER4) agonists stimulate ciliary cAMP signaling and promote glucagon and insulin secretion by α- and ß-cell lines and by mouse and human islets. Transport of GPCRs to primary cilia requires TULP3, whose knockdown in primary human and mouse islets relocalized ciliary FFAR4 and PTGER4 and impaired regulated glucagon or insulin secretion, without affecting ciliary structure. Our findings provide index evidence that regulated hormone secretion by islet α and ß cells is controlled by ciliary GPCRs providing new targets for diabetes.

Defect Engineered Bi2Te3 Nanosheets with Enhanced Haloperoxidase Activity for Marine Antibiofouling.

Defective bismuth telluride (Bi2Te3) nanosheets, an artificial nanozyme mimicking haloperoxidase activity (hPOD), show promise as eco-friendly, bactericidal, and antimicrofouling materials by enhancing cytotoxic hypohalous acid production from halides and H2O2. Microscopic and spectroscopic characterization reveals that controlled NaOH (upto X = 250 µL) etching of the nearly inactive non-transition metal chalcogenide Bi2Te3 nanosheets creates controlled defects (d), such as Bi3+species, in d-Bi2Te3-X that induces enhanced hPOD activity. d-Bi2Te3-250 exhibits approximately eight-fold improved hPOD than the as-grown Bi2Te3 nanosheets. The antibacterial activity of d-Bi2Te3-250 nanozymes, studied by bacterial viability, show 1, and 45% viability for Staphylococcus aureus and Pseudomonas aeruginosa, respectively, prevalent in marine environments. The hPOD mechanism is confirmed using scavengers, implicating HOBr and singlet oxygen for the effect. The antimicrofouling property of the d-Bi2Te3-250 nanozyme has been studied on Pseudomonas aeruginosa biofilm in a lab setting by multiple assays, and also on titanium (Ti) plates coated with the nanozyme mixed commercial paint, exposed to seawater in a real setting. All studies, including direct microscopic evidence, exhibit inhibition of microfouling, up to ≈73%, in the presence of nanozymes. This approach showcases that defect engineering can induce antibacterial, and antimicrofouling activity in non-transition metal chalcogenides, offering an inexpensive alternative to noble metals.

Microglia-mediated drug substance transfer promotes chemoresistance in brain tumors: insights from an in vitro co-culture model using GCV/Tk prodrug system.

BACKGROUND: It is well known that tumor-associated macrophages (TAMs) play essential roles in brain tumor resistance to chemotherapy. However, the detailed mechanisms of how TAMs are involved in brain tumor resistance are still unclear and lack a suitable analysis model. METHODS: A BV2 microglial cells with ALTS1C1 astrocytoma cells in vitro co-culture system was used to mimic the microglia dominating tumor stroma in the tumor invasion microenvironment and explore the interaction between microglia and brain tumor cells. RESULTS: Our result suggested that microglia could form colonies with glioma cells under high-density culturing conditions and protect glioma cells from apoptosis induced by chemotherapeutic drugs. Moreover, this study demonstrates that microglia could hijack drug substances from the glioma cells and reduce the drug intensity of ALTS1C1 via direct contact. Inhibition of gap junction protein prevented microglial-glioma colony formation and microglia-mediated chemoresistance. CONCLUSIONS: This study provides novel insights into how glioma cells acquire chemoresistance via microglia-mediated drug substance transferring, providing a new option for treating chemo-resistant brain tumors.

Performance of Baveno VII criteria for the screening of varices needing treatment in patients with biliary atresia.

OBJECTIVE: Biliary atresia (BA) is the leading cause of liver cirrhosis and chronic liver insufficiency in children in the world. Gastroesophageal varices bleeding is an ominous complication of cirrhosis in BA patients and is associated with high morbidity and mortality. In this study, we aimed to investigate the utility of noninvasive Baveno VI and Baveno VII criteria for the screening of varices need treatment (VNT) and the need for liver transplantation in BA patients. METHODS: This study enrolled 48 BA patients (23 females and 25 males) who underwent an esophagogastroduodenoscopy (EGD) and transient elastography at a mean age of 11.18 ± 1.48 years; the clinical data were surveyed in a retrospective design. RESULTS: The sensitivity and negative predictive value of Baveno VI and Baveno VII criteria for the prediction of VNT in BA patients are both 100% and 100%, respectively. The VNT missing rate of Baveno VI and Baveno VII criteria are both 0% in our cohort. The Baveno VI, expanded Baveno VI, and Baveno VII criteria are also predictive of the need for liver transplantation in our cohort (OR = 10.33, 4.24, and 21.33; p = 0.009, 0.03, and 0.007, respectively). CONCLUSION: The Baveno VI and Baveno VII criteria are useful for the screening of VNT and minimize non-necessary invasive EGD in BA patients with low VNT missing rates. The Baveno VI, expanded Baveno VI, and Baveno VII criteria are associated with the need for liver transplantation.

Real-world efficacy and safety of low-dose pembrolizumab in patients with advanced and refractory gynecologic cancers.

OBJECTIVE: The approved standard dose of pembrolizumab (200 mg administrated every 3 weeks) for cancer treatment imposes a significant financial burden on patients. However, no study has analyzed the clinical outcomes of low-dose pembrolizumab among individuals diagnosed with gynecologic cancer. The primary objective of this study was to assess the effectiveness and safety of a low-dose pembrolizumab regimen in real-world clinical practice. METHODS: We retrospectively assessed the efficacy and safety data of patients with gynecologic malignancies who received pembrolizumab between 2017 and 2022 at Kaohsiung Chang Gung Memorial Hospital. Furthermore, we conducted a comparative analysis of the objective response rate (ORR) and progression-free survival (PFS) between patients with deficient mismatch repair (dMMR) and proficient MMR (pMMR). RESULTS: A total of thirty-nine patients were included and received pembrolizumab at fixed dosages of 50 mg (5.1%), 100 mg (84.6%) and 200 mg (10.3%) per cycle. Compared to the pMMR group, the dMMR group exhibited a tendency toward improved ORR (45.5% vs. 13.0%, p = 0.074), and notably, the median duration of response remained unreached. There was no significant difference in PFS between the dMMR and pMMR groups; however, the patients with dMMR in tumor tissue had a trend of better survival (p = 0.079). Incidence of immune-related adverse events (irAEs) of any grade was observed in 13 patients (33.3%), with 3 individuals (7.7%) experiencing grade 3 or 4 events. CONCLUSION: Low-dose pembrolizumab may be a cost-effective and safe treatment option without compromising clinical outcomes in patients with refractory gynecologic cancers.

Follow-up care and assessment of comorbidities and complications in patients with primary aldosteronism: The clinical practice guideline of the Taiwan Society of aldosteronism.

Primary aldosteronism (PA) is the most common form of endocrine hypertension, characterized by excess aldosterone production that leads to an increased risk of cardiovascular events and target organ damage. Both adrenalectomy and medical treatment have shown efficacy in improving clinical outcomes and comorbidities associated with PA, including a specific subtype of PA with autonomous cortisol secretion (ACS). Understanding the comorbidities of PA and establishing appropriate follow-up protocols after treatment are crucial for physicians to enhance morbidity and mortality outcomes in patients with PA. Additionally, the screening for hypercortisolism prior to surgery is essential, as the prognosis of patients with coexisting PA and ACS differs from those with PA alone. In this review, we comprehensively summarize the comorbidities of PA, encompassing cardiovascular, renal, and metabolic complications. We also discuss various post-treatment outcomes and provide insights into the strategy for glucocorticoid replacement in patients with overt or subclinical hypercortisolism. This clinical practice guideline aims to equip medical professionals with up-to-date information on managing concurrent hypercortisolism, assessing treatment outcomes, and addressing comorbidities in patients with PA, thereby improving follow-up care.

The predictors of long-term outcomes after targeted therapy for primary Aldosteronism.

Unilateral primary aldosteronism is thought to be a surgically curable disease, and unilateral adrenalectomy is the mainstay treatment. The Primary Aldosteronism Surgical Outcome (PASO) consensus was developed to assess clinical and biochemical outcomes to standardize the classification of surgical outcomes. However, fewer than half of patients are cured of hypertension after adrenalectomy; therefore, preoperative patient counseling and evaluation might be necessary. Moreover, current studies show that genetic mutations and histopathology classification are associated with the treatment outcome. The Task Force of Taiwan PA recommends using a specific scoring system, including the PASO score and nomogram-based preoperative score, to predict the clinical outcome before adrenalectomy. Herein, we discuss the associations of current histopathological classification and specific somatic gene mutations with clinical outcomes after surgery.

Effect of peroral endoscopic myotomy on growth and esophageal motility for pediatric esophageal achalasia.

BACKGROUND/PURPOSE: Peroral endoscopic myotomy (POEM), a novel minimally invasive treatment for esophageal achalasia, has been shown to be effective and safe for both adult and pediatric patients. However, studies on its application in children in Taiwan and its impact on growth and esophageal motility are lacking. METHODS: We conducted a retrospective study on consecutive pediatric patients who were diagnosed with esophageal achalasia at National Taiwan University Hospital and underwent POEM during 2015-2022. Disease characteristics and treatment outcomes were analyzed. RESULTS: Ten patients (age 16.9 ± 3.1 years), nine newly diagnosed and one previously treated with pneumatic dilatation, underwent POEM for achalasia (type I/II/III: 3/7/0). Average symptom duration before diagnosis was 19.4 ± 19.9 months, mean POEM procedure time was 83.6 ± 30.7 min, and clinical success (Eckardt score ≤3) was achieved in all patients. Eight patients experienced mild adverse events during POEM, but none required further endoscopic or surgical intervention. Over a mean follow-up period of 3.7 ± 1.6 years, mean Eckardt score decreased significantly from 5.7 ± 2.4 to 1.1 ± 0.7 (p = 0.0001). The BMI z-score also increased significantly after POEM (p = 0.023). Five patients received follow-up high-resolution impedance manometry (HRIM), and all had improved lower esophageal sphincter resting pressures (p = 0.011), body contractility, and bolus transit (p = 0.019). CONCLUSION: POEM is an effective and safe treatment for pediatric achalasia in Taiwan. Early diagnosis and treatment with POEM may help to restore esophageal function and nutrition status in children.

Treatment of primary aldosteronism: Clinical practice guidelines of the Taiwan Society of Aldosteronism.

Primary aldosteronism (PA) is the most common cause of secondary hypertension and one of the few medical diseases that can be cured by surgery. Excessive aldosterone secretion is highly associated with cardiovascular complications. Many studies have shown that patients with unilateral PA treated with surgery have better survival, cardiovascular, clinical, and biochemical outcomes than those who receive medical treatment. Consequently, laparoscopic adrenalectomy is the gold standard for treating unilateral PA. Surgical methods should be individualized according to the patient's tumor size, body shape, surgical history, wound considerations, and surgeon's experience. Surgery can be performed through a transperitoneal or retroperitoneal approach, and via a single-port or multi-port laparoscopic approach. However, total or partial adrenalectomy remains controversial in treating unilateral PA. Partial excision will not completely eradicate the disease and is prone to recurrence. Mineralocorticoid receptor antagonists should be considered for patients with bilateral PA or patients who cannot undergo surgery. There are also emerging alternative interventions, including radiofrequency ablation and transarterial adrenal ablation, for which data on long-term outcomes are currently lacking. The Task Force of Taiwan Society of Aldosteronism developed these clinical practice guidelines with the aim of providing medical professionals with more updated information on the treatment of PA and improving the quality of care.

Ethacridine inhibits SARS-CoV-2 by inactivating viral particles.

The respiratory disease COVID-19 is caused by the coronavirus SARS-CoV-2. Here we report the discovery of ethacridine as a potent drug against SARS-CoV-2 (EC50 ~ 0.08 µM). Ethacridine was identified via high-throughput screening of an FDA-approved drug library in living cells using a fluorescence assay. Plaque assays, RT-PCR and immunofluorescence imaging at various stages of viral infection demonstrate that the main mode of action of ethacridine is through inactivation of viral particles, preventing their binding to the host cells. Consistently, ethacridine is effective in various cell types, including primary human nasal epithelial cells that are cultured in an air-liquid interface. Taken together, our work identifies a promising, potent, and new use of the old drug via a distinct mode of action for inhibiting SARS-CoV-2.

Fragment Linker Prediction Using the Deep Encoder-Decoder Network for PROTACs Drug Design.

A drug discovery and development pipeline is a prolonged and complex process that remains challenging for both computational methods and medicinal chemists and has not been able to be resolved using computational methods. Deep learning has been utilized in various fields and achieved tremendous success in designing novel molecules in the pharmaceutical industry. Herein, we use state-of-the-art techniques to propose a deep neural network, AIMLinker, to rapidly design and generate meaningful drug-like proteolysis targeting chimeras (PROTACs) analogs. The model extracts the structural information from the input fragments and generates linkers to incorporate them. We integrate filters in the model to exclude nondruggable structures guided via protein-protein complexes while retaining molecules with potent chemical properties. The novel PROTACs subsequently pass through molecular docking, taking root-mean-square deviation (RMSD), relative Gibbs free energy (ΔΔGbinding), molecular dynamics (MD) simulation, and free energy perturbation (FEP) calculations as the measurement criteria for testing the robustness and feasibility of the model. The generated novel PROTACs molecules possess similar structural information with superior binding affinity to the binding pockets compared to the existing CRBN-dBET6-BRD4 ternary complexes. We demonstrate the effectiveness of the methodology of leveraging AIMLinker to design novel compounds for PROTACs molecules exhibiting better chemical properties compared to the dBET6 crystal pose.

Changes of ECG parameters after BNT162b2 vaccine in the senior high school students.

The purpose of this study is to determine the ECG parameter change and the efficacy of ECG screening for cardiac adverse effect after the second dose of BNT162b2 vaccine in young population. In December 2021, in cooperation with the school vaccination system of Taipei City government, we performed a ECG screening study during the second dose of BNT162b2 vaccines. Serial comparisons of ECGs and questionnaire survey were performed before and after vaccine in four male-predominant senior high schools. Among 7934 eligible students, 4928 (62.1%) were included in the study. The male/female ratio was 4576/352. In total, 763 students (17.1%) had at least one cardiac symptom after the second vaccine dose, mostly chest pain and palpitations. The depolarization and repolarization parameters (QRS duration and QT interval) decreased significantly after the vaccine with increasing heart rate. Abnormal ECGs were obtained in 51 (1.0%) of the students, of which 1 was diagnosed with mild myocarditis and another 4 were judged to have significant arrhythmia. None of the patients needed to be admitted to hospital and all of these symptoms improved spontaneously. Using these five students as a positive outcome, the sensitivity and specificity of this screening method were 100% and 99.1%, respectively.  Conclusion: Cardiac symptoms are common after the second dose of BNT162b2 vaccine, but the incidences of significant arrhythmias and myocarditis are only 0.1%. The serial ECG screening method has high sensitivity and specificity for significant cardiac adverse effect but cost effect needs further discussed. What is Known: • The incidence of cardiac adverse effects was reported to be as high as 1.5 per 10 000 persons after the second dose BNT162b2 COVID-19 vaccine in the young male population based on the reporting system. What is New: • Through this mass ECG screening study after the second dose of BNT162b2 vaccine we found: (1) The depolarization and repolarization parameters (QRS duration and QT interval) decreased significantly after the vaccine with increasing heart rate; (2) the incidence of post-vaccine myocarditis and significant arrhythmia are 0.02% and 0.08%; (3) The serial ECG screening method has high sensitivity and specificity for significant cardiac adverse effect.

Three Ways to Improve Arm Function in the Chronic Phase After Stroke by Robotic Priming Combined With Mirror Therapy, Arm Training, and Movement-Oriented Therapy.

OBJECTIVE: To examine the effects of bilateral robotic priming combined with mirror therapy (R-mirr) vs bilateral robotic priming combined with bilateral arm training (R-bilat), relative to the control approach of bilateral robotic priming combined with movement-oriented training (R-mov) in patients with stroke. DESIGN: A single-blind, preliminary, randomized controlled trial. SETTING: Four outpatient rehabilitation settings. PARTICIPANTS: Outpatients with stroke and mild to moderate motor impairment (N=63). INTERVENTIONS: Patients received 6 weeks of clinic-based R-mirr, R-bilat, or R-mov for 90 min/d, 3 d/wk, plus a transfer package at home for 5 d/wk. MAIN OUTCOME MEASURES: Fugl-Meyer Assessment Upper Extremity subscale (FMA-UE), ABILHAND, and Stroke Impact Scale v3.0 scores before, immediately after, and 3 months after treatment as well as lateral pinch strength and accelerometry before and immediately after treatment. RESULTS: The posttest results favored R-mirr over R-bilat and R-mov on the FMA-UE score (P<.05). Follow-up analysis revealed that significant improvement in FMA-UE score was retained at the 3-month follow-up in the R-mirr over R-bilat or R-mov (P<.05). Significant improvements were not observed in the R-mirr over R-bilat and R-mov on other outcomes. CONCLUSIONS: Between-group differences were only detected for the primary outcome, FMA-UE. R-mirr was more effective at enhancing upper limb motor improvement, and the effect has the potential to be maintained at 3 months of follow-up.

The Biosynthetic Gene Cluster of Mushroom-Derived Antrocin Encodes Two Dual-Functional Haloacid Dehalogenase-like Terpene Cyclases.

(-)-Antrocin (1), produced by the medicinal mushroom Antrodia cinnamomea, is a potent antiproliferative compound. The biosynthetic gene cluster of 1 was identified, and the pathway was characterized by heterologous expression. We characterized a haloacid dehalogenase-like terpene cyclase AncC that biosynthesizes the drimane-type sesquiterpene (+)-albicanol (2) from farnesyl pyrophosphate (FPP). Biochemical characterization of AncC, including kinetic studies and mutagenesis, demonstrated the functions of two domains: a terpene cyclase (TC) and a pyrophosphatase (PPase). The TC domain first cyclizes FPP to albicanyl pyrophosphate, and the PPase domain then removes the pyrophosphate to form 2. Intriguingly, AncA (94 % sequence identity to AncC), in the same gene cluster, converts FPP into (R)-trans-γ-monocyclofarnesol instead of 2. Notably, Y283/F375 in the TC domain of AncA serve as a gatekeeper in controlling the formation of a cyclofarnesoid rather than a drimane-type scaffold.

The Phosphoprotein Synapsin Ia Regulates the Kinetics of Dense-Core Vesicle Release.

Common fusion machinery mediates the Ca2+-dependent exocytosis of synaptic vesicles (SVs) and dense-core vesicles (DCVs). Previously, Synapsin Ia (Syn Ia) was found to localize to SVs, essential for mobilizing SVs to the plasma membrane through phosphorylation. However, whether (or how) the phosphoprotein Syn Ia plays a role in regulating DCV exocytosis remains unknown. To answer these questions, we measured the dynamics of DCV exocytosis by using single-vesicle amperometry in PC12 cells (derived from the pheochromocytoma of rats of unknown sex) overexpressing wild-type or phosphodeficient Syn Ia. We found that overexpression of phosphodeficient Syn Ia decreased the DCV secretion rate, specifically via residues previously shown to undergo calmodulin-dependent kinase (CaMK)-mediated phosphorylation (S9, S566, and S603). Moreover, the fusion pore kinetics during DCV exocytosis were found to be differentially regulated by Syn Ia and two phosphodeficient Syn Ia mutants (Syn Ia-S62A and Syn Ia-S9,566,603A). Kinetic analysis suggested that Syn Ia may regulate the closure and dilation of DCV fusion pores via these sites, implying the potential interactions of Syn Ia with certain DCV proteins involved in the regulation of fusion pore dynamics. Furthermore, we predicted the interaction of Syn Ia with several DCV proteins, including Synaptophysin (Syp) and soluble N-ethylmaleimide-sensitive factor attachment receptor (SNARE) proteins. By immunoprecipitation, we found that Syn Ia interacted with Syp via phosphorylation. Moreover, a proximity ligation assay (PLA) confirmed their phosphorylation-dependent, in situ interaction on DCVs. Together, these findings reveal a phosphorylation-mediated regulation of DCV exocytosis by Syn Ia.SIGNIFICANCE STATEMENT Although they exhibit distinct exocytosis dynamics upon stimulation, synaptic vesicles (SVs) and dense-core vesicles (DCVs) may undergo co-release in neurons and neuroendocrine cells through an undefined molecular mechanism. Synapsin Ia (Syn Ia) is known to recruit SVs to the plasma membrane via phosphorylation. Here, we examined whether Syn Ia also affects the dynamics of DCV exocytosis. We showed that Syn Ia regulates the DCV secretion rate and fusion pore kinetics during DCV exocytosis. Moreover, Syn Ia-mediated regulation of DCV exocytosis depends on phosphorylation. We further found that Syn Ia interacts with Synaptophysin (Syp) on DCVs in a phosphorylation-dependent manner. Thus, these results suggest that Syn Ia may regulate the release of DCVs via phosphorylation.

TRAX Provides Neuroprotection for Huntington's Disease Via Modulating a Novel Subset of MicroRNAs.

BACKGROUND: Huntington's disease (HD) is a neurodegenerative disease caused by CAG-repeat expansions (>36) in exon 1 of HTT, which dysregulates multiple cellular machineries. Translin-associated protein X (TRAX) is a scaffold protein with diverse functions, including suppressing the microRNA (miRNA)-mediated silencing by degrading pre-miRNA. To date, the role of TRAX in neurodegenerative diseases remains unknown. OBJECTIVES: We delineated the role of TRAX upregulation during HD progression. METHODS: Expression of TRAX in the brains of humans and three mouse models with HD were analyzed by immunohistochemistry staining, western blot, and quantitative reverse transcription-polymerase chain reaction. Adeno-associated viruses harboring TRAX short hairpin RNA were intrastriatally injected into HD mice to downregulate TRAX. HD-like symptoms were analyzed by behavioral and biochemical assessments. The miRNA-sequencing and RNA-sequencing analyses were used to identify the TRAX- regulated miRNA-messenger RNA (mRNA) axis during HD progression. The identified gene targets were validated biochemically in mouse and human striatal cells. RESULTS: We discovered that TRAX was upregulated in the brains of HD patients and three HD mouse models. Downregulation of TRAX enhanced 83 miRNAs (including miR-330-3p, miR-496a-3p) and subsequently changed the corresponding mRNA networks critical for HD pathogenesis (eg, DARPP-32 and brain-derived neurotrophic factor). Disruption of the TRAX-mediated miRNA-mRNA axis accelerated the progression of HD-like symptoms, including the degeneration of motor function, accumulation of mHTT aggregates, and shortened neurite outgrowth. CONCLUSIONS: We demonstrated that TRAX upregulation is authentic and protective in HD. Our study provides a novel layer of regulation for HD pathogenesis and may lead to the development of new therapeutic strategies for HD. © 2022 International Parkinson and Movement Disorder Society.

Functional association of NR4A3 downregulation with impaired differentiation in myeloid leukemogenesis.

The coincident downregulation of NR4A1 and NR4A3 has been implicated in myeloid leukemogenesis, but it remains unknown how these two genes function in myeloid cells and how their combined downregulation promotes myeloid leukemogenesis. Since NR4A1 abrogation is thought to confer a survival and proliferation advantage to myeloid cells, we hypothesized that downregulation of NR4A3 may have a complementary effect on myeloid cell differentiation. First, we tested the association between differentiation status of leukemic cells and NR4A3 expression using two large clinical datasets from patients with different acute myeloid leukemia (AML) subtypes. The analysis revealed a close association between differentiation status and different subtypes of AML Then, we probed the effects of differentiation-inducing treatments on NR4A3 expression and NR4A3 knockdown on cell differentiation using two myeloid leukemia cell lines. Differentiation-inducing treatments caused upregulation of NR4A3, while NR4A3 knockdown prevented differentiation in both cell lines. The cell culture findings were validated using samples from chronic myeloid leukemia (CML) patients at chronic, accelerated and blastic phases, and in acute promyelocytic leukemia (APL) patients before and after all trans-retinoic acid (ATRA)-based differentiation therapy. Progressive NR4A3 downregulation was coincident with impairments in differentiation in patients during progression to blastic phase of CML, and NR4A3 expression was increased in APL patients treated with ATRA-based differentiating therapy. Together, our findings demonstrate a tight association between impaired differentiation status and NR4A3 downregulation in myeloid leukemias, providing a plausible mechanistic explanation of how myeloid leukemogenesis might occur upon concurrent downregulation of NR4A1 and NR4A3.