The ubiquitin-proteasome pathway is responsible for the degradation of most cellular proteins in eukaryotes.It regulates almost all cellular activities, including cell proliferation, differentiation, apoptosis, gene transcription, and DNA repair.The dysfunction of the ubiquitin-proteasome pathway is associated with the pathogenesis of numerous human diseases, including cancer and neurodegenerative diseases.The marketed proteasome inhibitors have been successfully used to treat multiple myeloma and mantle cell lymphoma.Furthermore, novel inhibitors against the components of the ubiquitin-proteasome pathway are under developed and exhibit promising therapeutic effects in vivo.This paper will briefly introduce the progress on the drug discovery related to the ubiquitin-proteasome pathway.

Objective To discover a novel long noncoding RNA YLL066W-B (referred to as YLB), whose expression can be regulated by a ubiquitin ligases E3, Huwel/Tom1, and further investigate the regulatory effects of YLB on expression of multiple subtelomeric genes. Methods Yeast strains (including Tom1△, YLB-HA, HA-YLB, pYES2-HA-YLB and YLB△) were constructed according to the principle of PCR-based tagging of yeast genes. The effects of Tom1 deletion on gene expression were analyzed by real-time PCR and DNA microarray. The protein levels were detected by Western blot. We further performed quantitative real time-PCR to analyze the inlfuence of YLB on expression of multiple subtelomerical genes.Results We found that deletion of Tom1 in yeast could affect the expression of multiple genes and greatly up-regulated the expression of YLB, which is implicated in cell cycle regulation. By analyzing its nucleotide sequence(171 bp)and detecting protein expression, we speculate that the transcriptional product of YLB is a long noncoding RNA (lncRNA). Although YLB is not homologous to any protein-encoding sequences by NCBI blast, it is homologous to the upstream or downstream regions of the open reading frame of several subtelomerically-encoded genes, including those from pau family and DNA helicase Yrf family. Thus, it is possible that YLB is involved in the regulation of these subtelomerically-encoded genes. Accordingly, deletion of YLB markedly up-regulated the mRNA levels of Yrf1-4, pau4 and pau22, whereas over-expression of YLB greatly down-regulated their expression.Conclusion We have discovered the novel lncRNA YLB. The expression of YLB could be negatively regulated by Tom1, and YLB could regulate the expression of multiple subtelomeric genes.

Objective To investigate neuroprotective mechanisms of vinpocetine by observing the effects of vinpocetine injection on the expressions of peroxisome proliferators-activated receptor γ(PPARγ),nuclear factor (NF)-κB p65,cyclooxygenase-2 (COX-2) in the ischemic cortex,and infarct volume after focal cerebral ischemia-reperfusion in rats.Methods A focal cerebral ischemia-reperfusion injury model was induced by suture method.The rats were randomly divided into a normal control,a cerebral ischemiareperfusion and a vinpocetine groups.They were also divided into either a day 7 subgroup or a day 14 subgroup (n =6 in each subgroup) according to the reperfusion time.Western blot was used to detect the expression levels of PPARγand NF-κB P65 in the ischemic cortex.Triphenyl tetrazolium staining was used to detect the volume of cerebral infarction.Results Western blot showed that at day 7 and 14 after cerebral ischemia-reperfusion,expression levels of PPARκ (all P＜0.001) and NF-κB p65 (all P＜0.001) in the cerebral ischemia-reperfusion group were significantly higher than those in the sham operation group,the expression levels of PPARκ (all P ＜0.05) in the vinpocetine group were significantly higher than those in the cerebral ischemia-reperfusion group,but the expression levels of NF-κB p65 (all P ＜0.05) were significantly lower than those in the cerebral ischemia-reperfusion group.Reverse transcription polymerase chain reaction showed that COX-2 mRNA expression levels were upregulated significantly at day 7 and 14 after cerebral ischemia-reperfusion compared with the sham operation group (all P ＜ 0.001),the expression levels of COX-2 mRNA in the vinpocetine group were significantly downregulated compared with the cerebral ischemia-reperfusion group (all P＜ 0.05).The infarct volumes at day 7 (134.308± 9.954 mm3vs.185.543 ± 9.100 mm3;q=10.659,P＜0.001) and at day 14 (137.865 ± 9.094 mm3vs.183.210±4.368 mm3;q=11.166,P＜0.001) in the vinpocetine group were significantly less than those in the cerebral ischemia-reperfusion group.Conclusions Vimpocetine significantly reduces infarct vohme after focal cerebral ischemia-reperfusion,its mechanism may be associated with upreguhtion of PPARγexpression and downreguhtion of the expressions of NF-κB p65 and COX-2.

Objective To analyze the genetic changes and detailed clinical presentations of 5 maturity-onset diabetes of the young (MODY) cases in order to enhance the knowledge about MODY in children.Methods Seventy-eight patients initially diagnosed as diabetes mellitus between January 1 and December 31,2015 in Capital Institute of Pediatrics were retrospectively studied.Nine of them were suspected of MODY,and 5 patients were diagnosed as MODY through gene test.Clinical informations were collected including age,gender,main complaint,family history,body mass index (BMI),fasting blood glucose,fasting blood insulin,2-hour blood glucose and insulin after oral glucose tolerance test and glycosylated hemoglobin.The blood glucose was monitored dynamically in 2 patients.Targeted capture panel was designed to capture the 16 genes related to MODY,including 12 genes from MODY1 to MODY13 type and 4 genes with weak evidence of MODY according to Human Gene Mutation Database Exome capture,and Next-Generation sequencing on a HiSeq2000 (Illumina) was performed.After bioinformatics analysis,all prioritized variants detected in patients were validated by Sanger sequencing,including the probands and their parents.Results Five patients were confirmed as MODY by molecular diagnosis,accounting for 6.4％ of all the 78 patients in 2015.The ratio of male to female was 2 ∶ 3.The ages at diagnosis ranged from 2 to 11 years old,and the median age was 3 years old.Two cases were found to have abnormal blood glucose in physical examination.The rest 3 cases were discovered with abnormal blood glucose during hospitalization because of pneumonia (1 case)or diarrhea (2 cases).In 4 cases,their mothers had gestational diabetes history,in 1 case the father suffering from diabetes.BMI ranged 15.68-23.40 kg/m2.Fasting blood glucose was 6.3-7.2 mmol/L.Fasting blood insulin was 0.5-8.0 IU/L.Glucose tolerance test results showed that blood glucose of the patients was 8.6-10.8 mmol/L after 2 hours.The level of glycosylated hemoglobin was 5.5％-6.7％.Blood glucose was 3.9-13.0 mmol/L.All the 5 confirmed patients were caused by GCK gene mutation (MODY2 type).The mutations detected were located at Exon7 (2 cases),Exon4 (1 case),Exon5 (1 case),and Exon10 (1 case).Conclusions All the confirmed MODY patients were identified either through medical exam or infectious disease,and all had positive family history.Their BMI ranged widely.Fasting blood glucose was slightly elevated and glycosylated hemoglobin was normal or slightly elevated,but fasting blood insulin was normal in all the patients.Abnormal glucose tolerance test results were found in all 5 patients.Glycosylated hemoglobin was normal or slightly elevated.MODY2 was the only subtype detected in this group,which indicated that the common type in children was different from that in adults.

Objective Congenital nephrogenic diabetes insipidus (CNDI) is a rare disease, the aim of this article is to help better understanding of this disease. Methods The clinical features, genetic analysis and treatments of two siblings with CNDI were retrospectively analyzed, and related literatures were reviewed. Results Both brothers had polydispia, polyuria and low concentrate urine continuously, and they both had a mutation in AQP 2 conifrmmed with Sanger sequencing. This novel frame shift mutation caused arginine of 254 to histidine, and prolonged AQP 2 protein. Conclusions Gene analysis can help diagnosis of CNDI. Amiloride is useful option for treatment.

Objective To analyze the clinical characteristics and mutation of SLC26A3 gene of a patient with congenital chloride diarrhea in order to deepen the understanding of the disease.Methods The clinical data of the patient who was admitted in Affiliated Hospital of Capital Pediatric Institute in June 2014 were collected.Venous blood of the proband and his parents (2 mL for each) had been extracted for genomic DNA isolation.The 21 exons of SLC26A3 gene were amplified with polymerase chain reaction and screened for mutations by sequencing.Results The main clinical features of the patient included polyhydramnios,preterm,normal birth weight,watery diarrhea,low weight and severe electrolyte disturbances with hypochloremia,hypokalemia,hyponatremia and metabolic alkalosis.Renin angiotensin and aldosterone were high.His urine chloride concentration was low and fecal chloride concentration was high (＞ 90mmol/L).After oral salt substitution therapy with KCl and NaCl [3 mmol/(kg · d),4 mmol/(kg · d)],the electrolyte was better,alkalosis was alleviated,and growth and development were improved.The gene analysis revealed that the patient carried nt1631T ＞ A homozygous mutation on exon 15 which lead to Ile544Asn mutation in the predicted SLC26A3 transmembrane protein sequence,which was considered to be responsible for the functional abnormality of the Cl-/HCO3-protein.His parents were carriers of SLC26A3 gene and their clinical phenotype was normal.Conclusions Congenital chloride diarrhea is a rare autosomal recessive disorder and easily misdiagnosed.The patient of early postnatal diarrhea with persistent hypochloremia,hypokalemia,hyponatremia and metabolic alkalosis should be thought about this disease.Genetic analysis can help make the diagnosis.The prognosis is good if a patient has an early diagnosis and appropriate management.

Objective To explore the effect of thyroxine (TH) on the migration of hippocampal neurons in newborn rat exposed to tritiated water (HTO).Methods The hippocampal neurons from neonatal rats were primarily cultured,7 days later,randomly divided into control group,HTO group,TH group and HTO + TH group(3.7 × 105 Bq/ml HTO and 0.3 μg/ml TH were simultaneously added).After 24 h,the distance of neuronal migration was measured with Leica AF 6000,the expressions of BDNF and Reelin mRNA in neurons were analyzed with reverse transcription polymerase chain reaction (RT-PCR),the expression of β-tubulin protein in neurons was assayed with Western blot and immunocytochemical staining.Results Compared with control group,the expression of Reelin mRNA,BDNF mRNA and β-tubulin in HTO group were significantly reduced(t =5.80,5.48,5.47,P ＜ 0.01),but those in HTO + TH group and TH group were obviously increased (t =7.75,12.06,13.65,P ＜ 0.01 ;t =4.34,5.47,5.65,P ＜0.01)and higher than that in HTO group (t =2.92,10.32,8.76,P ＜ 0.01 ;t =18.07,20.55,40.13,P ＜0.01).Accordingly,the neuronal migration distance in HTO group was much shorter than that in control (t =8.62,P ＜ 0.01),and in HTO + TH group and TH group was far longer than that in control(t =7.64,4.93,P＜0.01).Moreover,the neuronal migration distance in HTO + TH group was notably elongated in comparison with that in HTO group(t =11.32,12.31,P ＜ 0.01).Conclusions Thyroxine may promote the migration of hippocampal neurons in newborn rat exposed to HTO.

Objective To report clinical characteristics and genetic results of two sisters suffered from congenital adrenal cortex hyperplasia (17-α-hydroxylase deficiency), and relevant literatures were reviewed. Methods Clinical manifestation and laboratory examination data of two sister cases of 17-α-hydroxylase deficiency enrolled in Capital Institute of Pediatrics in March 2016 were analyzed. Sanger sequencing and MLPA for CYP17A1 genes were performed and the parents' genes were also verified. Results The two patients were four years and 10 years old, both suffered from hypokalemia after infections, and hypergonadotrophin gonad hypofunction. One case was with slightly high blood pressure. Laboratory test results showed potassium fluctuation tendency in 1.9~4.0 mmol/L, 17-OHP and DHEA was decreased. Enhanced CT showed different degree of adrenal gland enlargement. Chromosome examination of the older sister is 46, XY. Both sisters demonstrated heterozygous mutation of CYP17A1 gene. The molecular genetic analysis suggested a c.985_987delTACinsAA from father and a deletion spanning exons 1-7 of the CYP17A1 gene from mother. Conclusion 17-α-hydroxylase enzyme deficiency can be diagnosed before adolescence. Clinical hypokalemia with unknown reason and high blood pressure may indicate the disease. The diagnosis can be confirmed with gene sequencing of CYP17A1.

Objective A 10-years-old girl with Schimke immuno-osseous dysplasia ( SIOD ) was reported and a literature review presented to provide clinical and genetic information of this rare disease. Methods Retrospective analysis of a case of SIOD in Capital Institute of Pediatrics was reported. The patient and her parents' DNA were extracted from blood for detecting SMARCALl gene mutation. Literatures of the disease were reviewed. Results The patient was a ten-years-old girl who admitted because of slow growth in height for 3 years. Herstaturewas123cm(T(p.Q149X)andc.1933C>T(p.R645C)compound heterozygous mutation. A novel nonsense c.445C>T(p. Q149X)was found. One reported missense mutations c. 1933C>T(p. R645C) was detected. We reviewed literatures and found that there were 4 confirmed cases in China including this one. All the 4 cases had the characteristic of short stature, special facial features, osseous dysplasia, pigmentations in body, and proteinuria. However the severity of the disease and genetic changes are not the same. Conclusion When a patient was admitted because of short stature, diagnosis of SIOD should be suspected if he or she also had special facial feature, osseous dysplasia, café-au-lait spots, and proteinuria. Gene test is a tool to help us to make a definite diagnosis of SIOD.

OBJECTIVE: Two brothes with Seckel's syndrome 1(SCKL1) were reported and a literature review was carried to provide clinical and genetic information of this rare disease. METHODS: Clinical data of the two children were collected, and the peripheral blood was extracted for whole exome sequencing. Literature of the disease were reviewed. RESULTS: The two patients were 11 years and 9.5 years old when examined for short stature. They presented with intrauterine growth retardation, intellectual disability, microcephaly, birdhead-like face and coffee au lait spots. The bone age was more than 2 years behind the chronical age and the growth hormone levels were normal. Whole exome sequencing revealed novel compound heterozygous variants c.1A>G (p.M1?) and c.4853-18A>G of ART gene in both children. CONCLUSION Children with prenatal onset short stature, developmental delay, microcephaly and special facial featuresshould be considered for the possibility of Seckel's syndrome, whole exome sequencing could help to confirm the clinical diagnosis.
Ataxia Telangiectasia Mutated Proteins/genetics* ; Child ; Dwarfism/genetics* ; Humans ; Intellectual Disability/genetics* ; Male ; Microcephaly/genetics* ; Siblings ; Whole Exome Sequencing