A bisulfite-assisted and ligation-based qPCR amplification technology for locus-specific pseudouridine detection at base resolution.

Over 150 types of chemical modifications have been identified in RNA to date, with pseudouridine (Ψ) being one of the most prevalent modifications in RNA. Ψ plays vital roles in various biological processes, and precise, base-resolution detection methods are fundamental for deep analysis of its distribution and function. In this study, we introduced a novel base-resolution Ψ detection method named pseU-TRACE. pseU-TRACE relied on the fact that RNA containing Ψ underwent a base deletion after treatment of bisulfite (BS) during reverse transcription, which enabled efficient ligation of two probes complementary to the cDNA sequence on either side of the Ψ site and successful amplification in subsequent real-time quantitative PCR (qPCR), thereby achieving selective and accurate Ψ detection. Our method accurately and sensitively detected several known Ψ sites in 28S, 18S, 5.8S, and even mRNA. Moreover, pseU-TRACE could be employed to measure the Ψ fraction in RNA and explore the Ψ metabolism of different pseudouridine synthases (PUSs), providing valuable insights into the function of Ψ. Overall, pseU-TRACE represents a reliable, time-efficient and sensitive Ψ detection method.

HBO1 catalyzes lysine lactylation and mediates histone H3K9la to regulate gene transcription.

Lysine lactylation (Kla) links metabolism and gene regulation and plays a key role in multiple biological processes. However, the regulatory mechanism and functional consequence of Kla remain to be explored. Here, we report that HBO1 functions as a lysine lactyltransferase to regulate transcription. We show that HBO1 catalyzes the addition of Kla in vitro and intracellularly, and E508 is a key site for the lactyltransferase activity of HBO1. Quantitative proteomic analysis further reveals 95 endogenous Kla sites targeted by HBO1, with the majority located on histones. Using site-specific antibodies, we find that HBO1 may preferentially catalyze histone H3K9la and scaffold proteins including JADE1 and BRPF2 can promote the enzymatic activity for histone Kla. Notably, CUT&Tag assays demonstrate that HBO1 is required for histone H3K9la on transcription start sites (TSSs). Besides, the regulated Kla can promote key signaling pathways and tumorigenesis, which is further supported by evaluating the malignant behaviors of HBO1- knockout (KO) tumor cells, as well as the level of histone H3K9la in clinical tissues. Our study reveals HBO1 serves as a lactyltransferase to mediate a histone Kla-dependent gene transcription.

Desmoglein 2 and desmocollin 2 depletions promote malignancy through distinct mechanisms in triple-negative and luminal breast cancer.

BACKGROUND: Aberrant expressions of desmoglein 2 (Dsg2) and desmocollin 2(Dsc2), the two most widely distributed desmosomal cadherins, have been found to play various roles in cancer in a context-dependent manner. Their specific roles on breast cancer (BC) and the potential mechanisms remain unclear. METHODS: The expressions of Dsg2 and Dsc2 in human BC tissues and cell lines were assessed by using bioinformatics analysis, immunohistochemistry and western blotting assays. Wound-healing and Transwell assays were performed to evaluate the cells' migration and invasion abilities. Plate colony-forming and MTT assays were used to examine the cells' capacity of proliferation. Mechanically, Dsg2 and Dsc2 knockdown-induced malignant behaviors were elucidated using western blotting assay as well as three inhibitors including MK2206 for AKT, PD98059 for ERK, and XAV-939 for ß-catenin. RESULTS: We found reduced expressions of Dsg2 and Dsc2 in human BC tissues and cell lines compared to normal counterparts. Furthermore, shRNA-mediated downregulation of Dsg2 and Dsc2 could significantly enhance cell proliferation, migration and invasion in triple-negative MDA-MB-231 and luminal MCF-7 BC cells. Mechanistically, EGFR activity was decreased but downstream AKT and ERK pathways were both activated maybe through other activated protein tyrosine kinases in shDsg2 and shDsc2 MDA-MB-231 cells since protein tyrosine kinases are key drivers of triple-negative BC survival. Additionally, AKT inhibitor treatment displayed much stronger capacity to abolish shDsg2 and shDsc2 induced progression compared to ERK inhibition, which was due to feedback activation of AKT pathway induced by ERK inhibition. In contrast, all of EGFR, AKT and ERK activities were attenuated, whereas ß-catenin was accumulated in shDsg2 and shDsc2 MCF-7 cells. These results indicate that EGFR-targeted therapy is not a good choice for BC patients with low Dsg2 or Dsc2 expression. Comparatively, AKT inhibitors may be more helpful to triple-negative BC patients with low Dsg2 or Dsc2 expression, while therapies targeting ß-catenin can be considered for luminal BC patients with low Dsg2 or Dsc2 expression. CONCLUSION: Our finding demonstrate that single knockdown of Dsg2 or Dsc2 could promote proliferation, motility and invasion in triple-negative MDA-MB-231 and luminal MCF-7 cells. Nevertheless, the underlying mechanisms were cellular context-specific and distinct.

The mitochondrial genome of Monoserius pennarius (Linnaeus, 1758) from the East China Sea.

The species Monoserius pennarius (Linnaeus, 1758), is particularly abundant in the tropical Indo-West Pacific east of Sri Lanka, yet very limited genetic information exists for this species. Here, we report the assembled-linear mitochondrial genome of M. pennarius collected from the East China Sea. The 15,197 bp mitogenome contains 13 protein-coding genes (PCGs), two tRNA genes, and two rRNA genes. Notably, the gene order in this mitogenome differs from that of other hydrozoans within the same taxonomic order. Phylogenetic analysis, based on 13 concatenated mitochondrial PCGs, recovered M. pennarius as a sister of Nemalecium lighti (Hargitt, 1924), outside the other Leptothecata hydrozoans, suggesting paraphyly of Leptothecata. The mitogenome of M. pennarius, serving as the first publicly available for the family Aglaopheniidae, holds foreseeable value for investigating Leptothecata evolution.

TXNIP/NLRP3 aggravates global cerebral ischemia-reperfusion injury-induced cognitive decline in mice.

Global cerebral ischemia/reperfusion (GCI/R) injury poses a risk for cognitive decline, with neuroinflammation considered pivotal in this process. This study aimed to unravel the molecular mechanisms underlying GCI/R injury and propose a potential therapeutic strategy for associated cognitive deficits. Utilizing bioinformatics analysis of a public microarray profile (GSE30655 and GSE80681) in cerebral ischemic mice, it was observed that neuroinflammation emerged as a significant gene ontology item, with an increase in the expression of thioredoxin-interacting protein (TXNIP) and NLRP3 genes. Experimental models involving bilateral occlusion of the common carotid arteries in mice revealed that GCI/R induced cognitive impairment, along with a time-dependent increase in TXNIP and NLRP3 levels. Notably, TXNIP knockdown alleviated cognitive dysfunction in mice. Furthermore, the introduction of adeno-associated virus injection with TXNIP knockdown reduced the number of activated microglia, apoptosis neurons, and levels of oxidative stress and inflammatory cytokines in the hippocampus. Collectively, these findings underscore the significance of TXNIP/NLRP3 in the hippocampus in exacerbating cognitive decline due to GCI/R injury, suggesting that TXNIP knockdown holds promise as a therapeutic strategy.

Locus-specific detection of pseudouridine with CRISPR-Cas13a.

We combined the CRISPR-Cas13a system with CMC chemical labeling, developing an approach that enables precise identification of pseudouridine (Ψ) sites at specific loci within ribosomal RNA (rRNA), messenger RNA (mRNA) and small nuclear RNAs (snRNA). This method, with good efficiency and simplicity, detects Ψ sites through fluorescence measurement, providing a straightforward and fast validation for targeted Ψ sites of interest.

New onset or recurrence of uveitis following COVID-19 infection.

BACKGROUND: While the 2019 novel coronavirus disease (COVID-19) pandemic has resulted in millions of cases worldwide, there is increasing recognition of a wide range of ocular manifestations associated with the virus, including uveitis. Uveitis is an inflammatory condition of the uveal tract of the eye that can lead to permanent vision loss if not treated promptly. Here we report a retrospective observational study of patients who presented with new onset or recurrent uveitis following COVID-19 infection. METHODS: This is a retrospective observational study conducted at the Beijing Tongren Hospital. We identified patients who presented with symptoms of non-infectious active uveitis with positive real-time reverse transcription polymerase chain reaction (RT-PCR) of COVID-19 within 4 weeks. All patients received ophthalmic examinations, including anterior and posterior segment imaging, to assess the extent of ocular involvement. RESULTS: The 18 patients with a total of 33 eyes included in this study presented with symptoms of active uveitis within 4 weeks of their positive COVID-19 RT-PCR test. Among them, 9 patients presented with the development of uveitis following COVID-19 infection, and 9 patients had relapsed uveitis after COVID-19 infection. Treatment with corticosteroids resulted in improvement of symptoms and resolution of inflammation in all cases. In this study, all patients did not experience any adverse drug reactions during treatment. CONCLUSION: Our observational study highlights the potential for new onset or recurrence of uveitis following COVID-19 infection. TRIAL REGISTRATION: https://www.chictr.org.cn/ ; identifier: ChiCTR2100044365, date: 03/17/2023.

The characteristics of acute macular neuroretinopathy following COVID-19 infection.

BACKGROUND: In this study, we report a case series of acute macular neuroretinopathy (AMN) associated with COVID-19 infection. METHODS: This retrospective observational study was conducted at Beijing Tongren Hospital. We reviewed patients who were diagnosed with AMN within one month of testing positive for COVID-19 using real-time reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: A total of 11 AMN patients (20 eyes) were included in the study. The mean age was 33.8 ± 12.6 years. The average interval between a positive COVID-19 PCR test and the onset of ocular symptoms was 2.8 ± 2.5 days. The mean follow-up period for the patients was 12.5 ± 3.8 weeks. Imaging characteristics of AMN patients following COVID-19 infection included areas of low reflectivity on near-infrared reflectance (NIR) imaging, hyperreflective lesions at the level of the outer plexiform layer (OPL) and outer nuclear layer (ONL) and disruption of the ellipsoid zone (EZ) on spectral domain optical coherence tomography (SD-OCT) B-scans. Visual field examinations revealed parafoveal scotomas that closely corresponded to the clinical lesions. Optical coherence tomography angiography (OCT-A) demonstrated impaired perfusion in the deep retinal vascular plexus. Fluorescein angiography (FA), indocyanine green angiography (ICGA), and spontaneous fundus autofluorescence showed no significant abnormalities. During follow-up, partial improvement in retinal lesions was observed in NIR imaging and SD-OCT in some patients, but a proportion of patients still exhibited persistent retinal damage and no improvement in visual field scotomas. CONCLUSION: COVID-19-related AMN share similar clinical and imaging features with AMN due to other causes, as evidenced by the persistent presence of visual field scotomas over a longer duration. TRAIL REGISTRATION: https://www.chictr.org.cn/ ; identifier: ChiCTR2100044365.

Detection, Clinical Application, and Manipulation of RNA Modifications.

ConspectusWith increasing research interest, more than 170 types of chemical modifications of RNA have been characterized. The epigenetic modifications of RNA do not alter the primary sequence of RNA but modulate the gene activity. Increasing numbers of regulatory functions of these RNA modifications, particularly in controlling mRNA fate and gene expression, are being discovered. To gain a deeper understanding of the biological significance and clinical prospects of RNA modifications, the development of innovative labeling and detection methodologies is of great importance. Owing to the dynamic features of RNA modifications and the fact that only a portion of genes are modified, detection methods should accurately reveal the precise distribution and modification level of RNA modifications. In general, detection methodologies identify specific RNA modifications in two ways: (1) enriching modification-containing RNAs; and (2) altering the Watson-Crick base pairing pattern to produce truncation or mutation signatures. Additionally, it is important to develop flexible and accurate manipulation tools that enable the installation or removal of RNA modifications at specific positions to investigate the biological functions of a single site. With the development of detection and manipulation methods, the scientific understanding of the biological functions of RNA modifications has increased, paving the way for applications of RNA modifications in disease diagnosis and treatments.In this Account, we provide a brief summary of recent efforts to develop methodologies for detecting RNA modifications. Through the evolution of these detection techniques, our team has uncovered the potential biological roles of RNA modifications in diseases such as diabetic cardiovascular complications, viral infections, and hematologic malignancies. We mainly summarize the recently developed strategies for manipulating RNA modifications. The advent of these programmable editing tools allows for the precise installation or removal of RNA modifications at specific positions. As a result, the biological functions of RNA modifications at these specific loci could be identified, further advancing our knowledge in this field.With this Account, we anticipate providing chemical and biological researchers with comprehensive strategies to discover the underlying mechanisms of RNA modification-mediated biological processes. Although the field of RNA modifications has undergone rapid progress in recent years, our understanding of most of these RNA modifications remains incomplete. We hope to inspire efforts to expand the toolbox for investigating RNA modifications and promote translational research on epigenetics in clinical diagnosis and treatment.

Comparative Efficacy and Safety of Chinese Patent Medicines for Cervical High-risk Human Papillomavirus Infection: A Bayesian Network Meta-analysis.

Background: Many Chinese patent medicines have been reported to show anti-tumor cell effects on cervical cancer. To estimate the comparative effectiveness and safety of Chinese patent medicines for cervical high-risk human papillomavirus (HR-HPV) infection. Methods: Randomized controlled trials (RCTs) of Chinese patent medicines for HR-HPV infection were searched in eight databases until 31 August 2022, and two review authors independently extracted data and assessed the risk of bias. Outcomes concerning efficacy were evaluated as odds ratio (OR) and 95% credible intervals (CrI) utilizing R 4.1.2 and Stata 16.1. The protocol was registered on the International Prospective Register of Systematic Reviews (CRD42022351120). Results: We ultimately identified 60 RCTs that involved 5,951 participants and 8 interventions. Chinese patent medicines combined with recombinant human interferon (rhIFN) have better treatment effects than rhIFN alone. The results showed that Baofukang suppository (BFK) combined with rhIFN is greater for the rate of HR-HPV clearance follow-up at 6 months (SUCRA = 78.16%). Kushen gel (KS) combined with rhIFN ranked first for the rate of HR-HPV clearance after treatment (SUCRA = 90.77%). Furthermore, KS + rhIFN is most likely to be the best intervention for improving the clinical effectiveness rate (SUCRA = 87.39%). Adverse reactions were not statistically significant in BFK + rhIFN versus BFK, BFK + rhIFN versus rhIFN, and BFK versus rhIFN. Conclusion: The combination of Chinese patent medicines with rhIFN may demonstrate a higher efficacy than rhIFN alone in clearing the virus and improving cervical symptoms. Weighing with the clinical comprehensive efficacy, BFK + rhIFN and KS + rhIFN maybe the optimal treatments for cervical HR-HPV infection. However, more high-quality randomized controlled trials are needed in the future to further confirm the efficacy and safety of proprietary Chinese medicines for cervical HR-HPV infection.

[Genetic Subtypes and Pretreatment Drug Resistance in the Newly Reported Human Immunodeficiency Virus-Infected Men Aged≥50 Years Old in Guangxi].

Objective To analyze the genetic subtypes of human immunodeficiency virus (HIV) and the prevalence of pretreatment drug resistance in the newly reported HIV-infected men in Guangxi. Methods The stratified random sampling method was employed to select the newly reported HIV-infected men aged≥50 years old in 14 cities of Guangxi from January to June in 2020.The pol gene of HIV-1 was amplified by nested reverse transcription polymerase chain reaction and then sequenced.The mutation sites associated with drug resistance and the degree of drug resistance were then analyzed. Results A total of 615 HIV-infected men were included in the study.The genetic subtypes of CRF01_AE,CRF07_BC,and CRF08_BC accounted for 57.4% (353/615),17.1% (105/615),and 22.4% (138/615),respectively.The mutations associated with the resistance to nucleoside reverse transcriptase inhibitors (NRTI),non-nucleoside reverse transcriptase inhibitors (NNRTI),and protease inhibitors occurred in 8 (1.3%),18 (2.9%),and 0 patients,respectively.M184V (0.7%) and K103N (1.8%) were the mutations with the highest occurrence rates for the resistance to NRTIs and NNRTIs,respectively.Twenty-two (3.6%) patients were resistant to at least one type of inhibitors.Specifically,4 (0.7%),14 (2.3%),4 (0.7%),and 0 patients were resistant to NRTIs,NNRTIs,both NRTIs and NNRTIs,and protease inhibitors,respectively.The pretreatment resistance to NNRTIs had much higher frequency than that to NRTIs (2.9% vs.1.3%;χ2=3.929,P=0.047).The prevalence of pretreatment resistance to lamivudine,zidovudine,tenofovir,abacavir,rilpivirine,efavirenz,nevirapine,and lopinavir/ritonavir was 0.8%, 0.3%, 0.7%, 1.0%, 1.3%, 2.8%, 2.9%, and 0, respectively. Conclusions CRF01_AE,CRF07_BC,and CRF08_BC are the three major strains of HIV-infected men≥50 years old newly reported in Guangxi,2020,and the pretreatment drug resistance demonstrates low prevalence.

U-shaped association between low-density lipoprotein cholesterol levels and risk of all-cause mortality mediated by post-stroke infection in acute ischemic stroke.

During the acute stage of ischemic stroke, it remains unclear how to interpret the low low-density lipoprotein cholesterol (LDL-C) level. We aimed to evaluate the association between LDL-C levels, post-stroke infection, and all-cause mortality. 804,855 ischemic stroke patients were included. Associations between LDL-C levels, infection, and mortality risk were estimated by multivariate logistic regression models and displayed by restricted cubic spline curves. Mediation analysis was performed under counterfactual framework to elucidate the mediation effect of post-stroke infection. The association between LDL-C and mortality risk was U-shaped. The nadir in LDL-C level with the lowest mortality risk was 2.67 mmol/L. Compared with the group with LDL-C = 2.50-2.99 mmol/L, the multivariable-adjusted odds ratio for mortality was 2.22 (95% confidence intervals (CI): 1.77-2.79) for LDL-C <1.0 mmol/L and 1.22 (95% CI: 0.98-1.50) for LDL-C ≥5.0 mmol/L. The association between LDL-C and all-cause mortality was 38.20% (95% CI: 5.96-70.45, P = 0.020) mediated by infection. After stepwise excluding patients with increasing numbers of cardiovascular risk factors, the U-shaped association between LDL-C and all-cause mortality and the mediation effects of infection remained consistent with the primary analysis, but the LDL-C interval with the lowest mortality risk increased progressively. The mediation effects of infection were largely consistent with the primary analysis in subgroups of age ≥65 years, female, body mass index <25 kg/m2, and National Institutes of Health Stroke Scale ≥16. During the acute stage of ischemic stroke, there is a U-shaped association between LDL-C level and all-cause mortality, where post-stroke infection is an important mediating mechanism.

Transcriptome-wide identification of single-stranded RNA binding proteins.

RNA-protein interactions are precisely regulated by RNA secondary structures in various biological processes. Large-scale identification of proteins that interact with particular RNA structure is important to the RBPome. Herein, a kethoxal assisted single-stranded RNA interactome capture (KASRIC) strategy was developed to globally identify single-stranded RNA binding proteins (ssRBPs). This approach combines RNA secondary structure probing technology with the conventional method of RNA-binding proteins profiling, realizing the transcriptome-wide identification of ssRBPs. Applying KASRIC, we identified 3180 candidate RBPs and 244 candidate ssRBPs in HeLa cells. Importantly, the 244 candidate ssRBPs contained 55 previously reported ssRBPs and 189 novel ssRBPs. Function analysis of the candidate ssRBPs exhibited enrichment in cellular processes related to RNA splicing and RNA degradation. The KASRIC strategy will facilitate the investigation of RNA-protein interactions.

[Percutaneous foraminal endoscopy for the treatment of lumbar lateral recess stenosis in elderly].

OBJECTIVE: To investigate the clinical efficacy and safety of percutaneous foraminal endoscopy in the treatment of lumbar lateral recess stenosis in elderly. METHODS: The clinical data of 31 elderly patients with lumbar lateral recess stenosis treated by percutaneous foraminal endoscopic decompression from March 2018 to August 2019 were retrospectively analyzed. Including 16 males and 15 females, aged from 65 to 81 years with an average of (71.13±5.20) years, the course of disease ranged from 3 months to 7 years with an average of (14.36±6.52) months. Visual analogue scale (VAS) and Oswestry disability index (ODI) were used to assess clinical symptom and functional status before operation and 1, 6, 12 months after operation. At the final follow-up, the modified Macnab standard was used to evaluate clinical efficacy. RESULTS: All patients were completed the operation successfully. The operation time was from 75 to 120 min with an average of (97.84±11.22 ) min. All 31 patients were followed up from 12 to 28 months with an average of (17.29±5.56) months. Postoperative lumbago-leg pain VAS and ODI were significantly improved at 1, 6, and 12 months(P<0.01). At the final follow-up, according to the modified Macnab standard to evaluate the effect, 23 got excellent results, 5 good, 3 fair. One patient had severe adhesions between peripheral tissues and nerve root, and postoperative sensory abnormalities in the lower extremities were treated conservatively with traditional Chinese medicine and neurotrophic drugs, which recovered at 2 weeks after surgery. No complications such as nerve root injury and infection occurred. CONCLUSION: The intervertebral foraminal endoscopy technique, which is performed under local anesthesia for a short period of operation, ensures adequate decompression while minimizing complications, and is a safe and effective surgical procedure for elderly patients with lumbar lateral recess stenosis.

ENO1 expression and Erk phosphorylation in PDAC and their effects on tumor cell apoptosis in a hypoxic microenvironment.

OBJECTIVE: Hypoxia is an important feature of pancreatic ductal adenocarcinoma (PDAC). Previously, we found that hypoxia promotes ENO1 expression and PDAC invasion. However, the underlying molecular mechanism was remains unclear. METHODS: The relationship between ENO1 expression and clinicopathological characteristics was analyzed in 84 patients with PADC. The effects of CoCl2-induced hypoxia and ENO1 downregulation on the apoptosis, invasion, and proliferation of PDAC cells were evaluated in vitro and in vivo. Hypoxia- and ENO1-induced gene expression was analyzed by transcriptomic sequencing. RESULTS: The prognosis of PDAC with high ENO1 expression was poor (P < 0.05). High ENO1 expression was closely associated with histological differentiation and tumor invasion in 84 PDAC cases (P < 0.05). Hypoxia increased ENO1 expression in PDAC and promoted its migration and invasion. Apoptotic cells and the apoptosis marker caspase-3 in the CoCl2-treated ENO1-sh group were significantly elevated (P < 0.05). Transcriptomic sequencing indicated that CoCl2-induced PDAC cells initiated MAPK signaling. Under hypoxic conditions, PDAC cells upregulated ENO1 expression, thereby accelerating ERK phosphorylation and inhibiting apoptosis (P < 0.05). Consistent results were also observed in a PDAC-bearing mouse hindlimb ischemia model. CONCLUSIONS: Hypoxia-induced ENO1 expression promotes ERK phosphorylation and inhibits apoptosis, thus leading to PDAC survival and invasion. These results suggest that ENO1 is a potential therapeutic target for PDAC.

[Value of functional echocardiographic parameters in predicting refractory septic shock in neonates]. / åŠŸèƒ½æ€§è¶ å£°å¿ƒåŠ¨å›¾å‚æ•°åœ¨æ–°ç”Ÿå„¿è„“æ¯’ç—‡ä¼‘å ‹ä¸­çš„ä¸´åºŠåº”ç”¨ä»·å€¼.

OBJECTIVES: To study the value of functional echocardiographic parameters in predicting refractory septic shock in neonates. METHODS: A total of 72 neonates with septic shock were enrolled. According to the highest value of septic shock score, they were divided into two groups: refractory (n=30) and non-refractory (n=42). The two groups were compared in terms of clinical data, laboratory findings, and functional echocardiographic parameters. The receiver operating characteristic (ROC) curve was used to evaluate the performance of functional echocardiographic parameters in predicting refractory septic shock. RESULTS: Compared with the non-refractory group, the refractory group had significantly lower cardiac output and cardiac index (CI) and a significantly higher mean arterial pressure (MAP)/CI ratio (P<0.05). CI had a cut-off value of 2.6 L/(min·m2), a sensitivity of 79%, a specificity of 83%, and an area under the ROC curve (AUC) of 0.841 in predicting septic shock-related death (P<0.05), and MAP/CI ratio had a cut-off value of 11.4, a sensitivity of 83%, a specificity of 73%, and an AUC of 0.769 (P<0.05). CI had a cut-off value of 2.9 L/(min·m2), a sensitivity of 69%, a specificity of 69%, and an AUC of 0.717 in predicting all-cause death within 28 days (P<0.05). CONCLUSIONS: CI and MAP/CI ratio can be useful for early prediction of septic shock-related death in neonates.

Mycn regulates intestinal development through ribosomal biogenesis in a zebrafish model of Feingold syndrome 1.

Feingold syndrome type 1, caused by loss-of-function of MYCN, is characterized by varied phenotypes including esophageal and duodenal atresia. However, no adequate model exists for studying the syndrome's pathological or molecular mechanisms, nor is there a treatment strategy. Here, we developed a zebrafish Feingold syndrome type 1 model with nonfunctional mycn, which had severe intestinal atresia. Single-cell RNA-seq identified a subcluster of intestinal cells that were highly sensitive to Mycn, and impaired cell proliferation decreased the overall number of intestinal cells in the mycn mutant fish. Bulk RNA-seq and metabolomic analysis showed that expression of ribosomal genes was down-regulated and that amino acid metabolism was abnormal. Northern blot and ribosomal profiling analysis showed abnormal rRNA processing and decreases in free 40S, 60S, and 80S ribosome particles, which led to impaired translation in the mutant. Besides, both Ribo-seq and western blot analysis showed that mTOR pathway was impaired in mycn mutant, and blocking mTOR pathway by rapamycin treatment can mimic the intestinal defect, and both L-leucine and Rheb, which can elevate translation via activating TOR pathway, could rescue the intestinal phenotype of mycn mutant. In summary, by this zebrafish Feingold syndrome type 1 model, we found that disturbance of ribosomal biogenesis and blockage of protein synthesis during development are primary causes of the intestinal defect in Feingold syndrome type 1. Importantly, our work suggests that leucine supplementation may be a feasible and easy treatment option for this disease.

Mucosal associated Lymphoid Tissue Lymphoma of the uvea: an analysis of 3 cases.

BACKGROUND: Ocular mucosa-associated lymphoid tissue (MALT) lymphoma involving orbit and conjunctiva usually has an indolent clinical course with "salmon patch" mass as typical presentation. This study is to report a series of rare cases and investigate the clinical and pathological features of ocular MALT lymphoma that involved uveal tissue primarily and presented as posterior scleritis. METHODS: This retrospective, observational study was conducted at Beijing Tongren Hospital. From 2018 to 2020, 3 cases of 3 eyes (2 female patients and 1 male patient) with ocular MALT lymphoma that involved uveal tissue primarily and presented as posterior scleritis were included in the study. All patients had complaints of red eyes with blurred vision. The average age was 56.33 ± 2.08 years old and the average time from initial diagnosis to pathological diagnosis was 3.00 ± 1.73 months. Ophthalmic examinations including best-corrected visual acuity (BCVA), intraocular pressure (IOP), slit lamp microscope examinations, fundus photography, B-scan ultrasonography, ultrasound biomicroscope (UBM), optical coherence tomography (OCT), fundus fluorescein angiography (FFA) and indocyanine green angiography (ICGA) were conducted. Systemic workups including orbital magnetic resonance imaging (MRI), positron emission tomography-computed tomography (PET-CT) and blood autoimmune antibody tests were also conducted. Pathological tissue from patients were obtained through surgeries. Biopsy examinations were performed to accurately determine pathological diagnosis. All the information of clinical, imaging and pathological changes were collected and analyzed. RESULTS: At the initial diagnosis, the BCVA of involved eyes decreased seriously while the IOP were normal. All involved eyeball showed extensive hyperemia and local thickening in the wall of eyeballs. B-scan ultrasonography showed mass with abundant blood and irregular cysts inside the eyeball wall and in the retrobulbar orbit, surrounding the ocular wall and optic nerve. UBM showed solid lesions with low and medium echo under the conjunctiva and inside the ciliary body of 2 cases. OCT showed posterior polar wavy rise of RPE and local neuroepithelial detachment in all cases. FFA and ICGA showed vascular abnormalities (patch-like strong fluorescence and fluorescence leakage) and local thickening in retina and choroid (Rectangle-like weak fluorescence below the macula). The posterior wall of the eyeball was thickened and enhanced in MRI. PET-CT also showed thickening of posterior wall of eyeballs and increased metabolic activity but there was no sign of autoimmune disease. All patients were diagnosed as MALT lymphoma through pathologic examinations of biopsy tissue. CONCLUSIONS: The onset of primary ocular MALT lymphoma in uvea is hidden. The early clinical manifestations are lack of specificity and misleading. B-scan ultrasonography has characteristic manifestations and is valuable in diagnosis. However, pathological diagnosis through tissue biopsy is irreplaceable.