Krüppel-like factor 10 regulates the contractile properties of skeletal muscle fibers in mice.

INTRODUCTION/AIMS: Klf10 is a member of the Krüppel-like family of transcription factors, which is implicated in mediating muscle structure (fiber size, organization of the sarcomere), muscle metabolic activity (respiratory chain), and passive force. The aim of this study was to further characterize the roles of Klf10 in the contractile properties of skeletal muscle fibers. METHODS: Fifty-two single fibers were extracted from female wild-type (WT) and Klf10 knockout (KO) oxidative (soleus) and glycolytic (extensor digitorum longus [EDL]) skinned muscles. Each fiber was immersed successively in relaxing (R), washing (W), and activating (A) solutions. Calcium was included in the activating solution to induce a maximum contraction of the fiber. The maximum force (Fmax ) was measured and normalized to the cross-sectional area to obtain the maximum stress (Stressmax ). After a steady state in contraction was reached, a quick stretch-release was performed; the force at the maximum stretch (Fstretch ) was measured and the stiffness was assessed. RESULTS: Deletion of the Klf10 gene induced changes in the contractile parameters (Fmax , Stressmax , Stiffness), which were lower and higher for soleus and EDL fibers compared with littermates, respectively. These measurements also revealed changes in the proportion and resistance of attached cross-bridges. DISCUSSION: Klf10 plays a major role in the homeostasis of the contractile behavior of skeletal muscle fibers in a muscle fiber type-specific manner. These findings further implicate important roles for Klf10 in skeletal muscle function and shed new light on understanding the molecular processes regulating the contractility of skeletal muscle fibers.

ZNF655 is involved in development and progression of non-small-cell lung cancer.

AIMS: Non-small cell lung cancer (NSCLC) is a malignant tumor with high mortality, which seriously endangers human health. The clinical significance, biological function and potential mechanism of Zinc finger protein 655 (ZNF655) in NSCLC are discussed in this study. MATERIALS AND METHODS: The expression level of ZNF655 in NSCLC was clarified by immunohistochemical (IHC) staining. Subsequently, lentivirus-mediated shRNA was used to construct ZNF655 knock down NSCLC cells NCI-H1299 and A549. In vitro and in vivo loss of function assays were used to evaluate the malignant behaviors of the cells. KEY FINDINGS: The expression level of ZNF655 was abnormally abundant in NSCLC. The decrease of ZNF655 expression led to the inhibition of the malignant behaviors of NSCLC, which was manifested by weakened proliferation, increased sensitivity to apoptosis, cycle repression at G2 and weakened migration. Consistently, downregulation of ZNF655 reduced tumorigenesis in mouse xenograft model. Moreover, decreased expression of ZNF655 resulted in upregulated expression of Bad, Bax, Fas, p21, p27, Caspase 3 and Caspase 8 in NSCLC cells. NCI-H1299 cells with ZNF655 knockdown resulted in decreased phosphorylation of Akt, downregulation of CDK6 and PIK3CA, and upregulation of MAPK9. Collectively, ZNF655 may regulate apoptosis of NSCLC cells through PI3K/Akt and p53 signaling pathways. SIGNIFICANCE: ZNF655 possessed a promoting effect in the progression of NSCLC, which may serve as a promising molecular target for clinical treatment.

A sequence-based prediction of Kruppel-like factors proteins using XGBoost and optimized features.

Krüppel-like factors (KLF) refer to a group of conserved zinc finger-containing transcription factors that are involved in various physiological and biological processes, including cell proliferation, differentiation, development, and apoptosis. Some bioinformatics methods such as sequence similarity searches, multiple sequence alignment, phylogenetic reconstruction, and gene synteny analysis have also been proposed to broaden our knowledge of KLF proteins. In this study, we proposed a novel computational approach by using machine learning on features calculated from primary sequences. To detail, our XGBoost-based model is efficient in identifying KLF proteins, with accuracy of 96.4% and MCC of 0.704. It also holds a promising performance when testing our model on an independent dataset. Therefore, our model could serve as an useful tool to identify new KLF proteins and provide necessary information for biologists and researchers in KLF proteins. Our machine learning source codes as well as datasets are freely available at https://github.com/khanhlee/KLF-XGB.

Anti-integrin αv therapy improves cardiac fibrosis after myocardial infarction by blunting cardiac PW1+ stromal cells.

There is currently no therapy to limit the development of cardiac fibrosis and consequent heart failure. We have recently shown that cardiac fibrosis post-myocardial infarction (MI) can be regulated by resident cardiac cells with a fibrogenic signature and identified by the expression of PW1 (Peg3). Here we identify αV-integrin (CD51) as an essential regulator of cardiac PW1+ cells fibrogenic behavior. We used transcriptomic and proteomic approaches to identify specific cell-surface markers for cardiac PW1+ cells and found that αV-integrin (CD51) was expressed in almost all cardiac PW1+ cells (93% ± 1%), predominantly as the αVß1 complex. αV-integrin is a subunit member of the integrin family of cell adhesion receptors and was found to activate complex of latent transforming growth factor beta (TGFß at the surface of cardiac PW1+ cells. Pharmacological inhibition of αV-integrin reduced the profibrotic action of cardiac PW1+CD51+ cells and was associated with improved cardiac function and animal survival following MI coupled with a reduced infarct size and fibrotic lesion. These data identify a targetable pathway that regulates cardiac fibrosis in response to an ischemic injury and demonstrate that pharmacological inhibition of αV-integrin could reduce pathological outcomes following cardiac ischemia.

Colon adenocarcinoma-derived cells that express induced-pluripotent stem cell markers possess stem cell function.

AIMS: Much work has been done to find markers of cancer stem cells (CSCs) that distinguish them from the tumor bulk cells and normal cells. Recent CSC research has applied the induced pluripotent stem cell (iPSC) concept. In this study, we investigated the expression of a panel of iPSC markers in primary colon adenocarcinoma (CA)-derived cell lines. MATERIALS AND METHODS: Expression of iPSC markers by CA-derived primary cell lines was interrogated using immunocytochemistry, western blotting and RT-qPCR. The stem cell function of these cells was then assessed in vitro using differentiation and tumorsphere assays. RESULTS: Expression of iPSC markers OCT4, SOX2, NANOG, KLF4 and c-MYC was more widespread in high-grade CA (HGCA) cell lines than low-grade CA (LGCA) cell lines, as demonstrated by western blotting and RT-qPCR. These cells could be induced to differentiate down the three embryonic lineages. Cells derived from HGCA were more capable of forming tumorspheres than those derived from LGCA. EpCAM sorting revealed that a population enriched for EpCAMHigh cells formed larger tumorspheres than EpCAMLow cells. Pluripotency markers, SSEA4 and TRA-1-60, were co-expressed by a small subpopulation of cells that also co-expressed SOX2 in 75% and OCT4 in 50% of the cell lines. CONCLUSIONS: CA-derived primary cell lines contain tumorsphere-forming cells which express key pluripotency genes and can differentiate down 3 embryonic lineages, suggesting a pluripotent CSC-like phenotype. There appear to be two iPSC-like subpopulations, one with high EpCAM expression which forms larger tumorspheres than another with low EpCAM expression. Furthermore, these cells can be characterized based on iPSC marker expression, as we have previously demonstrated in the original CA tumor tissues.

KLF1/EKLF expression in acute leukemia is correlated with chromosomal abnormalities.

KLF1 (EKLF) is a master regulator of erythropoiesis and controls expression of a wide array of target genes. We interrogated human tissue microarray samples via immunohistological analysis to address whether levels of KLF1 protein are associated with leukemia. We have made the unexpected findings that higher KLF1 levels are correlated with cells containing abnormal chromosomes, and that high KLF1 expression is not limited to acute myeloid leukemia (AML) associated with erythroid/megakaryoblastic differentiation. Expression of KLF1 is associated with poor survival. Further analyses reveal that KLF1 directly regulates a number of genes that play a role in chromosomal integrity. Together these results suggest that monitoring KLF1 levels may provide a new marker for risk stratification and prognosis in patients with AML.

Krüppel-like Factor 5 Regulates Stemness, Lineage Specification, and Regeneration of Intestinal Epithelial Stem Cells.

BACKGROUND & AIMS: Self-renewal and multipotent differentiation are cardinal properties of intestinal stem cells (ISCs), mediated in part by WNT and NOTCH signaling. Although these pathways are well characterized, the molecular mechanisms that control the 'stemness' of ISCs are still not well defined. Here, we investigated the role of Krüppel-like factor 5 (KLF5) in regulating ISC functions. METHODS: We performed studies in adult Lgr5EGFP-IRES-creERT2;Rosa26LSLtdTomato (Lgr5Ctrl) and Lgr5EGFP-IRES-creERT2;Klf5fl/fl;Rosa26LSLtdTomato (Lgr5ΔKlf5) mice. Mice were injected with tamoxifen to activate Cre recombinase, which deletes Klf5 from the intestinal epithelium in Lgr5ΔKlf5 but not Lgr5Crtl mice. In experiments involving irradiation, mice were subjected to 12 Gy total body irradiation (TBI). Tissues were collected for immunofluorescence (IF) analysis and next generation sequencing. Oganoids were derived from fluoresecence activated cell sorted- (FACS-) single cells from tamoxifen-treated Lgr5ΔKlf5 or Lgr5Crtl mice and examined by immunofluorescence stain. RESULTS: Lgr5+ ISCs lacking KLF5 proliferate faster than control ISCs but fail to self-renew, resulting in a depleted ISC compartment. Transcriptome analysis revealed that Klf5-null Lgr5+ cells lose ISC identity and prematurely differentiate. Following irradiation injury, which depletes Lgr5+ ISCs, reserve Klf5-null progenitor cells fail to dedifferentiate and regenerate the epithelium. Absence of KLF5 inactivates numerous selected enhancer elements and direct transcriptional targets including canonical WNT- and NOTCH-responsive genes. Analysis of human intestinal tissues showed increased levels of KLF5 in the regenerating epithelium as compared to those of healthy controls. CONCLUSION: We conclude that ISC self-renewal, lineage specification, and precursor dedifferentiation require KLF5, by its ability to regulate epigenetic and transcriptional activities of ISC-specific gene sets. These findings have the potential for modulating ISC functions by targeting KLF5 in the intestinal epithelium.

Male patient 46,XX SRY-negative and unambiguous genitalia: A case report / Paciente masculino con cariotipo 46 XX negativo para el gen SRY y sin ambigüedad genital: reporte de un caso

In most cases, male sexual differentiation occurs with SRY gene mediation. However, exceptional genotypes have been identified, as shown in this paper. This was a male adult patient seen at the Servicio de Paternidades, Instituto de Genética, Universidad Nacional de Colombia. The following procedures were carried out: Amelogenin gene and short tandem repeat analyses using human identification commercial kits, conventional karyotype, SRY fluorescent in situ hybridization, PCR analysis for Y chromosome microdeletions, clinical evaluation, and genetic counseling. We present an adult male with unambiguous genitalia, karyotype 46,XX, and an SRY negative and ZFY positive molecular profile. The diagnosis of nonsyndromic 46,XX testicular disorder of sex development (DSD) -a rare genetic condition- was established. Only 20 % of similarly diagnosed patients are SRY negative and exhibit diverse molecular profiles. Until now, available evidence seems to indicate that, even in the absence of SRY, the ZFY factor is involved in male sexual differentiation.

En la mayoría de los casos, la diferenciación sexual masculina ocurre con la participación del gen SRY. Sin embargo, se pueden presentar otros genotipos excepcionales, como en el caso que se presenta en este reporte. Se trata de un paciente adulto de sexo masculino atendido en el Servicio de Paternidades del Instituto de Genética de la Universidad Nacional de Colombia. Se le hicieron los análisis del gen de la amelogenina y de repeticiones cortas en tándem (Short Tandem Repeat, STR) específicas para el gen SRY con estuches comerciales de identificación humana, así como los de cariotipo convencional e hibridación in situ fluorescente del SRY, y el estudio de microdeleciones del cromosoma Y mediante reacción en cadena de la polimerasa (PCR). Se le hizo la evaluación clínica y se le brindó asesoramiento genético. El paciente no presentaba ambigüedad genital, su cariotipo era 46 XX, y el perfil molecular era negativo para el gen SRY y positivo para el ZFY. Se le diagnosticó un trastorno de diferenciación sexual 46 XX testicular no sindrómico, una rara condición genética. Solo el 20 % de los pacientes con este diagnóstico son negativos para SRY y exhiben perfiles moleculares diversos. La información disponible parece indicar que el ZFY está relacionado con la diferenciación sexual masculina, aún en ausencia del gen SRY.

Dysregulation of Krüppel-like factor 12 in the development of endometrial cancer.

OBJECTIVE: Endometrial cancer (EC) remains a malignancy with poor survival outcome. To investigate the role of Krüppel-like factor 12 (KLF12), a transcription factor, in the progression of human EC. METHODS: Immunohistochemistry, real time-PCR and western blot analysis of KLF12 expression in EC patients' tissues. Bioinformatics analysis revealed the clinical importance of KLF12 expression and survival ratio. Overexpression of KLF12 was generated using the ViraPower Adenoviral Expression System in EC cell lines. Cell viability assay, cell apoptosis assay and cell migration assay were used to determine cell proliferation, cell apoptosis and cell migration, respectively. Western blot analysis was carried out to determine the protein levels in cell lines and animal tissues. RESULTS: The expression of KLF12 was observed to be much higher in human EC tissues compared with normal endometrium. Moreover, KLF12 expression was correlated positively with disease recurrence and was also associated with decreased survival probability. The overexpression of KLF12 in EC cell lines resulted in increased cell proliferation, decreased cell apoptosis and enhanced cell migration. Furthermore, overexpression of KLF12 also increased tumor size in vivo. Moreover, up-regulation of KLF12 dramatically increased the expression levels of MMP2, MMP9, pAKT S473 and CCND1. Our research reveals that overexpressed KLF12 contributes the growth of EC tumor by activating AKT signaling and increasing CCND1expression level. CONCLUSIONS: To our knowledge, this is the first study to explore the significance of KLF12 in the development of EC, and KLF12 is expected to provide a novel potential therapeutic target for EC treatment.

Krüppel-like factor 4 expression in solid tumor prognosis: A meta-analysis.

BACKGROUND: Accumulating studies have demonstrated that Krüppel-like factor 4 (KLF4) can act as a tumor suppressor or oncogene in the carcinogenesis of diverse cancers. The prognostic value of KLF4 in various human solid cancers remains controversial. Thus, the present meta-analysis was conducted to evaluate the prognostic value of KLF4 in solid tumors. METHODS: Eligible literature was retrieved by searching the PubMed, Embase, and Cochrane Library. Combined hazard ratios (HRs) for overall survival (OS) and disease-free survival (DFS) were assessed using fixed-effects and random-effects models. Meta-regression and subgroup analyses were performed to identify the source of heterogeneity. In addition, publication bias was assessed using Begg's funnel plot and Egger's regression asymmetry test. RESULTS: The 22 eligible studies finally enrolled a total of 2988 patients to assess the prognostic value of KLF4 in solid tumors. Low KLF4 expression was clearly related to worse OS (HR = 1.71, 95% confidence interval [CI] = 1.30-2.24, P < 0.001) and DFS (HR = 1.74, 95% CI = 1.34-2.26, P < 0.001), indicating that low KLF4 expression could be an independent prognostic factor for poor survival in solid cancers. CONCLUSION: KLF4 might be a potential marker to predict prognosis in solid cancer patients.

Kruppel-like factor 4 (KLF-4) plays a crucial role in simvastatin (SVT)-induced differentiation of rabbit articular chondrocytes.

Simvastatin is a cholesterol-lowing reagent that is derived synthetically from the fermentation of Aspergillus terreus. Recently, SVT has been shown to possess a protective effect of chondrocytes. Kruppel-like factor 4 (KLF-4) is a zinc finger transcription factor that plays crucial roles during the development and maintenance of multiple organs. However, the roles of KLF-4 in chondrocytes have not been well unknown. Here, we investigated whether KLF-4 regulates SVT-caused differentiated phenotype of chondrocytes. A KLF-4 cDNA or KLF-4 siRNA was transfected into SVT-treated chondrocytes. Western blot analysis, RT-PCR and immunofluorescence staining analyzed expression of type II collagen and SOX-9, marker proteins of differentiation. The results showed overexpression of KLF-4 accelerates SVT-induced type II collagen expression, as determined by western blot analysis and causes sulfated-proteoglycan synthesis, as detected by Alcian blue staining. RT-PCR revealed that ectopic expression of KLF-4 induces SVT-caused SOX-9, a transcription factor of type II collagen, expression. Transfection of KLF-4 siRNA reversed SVT-caused type II collagen and SOX-9 expression and inhibited SVT-induced sulfated proteoglycan production. This study indicates that KLF-4 plays critical role in SVT-caused chondrocytes differentiation.

Hypermethylated ZNF582 and PAX1 genes in mouth rinse samples as biomarkers for oral dysplasia and oral cancer detection.

BACKGROUND: Effective biomarkers for oral cancer screening are important for early diagnosis and treatment of oral cancer. METHODS: Oral epithelial cell samples collected by mouth rinse were obtained from 65 normal control subjects, 108 patients with oral potentially malignant disorders, and 94 patients with oral squamous cell carcinoma (OSCC). Methylation levels of zinc-finger protein 582 (ZNF582) and paired-box 1 (PAX1) genes were quantified by real-time methylation-specific polymerase chain reaction after bisulfite conversion. RESULTS: An abrupt increase in methylated ZNF582 (ZNF582m ) and PAX1 (PAX1m ) levels and positive rates from mild dysplasia to moderate/severe dysplasia, indicating that both ZNF582m and PAX1m are effective biomarkers for differentiating moderate dysplasia or worse (MODY+) oral lesions. When ZNF582m /PAX1m tests were used for identifying MODY+ oral lesions, the sensitivity, specificity, and odds ratio (OR) were 0.65/0.64, 0.75/0.82, and 5.6/8.0, respectively. CONCLUSION: Hypermethylated ZNF582 and PAX1 genes in oral epithelial cells collected by mouth rinse are effective biomarkers for the detection of oral dysplasia and oral cancer.

KLF15 Inhibits Cell Proliferation in Gastric Cancer Cells via Up-Regulating CDKN1A/p21 and CDKN1C/p57 Expression.

BACKGROUND: Krüppel-like factors (KLFs) have been identified in multi-cancers and act as oncogenes or tumor suppressors. The function of KLF15, one member of KLFs, has not been well elucidated, especially in gastric cancer (GC). AIMS: This study was designed to investigate the prognostic value and biological functions of KLF15 in GC. METHODS: KLF15 protein expression in GC patients was evaluated by immunohistochemistry assays in 50 paired GC tissues and adjacent normal tissues, and correlations between KLF15 expression and clinicopathological characteristics and prognosis were analyzed. Then, we investigated the over-expression of KLF15 on cell proliferation and its mechanism in GC cells. RESULTS: KLF15 expression levels were significantly down-regulated in GC tissues compared to adjacent normal tissues. And KLF15 expression was negatively correlated with clinical stage, lymphatic metastasis, and distant metastasis. Furthermore, KLF15 expression could predict prognosis in patients with GC. Moreover, over-expression of KLF15 could inhibit cell proliferation partly via regulating CDKN1A/p21 and CDKN1C/p57. CONCLUSION: These findings demonstrate that KLF15 plays a significant role in GC progression and could be a therapeutic target for GC.

Molecular markers of putative spermatogonial stem cells in the domestic cat.

Spermatogonial stem cells (SSCs) are an important tool for fertility preservation and species conservation. The ability to expand SSCs by in vitro culture is a crucial premise for their use in assisted reproduction. Because SSCs represent a small proportion of the germ cells in the adult testis, culture success is aided by pre-enrichment through sorting techniques based on cell surface-specific markers. Given the importance of the domestic cat as a model for conservation of endangered wild felids, herein we sought to examine culture conditions as well as molecular markers for cat SSCs. Using a cell culture medium for mouse SSCs supplemented with glial cell-derived neurotrophic factor (GDNF), germ cells from prepuberal cat testes remained viable in culture for up to 43 days. Immunohistochemistry for promyelocytic leukaemia zinc finger (PLZF) protein on foetal, prepuberal and adult testis sections revealed a pattern of expression consistent with the labelling of undifferentiated spermatogonia. Fluorescence-activated cell sorting (FACS) with an antibody against epithelial cell adhesion molecule (EPCAM) was used to sort live cells. Then, the gene expression profile of EPCAM-sorted cells was investigated through RT-qPCR. Notably, EPCAM (+) cells expressed relatively high levels of CKIT (CD117), a surface protein typically expressed in differentiating germ cells but not SSCs. Conversely, EPCAM (-) cells expressed relatively high levels of POU domain class 5 transcription factor 1 (POU1F5 or OCT4), clearly a germ line stem cell marker. These results suggest that cat SSCs would probably be found within the population of EPCAM (-) cells. Future studies should identify additional surface markers that alone or in combination can be used to further enrich SSCs from cat germ cells.

Krüpple-like factor 10 regulates radio-sensitivity of pancreatic cancer via UV radiation resistance-associated gene.

BACKGROUND AND PURPOSE: Krüpple-like factor 10 (Klf10), an early response gene of TGFß, was reported to be a prognostic biomarker for pancreatic cancer survival. The role of Klf10 in predicting tumor response to cancer treatment is unknown. MATERIALS AND METHODS: Genetically manipulated MiaPaCa and Panc-1 cells were established to evaluate clonogenic survival, autophagy, apoptosis and DNA repair after radiation. The interaction between Klf10 and UV radiation resistance-associated gene (UVRAG) was demonstrated by ChiP-PCR and luciferase reporter assay. Orthotopic murine tumor model and clinical specimens were used to evaluate radio-sensitivity of pancreatic cancer. RESULTS: We found Klf10 silencing correlates with enhanced pancreatic cancer clonogenic survival and murine tumor growth after radiation. UVRAG was an essential down-stream mediator transcriptionally suppressed by Klf10. Silencing UVRAG mRNA in Klf10 depleted Panc-1 cells reversed the radio-resistant phenotypes including decreased apoptosis and enhanced DNA repair as well as autophagy. Metformin, an anti-diabetic agent, was found to increase Klf10 and suppress UVRAG expression to improve radiation cytotoxicity in pancreatic cancer. The predictive value of Klf10 in radiation response and the inverse correlation with UVRAG were confirmed in cohorts of pancreatic cancer patients. CONCLUSIONS: Klf10 is a potential biomarker in predicting and sensitizing radiation effect in pancreatic cancer.

Heterogeneous histomorphology, yet homogeneous vascular smooth muscle cell dedifferentiation, characterize human aneurysm disease.

OBJECTIVE: Abdominal aortic aneurysm (AAA) is a frequent, potentially life-threatening, disease that can only be treated by surgical means such as open surgery or endovascular repair. No alternative treatment is currently available, and despite expanding knowledge about the pathomechanism, clinical trials on medical aneurysm abrogation have led to inconclusive results. The heterogeneity of human AAA based on histologic examination is thereby generally neglected. In this study we aimed to further elucidate the role of these differences in aneurysm disease. METHODS: Tissue samples from AAA and popliteal artery aneurysm patients were examined by histomorphologic analysis, immunohistochemistry, Western blot, and polymerase chain reaction. The results were correlated with clinical data such as aneurysm diameter and laboratory results. RESULTS: The morphology of human AAA vessel wall probes varies tremendously based on the grade of inflammation. This correlates with increasing intima/media thickness and upregulation of the vascular endothelial growth factor cascade but not with any clinical parameter or the aneurysm diameter. The phenotypic switch of vascular smooth muscle cells occurred regardless of the inflammatory state and expressional changes of the transcription factors Kruppel-like factor-4 and transforming growth factor-ß lead to differential protein localization in aneurysmal compared with control arteries. These changes were in similar manner also observed in samples from popliteal artery aneurysms, which, however, showed a more homogenous phenotype. CONCLUSIONS: Heterogeneity of AAA vessel walls based on inflammatory morphology does not correlate with AAA diameter yet harbors specific implications for basic research and possible aneurysm detection.

Immunolocalization of proteins in the spermatogenesis process of canine.

Spermatogenesis is a process in which differentiated cells are produced and the adult stem cell population-known as spermatogonial stem cells (SSCs)-is continuously replenished. However, the molecular mechanisms underlying these processes are not fully understood in the canine species. We addressed this in this study by analysing the expression of specific markers in spermatogonia of seminiferous tubules of canine testes. SSCs at different stages of reproductive development (prepubertal and adult) were examined by immunohistochemistry and flow cytometry. Glial cell-derived neurotrophic factor family receptor alpha-1 (GFRA1), deleted in azoospermia-like (DAZL) and promyelocytic leukaemia zinc finger (PLZF) were expressed in SSCs, while stimulated by retinoic acid gene 8 (STRA8) was detected only in undifferentiated spermatogonia in prepubertal testis and differentiated spermatogonia and spermatocytes in adult canine. Octamer-binding transcription factor 4 (OCT4) showed an expression pattern, and the levels did not differ between the groups examined. However, C-kit expression varied as a function of reproductive developmental stage. Our results demonstrate that these proteins play critical roles in the self-renewal and differentiation of SSCs and can serve as markers to identify canine spermatogonia at specific stages of development.

Mechanisms of Hypothermic Machine Perfusion to Decrease Donation After Cardiac Death Graft Inflammation: Through the Pathway of Upregulating Expression of KLF2 and Inhibiting TGF-ß Signaling.

Hypothermic machine perfusion (HMP) has been known as an efficient way to improve kidney graft function, but the underlying mechanisms remain unclear. Here, we adopt a rabbit reperfusion mode to investigate the upstream mechanisms of end-ischemic HMP of kidneys from donors after cardiac death (DCD), with static cold storage (CS) as a control. Eighteen New Zealand healthy male rabbits (12 weeks old, with a weight of 3.0 ± 0.2 kg) were randomly divided into three groups: HMP group, CS group, and Normal group (n = 6). The left kidney of rabbits underwent warm ischemia for 25 min through clamping the left renal pedicle and then reperfusion for 1 h. Then the left kidneys were preserved by CS or HMP (4°C for 4 h) ex vivo respectively, after they were autotransplanted and rabbits were submitted to a right nephrectomy. Twenty-four hours after reperfusion, all left renal specimens were collected. Finally, the expression of Krüppel-like factor 2 (KLF2), transforming growth factor-ß (TGF-ß) and SMAD4 protein in renal cortical tissue were detected by immunoblotting, and the TGF-ß and SMAD4 expressions were further confirmed by immunohistochemistry analysis. We found that expression of KLF2 in HMP group was significantly higher than CS group (P = 0.011), while expression of TGF-ß and SMAD4 in HMP group were significantly lower than CS group (P = 0.002, P = 0.01, respectively); Compared with normal group, the expression of TGF-ß and SMAD4 in HMP and CS group significantly increased (P<0.05). Compared with CS group, TGF-ß and SMAD4 protein were equally down-regulated in glomerular and the tubular epithelial cells in HMP group confirmed by immunohistochemistry. In conclusion, HMP may decrease DCD kidneys inflammation through the pathway of upregulating expression of KLF2 and inhibiting TGF-ß signaling after transplantation.

Gli2 protein expression level is a feasible marker of ligand-dependent hedgehog activation in pancreatic neoplasms.

The hedgehog pathway is known to promote proliferation of pancreatic ductal adenocarcinoma (PDA) and has been shown to restrain tumor progression. To understand how hedgehog causes these effects, we sought to carefully examine protein expression of hedgehog signaling components during different tumor stages. Genetically engineered mice, Pdx1-Cre;LSL-KrasG12D and Pdx1-Cre;LSL-KrasG12D;p53lox/+, were utilized to model distinct phases of tumorigenesis, pancreatic intraepithelial neoplasm (PanIN) and PDA. Human pancreatic specimens of intraductal papillary mucinous neoplasm (IPMN) and PDA were also employed. PanIN and IPMN lesions highly express Sonic Hedgehog, at a level that is slightly higher than that observed in PDA. GLI2 protein is also expressed in both PanIN/IPMN and PDA. Although there was no difference in the nuclear staining, the cytoplasmic GLI2 level in PDA was modest in comparison to that in PanIN/IPMN. Hedgehog interacting protein was strongly expressed in the precursors, whereas the level in PDA was significantly attenuated. There were no differences in expression of Patched1 at early and late stages. Finally, a strong correlation between Sonic Hedgehog and GLI2 staining was found in both human and murine pancreatic tumors. The results indicate that the GLI2 protein level could serve as a feasible marker of ligand-dependent hedgehog activation in pancreatic neoplasms.

Krüppel-like factor 4 is a novel prognostic predictor for urothelial carcinoma of bladder and it regulates TWIST1-mediated epithelial-mesenchymal transition.

BACKGROUND: Krüppel-like factor 4 (KLF4) exerts tumor suppressive or oncogenic functions in a cell-type-dependent manner, but its prognostic role in urothelial carcinoma of bladder (UCB) remains unclear. We aimed to determine how KLF4 regulates epithelial-mesenchymal transition (EMT) and predicts patient survival in UCB. PATIENTS AND METHODS: The roles of KLF4 and other EMT regulators in cancer progression were studied in UCB specimens of 398 patients, UCB cell lines. The results were validated by open-access The Cancer Genome Atlas dataset. RESULTS: Over a median follow-up of 46.5 months, tissue microarray demonstrated that strong KLF4 expression was associated with higher risk toward metastasis and death (P<0.001). KLF4 expression positively correlated with TWIST1 and vimentin, and inversely correlated with E-cadherin expression. Metastasis-free survival was poorest in KLF4/TWIST1 coexpression group, followed by KLF4 or TWIST1 expression-alone group, and no-expression group (P<0.001). Multivariate analysis substantiated that KLF4/TWIST1 coexpression independently predicted overall mortality and metastasis risk with hazard ratios of 2.43 (95% CI: 1.65-3.64) and 7.54 (CI: 4.03-12.10). The Cancer Genome Atlas dataset of bladder cancer also revealed a trend toward decreased overall survival in the high KLF4 expression group as compared to the low KLF4 group. In vitro, KLF4 is accompanied with decreased E-cadherin and ß-catenin expressions, increased vimentin and fibronectin expressions, and enhanced migration/invasion. KLF4 knockdown suppressed TWIST1 expression and inhibited EMT, migration and invasion, whereas enforced KLF4 overexpression activated TWIST1 expression and restored EMT and metastatic phenotype. Furthermore, TWIST1 knockdown abolished KLF4-faciliated EMT and metastatic feature without affecting KLF4 expression. CONCLUSIONS: KLF4 promotes TWIST1-mediated EMT and may represent a novel prognostic predictor in UCB.