Antileukemic effect of venetoclax and hypomethylating agents via caspase-3/GSDME-mediated pyroptosis.

BACKGROUND: The identifying of B-cell lymphoma 2 (Bcl-2) as a therapeutic target has led to a paradigm shift in acute myeloid leukemia (AML) treatment. Pyroptosis is a novel antitumor therapeutic mechanism due to its cytotoxic and immunogenic effects. The combination of venetoclax and hypomethylating agents (HMAs) has been shown to lead to durable responses and significantly improve prognosis in patients with AML. However, our understanding of the mechanisms underlying this combinatorial activity is evolving. METHODS: We investigated whether the Bcl-2 inhibitor venetoclax induces AML cell pyroptosis and identified pyroptosis effector proteins. Via using western blotting, immunoprecipitation, RNA interference, CCK8 assays, and LDH assays, we explored the mechanism underlying the pyroptotic effect. The relationship between the expression of the pyroptosis effector protein GSDME and AML prognosis was investigated. The effect of GSDME demethylation combined with venetoclax treatment on pyroptosis was investigated and confirmed in mouse models and clinical samples. RESULTS: Venetoclax induces pyroptosis that is mediated by caspase-3-dependent GSDME cleavage. Mechanistically, venetoclax upregulates caspase-3 and GSDME cleavage by activating the intrinsic apoptotic pathway. GSDME is downregulated in AML by promoter methylation, and low GSDME expression is significantly associated with poor prognosis, based on public databases and patient sample analysis. In vivo and in vitro experiments showed that GSDME overexpression or HMAs-mediated restoration of GSDME expression significantly increased venetoclax-induced pyroptosis in AML. CONCLUSION: GSDME-mediated pyroptosis may be a novel aspect of the antileukemic effect of Bcl-2 inhibitors. This finding offers new insights into potential biomarkers and therapeutic strategies, identifying an important mechanism explaining the clinical activity of venetoclax and HMAs in AML.

Silencing of miR-132-3p protects against neuronal injury following status epilepticus by inhibiting IL-1ß-induced reactive astrocyte (A1) polarization.

Mesial temporal lobe epilepsy (MTLE) is one of the most common refractory epilepsies and is usually accompanied by a range of brain pathological changes, such as neuronal injury and astrocytosis. Naïve astrocytes are readily converted to cytotoxic reactive astrocytes (A1) in response to inflammatory stimulation, suppressing the polarization of A1 protects against neuronal death in early central nervous system injury. Our previous study found that pro-inflammatory cytokines and miR-132-3p (hereinafter referred to as "miR-132") expression were upregulated, but how miR-132 affected reactive astrocyte polarization and neuronal damage during epilepsy is not fully understood. Here, we aimed to explore the effect and mechanism of miR-132 on A1 polarization. Our results confirmed that A1 markers were significantly elevated in the hippocampus of MTLE rats and IL-1ß-treated primary astrocytes. In vivo, knockdown of miR-132 by lateral ventricular injection reduced A1 astrocytes, neuronal loss, mossy fiber sprouting, and remitted the severity of status epilepticus and the recurrence of spontaneous recurrent seizures. In vitro, the neuronal cell viability and axon length were reduced by additional treatment with A1 astrocyte conditioned media (ACM), and downregulation of astrocyte miR-132 rescued the inhibition of cell activity by A1 ACM, while the length of axons was further inhibited. The regulation of miR-132 on A1 astrocytes may be related to its target gene expression. Our results show that interfering with astrocyte polarization may be a breakthrough in the treatment of refractory epilepsy, which may extend to the research of other astrocyte polarization-mediated brain injuries.

[Clinical features and prognosis in 20 children with rhabdomyosarcoma]. / 20例横纹肌肉瘤患儿的临床特点及预后分析.

OBJECTIVES: To study the clinical features of children with rhabdomyosarcoma (RMS) and the influencing factors for prognosis. METHODS: A retrospective analysis was performed on the clinical and follow-up data of 20 children with RMS who were admitted to the Department of Pediatric Hematology, Xiangya Hospital of Central South University, from June 2014 to September 2020. RESULTS: The most common clinical symptoms of the 20 children with RMS at the first visit were painless mass (13/20, 65%), exophthalmos (4/20, 20%), and abdominal pain (3/20, 15%). According to the staging criteria of Intergroup Rhabdomyosarcoma Study Group (IRSG), there was 1 child (5%) with stage I RMS, 4 (20%) with stage II RMS, 9 (45%) with stage III RMS, and 6 (30%) with stage IV RMS. The median follow-up time was 19 months for the 20 children (range: 3-93 months), with a 2-year overall survival (OS) rate of 79.5% (95%CI: 20.1-24.3) and a 2-year event-free survival (EFS) rate of 72.0% (95%CI: 19.5-23.9). Pleomorphic RMS was associated with the reduced 2-year OS rate (P<0.05), and distant metastasis, IRSG stage IV RMS, and high-risk RMS were associated with the reduced 2-year EFS rate (P<0.05). CONCLUSIONS: RMS has no specific clinical symptoms at the first visit, with painless mass as the most common symptom. Distant metastasis, IRSG stage, and risk degree may be associated with the prognosis of children with RMS.

Biotrophy-specific downregulation of siderophore biosynthesis in Colletotrichum graminicola is required for modulation of immune responses of maize.

The hemibiotrophic maize pathogen Colletotrichum graminicola synthesizes one intracellular and three secreted siderophores. eGFP fusions with the key siderophore biosynthesis gene, SID1, encoding l-ornithine-N(5) -monooxygenase, suggested that siderophore biosynthesis is rigorously downregulated specifically during biotrophic development. In order to investigate the role of siderophores during vegetative development and pathogenesis, SID1, which is required for synthesis of all siderophores, and the non-ribosomal peptide synthetase gene NPS6, synthesizing secreted siderophores, were deleted. Mutant analyses revealed that siderophores are required for vegetative growth under iron-limiting conditions, conidiation, ROS tolerance, and cell wall integrity. Δsid1 and Δnps6 mutants were hampered in formation of melanized appressoria and impaired in virulence. In agreement with biotrophy-specific downregulation of siderophore biosynthesis, Δsid1 and Δnps6 strains were not affected in biotrophic development, but spread of necrotrophic hyphae was reduced. To address the question why siderophore biosynthesis is specifically downregulated in biotrophic hyphae, maize leaves were infiltrated with siderophores. Siderophore infiltration alone did not induce defence responses, but formation of biotrophic hyphae in siderophore-infiltrated leaves caused dramatically increased ROS formation and transcriptional activation of genes encoding defence-related peroxidases and PR proteins. These data suggest that fungal siderophores modulate the plant immune system.

An adequate Fe nutritional status of maize suppresses infection and biotrophic growth of Colletotrichum graminicola.

Iron (Fe) is an essential element for plant pathogens as well as for their host plants. As Fe plays a central role in pathogen virulence, most plants have evolved Fe-withholding strategies to reduce Fe availability to pathogens. On the other hand, plants need Fe for an oxidative burst in their basal defense response against pathogens. To investigate how the plant Fe nutritional status affects plant tolerance to a hemibiotrophic fungal pathogen, we employed the maize-Colletotrichum graminicola pathosystem. Fungal infection progressed rapidly via biotrophic to necrotrophic growth in Fe-deficient leaves, while an adequate Fe nutritional status suppressed the formation of infection structures of C. graminicola already during the early biotrophic growth phase. As indicated by Prussian blue and 3,3'-diaminobenzidine (DAB) staining, the retarding effect of an adequate Fe nutritional status on fungal development coincided temporally and spatially with the recruitment of Fe to infection sites and a local production of H2 O2 . A similar coincidence between local Fe and H2 O2 accumulation was found in a parallel approach employing C. graminicola mutants affected in Fe acquisition and differing in virulence. These results indicate that an adequate Fe nutritional status delays and partially suppresses the fungal infection process and the biotrophic growth phase of C. graminicola, most likely via the recruitment of free Fe to the fungal infection site for a timely oxidative burst.

Endogenous S100P-mediated autophagy regulates the chemosensitivity of leukemia cells through the p53/AMPK/mTOR pathway.

Autophagy, a highly regulated lysosome-dependent catabolic pathway, has garnered increasing attention because of its role in leukemia resistance. Among the S100 family of small calcium-binding proteins, S100P is differentially expressed in various tumor cell lines, thereby influencing tumor occurrence, invasion, metastasis, and drug resistance. However, the relationship between S100P and autophagy in determining chemosensitivity in leukemia cells remains unexplored. Our investigation revealed a negative correlation between S100P expression and the clinical status in childhood leukemia, with its presence observed in HL-60 and Jurkat cell lines. Suppression of S100P expression resulted in increased cell proliferation and decreased chemosensitivity in leukemia cells, whereas enhancement of S100P expression inhibited cell proliferation and increased chemosensitivity. Additionally, S100P knockdown drastically promoted autophagy, which was subsequently suppressed by S100P upregulation. Moreover, the p53/AMP-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) pathway was found to be functionally associated with S100P-mediated autophagy. Knockdown of S100P expression led to a decrease in p53 and p-mTOR levels and an increase in p-AMPK expression, ultimately promoting autophagy. This effect was reversed by administration of Tenovin-6 (a p53 activator) and Compound C (an AMPK inhibitor). The findings of our in vivo experiments provide additional evidence supporting the aforementioned data. Specifically, S100P inhibition significantly enhanced the growth of HL-60 tumor xenografts and increased the expression of microtubule-associated protein 1 light chain 3 and p-AMPK in nude mice. Consequently, it can be concluded that S100P plays a regulatory role in the chemosensitivity of leukemia cells by modulating the p53/AMPK/mTOR pathway, which controls autophagy in leukemia cells.

Effect of rituximab on immune status in children with aggressive mature B-cell lymphoma/leukemia-a prospective study from CCCG-BNHL-2015.

Background: Limited research has been conducted on the impact of rituximab on immune function and the incidence of side effects in children undergoing combination chemotherapy for aggressive mature B-cell lymphoma/leukemia. Methods: Clinical data from 85 patients with primary pediatric aggressive mature B-cell lymphoma/leukemia, treated according to the Chinese Children's Cancer Group (CCCG)-mature B-cell non-Hodgkin lymphoma (BNHL)-2015 protocol from June 1, 2015, to December 1, 2022, were collected from three tertiary medical centers in China. Patients with pre-existing malignancies or primary immune deficiencies (PIDs) were excluded. Results: Between June 1, 2015, and December 1, 2022, 85 patients (65 [76.5%] boys and 20[23.5%] girls; mean age, 6.95 years) were enrolled, and immune data at baseline during follow-up were analyzed. At the end of chemotherapy, a higher proportion of patients in the R4 group exhibited a decrease in peripheral blood CD3- CD19+ B cells (20[100%] of 20 vs 13[47.8%] of 18, p = 0.04), CD3+ T cells (21[91.3%] of 23 vs 14[60.9%] of 23, p = 0.016), and serum IgM (14[60.9%] of 23 vs 4[17.4%] of 23, p = 0.003) compared to the R3 group. However, these differences were no longer statistically significant six months after chemotherapy administration. The combination of rituximab with AA was associated with a higher incidence of significant thrombocytopenia (49[81.7%] of 60 vs 29[52.7%] of 55, p = 0.001) and infection (35[58.3%] of 60 vs 17[30.9%] of 55, p = 0.003) compared to AA alone. Furthermore, the combination of rituximab with BB was linked to a higher incidence of significant thrombocytopenia (32[52.5%] of 61 vs 31[31.0%] of 100, p = 0.007) compared to BB alone. Conclusions: While the effects of rituximab in combination with intense chemotherapy for childhood aggressive mature B-cell lymphoma/leukemia on children's immune function generally recovers within six months it may still prolong the recovery from immunoglobulinemia, posing a risk of secondary infections. Further studies are required to identify children with potential primary immunodeficiencies.

Extracellular SQSTM1 exacerbates acute pancreatitis by activating autophagy-dependent ferroptosis.

ABBREVIATIONS: 5-HETE, 5-hydroxyeicosatetraenoic acid; ACSL4, acyl-CoA synthetase long chain family member 4; AP, acute pancreatitis; ATG, autophagy related; AGER, advanced glycosylation end-product specific receptor; DAMPs, danger/damage-associated molecular patterns; FTH1, ferritin heavy chain 1; GPX4, glutathione peroxidase 4; IL, interleukin; INSR, insulin receptor; MAP1LC3B, microtubule associated protein 1 light chain 3 beta; MDA, malondialdehyde; MPO, myeloperoxidase; PRRs, pattern recognition receptors; PUFA, polyunsaturated fatty acid; RNAi, RNA interference; SQSTM1, sequestosome 1; TNF, tumor necrosis factor; TLR, toll like receptor.

Screening and validating circular RNAs that estimate disease risk and treatment response of pediatric acute myeloid leukemia: a microarray-based analyses and RT-qPCR validation.

PURPOSE: Circular RNA (circRNA) is a type of novel non-coding RNA with close involvement in the tumorigenesis and treatment response of leukemias. This study aimed to screen and validate candidate circRNAs that estimate disease risk and response to induction therapy of pediatric acute myeloid leukemia (AML). METHODS: Bone marrow samples were obtained from 4 complete response (CR) pediatric AML patients, 4 non-CR pediatric AML patients, and 4 controls to screen differentially expressed circRNAs (DECs) through microarray analyses. Ten candidate circRNAs were selected and validated in 40 pediatric AML patients and 10 controls through reverse transcription-quantitative polymerase chain reaction. RESULTS: Microarray assay discovered 378 upregulated DECs and 688 downregulated DECs in pediatric AML patients vs. controls; 832 upregulated DECs and 950 downregulated DECs in CR AML patients vs. non-CR AML patients. Then cross-analysis identified 441 DECs that both related to pediatric AML risk and CR achievement. Further validation of ten candidate circRNAs in larger sample-sized populations showed that circ_0032891, circ_0076995, circ_0014352, circ_0047663, circ_0007444, circ_0001684, circ_0000544, and circ_0005354 were related to pediatric AML risk; circ_0032891, circ_0076995, circ_0014352, circ_0047663, circ_0007444, circ_0001684, and circ_0000544 were related to CR achievement in pediatric AML patients. Regarding the correlation of candidate circRNAs with survival profile, only circ_0032891, circ_0076995, and circ_0000544 forecasted event-free survival; circ_0076995 and circ_0001684 estimated overall survival in pediatric AML patients. CONCLUSION: CircRNA profile is intensively implicated in the disease risk and treatment response of pediatric AML, especially that circ_0032891, circ_0000544, circ_0076995, and circ_0001684 are related to pediatric AML risk, CR achievement, and survival.

Endogenous HMGB1 regulates GSDME-mediated pyroptosis via ROS/ERK1/2/caspase-3/GSDME signaling in neuroblastoma.

Pyroptosis, a newly discovered mode of programmed cell death (PCD), is important in the regulation of cancer development. High mobility group box 1 (HMGB1) is a non-histone nuclear protein that is closely related to tumor development and chemotherapy resistance. However, whether endogenous HMGB1 regulates pyroptosis in neuroblastoma remains unknown. Here, we showed that HMGB1 showed ubiquitous higher expression in SH-SY5Y cells and clinical tumors, and was positively correlated with the risk factors of patients with neuroblastoma. Knockdown of GSDME or pharmacological inhibition of caspase-3 blocked pyroptosis and cytosolic translocation of HMGB1. Moreover, knockdown of HMGB1 inhibited cisplatin (DDP) or etoposide (VP16)-induced pyroptosis by decreasing GSDME-NT and cleaved caspase-3 expression, resulting in cell blebbing and LDH release. Knockdown of HMGB1 expression increased the sensitivity of SH-SY5Y cells to chemotherapy and switched pyroptosis to apoptosis. Furthermore, the ROS/ERK1/2/caspase-3/GSDME pathway was found to be functionally connected with DDP or VP16-induced pyroptosis. Hydrogen peroxide (H2O2, a ROS agonist) and EGF (an ERK agonist) promoted the cleavage of GSDME and caspase-3 in DDP or VP16 treatment cells, both of which were inhibited by HMGB1 knockdown. Importantly, these data were further supported by the in vivo experiment. Our study suggests that HMGB1 is a novel regulator of pyroptosis via the ROS/ERK1/2/caspase-3/GSDME pathway and a potential drug target for therapeutic interventions in neuroblastoma.

TXNDC12 inhibits lipid peroxidation and ferroptosis.

Ferroptosis is a type of regulated cell death characterized by lipid peroxidation and subsequent damage to the plasma membrane. Here, we report a ferroptosis resistance mechanism involving the upregulation of TXNDC12, a thioredoxin domain-containing protein located in the endoplasmic reticulum. The inducible expression of TXNDC12 during ferroptosis in leukemia cells is inhibited by the knockdown of the transcription factor ATF4, rather than NFE2L2. Mechanistically, TXNDC12 acts to inhibit lipid peroxidation without affecting iron accumulation during ferroptosis. When TXNDC12 is overexpressed, it restores the sensitivity of ATF4-knockdown cells to ferroptosis. Moreover, TXNDC12 plays a GPX4-independent role in inhibiting lipid peroxidation. The absence of TXNDC12 enhances the tumor-suppressive effects of ferroptosis induction in both cell culture and animal models. Collectively, these findings demonstrate an endoplasmic reticulum-based anti-ferroptosis pathway in cancer cells with potential translational applications.

Splicing Interruption by Intron Variants in CSNK2B Causes Poirier-Bienvenu Neurodevelopmental Syndrome: A Focus on Genotype-Phenotype Correlations.

CSNK2B has recently been identified as the causative gene for Poirier-Bienvenu neurodevelopmental syndrome (POBINDS). POBINDS is a rare neurodevelopmental disorder characterized by early-onset epilepsy, developmental delay, hypotonia, and dysmorphism. Limited by the scarcity of patients, the genotype-phenotype correlations in POBINDS are still unclear. In the present study, we describe the clinical and genetic characteristics of eight individuals with POBINDS, most of whom suffered developmental delay, generalized epilepsy, and hypotonia. Minigene experiments confirmed that two intron variants (c.367+5G>A and c.367+6T>C) resulted in the skipping of exon 5, leading to a premature termination of mRNA transcription. Combining our data with the available literature, the types of POBINDS-causing variants included missense, nonsense, frameshift, and splicing, but the variant types do not reflect the clinical severity. Reduced casein kinase 2 holoenzyme activity may represent a unifying pathogenesis. We also found that individuals with missense variants in the zinc finger domain had manageable seizures (p = 0.009) and milder intellectual disability (p = 0.003) than those with missense variants in other domains of CSNK2B. This is the first study of genotype-phenotype correlations in POBINDS, drawing attention to the pathogenicity of intron variants and expanding the understanding of neurodevelopmental disorders.

A novel STAT1 loss-of-function mutation associated with Mendelian susceptibility to mycobacterial disease.

Mendelian susceptibility to mycobacterial diseases (MSMD) is a rare congenital immune deficiency characterized by susceptibility to weakly virulent mycobacteria. Loss-of-function (LOF) mutation of signal transducer and activator of transcription 1 (STAT1) is one of the common genetic causes of MSMD. In this study, we identified a patient who presented with multiple lymph node enlargements and multiple osteolytic disruptions. Mycobacterium gordonae infection was confirmed by metagenomic next-generation sequencing. Whole-exome sequencing identified a novel paternal heterozygous mutation in exon 22 of STAT1 (NM_007315.4, c.1892T>C, p.Val631Ala). This variant was confirmed pathogenic by multiple software predictions. Based on functional assays, STAT1 expression in STAT1V631A cells was not different from STAT1WT cells. But STAT1V631A mutation caused much lower activation of STAT1 when stimulated by interferon-γ (IFN-γ). Fluorescence localization analysis revealed that both STAT1V631A and STAT1WT proteins were located in the cytoplasm, and only a few STAT1V631A proteins were translocated to the nucleus in response to IFN-γ. These results suggest that STAT1V631A leads to LOF in IFN-γ-mediated mycobacterial immunity, resulting in MSMD. Treatment with antibiotics has achieved ideal disease control for this patient, and no adverse events occurred during follow-up. The STAT1 LOF deficiency is a genetic cause of MSMD, which should be considered in patients with mycobacterial disease, especially those with bone involvement.

Clinical characteristics, pathology features and outcomes of pediatric myeloid sarcoma: A retrospective case series.

Purpose: Myeloid sarcoma (MS) is a rare extramedullary mass with myeloid expression, which is easy to be missed and misdiagnosed, especially in the pediatric population. We analyze the clinicopathological characteristics, immunophenotypic, cytogenetic, and molecular studies, therapeutic approaches, and outcomes, to optimize the management of such patients. Methods: A retrospective, single-center, case series study of eleven children diagnosed with MS by pathology was performed. Results: The male-to-female ratio was 8:3, and the median age at diagnosis was 7 years. The most commonly involved sites were the skin and orbital region, followed by lymph nodes, central nervous system, and testis. Seven cases (64%) with Class I-MS and four cases (36%) presented as Class II-MS. Immunohistochemically, MPO and CD117 were the most commonly expressed markers, followed by CD33, CD43, CD34, CD68, and lysozyme. Chromosomal abnormalities were detected in 4 patients. Two patients had the presence of deleterious mutations (FLT3, ASXL, KIT, and DHX15) on molecular detection. Ten patients were treated with chemotherapy based on AML regimens. The median follow-up time was 33.5 months in eleven patients. Two patients relapsed, one died, and one lost to follow-up. The 2-year overall survival (OS) rate estimated by Kaplan-Meier curves was 90.9% ± 8.7%, and the event-free survival (EFS) rate was 64.9% ± 16.7%. Conclusions: MS diagnosis is usually challenging. Adequate tumor biopsy and expanded immunohistochemistry are necessary for the correct diagnosis of MS. Early and regular systemic chemotherapy promises long-term survival.

Restoration of Sarco/Endoplasmic Reticulum Ca2+-ATPase Activity Functions as a Pivotal Therapeutic Target of Anti-Glutamate-Induced Excitotoxicity to Attenuate Endoplasmic Reticulum Ca2+ Depletion.

Glutamate-induced excitotoxicity is a pathological basis of many acute/chronic neurodegenerative diseases. Sarco/endoplasmic reticulum Ca2+-ATPase (SERCA2b) is a membrane-embedded P-type ATPase pump that manages the translocation of calcium ions (Ca2+) from cytosol into the lumen of the endoplasmic reticulum (ER) calcium stores. It participates in a wide range of biological functions in the central nervous system (CNS). However, the role of SERCA2b in glutamate-induced excitotoxicity and its mechanism must be elucidated. Herein, we demonstrate that SERCA2b mutants exacerbate the excitotoxicity of hypo-glutamate stimulation on HT22 cells. In this study, SERCA2b mutants accelerated Ca2+ depletion through loss-of-function (reduced pumping capacity) or gain-of-function (acquired leakage), resulting in ER stress. In addition, the occurrence of ER Ca2+ depletion increased mitochondria-associated membrane formation, which led to mitochondrial Ca2+ overload and dysfunction. Moreover, the enhancement of SERCA2b pumping capacity or inhibition of Ca2+ leakage attenuated Ca2+ depletion and impeded excitotoxicity in response to hypo-glutamate stimulation. In conclusion, SERCA2b mutants exacerbate ER Ca2+-depletion-mediated excitotoxicity in glutamate-sensitive HT22 cells. The mechanism of disruption is mainly related to the heterogeneity of SERCA2b mutation sites. Stabilization of SRECA2b function is a critical therapeutic approach against glutamate-induced excitotoxicity. These data will expand understanding of organelle regulatory networks and facilitate the discovery and creation of drugs against excitatory/inhibitory imbalance in the CNS.

The second-tier status of fragile X syndrome testing for unexplained intellectual disability/global developmental delay in the era of next-generation sequencing.

Objective: Although many unexplained intellectual disability/global developmental delay (ID/GDD) individuals have benefited from the excellent detection yield of copy number variations and next-generation sequencing testing, many individuals still who suffer from ID/GDD of unexplained etiology. In this study, we investigated the applicability of fragile X syndrome (FXS) testing in unexplained ID/GDD individuals with negative or absent genetic testing. Methods: In this study, we used the triplet repeat primed polymerase chain reaction to evaluate the value and application of fragile X testing in unexplained ID/GDD individuals with negative or absent genetic testing (n = 681) from three hospitals. Results: Of the 681 ID/GDD individuals with negative or absent genetic testing results detected by FXS testing, 12 men and one woman were positive. This corresponded to a diagnostic yield of 1.9% for FXS testing in our cohort. All FXS individuals had either a family history of ID/GDD or suggestive clinical features. The detection yield of FXS testing in ID/GDD individuals who completed genetic testing (2.70%, 12/438) was significantly higher than in individuals without any genetic testing (0.40%, 1/243). Conclusions: This is the first report of FXS testing in ID/GDD individuals who lacked previous genetic testing, which promotes standardization of the FXS diagnostic process. These results highlight the utility of FXS testing of unexplained ID/GDD individuals with negative results from standard genetic testing. In the era of next-generation sequencing, FXS testing is more suitable as a second-tier choice and provides clinicians and geneticists with auxiliary references for tracing the etiology of ID/GDD.

Anti-IgLON5 disease in a pediatric patient with Langerhans cell histiocytosis.

INTRODUCTION: Anti-IgLON5 disease is a rare autoimmune disease of the central nervous system. Different from the previous autoimmune encephalitis, the disease is a chronic progressive disease characterized by abnormal sleep, sleep apnea and motor disorders, which is prone to misdiagnosis and missed diagnosis. METHODS: We report a unique case of anti-IgLON5 disease in a pediatric patient with Langerhans cell histiocytosis (LCH). He gradually developed increased muscle tone and nystagmus during chemotherapy and showed signs of meningeal enhancement on cranial imaging. Due to insufficient evidence of LCH invasion of the central nervous system, the presence of autoimmune encephalitis-related antibodies was investigated by using cell-based assay (CBA) experiment in indirect immuno-fluorescence assay (IFA). RESULTS: Clinical manifestations of sleep disorders and motor disorders, plus the presence of IgLON5 IgG antibodies (1:30) in the serum leading to a confirmed diagnosis of anti-IgLON5 disease. CONCLUSION: Anti-IgLON5 disease is rare and almost no cases of children have been reported. In view of the difficult to recognize symptoms in pediatric patients, especially those with other comorbidities. Clinicians should raise their awareness of this disease and pay attention to the detection of autoimmune antibodies.

Knockdown of HMGB1 Suppresses Hypoxia-Induced Mitochondrial Biogenesis in Pancreatic Cancer Cells.

PURPOSE: To explore the regulatory effect of HMGB1 upon hypoxia-induced mitochondrial biogenesis in pancreatic cancer PANC1/CFPAC1 cells. METHODS: After a down-regulation of HMGB1 expression by lentivirus-mediated RNAi, the effect of knocking down HMGB1 on hypoxia-induced mitochondrial biogenesis was examined. NRF-1/TFAM expression, mtDNA copy number, ATP content and mitochondrial number/morphology in hypoxia-treated pancreatic cancer cells were detected by quantitative reverse transcription-polymerase chain reaction (qRT-PCR), Western blot, mtDNA and ATP assay kits and electron microscopy, respectively. Cell proliferation was measured by MTS assay. And protein and acetylation levels of PGC-1α and SIRT1 activity were detected by Western blot, immunoprecipitation (IP) and SIRT1 activity kit. RESULTS: Hypoxia enhanced the expressions of NRF-1/TFAM, boosted mtDNA copy number and ATP content and increased the number of mitochondria in pancreatic cancer cells while induction was suppressed by a knockdown of HMGB1. Knocking down HMGB1 expression lowered hypoxia-induced PGC-1α/SIRT1 expression and activity, phosphorylation of AMPK. PGC-1α over-expression by a plasmid transfection failed to boost mtDNA copy number or ATP content in HMGB1-knockdown cells. A knockdown of HMGB1 attenuated hypoxia with AICAR (an AMPK activator)-induced expression of NRF-1, TFAM, PGC-1α, SIRT1 and the proteins of complexes Ⅰ& Ⅲ and reduced the acetylation level of PGC-1α/SIRT1 activity. Additionally, SRT1720 (a SIRT1 activator)-induced elevation in SIRT1 activity boosted hypoxia-induced PGC-1α deacetylation, except in HMGB1-knockdown cells. CONCLUSION: As a novel regulator of mitochondrial biogenesis via AMPK/SIRT1 pathway under hypoxia, HMGB1 may become a potential drug target for therapeutic interventions in pancreatic cancer.

Homophily Preserving Community Detection.

As a fundamental problem in social network analysis, community detection has recently attracted wide attention, accompanied by the output of numerous community detection methods. However, most existing methods are developed by only exploiting link topology, without taking node homophily (i.e., node similarity) into consideration. Thus, much useful information that can be utilized to improve the quality of detected communities is ignored. To overcome this limitation, we propose a new community detection approach based on nonnegative matrix factorization (NMF), namely, homophily preserving NMF (HPNMF), which models not only link topology but also node homophily of networks. As such, HPNMF is able to better reflect the inherent properties of community structure. In order to capture node homophily from scratch, we provide three similarity measurements that naturally reveal the association relationships between nodes. We further present an efficient learning algorithm with convergence guarantee to solve the proposed model. Finally, extensive experiments are conducted, and the results demonstrate that HPNMF has strong ability to outperform the state-of-the-art baseline methods.

HMGB1-mediated autophagy regulates sodium/iodide symporter protein degradation in thyroid cancer cells.

BACKGROUND: Sodium/iodide symporter (NIS)-mediated iodide uptake plays an important physiological role in regulating thyroid gland function, as well as in diagnosing and treating Graves' disease and thyroid cancer. High-mobility group box 1 (HMGB1), a highly conserved nuclear protein, is a positive regulator of autophagy conferring resistance to chemotherapy, radiotherapy and immunotherapy in cancer cells. Here the authors intended to identify the role of HMGB1 in Hank's balanced salt solution (HBSS)-induced autophagy, explore NIS protein degradation through a autophagy-lysosome pathway in thyroid cancer cells and elucidate the possible molecular mechanisms. METHODS: Immunohistochemical staining and reverse transcription-polymerase chain reaction (RT-PCR) were performed for detecting the expression of HMGB1 in different tissues. HMGB1 was knocked down by lentiviral transfection in FTC-133/TPC-1 cells. Autophagic markers LC3-II, p62, Beclin1 and autophagosomal formation were employed for evaluating HMGB1-mediated autophagy in HBSS-treated cells by Western blot, immunofluorescence and electron microscopy. Western blot, quantitative RT-PCR and gamma counter analysis were performed for detecting NIS expression and iodide uptake in HMGB1-knockdown cells after different treatments. The reactive oxygen species (ROS) level, ROS-mediated LC3-II expression and HMGB1 cytosolic translocation were detected by fluorospectrophotometer, flow cytometry, Western blot and immunofluorescence. HMGB1-mediated AMPK, mTOR and p70S6K phosphorylation (p-AMPK, p-mTOR & p-p70S6K) were detected by Western blot. Furthermore, a nude murine model with transplanted tumor was employed for examining the effect of HMGB1-mediated autophagy on imaging and biodistribution of 99mTcO4-. NIS, Beclin1, p-AMPK and p-mTOR were detected by immunohistochemical staining and Western blot in transplanted tumor samples. RESULTS: HMGB1 was a critical regulator of autophagy-mediated NIS degradation in HBSS-treated FTC-133/TPC-1 cells. And HMGB1 up-regulation was rather prevalent in thyroid cancer tissues and closely correlated with worse overall lymph node metastasis and clinical stage. HMGB1-knockdown dramatically suppressed autophagy, NIS degradation and boosted iodide uptake in HBSS-treated cells. Moreover, HBSS enhanced ROS-sustained autophagy and promoted the cytosolic translocation of HMGB1. A knockdown of HMGB1 suppressed LC3-II conversion and NIS degradation via an AMPK/mTOR-dependent signal pathway through a regulation of ROS generation, rather than ATP. Furthermore, these data were further supported by our in vivo experiment of xenografts formed by HMGB1 knockdown cells reverting the uptake of 99mTcO4- as compared with control shRNA-transfected cells in hunger group. CONCLUSIONS: Acting as a critical regulator of autophagy-mediated NIS degradation via ROS/AMPK/mTOR pathway, HMGB1is a potential intervention target of radioiodine therapy in thyroid cancer.