Radix Bupleuri aqueous extract attenuates MK801-induced schizophrenia-like symptoms in mice: Participation of intestinal flora.

Schizophrenia (SCZ) is a psychotic mental disorder characterized by cognitive, behavioral, and social impairments. However, current pharmacological treatment regimens are subpar in terms of effectiveness. This study aimed to investigate the function of Radix Bupleuri aqueous extract in SCZ in mouse models. The SCZ mouse model was established by MK-801 injection and feeding of Radix Bupleuri aqueous extract or combined antibiotics. Radix Bupleuri aqueous extract significantly improved the aberrant behaviors and neuronal damage in SCZ mice, upregulated SYP and PSD-95 expression and BDNF levels in hippocampal homogenates, down-regulated DA and 5-HT levels, and suppressed microglial activation in SCZ mice. Moreover, Radix Bupleuri aqueous extract improved the integrity of the intestinal tract barrier. The 16 S rRNA sequencing of feces showed that Radix Bupleuri extract modulated the composition of gut flora. Lactobacillus abundance was decreased in SCZ mice and reversed by Radix Bupleuri aqueous extract administration which exhibited a significant negative correlation with IL-6, IL-1ß, DA, and 5-HT, and a significant positive correlation with BDNF levels in hippocampal tissues. The abundance of Parabacteroides and Alloprevotella was increased in SCZ mice. It was reversed by Radix Bupleuri aqueous extract administration, which exhibited a positive correlation with IL-6, IL-1ß, and 5-HT and a negative correlation with BDNF. In conclusion, Radix Bupleuri aqueous extract attenuates the inflammatory response in hippocampal tissues and modulates neurotransmitter levels, exerting its neuroprotective effect in SCZ. Meanwhile, the alteration of intestinal flora may be involved in this process, which is expected to be an underlying therapeutic option in treating SCZ.

Clinical research of fibroscan ‒ TE-CAP at noninvasive diagnosis of hepatic steatosis in children

Abstract Background & aims The authors assess the diagnostic accuracy of the Transient Elastography-Controlled Attenuation Parameter (TE-CAP) in children of Southern China. Methods 105 obese or overweight children and adolescents were enrolled in the diagnostic test of TE-CAP assessment of hepatic steatosis using MRI-PDFF. Hepatic steatosis grades S0-S3 were classified. Statistical correlation, agreement and consistency between methods were evaluated. The diagnostic efficiency of TE-CAP was evaluated. The authors used the cutoff value of TE-CAP to detect hepatic steatosis in another 356 children. Results The Area Under Curve (AUC) of TE-CAP for grade ≥ S1, ≥ S2, and ≥ S3 steatosis were 0.975, 0.984, and 0.997, respectively. For detecting ≥ S1 steatosis, TE-CAP had a sensitivity of 96 % and a specificity of 97 %. For detecting ≥ S2 steatosis, TE-CAP had a sensitivity of 97 % and a specificity of 93 %. For detecting ≥ S3 steatosis, TE-CAP had a sensitivity of 1 and a specificity of 94 %. TE-CAP and MRI-PDFF had a linear correlation (r = 0. 0.87, p < 0.001). The hepatic steatosis was identified in 40.2 % (143/356) of children in which the obesity and overweight were 69.8 % (113/162) and 40.0 % (18/45). Conclusion TE-CAP showed excellent diagnostic accuracy in pediatric hepatic steatosis.

Gut microbiota in children with split-dose bowel preparations revealed by metagenomics.

Objective: Split-dose polyethylene glycol (PEG) is routinely used for bowel preparation before colonoscopy. This study aimed to investigate the composition of gut microbiota and its functions in pediatric patients undergoing split-dose PEG bowel preparation for colonoscopy to understand the stability and resilience of gut microbiota. Material and methods: From September to December 2021, 19 pediatric patients were enrolled at Shenzhen Children's Hospital and 76 samples (4 time points) were analyzed using metagenomics. Time points included Time_1 (one day before bowel preparation), Time_2 (one day after colonoscopy), Time_3 (two weeks after bowel preparation), and Time_4 (four weeks after bowel preparation). Result: Alpha diversity comparison at both the species and gene levels showed a decrease in community richness after colonoscopy, with little statistical significance. However, the Shannon diversity index significantly decreased (P<0.05) and gradually returned to pre-preparation levels at two weeks after bowel preparation. The genus level analysis showed six genera (Eubacterium, Escherichia, Intertinibacter, Veillonella, Ruminococcaceae unclassified, and Coprobacillus) significantly different across the four time periods. Additionally, at the species level, the abundance of Escherichia coli, Bacteroides fragilis, and Veillonella parvula significantly increased at one day after colonoscopy before gradually decreasing at two weeks after bowel preparation. In contrast, the abundance of Intertinibacter bartlettii decreased at one day after colonoscopy but then recovered at two weeks after bowel preparation, reaching the preoperative level at four weeks after bowel preparation. Furthermore, five functional pathways (base excision repair, biosynthesis of ansamycins, biosynthesis of siderophore group nonribosomal peptide, flavonoid biosynthesis, and biosynthesis of type II polyketide products) were significantly different across the four time periods, with recovery at two weeks after bowel preparation and reaching preoperative levels at four weeks after bowel preparation. Conclusions: Gut microbiota at the genus level, species level, and functional pathways are impacted in pediatric patients undergoing split-dose PEG bowel preparation and colonoscopy, with recovery two weeks following bowel preparation. However, the phylum level was not impacted. Modifications in gut microbiota composition and function may be investigated in future studies of bowel preparation. This study highlights the stability and resilience of gut microbiota among pediatric patients during bowel preparation.

The regulatory role of alternative splicing in inflammatory bowel disease.

Inflammatory bowel disease (IBD) mainly includes Crohn's disease and ulcerative colitis. These diseases have a progressive course of chronic relapse and remission and affect a large number of children and adults worldwide. The burden of IBD is rising worldwide, with levels and trends varying greatly in countries and regions. Like most chronic diseases, the costs associated with IBD are high, including hospitalizations, outpatient and emergency visits, surgeries, and pharmacotherapies. However, there is no radical cure for it yet, and its therapeutic targets still need further study. Currently, the pathogenesis of IBD remains unclear. It is generally assumed that the occurrence and development of IBD are related to the environmental factors, gut microbiota, immune imbalance, and genetic susceptibility. Alternative splicing contributes to a various diseases, such as spinal muscular atrophy, liver diseases, and cancers. In the past, it has been reported that alternative splicing events, splicing factors, and splicing mutations were associated with IBD, but there were no reports on the practical application for clinical diagnosis and treatment of IBD using splicing-related methods. Therefore, this article reviews research progress on alternative splicing events, splicing factors, and splicing mutations associated with IBD.

Phylogenetic Comparison and Splicing Analysis of the U1 snRNP-specific Protein U1C in Eukaryotes.

As a pivotal regulator of 5' splice site recognition, U1 small nuclear ribonucleoprotein (U1 snRNP)-specific protein C (U1C) regulates pre-mRNA splicing by interacting with other components of the U1 snRNP complex. Previous studies have shown that U1 snRNP and its components are linked to a variety of diseases, including cancer. However, the phylogenetic relationships and expression profiles of U1C have not been studied systematically. To this end, we identified a total of 110 animal U1C genes and compared them to homologues from yeast and plants. Bioinformatics analysis shows that the structure and function of U1C proteins is relatively conserved and is found in multiple copies in a few members of the U1C gene family. Furthermore, the expression patterns reveal that U1Cs have potential roles in cancer progression and human development. In summary, our study presents a comprehensive overview of the animal U1C gene family, which can provide fundamental data and potential cues for further research in deciphering the molecular function of this splicing regulator.

Phylogenetic comparison and splice site conservation of eukaryotic U1 snRNP-specific U1-70K gene family.

Eukaryotic cells can expand their coding ability by using their splicing machinery, spliceosome, to process precursor mRNA (pre-mRNA) into mature messenger RNA. The mega-macromolecular spliceosome contains multiple subcomplexes, referred to as small nuclear ribonucleoproteins (snRNPs). Among these, U1 snRNP and its central component, U1-70K, are crucial for splice site recognition during early spliceosome assembly. The human U1-70K has been linked to several types of human autoimmune and neurodegenerative diseases. However, its phylogenetic relationship has been seldom reported. To this end, we carried out a systemic analysis of 95 animal U1-70K genes and compare these proteins to their yeast and plant counterparts. Analysis of their gene and protein structures, expression patterns and splicing conservation suggest that animal U1-70Ks are conserved in their molecular function, and may play essential role in cancers and juvenile development. In particular, animal U1-70Ks display unique characteristics of single copy number and a splicing isoform with truncated C-terminal, suggesting the specific role of these U1-70Ks in animal kingdom. In summary, our results provide phylogenetic overview of U1-70K gene family in vertebrates. In silico analyses conducted in this work will act as a reference for future functional studies of this crucial U1 splicing factor in animal kingdom.

The diagnostic and treatment values of double-balloon enteroscopy in children's Meckel's diverticular bleeding.

ABSTRACT: The diagnostic and treatment values and safety of preoperative double-balloon enteroscopy (DBE) for Meckel's diverticula (MD) bleeding in children by retrospective review and analyses.The clinical data were collected and analyzed from 10 cases of children with MD receiving preoperative DBE examination and postoperative pathological confirmation. The diagnostic and treatment values and safety were assessed through the comparison of the DBE results and intra-operative observations and subsequently postoperative pathological results.Total cases are 10, 7 males and 3 females. The male to female ratio is 2.3 to 1. The youngest patient is 3.3 years old and oldest 12.1, the average age is 7.4 ±â€Š3.0. The lowest body weight is 12.6 kg and the average is 32.5 ±â€Š18.9 kg. The hematochezia was the main clinical manifestation in all patients with anemia and moderate to severe anemia were common (9/10, 90%). All patients had and tolerated the DBE procedures via anal route with 100% success rate. There were no observable complications during the examinations and post operations. All patients were diagnosed with MD by DBE. Exploratory laparoscopy and surgical operations were subsequently performed. All surgical samples were confirmed by pathology as bleeding MD. The postoperative follow-ups up to April 2019 (from 3 to 12 months) do not show any bleeding sign. Pathological examinations found ectopic gastric mucosa in 9 patients (90%) and one case had both ectopic gastric mucosa pancreatic tissue (10%). The distance of MD to ileocecal valve was from 60 to 100 cm (average 81.0 ±â€Š16.0 cm) by DBE examinations. Surgery showed similar findings from 30 to 100 cm (average 71.0 ±â€Š18.5) consistently to DBE. There is no statistical significance between 2 methods (Ζ = 1.715, Ρ = .086).DBE examination proves to be a safe method for diagnosing children's MD disease and can reliably determine the bleeding lesions in children's MD, providing valuable guidance for surgical treatment of children's MD bleeding.

The Twists and Turns of Diagnosis and Treatment of Pediatric Neuro-Behcet's Disease: A Case Report and Literature Review.

Background: The neurological manifestation of Behcet's disease (BD) is known as Neuro-Behcet's disease (NBD). The lack of a specific diagnostic method for NBD renders the diagnosis and treatment of NBD challenging. Methods and Results: We report a boy aged 11 years and 11 months who underwent right-eye intraocular lens implantation, appendectomy, perianal abscess removal, thalidomide therapy, and infliximab infusions for his Crohn disease. Magnetic resonance venography (MRV) and magnetic resonance imaging (MRI) were performed to address the onset of headache during the course of his treatment, and cerebral venous sinus thrombosis was detected. After the diagnosis of NBD, the patient was treated with anticoagulation therapy (nadroparin calcium), low-dose corticosteroids, and an immunosuppressant (cyclophosphamide), and consequently, he recovered. Conclusion: This case report shows that NBD is prone to misdiagnosis and missed diagnosis and should be diagnosed based on clinical manifestations and results from colonoscopy, pathological examination, and MRI or MRV.

Knee Joint Swelling at Presentation: A Case of Pediatric Crohn Disease With a TNFAIP3 Mutation.

Crohn disease (CD) is a chronic inflammatory disease, and its incidence in children is rising. Despite extensive reports and investigations, the pathogenesis of CD has not been clearly elucidated, particularly in regard to triggering factors. A genetic predisposition is considered important when investigating the mechanism leading to CD, and the discovery of new CD-associated genes has increased our understanding of its immunopathogenesis and improved the efficacy of its treatment of CD. Early detection and treatment (eg, as children) with gene-based precision therapy can effectively prevent complications related to CD. In this case, a Chinese Han boy with CD associated with a mutation of tumor necrosis factor α-induced protein 3 was treated with recombinant human tumor necrosis factor-a receptor II:IgG Fc fusion protein. We suspected the boy had CD because of chronic abdominal pain, aphthous stomatitis, moderate anemia, a high erythrocyte sedimentation rate (36-79 mm/h), multiple intestinal ulcers, knee joint swelling, and a tumor necrosis factor α-induced protein 3 mutation. After total enteral nutrition and hormone therapy for 5 months, his abdominal pain and joint symptoms did not improve, so we started gene-based precision therapy with recombinant human tumor necrosis factor-a receptor II: IgG Fc fusion protein, which may play an important role in restricting TNF-α-induced NF-κB signaling. After 3 weeks, inflammation indicators were within the normal range, and multiple ulcers and joint symptoms were relieved. The present case demonstrates a safe therapeutic schedule that leads to rapid improvements in the clinical and biochemical status of patients with CD.

The role of microRNA in cisplatin resistance or sensitivity.

INTRODUCTION: Cisplatin is a chemotherapy drug that has been used to treat a number of cancers for decades, and is still one of the most commonly used anti-cancer agents. However, some patients do not respond to cisplatin while other patients who were originally sensitive to cisplatin eventually develop chemoresistance, leading to treatment failure or/and tumor recurrence. AREAS COVERED: Different mechanisms contribute to cisplatin resistance or sensitivity, involving multiple pathways or/and processes such as DNA repair, DNA damage response, drug transport, and apoptosis. Among the various mechanisms, it appears that microRNAs play an important role in determining the resistance or sensitivity. In this article, we analyzed and summarized recent findings in this area, with the aim that these data can aid further research and understanding, leading to the eventual reduction of cisplatin resistance. EXPERT COMMENTARY: microRNAs can positively or negatively regulate cisplatin resistance by acting on molecules or/and pathways related to apoptosis, autophagy, hypoxia, cancer stem cells, NF-κB, and Notch1. It appears that the modulation of relevant microRNAs can effectively re-sensitize cancer cells to cisplatin regimen in certain types of cancers including breast, colorectal, gastric, liver, lung, ovarian, prostate, testicular, and thyroid cancers.

Knockdown of Long Noncoding RNAs of Maternally Expressed 3 Alleviates Hyperoxia-Induced Lung Injury via Inhibiting Thioredoxin-Interacting Protein-Mediated Pyroptosis by Binding to miR-18a.

Long-term hyperoxia exposure may cause lung damage with characteristic inflammation. Long noncoding RNA of maternally expressed 3 (MEG3) is up-regulated in lung tissues exposed to hyperoxia; however, the underlying mechanism is unclear. Hyperoxia-induced cells and mouse models were used to study these mechanisms. Molecular assays were used to detect cell viability, cytotoxicity, and expression of miR-18a, MEG3, and inflammatory cytokines. The interaction among MEG3, miR-18a, and thioredoxin-interacting protein (TXNIP) was verified; and pyroptosis-related proteins were analyzed. The in vivo model was established by exposing MEG3 knockdown mice to hyperoxia. Hematoxylin and eosin staining was used to assess pathologic alterations of lung tissues. Hyperoxia suppressed cell viability, induced cell damage, and exacerbated the secretion of IL-1ß and IL-18. Hyperoxia inhibited miR-18a, with increased expression of MEG3, TXNIP, and nonobese diabetic-like receptor family pyrin domain containing 3 (NLRP3). MEG3 aggravated TXNIP expression by binding to miR-18a. Knockdown of MEG3 rescued hyperoxia-induced pyroptosis by up-regulating miR-18a. Furthermore, knockdown of MEG3 inhibited NLRP3 inflammasome activity and caspase-1 signaling by miR-18a. In vivo knockdown of MEG3 and overexpression of miR-18a relieved hyperoxia-induced lung injury via restraining NLRP3 inflammasome-mediated pyroptosis, whereas miR-18a inhibition reversed these effects. In conclusion, knockdown of MEG3 inhibits pyroptosis to alleviate hyperoxia lung injury by suppressing NLRP3 inflammasome and caspase-1 signaling via regulating miR-18a-TXNIP axis.

Accuracy of multi-echo Dixon sequence in quantification of hepatic steatosis in Chinese children and adolescents.

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is currently the outstanding cause of chronic liver disease in children and adolescents, especially in overweight and obese groups. Liver biopsy is the reference standard to diagnose NAFLD but invasive, thus it is not the best choice in clinical diagnosis and follow-up. Magnetic resonance (MR) is widely used in clinical trials to noninvasively quantify liver fat content in adults and children in foreign countries. While currently, it is rarely used in Chinese children and adolescents. We postulated that quantifying hepatic steatosis by MR could be extended to children and adolescents in China. AIM: To investigate the accuracy of MR imaging (MRI) in quantifying liver fat with MR spectroscopy (MRS) as a reference. A secondary goal was to assess the prevalence of NAFLD in overweight and obese Chinese children and adolescents. METHODS: There were 86 children and adolescents enrolled in this study, including 65 overweight and obese children and 21 healthy children. The participants underwent MRI and MRS. MRI and MRS were performed using multi-echo Dixon and HISTO sequences, respectively, to calculate hepatic proton density fat fraction (PDFF). Hepatic steatosis was diagnosed using MRS-PDFF > 5% as the threshold. Spearman's analysis was used to evaluate the correlation between MRI and MRS. The agreement between these two methods was assessed by Bland-Altman analysis. RESULTS: The MRI-PDFF in the MRS region of interest and the entire liver was 9.9% ± 10.3% with a range of 0.3%-39.9%, and 10.6% ± 9.4% with a range of 1.9%-38.9%, respectively. The MRS-PDFF was 9.1% ± 10.0%, with a range of 0.5%-37.8%. The incidence of hepatic steatosis detected by MRS-PDFF was 46.5% (40/86) of all participants, all of whom belonged to the overweight and obese group. Spearman's analysis indicated an excellent correlation between multi-echo Dixon and MRS (r > 0.9, P < 0.01). Bland-Altman analysis also demonstrated a good agreement between these two methods. CONCLUSION: Multi-echo Dixon shows an excellent correlation and agreement with MRS in quantifying liver fat content and could be a potential tool to detect hepatic steatosis in Chinese children and adolescents.

[A case of congenital bile acid synthesis disorder type 2 and literature review].

OBJECTIVE: To summarize the clinical features, biochemical change and genetic mutations of a neonate with congenital bile acid synthesis disorder type 2. METHODS: Clinical features, blood biochemical index, gene analysis and treatment of the patient were reviewed. RESULTS: The patient presented with the symptoms of jaundice 3 days after birth but without skin itching. Pale stool was noted. Subsequently, he presented with hepatomegaly, blood coagulation disorders, left cochlear nerve damage, liver cirrhosis and remarkable growth retardation. Serum biochemistries showed that bilirubin and transaminase were elevated, while γ -GT and total bile acid was normal. Abdominal ultrasonography indicated decline of gallbladder contraction. Cholangiography showed normal extra- and intrahepatic bile ducts and patent biliary tract. Liver biopsy showed intrahepatic cholestasis. Gene testing has identified a homozygous mutation in AKR1D1 gene. CONCLUSION: Congenital bile acid synthesis disorder should be suspected when a neonate has presented with jaundice, elevated bilirubin and transaminase, normal or reduced TBA and γ -GT. Genetic testing and urine mass spectrometry analysis can diagnose congenital bile acid synthesis disorder. Early therapy is crucial to patients with congenital bile acid synthesis disorder.

Infant cholestasis patient with a novel missense mutation in the AKR1D1 gene successfully treated by early adequate supplementation with chenodeoxycholic acid: A case report and review of the literature.

Steroid 5ß-reductase [aldo-keto reductase family 1 member D1 (AKR1D1)] is essential for bile acid biosynthesis. Bile acid deficiency caused by genetic defects in AKR1D1 leads to life-threatening neonatal hepatitis and cholestasis. There is still limited experience regarding the treatment of this disease. We describe an infant who presented with hyperbilirubinemia and coagulopathy but normal bile acid and γ-glutamyltransferase. Gene analysis was performed using genomic DNA from peripheral lymphocytes from the patient, his parents, and his elder brother. The patient was compound heterozygous for c.919C>T in exon 8 and exhibited a loss of heterozygosity of the AKR1D1 gene, which led to an amino acid substitution of arginine by cysteine at amino acid position 307 (p.R307C). Based on these mutations, the patient was confirmed to have primary 5ß-reductase deficiency. Ursodeoxycholic acid (UDCA) treatment did not have any effect on the patient. However, when we changed to chenodeoxycholic acid (CDCA) treatment, his symptoms and laboratory tests gradually improved. It is therefore crucial to supplement with an adequate dose of CDCA early to improve clinical symptoms and to normalize laboratory tests.

Brain damage resembling acute necrotizing encephalopathy as a specific manifestation of haemophagocytic lymphohistiocytosis - induced by hypersensitivity.

BACKGROUND: Both haemophagocytic lymphohistiocytosis and acute necrotizing encephalopathy are life-threatening condition. It presents major diagnostic difficulties, since it may have a diversity in clinical picture and with many conditions leading to the same clinical presentation. So it is key important to understand the disorders. CASE PRESENTATION: We report a pediatric case of haemophagocytic lymphohistiocytosis with specific presentation which predominantly featured as acute necrotizing encephalopathy of childhood. We discuss the diagnosis and differential diagnosis, and speculate the etiology of haemophagocytic lymphohistiocytosis is due to hypersensitivity. CONCLUSION: Haemophagocytic lymphohistiocytosis and brain damage in this case may be induced by hypersensitivity, which have good clinical outcome if diagnosed and treated early.

Diversity of Gut Microbiota Metabolic Pathways in 10 Pairs of Chinese Infant Twins.

Early colonization of gut microbiota in human gut is a complex process. It remains unclear when gut microbiota colonization occurs and how it proceeds. In order to study gut microbiota composition in human early life, the present study recruited 10 healthy pairs of twins, including five monozygotic (MZ) and five dizygotic (DZ) twin pairs, whose age ranged from 0 to 6 years old. 20 fecal samples from these twins were processed by shotgun metagenomic sequencing, and their averaged data outputs were generated as 2G per sample. We used MEGAN5 to perform taxonomic and functional annotation of the metagenomic data, and systematically analyzed those 20 samples, including Jaccard index similarity, principle component, clustering, and correlation analyses. Our findings indicated that within our study group: 1) MZ-twins share more microbes than DZ twins or non-twin pairs, 2) gut microbiota distribution is relatively stable at metabolic pathways level, 3) age represents the strongest factor that can account for variation in gut microbiota, and 4) a clear metabolic pathway shift can be observed, which speculatively occurs around the age of 1 year old. This research will serve as a base for future studies of gut microbiota-related disease research.

[Analysis of clinical characteristics of hypoxic hepatitis in children].

OBJECTIVE: To explore the etiology and clinical characteristics of hypoxic hepatitis (HH) in children. METHOD: Clinical data of 7 patients with HH in Shenzhen Children's Hospital from January 2011 to March 2014 were retrospectively reviewed. RESULT: Seven cases diagnosed as HH, age from 4 months to 11 years, were admitted to pediatric intensive care unit (PICU), and accounted for 0.32% of patients in PICU during the same period. The primary causes of HH were respiratory failure and cardiac shock caused by severe hand-foot-and-mouth disease, fulminant myocarditis, infant muggy syndrome . Serologic tests for hepatitis B virus, hepatitis C virus, as well as serum antibody and DNA for Epstein-Barr virus and cytomegalovirus were all negative. There was an increase of alanine aminotransferase (ALT) (≥20 time supper limit of normal (ULN), the highest ALT was more than 130 times ULN in all the patients, which was decreased to 2 times ULN from peak within 10 days. There was a significant relationship between ALT and aspartate aminotransferase(AST)in 3 cases(r=1.000, 1.000, and 0.833, respectively, P<0.05), ALT and lactate dehydrogenase (LDH)in 2 cases(r=1.000 and 0.886, respectively, P<0.05), ALT and blood urea nitrogen(BUN)in 1 case(r=1.000, P<0.05), and ALT and creatine kinase(CK)in 1 case(r=0.964, P<0.05). The ALT, AST and LDH returned to normal soon after the primary diseases were controlled. CONCLUSION: Severe heart failure, hypoxemia, shock, etc. are the leading primary diseases causing HH. The sharp increase in ALT, AST and LDH is the typical laboratory manifestion in HH after the onset, which may decline to normal shortly after the treatment, sometimes complicated with reversible change in BUN or CK.

Nexrutine inhibits cancer cell growth as a consequence of mitochondrial damage and mitophagy.

BACKGROUND/AIMS: Nexrutine is an herbal extract of Phellodendron amurense and has been used as nutrient supplement in China as well as America. Potential protection effect of Nexrutine has been reported. METHODS: To investigate the mechanism of Nexrutine, we used the HeLa, U2OS and HCT116 as a model. Based on the acidification of cell culture media, we examined the lactate, mitochondria damage as well as mitophagy status by corresponding assay. RESULTS: Our data suggest that Nexrutine alters the cellular glucose metabolism to promote lactate production. This effect is caused by mitochondrial damage, not an alteration to lactate dehydrogenase activity. As a result of the mitochondrial damage, cell proliferation was inhibited and was associated with an elevation in p21/p27 proteins, which are both important cell cycle inhibitors. As another consequence of the mitochondrial damage, mitophagy was highly activated in Nexrutine-treated cells in a dose-dependent manner. When the autophagy pathway was blocked by siRNAs against BECN1 or ATG7, the growth inhibition caused by Nexrutine was reversed. CONCLUSION: Our study revealed that autophagy plays an important role in the inhibition of cancer cell proliferation by Nexrutine.

Radiosensitization of MDA-MB-231 breast tumor cells by adenovirus-mediated overexpression of a fragment of the XRCC4 protein.

Incomplete DNA repair or misrepair can contribute to the cytotoxicity of DNA double-strand breaks. Consequently, interference with double-strand break repair, by pharmacologic or genetic means, is likely to sensitize tumor cells to ionizing radiation. The current studies were designed to inhibit the nonhomologous end joining repair pathway by interfering with the function of the XRCC4/ligase IV complex. A PCR-generated fragment of the XRCC4 gene, encompassing the homodimerization and ligase IV-binding domains, was inserted into a plasmid vector (pFLAG-CMV-2) expressing the FLAG peptide and the cassette encoding FLAG-tagged XRCC4 fragment was cloned into an adenoviral vector. Both the plasmid and the corresponding adenovirus elicited robust expression of a truncated XRCC4 protein designed to compete in a dominant-negative fashion with full-length XRCC4 for binding to ligase IV. Binding of the XRCC4 fragment to ligase IV in vivo was confirmed by immunoprecipitation. Clonogenic survival assays showed that the adenovirus expressing the truncated XRCC4 protein sensitizes MDA-MB-231 breast tumor cells to ionizing radiation, presumably through interference with the functional activity of ligase IV, leading to inhibition of the final ligation step in end joining. These studies support the potential clinical utility of combining radiation therapy with agents that inhibit DNA double-strand break repair.