Ubiquitin protein E3 ligase ASB9 suppresses proliferation and promotes apoptosis in human spermatogonial stem cell line by inducing HIF1AN degradation

BACKGROUND: Spermatogonial stem cells (SSCs) are critical for sustaining spermatogenesis. Even though several regulators of SSC have been identified in rodents, the regulatory mechanism of SSC in humans has yet to be discovered. METHODS: To explore the regulatory mechanisms of human SSCs, we analyzed publicly available human testicular single-cell sequencing data and found that Ankyrin repeat and SOCS box protein 9 (ASB9) is highly expressed in SSCs. We examined the expression localization of ASB9 using immunohistochemistry and overexpressed ASB9 in human SSC lines to explore its role in SSC proliferation and apoptosis. Meanwhile, we used immunoprecipitation to find the target protein of ASB9 and verified its functions. In addition, we examined the changes in the distribution of ASB9 in non-obstructive azoospermia (NOA) patients using Western blot and immunofluorescence. RESULTS: The results of uniform manifold approximation and projection (UMAP) clustering and pseudotime analysis showed that ASB9 was highly expressed in SSCs, and its expression gradually increased during development. The immunohistochemical and dual-color immunofluorescence results displayed that ASB9 was mainly expressed in nonproliferating SSCs. Overexpression of ASB9 in the SSC line revealed significant inhibition of cell proliferation and increased apoptosis. We predicted the target proteins of ASB9 and verified that hypoxia-inducible factor 1-alpha inhibitor (HIF1AN), but not creatine kinase B-type (CKB), has a direct interaction with ASB9 in human SSC line using protein immunoprecipitation experiments. Subsequently, we re-expressed HIF1AN in ASB9 overexpressing cells and found that HIF1AN reversed the proliferative and apoptotic changes induced by ASB9 overexpression. In addition, we found that ABS9 was significantly downregulated in some NOA patients, implying a correlation between ASB9 dysregulation and impaired spermatogenesis. CONCLUSION: ASB9 is predominantly expressed in human SSCs, it affects the proliferation and apoptotic process of the SSC line through HIF1AN, and its abnormal expression may be associated with NOA.

RGS12 represses oral squamous cell carcinoma by driving M1 polarization of tumor-associated macrophages via controlling ciliary MYCBP2/KIF2A signaling / 国际口腔科学杂志·英文版

Tumor-associated macrophages (TAMs) play crucial roles in tumor progression and immune responses. However, mechanisms of driving TAMs to antitumor function remain unknown. Here, transcriptome profiling analysis of human oral cancer tissues indicated that regulator of G protein signaling 12 (RGS12) regulates pathologic processes and immune-related pathways. Mice with RGS12 knockout in macrophages displayed decreased M1 TAMs in oral cancer tissues, and extensive proliferation and invasion of oral cancer cells. RGS12 increased the M1 macrophages with features of increased ciliated cell number and cilia length. Mechanistically, RGS12 associates with and activates MYC binding protein 2 (MYCBP2) to degrade the cilia protein kinesin family member 2A (KIF2A) in TAMs. Our results demonstrate that RGS12 is an essential oral cancer biomarker and regulator for immunosuppressive TAMs activation.

lncR-GAS5 upregulates the splicing factor SRSF10 to impair endothelial autophagy, leading to atherogenesis / 医学前沿

Long noncoding RNAs (lncRNAs) play a critical role in the regulation of atherosclerosis. Here, we investigated the role of the lncRNA growth arrest-specific 5 (lncR-GAS5) in atherogenesis. We found that the enforced expression of lncR-GAS5 contributed to the development of atherosclerosis, which presented as increased plaque size and reduced collagen content. Moreover, impaired autophagy was observed, as shown by a decreased LC3II/LC3I protein ratio and an elevated P62 level in lncR-GAS5-overexpressing human aortic endothelial cells. By contrast, lncR-GAS5 knockdown promoted autophagy. Moreover, serine/arginine-rich splicing factor 10 (SRSF10) knockdown increased the LC3II/LC3I ratio and decreased the P62 level, thus enhancing the formation of autophagic vacuoles, autolysosomes, and autophagosomes. Mechanistically, lncR-GAS5 regulated the downstream splicing factor SRSF10 to impair autophagy in the endothelium, which was reversed by the knockdown of SRSF10. Further results revealed that overexpression of the lncR-GAS5-targeted gene miR-193-5p promoted autophagy and autophagic vacuole accumulation by repressing its direct target gene, SRSF10. Notably, miR-193-5p overexpression decreased plaque size and increased collagen content. Altogether, these findings demonstrate that lncR-GAS5 partially contributes to atherogenesis and plaque instability by impairing endothelial autophagy. In conclusion, lncR-GAS5 overexpression arrested endothelial autophagy through the miR-193-5p/SRSF10 signaling pathway. Thus, miR-193-5p/SRSF10 may serve as a novel treatment target for atherosclerosis.

Single-nucleus transcriptomics reveals a gatekeeper role for FOXP1 in primate cardiac aging

Aging poses a major risk factor for cardiovascular diseases, the leading cause of death in the aged population. However, the cell type-specific changes underlying cardiac aging are far from being clear. Here, we performed single-nucleus RNA-sequencing analysis of left ventricles from young and aged cynomolgus monkeys to define cell composition changes and transcriptomic alterations across different cell types associated with age. We found that aged cardiomyocytes underwent a dramatic loss in cell numbers and profound fluctuations in transcriptional profiles. Via transcription regulatory network analysis, we identified FOXP1, a core transcription factor in organ development, as a key downregulated factor in aged cardiomyocytes, concomitant with the dysregulation of FOXP1 target genes associated with heart function and cardiac diseases. Consistently, the deficiency of FOXP1 led to hypertrophic and senescent phenotypes in human embryonic stem cell-derived cardiomyocytes. Altogether, our findings depict the cellular and molecular landscape of ventricular aging at the single-cell resolution, and identify drivers for primate cardiac aging and potential targets for intervention against cardiac aging and associated diseases.

Primary synovial sarcoma of lung: a clinicopathological analysis of 12 cases / 中华病理学杂志

Objective: To investigate the clinicopathological features, immunophenotype, molecular features and differential diagnosis of primary synovial sarcoma of the lung (PSSL). Methods: Twelve cases of PSSL were collected at Henan Provincial People's Hospital, during May 2010 and April 2021, and their clinicopathological parameters were summarized. SS18-SSX, H3K27Me3, and SOX2 were added to the original immunomarkers to evaluate their diagnostic value for PSSL. Results: The age of 12 patients when diagnosed ranged from 32 to 75 years (mean of 50 years). There were 7 males and 5 females, 2 left lung cases and 10 right lung cases. Of the 6 patients who underwent surgical resection, five cases were confined to lung tissue (T1), one case had mediastinal invasion (T3), two cases had regional lymph node metastasis (N1), and none had distal metastasis. Microscopically, 11 cases showed monophasic spindle cell type and one case showed biphasic type composed of mainly epithelial cells consisting of cuboidal to columnar cells with glandular and cribriform structures. It was difficult to make the diagnosis by using the biopsy specimens. Immunohistochemistry (IHC) showed CKpan expression in 8 of 12 cases; EMA expression in 11 of 12 case; TLE1 expression in 8 of 12 cases; S-100 protein expression in two of 12 cases; various expression of bcl-2 and vimentin in 12 cases, but no expression of SOX10 and CD34 in all the cases. The Ki-67 index was 15%-30%. The expression of SS18-SSX fusion antibody was diffusely and strongly positive in all 12 cases. SOX2 was partially or diffusely expressed in 8 of 12 cases, with strong expression in the epithelial component. H3K27Me3 was absent in 3 of 12 cases. SS18 gene translocation was confirmed by fluorescence in situ hybridization (FISH) test in all 12 samples. Six cases underwent surgery and postoperative chemotherapy, while the other six cases had chemotherapy alone. Ten patients were followed up after 9-114 months, with an average of 41 months and a median of 26 months. Five patients survived and five died of the disease within two years. Conclusions: PSSL is rare and has a broad morphological spectrum. IHC and molecular tests are needed for definitive diagnosis. Compared with current commonly used IHC markers, SS18-SSX fusion antibody has better sensitivity to PSSL, which could be used as an alternative for FISH, reverse transcription-polymerase chain reaction or next generation sequencing in the diagnosis of PSSL.

The OxyR and SoxR transcriptional regulators are involved in a broad oxidative stress response in Paraburkholderia xenovorans LB400

BACKGROUND: Aerobic metabolism generates reactive oxygen species that may cause critical harm to the cell. The aim of this study is the characterization of the stress responses in the model aromatic degrading bacterium Paraburkholderia xenovorans LB400 to the oxidizing agents paraquat and H 2 O2. METHODS: Antioxidant genes were identified by bioinformatic methods in the genome of P. xenovorans LB400, and the phylogeny of its OxyR and SoxR transcriptional regulators were studied. Functionality of the transcriptional regulators from strain LB400 was assessed by complementation with LB400 SoxR of null mutant P. aeruginosa ΔsoxR, and the construction of P. xenovorans pIZ oxyR that overexpresses OxyR. The effects of oxidizing agents on P. xenovorans were studied measuring bacterial susceptibility, survival and ROS formation after exposure to paraquat and H 2 O2. The effects of these oxidants on gene expression (qRT PCR) and the proteome (LC-MS/MS) were quantified. RESULTS: P. xenovorans LB400 possesses a wide repertoire of genes for the antioxidant defense including the oxyR , ahpC , ahpF , kat , trxB , dpsA and gorA genes, whose orthologous genes are regulated by the transcriptional regulator OxyR in E. coli . The LB400 genome also harbors the soxR, fumC , acnA , sodB , fpr and fldX genes, whose orthologous genes are regulated by the transcriptional regulator SoxR in E. coli . The functionality of the LB400 soxR gene was confirmed by complementation of null mutant P. aeruginosa Δ soxR . Growth, susceptibility, and ROS formation assays revealed that LB400 cells were more susceptible to paraquat than H2O2. Transcriptional analyses indicated the upregulation of the oxyR , ahpC1 , katE and ohrB genes in LB400 cells after exposure to H2O2, whereas the oxyR , fumC , ahpC1 , sodB1 and ohrB genes were induced in presence of paraquat. Proteome analysis revealed that paraquat induced the oxidative stress response proteins AhpCF and DpsA, the universal stress protein UspA and the RNA chaperone CspA. Both oxidizing agents induced the Ohr protein, which is involved in organic peroxide resistance. Notably, the overexpression of the LB400 oxyR gene in P. xenovorans significantly decreased the ROS formation and the susceptibility to paraquat, suggesting a broad OxyR regulated antioxidant response. CONCLUSIONS: This study showed that P. xenovorans LB400 possess a broad range oxidative stress response, which explain the high resistance of this strain to the oxidizing compounds paraquat and H2O2.

From azoospermia to macrozoospermia, a phenotypic continuum due to mutations in the ZMYND15 gene / 亚洲男科学杂志(英文版)

Thanks to tremendous advances in sequencing technologies and in particular to whole exome sequencing (WES), many genes have now been linked to severe sperm defects. A precise genetic diagnosis is obtained for a minority of patients and only for the most severe defects like azoospermia or macrozoospermia which is very often due to defects in the aurora kinase C (AURKC gene. Here, we studied a subject with a severe oligozoospermia and a phenotypic diagnosis of macrozoospermia. AURKC analysis did not reveal any deleterious variant. WES was then initiated which permitted to identify a homozygous loss of function variant in the zinc finger MYND-type containing 15 (ZMYND15 gene. ZMYND15 has been described to serve as a switch for haploid gene expression, and mice devoid of ZMYND15 were shown to be sterile due to nonobstructive azoospermia (NOA). In man, ZMYND15 has been associated with NOA and severe oligozoospermia. We confirm here that the presence of a bi-allelic ZMYND15 variant induces a severe oligozoospermia. In addition, we show that severe oligozoospermia can be associated macrozoospermia, and that a phenotypic misdiagnosis is possible, potentially delaying the genetic diagnosis. In conclusion, genetic defects in ZMYND15 can induce complete NOA or severe oligozoospermia associated with a very severe teratozoospermia. In our experience, severe oligozoospermia is often associated with severe teratozoospermia and can sometimes be misinterpreted as macrozoospermia or globozoospermia. In these instances, specific AURKC or dpy-19 like 2 (DPY19L2) diagnosis is usually negative and we recommend the direct use of a pan-genomic techniques such as WES.

circ_0003204 regulates the osteogenic differentiation of human adipose-derived stem cells via miR-370-3p/HDAC4 axis / 国际口腔科学杂志·英文版

Human adipose-derived stem cells (hASCs) are a promising cell type for bone tissue regeneration. Circular RNAs (circRNAs) have been shown to play a critical role in regulating various cell differentiation and involve in mesenchymal stem cell osteogenesis. However, how circRNAs regulate hASCs in osteogenesis is still unclear. Herein, we found circ_0003204 was significantly downregulated during osteogenic differentiation of hASCs. Knockdown of circ_0003204 by siRNA or overexpression by lentivirus confirmed circ_0003204 could negatively regulate the osteogenic differentiation of hASCs. We performed dual-luciferase reporting assay and rescue experiments to verify circ_0003204 regulated osteogenic differentiation via sponging miR-370-3p. We predicted and confirmed that miR-370-3p had targets in the 3'-UTR of HDAC4 mRNA. The following rescue experiments indicated that circ_0003204 regulated the osteogenic differentiation of hASCs via miR-370-3p/HDAC4 axis. Subsequent in vivo experiments showed the silencing of circ_0003204 increased the bone formation and promoted the expression of osteogenic-related proteins in a mouse bone defect model, while overexpression of circ_0003204 inhibited bone defect repair. Our findings indicated that circ_0003204 might be a promising target to promote the efficacy of hASCs in repairing bone defects.

Silencing DNMT1 Attenuates the Effect of WIF-1 Gene Promoter Methylation on the Biological Behavior of Chronic Myeloid Leukemia K562 Cells / 中国实验血液学杂志

OBJECTIVE@#To investigate the effect of silencing DNA methyltransferase 1(DNMT1) to the methylation of the promoter of the tumor suppressor gene wnt-1 (WIF-1) in human chronic myeloid leukemia (CML) cells.@*METHODS@#DNMT1 siRNAi plasmid was constructed and DNMT1 siRNAi was transfected into CML K562 cells. RT-PCR and Western blot were used to detect the expression of DNMT1 gene and related protein, and methylation PCR was used to detect WIF-1 gene promoter methylation level. The trypan blue exclusion and MTT assay were used to detect the cell proliferation, flow cytometry were used to detect the cell apoptosis rate, colony formation assay was used to detect cell colony formation ability. Expression of Wnt/β- catenin and its downstream signaling pathway proteins were detected by Western blot after DNMT1 gene was silenced.@*RESULTS@#The expression level of DNMT1 mRNA and its related protein in the experimental group were significantly lower than those in the control group and negative control group (P<0.05). After 72 hours of successful transfection, the WIF-1 gene in the control group and negative control group were completely methylated, while in the experimental group, the methylation level significantly decreased. The results of MSP showed that the PCR product amplified by the unmethylated WIF-1 primer in the experimental group increased significantly,while by the methylated WIF-1 primer decreased significantly. After 48 h of transfection, the OD value, viable cell number and colony formation of the cells in experimental group were significantly lower than those in the negative control group and the control group (P<0.05). The apoptosis rate of the cells in experimental group was significantly higher than those in the negative control group and control group (P<0.05). The expression levels of β- actin, myc, cyclin D1 and TCF-1 in K562 cells in the experimental group were significantly lower than those in the negative control group and control group (P<0.05).@*CONCLUSION@#Silencing DNMT1 gene can inhibit the proliferation and promote the apoptosis of K562 cells. The mechanism may be related to reverse the hypermethylation level of the WIF-1 gene promoter, thereby inhibit the activity of the Wnt/β- catenin signaling pathway.

Lrrc34 Is Highly Expressed in SSCs and Is Necessary for SSC Expansion In Vitro / 中国医学科学杂志(英文版)

Objective To discover critical genes contributing to the stemness and maintenance of spermatogonial stem cells (SSCs) and provide new insights into the function of the leucine-rich repeat (LRR) family member Lrrc34 (leucine-rich repeat-containing 34) in SSCs from mice. Methods Bioinformatic methods, including differentially expressed gene (DEG), gene ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses, were used to uncover latent pluripotency-related genes. Reverse transcription-polymerase chain reaction (RT-PCR) and immunofluorescence analyses were utilized to verify the mRNA and protein expression levels, respectively. RNA interference of Lrrc34 using siRNA was performed to detect its transient impact on SSCs. Results Eight DEGs between ID4-EGFP+ (G) and ID4-EGFP+/TSPAN8High (TH), eight DEGs between G and ID4-EGFP+/TSPAN8Low (TL) and eleven DEGs between TH and TL were discovered, and eleven protein-protein interaction (PPI) modules were found to be significant in the PPI network of DEGs. One of the DEGs, Lrrc34, was selected as a potential pluripotency-related gene due to its differential expression among ID4-EGFP+ spermatogonia subsets and its interaction with fibroblast growth factor 2 in the fifth module. Immunofluorescence experiments exhibited specific expression of Lrrc34 in a subpopulation of undifferentiated spermatogonia marked by LIN28A, and RT-PCR experiments confirmed the high expression of Lrrc34 in SSCs from P7 and adult mice. The transient knockdown of Lrrc34 in SSCs resulted in reduced colony sizes and significant changes in the transcriptome and apoptotic pathways. Conclusion Lrrc34 is highly expressed in mouse SSCs and is required for SSC proliferation in vitro through effects on transcriptome and signaling transduction pathways.

MicroRNA-383-5p inhibits the progression of gastric carcinoma via targeting HDAC9 expression

MicroRNAs (miRNAs), as post-transcriptional regulators, have been reported to be involved in the initiation and progression of various types of cancer, including gastric cancer (GC). The present study aimed to investigate the role of miR-383-5p in gastric carcinogenesis. Cell viability was analyzed using CCK-8 kit. Annexin V-fluorescein isothiocyanate/propidium iodide double staining was used to evaluate cell apoptosis. The expression levels of miR-383-5p and histone deacetylase 9 (HDAC9) mRNA in GC tissues and cell lines were analyzed using RT-qPCR. The protein expression of HDAC9 was detected by western blotting. We found that HDAC9 was up-regulated and miR-383-5p was down-regulated in GC tissues and cell lines. High HDAC9 expression or low miR-383-5p expression was closely related to poor prognosis and metastasis in GC patients. HDAC9 knockout or miR-383-5p mimics led to growth inhibition and increased apoptosis in AGS and SGC-7901 cells. More importantly, we validated that miR-383-5p as a post-transcriptional regulator inhibited HDAC9 expression and was inversely correlated with HDAC9 expression in GC tissues. miR-383-5p had the opposite effects to HDAC9 in gastric carcinogenesis. miR-383-5p played an important role in gastric carcinogenesis, and it is one of the important mechanisms to regulate oncogenic HDAC9 in GC, which might be helpful in the development of novel therapeutic strategies for the treatment of GC.

Strawberry Notch 1 (SBNO1) promotes proliferation of spermatogonial stem cells via the noncanonical Wnt pathway in mice / 亚洲男科学杂志(英文版)

While it is known that spermatogonial stem cells (SSCs) initiate the production of male germ cells, the mechanisms of SSC self-renewal, proliferation, and differentiation remain poorly understood. We have previously identified Strawberry Notch 1 (SBNO1), a vertebrate strawberry notch family protein, in the proteome profile for mouse SSC maturation and differentiation, revealing SBNO1 is associated with neonatal testicular development. To explore further the location and function of SBNO1 in the testes, we performed Sbno1 gene knockdown in mice to study the effects of SBNO1 on neonatal testicular and SSC development. Our results revealed that SBNO1 is required for neonatal testicular and SSC development in mice. Particularly, in vitro Sbno1 gene knockdown with morpholino oligonucleotides caused a reduction of SSCs and inactivation of the noncanonical Wnt pathway, through Jun N-terminal kinases. Our study suggests SBNO1 maintains SSCs by promoting the noncanonical Wnt pathway.

Inactivation of MarR gene homologs increases susceptibility to antimicrobials in Bacteroides fragilis

ABSTRACT Bacteroides fragilis is the strict anaerobic bacteria most commonly found in human infections, and has a high mortality rate. Among other virulence factors, the remarkable ability to acquire resistance to a variety of antimicrobial agents and to tolerate nanomolar concentrations of oxygen explains in part their success in causing infection and colonizing the mucosa. Much attention has been given to genes related to multiple drug resistance derived from plasmids, integrons or transposon, but such genes are also detected in chromosomal systems, like the mar (multiple antibiotic resistance) locus, that confer resistance to a range of drugs. Regulators like MarR, that control expression of the locus mar, also regulate resistance to organic solvents, disinfectants and oxygen reactive species are important players in these events. Strains derived from the parental strain 638R, with mutations in the genes hereby known as marRI (BF638R_3159) and marRII (BF638R_3706) were constructed by gene disruption using a suicide plasmid. Phenotypic response of the mutant strains to hydrogen peroxide, cell survival assay against exposure to oxygen, biofilm formation, resistance to bile salts and resistance to antibiotics was evaluated. The results showed that the mutant strains exhibit statistically significant differences in their response to oxygen stress, but no changes were observed in survival when exposed to bile salts. Biofilm formation was not affected by either gene disruption. Both mutant strains however, became more sensitive to multiple antimicrobial drugs tested. This indicates that as observed in other bacterial species, MarR are an important resistance mechanism in B. fragilis.

Diagnostic utility of DREAM gene mRNA levels in thyroid tumours

ABSTRACT Objective The transcriptional repressor DREAM is involved in thyroid-specific gene expression, thyroid enlargement and nodular development, but its clinical utility is still uncertain. In this study we aimed to investigate whether DREAM mRNA levels differ in different thyroid tumors and how this possible difference would allow the use of DREAM gene expression as molecular marker for diagnostic and/or prognosis purpose. Materials and methods We quantified DREAM gene mRNA levels and investigated its mutational status, relating its expression and genetic changes to diagnostic and prognostic features of 200 thyroid tumors, being 101 malignant [99 papillary thyroid carcinomas (PTC) and 2 anaplastic thyroid carcinomas] and 99 benign thyroid lesions [49 goiter and 50 follicular adenomas (FA)]. Results Levels of mRNA of DREAM gene were higher in benign (0.7909 ± 0.6274 AU) than in malignant (0.3373 ± 0.6274 AU) thyroid lesions (p < 0.0001). DREAM gene expression was able to identify malignancy with 66.7% sensitivity, 85.4% specificity, 84.2% positive predictive value (PPV), 68.7% negative predictive value (NPV), and 75.3% accuracy. DREAM mRNA levels were also useful distinguishing the follicular lesions FA and FVPTC with 70.2% sensitivity, 73.5% specificity, 78.5% PPV, 64.1% NPV, and 71.6% accuracy. However, DREAM gene expression was neither associated with clinical features of tumor aggressiveness, nor with recurrence or survival. Six different genetic changes in non-coding regions of DREAM gene were also found, not related to DREAM gene expression or tumor features. Conclusion We suggest that DREAM gene expression may help diagnose thyroid nodules, identifying malignancy and characterizing follicular-patterned thyroid lesions; however, it is not useful as a prognostic marker.

The novel long noncoding RNA LOC283070 is involved in the transition of LNCaP cells into androgen-independent cells via its interaction with PHB2 / 亚洲男科学杂志(英文版)

We sought to investigate the underlying mechanism of action of the long noncoding RNA (lncRNA) LOC283070 in the development of androgen independence in prostate cancer. The interactions between LOC283070 and target proteins were investigated by RNA pull-down and RNA-binding protein immunoprecipitation (RIP) assays. Subcellular fractionation and quantitative reverse transcription-polymerase chain reaction (qRT-PCR) were used to detect the subcellular localization of LOC283070. Western blotting was performed to detect the expression of prohibitin 2 (PHB2). Luciferase activity assays were performed to evaluate the effects of LOC283070 and PHB2 on the androgen receptor (AR) signaling pathway. A methyl thiazolyl tetrazolium (MTT) assay and a growth curve assay were used to test cell viability. Flow cytometry was performed to analyze cell cycles. A transwell assay was employed to test cell migration. We identified PHB2 as an interaction partner of LOC283070 in the pull-down and RIP experiments. Furthermore, we confirmed that the enrichment of LOC283070 with PHB2 in androgen-independent LNCaP (LNCaP-AI) cells was much greater than that in LNCaP cells. Moreover, the expression of PHB2 was not significantly different between the two cell lines, and the expression of LOC283070 in the nuclei of the LNCaP-AI cells was significantly greater than that in the LNCaP cells. In vitro data revealed that PHB2 overexpression significantly inhibited AR activity and cell proliferation and migration and induced accumulation of prostate cancer cells in G0/G1 phase. Moreover, the overexpression of LOC283070 fully abrogated the effects of PHB2 overexpression. In conclusion, we found that LOC283070 can bind to PHB2 located in the nucleus and inhibit its effect, and this is one of the mechanisms by which LOC283070 is involved in the transition of LNCaP cells into androgen-independent cells.

Susceptibility weighted imaging: differentiating between calcification and hemosiderin / Imagem ponderada em suscetibilidade magnética: diferenciando calcificação de hemossiderina

Objective: To present a detailed explanation on the processing of magnetic susceptibility weighted imaging (SWI), demonstrating the effects of echo time and sensitive mask on the differentiation between calcification and hemosiderin. Materials and Methods: Computed tomography and magnetic resonance (magnitude and phase) images of six patients (age range 41– 54 years; four men) were retrospectively selected. The SWI images processing was performed using the Matlab’s own routine. Results: Four out of the six patients showed calcifications at computed tomography images and their SWI images demonstrated hyperintense signal at the calcification regions. The other patients did not show any calcifications at computed tomography, and SWI revealed the presence of hemosiderin deposits with hypointense signal. Conclusion: The selection of echo time and of the mask may change all the information on SWI images, and compromise the diagnostic reliability. Amongst the possible masks, the authors highlight that the sigmoid mask allows for contrasting calcifications and hemosiderin on a single SWI image. .

Objetivo: Expor em detalhes o processamento da imagem ponderada em suscetibilidade magnética (susceptibility weighted imaging – SWI), destacando o efeito da escolha do tempo de eco e da máscara sensível à diferenciação de calcificação e hemossiderina simultaneamente. Materiais e Métodos: Imagens de tomografia computadorizada e por ressonância magnética (magnitude e fase) foram selecionadas, retrospectivamente, de seis pacientes (idades entre 41 e 54 anos; quatro homens). O processamento das imagens SWI foi realizado em rotina própria no programa Matlab. Resultados: Dos seis pacientes estudados, quatro apresentaram calcificações nas imagens de tomografia computadorizada. Nestes, as imagens SWI mostraram sinal hiperintenso para as regiões de calcificações. Os outros dois pacientes não apresentaram calcificações nas imagens de tomografia computadorizada e apresentaram depósito de hemossiderina com sinal hipointenso na imagem SWI. Conclusão: A escolha do tempo de eco e da máscara pode alterar toda a informação da imagem SWI e comprometer a confiabilidade diagnóstica. Dentre as possíveis máscaras, destacamos que a máscara sigmoide permite contrastar calcificação e hemossiderina em uma única imagem SWI. .

Tissue expression and subcellular localization of Mipu1, a novel myocardial ischemia-related gene

Myocardial ischemic preconditioning up-regulated protein 1 (Mipu1), a novel zinc finger protein, was originally cloned using bioinformatic analysis and 5' RACE technology of rat heart after a transient myocardial ischemia/reperfusion procedure in our laboratory. In order to investigate the functions of Mipu1, the recombinant prokaryotic expression vector pQE31-Mipu1 was constructed and transformed into Escherichia coli M15(pREP4), and Mipu1-6His fusion protein was expressed and purified. The identity of the purified protein was confirmed by mass spectrometry. The molecular mass of the Mipu1 protein was 70.03779 kDa. The fusion protein was intracutaneously injected to immunize New Zealand rabbits to produce a polyclonal antibody. The antibody titer was approximately 1:16,000. The antibody was tested by Western blotting for specificity and sensitivity. Using the antibody, it was found that Mipu1 was highly expressed in the heart and brain of rats and was localized in the nucleus of H9c2 myogenic cells. The present study lays the foundation for further study of the biological functions of Mipu1.

A novel mutation of thyroid hormone receptor beta (I431V) impairs corepressor release, and induces thyroid hormone resistance syndrome / Uma nova mutação no TR beta (I431V) prejudica a liberação de correpressores e induz síndrome de resistência ao hormônio tireoideano

Resistance to thyroid hormone (RTH) is a rare disorder characterized by variable tissue hyporesponsiveness to thyroid hormone, usually caused by mutations in the thyroid hormone receptor beta (TRβ). We describe a large Brazilian family harboring a novel mutation affecting TRβ gene and inducing RTH. A 14-year-old girl was found to have elevated free T4 and free T3 plasma concentrations in coexistence with unsuppressed TSH and a questionable goiter. The diagnosis of RTH was verified by identification of a novel mutation (I431V) in the TRβ gene. Sixteen asymptomatic relatives of the proposita are also affected by the mutation. Functional studies showed that I431V mutation exerts dominant-negative effect on wild type TRβ, mainly by impairment of ligand-dependent release of corepressor SMRT. The presence of this mutation reduces potency, but does not affect efficacy of thyroid hormone action, in accordance with the clinical picture of eumetabolism of the affected individuals.

A resistência ao hormônio tireoideano (RHT) é uma doença rara, causada por variável hiporresponsividade dos tecidos aos hormônios tireoideanos, usualmente causada por mutações no receptor beta do hormônio tireoideano (TRβ). Descrevemos uma grande família brasileira portadora de uma nova mutação afetando o gene do TRβ, induzindo RHT. Uma paciente de 14 anos de idade apresentou concentrações plasmáticas elevadas de T4 e T3 livres, associadas a TSH não-suprimido e bócio questionável. O diagnóstico de RHT foi estabelecido pela identificação da mutação I431V no gene do TRβ. Dezesseis parentes assintomáticos da probanda também são afetados pela mutação. Estudos funcionais mostram que a mutação I431V exerce efeito dominante negativo sobre o TR selvagem, basicamente, por prejudicar a liberação do correpressor SMRT ligante-dependente. A presença desta mutação reduz a potência, mas não afeta a eficácia da ação do hormônio tireoideano, o que está de acordo com a apresentação clínica de eumetabolismo dos indivíduos afetados.

PIAS1 interacts with the KRAB zinc finger protein, ZNF133, via zinc finger motifs and regulates its transcriptional activity

Zinc finger protein 133 (ZNF133) is composed of a Kruppel-associated box (KRAB) domain and 14 contiguous zinc finger motifs. ZNF133 is regarded as a transcriptional repressor because the KRAB domain has potent repressor activity and the zinc finger motifs usually act in binding to DNA. However, we found that the zinc finger motifs of ZNF133 also possessed transcriptional repressor activity. By two-hybrid screening assay, we found that the zinc finger motifs of ZNF133 interacted with protein inhibitor of activated STAT1 (PIAS1). PIAS1 enhanced the transcriptional repression activity of ZNF133 through the zinc finger motifs. This effect of PIAS1 was relieved by an inhibitor of the histone deacetylases (HDACs). These results demonstrate that the transcriptional repressor activity of ZNF133 is regulated by both the KRAB domain and the zinc finger motifs, and that the repressive effect by zinc finger motifs is mediated by PIAS1.

Mutation analysis of p31(comet) gene, a negative regulator of Mad2, in human hepatocellular carcinoma

Failure of mitotic checkpoint machinery leads to the chromosomal missegregation and nuclear endoreduplication, thereby driving the emergence of aneuploidy and tetraploidy population. Although abnormal nuclear ploidy and the resulting impairment of mitotic checkpoint function are typical physiological event leading to human hepatocellular carcinoma, any mutational change of mitotic checkpoint regulators has not yet been discovered. Therefore, we investigated the mutation of p31(comet), a recently identified mitotic checkpoint regulator, in human hepatocellular carcinoma. Of 51 human hepatocellular carcinoma tissue and 6 cell lines tested, five samples exhibited nucleotide sequence variations dispersed on four sites within the entire coding sequence. Among these sites with sequence substitutions, three were found to be missense mutation accompanied with amino acid change but one was a silent mutation. Of these sequence substitutions, two were present in both tumor and non-tumor liver tissues, suggesting the possibility of polymorphism. The present findings indicate that p31(comet) does not have an impact on the formation of aneuploidy and tetraploidy found in human hepatocellular carcinoma.