BMP4 promotes SSEA-1(+) hUC-MSC differentiation into male germ-like cells in vitro

OBJECTIVES

Recent studies have demonstrated that primordial germ cells (PGC) can be differentiated from human umbilical cord mesenchymal stem cells (hUC-MSCs), and embryonic stem cells (ESCs) in vitro. Nevertheless, efficiencies were low and unstable. Here, whether hUC-MSCs can be induced to differentiate into germ-like cells with the aid of bone morphogenetic protein (BMP4) was investigated.

MATERIALS AND METHODS

Human umbilical cord mesenchymal stem cells were freshly isolated and cultured with BMP4. SSEA-1(+/-) cells were purified using magnetic-activated cell sorting (MACS) from the hUC-MSCs, and further induced with BMP4. Quantitative real-time PCR (qRT-PCR) and immunofluorescence analysis were used to determine PGC and germ-like cell-specific markers.

RESULTS

Human umbilical cord mesenchymal stem cells differentiated into SSEA-1(+) spherical PGC-like cells efficiently with 12.5 ng/ml BMP4. qRT-PCR and immunofluorescence analysis demonstrated that SSEA-1(+) cells expressed higher levels of PGC-specific markers than SSEA-1(-) cells. Furthermore, SSEA-1(+) cells were induced with BMP4 to differentiate into STRA8, SCP3, DMRT1 and PLZF-positive male germ-like cells, and some sperm-like cells were obtained by 7-14 days after induction.

CONCLUSION

These results suggest that SSEA-1(+) hUC-MSCs can differentiate into male germ-like cells in the presence of BMP4. This study provides an efficient protocol to study germ-cell development using hUC-MSCs.

CTCF-regulating endocrine function of pancreatic islet cells in transgenic mice

Pancreatic islet endocrine cells play crucial roles in regulation of glucose homeostasis. The differentiation and function of islet cells are regulated by various transcription factors, including Pax6, a member of the homeobox gene family. Pax6 plays a key role in the control of gene expression and islet cell development in the pancreas. Recent studies from our lab demonstrate for the first time that Pax6 transcription is regulated by CCCTC binding factor (CTCF), a nuclear protein and transcription regulator. CTCF downregulates Pax6 transcription through interaction with a repressor element located in Pax6 gene P0 promoter region. To further investigate the effect of CTCF on regulating Pax6 function in pancreatic islet cells, we measured blood glucose, insulin, and glucagons levels in newly established transgenic mice overexpressing CTCF. When compared to wild type mice, CTCF transgenic mice demonstrate an increase in insulin level and decrease in glucagon level resulting in lower blood glucose levels (hypoglycemia). In insulin tolerance test, hypoglycemia occurs quickly in CTCF transgenic mice and takes a recovery time. In the mean time, glucagon levels in CTCF mutant mice were significantly lower compared to its wild type counterpart. Our results indicate that CTCF transgenic mice are disordered in glucose homeostasis and suggest that CTCF is involved in regulating endocrine function of pancreatic islet cells by suppression of Pax6 expression.

Cloning and characterization of the drought-resistance OsRCI2-5 gene in rice (Oryza sativa L.)

The genomic expression profile of the super-hybrid rice Liangyoupeijiu female parent Pei'ai 64S in different tissues at different developmental stages under low temperature, drought, and high temperature stresses were detected using an Affymetrix GeneChip Rice Genome Array to screen upregulated and downregulated genes. In this study, we screened the drought-resistant gene OsRCI2-5, after which a constitutive OsRCI2-5 construct was created and transferred into Nipponbare. After polyethylene glycol-6000 and drought treatment, we found that the OsRCI2-5 gene improved the drought resistance of Nipponbare. Gene expression profiling showed that the OsRCI2-5 gene was expressed in the rice leaves, stems, and flower organs. Subcellular localization revealed that the gene was located in the membranes, and hence, we can deduce that a membrane signal peptide was responsible for signal transduction.

Cardiac hypertrophy is negatively regulated by miR-541

Heart failure is a leading cause of death in aging population. Cardiac hypertrophy is an adaptive reaction of the heart against cardiac overloading, but continuous cardiac hypertrophy is able to induce heart failure. We found that the level of miR-541 was decreased in angiotensin II (Ang-II) treated cardiomyocytes. Enforced expression of miR-541 resulted in a reduced hypertrophic phenotype upon Ang-II treatment in cellular models. In addition, we generated miR-541 transgenic mice that exhibited a reduced hypertrophic response upon Ang-II treatment. Furthermore, we found miR-541 is the target of microphthalmia-associated transcription factor (MITF) in the hypertrophic pathway and MITF can negatively regulate the expression of miR-541 at the transcriptional levels. MITF(ce/ce) mice exhibited a reduced hypertrophic phenotype upon Ang-II treatment. Knockdown of MITF also results in a reduction of hypertrophic responses after Ang-II treatment. Knockdown of miR-541 can block the antihypertrophic effect of MITF knockdown in cardiomyocytes upon Ang-II treatment. This indicates that the effect of MITF on cardiac hypertrophy relies on the regulation of miR-541. Our present study reveals a novel cardiac hypertrophy regulating pathway that was composed of miR-541 and MITF. Modulation of their levels may provide a new approach for tackling cardiac hypertrophy.

Clinical and cytogenomic studies in a case of infertility associated with a nonmosaic dicentric Y chromosome

In this study, a short stature male with infertility is reported. Semen analysis and serum concentrations of FSH, LH, T and PRL were estimated. Chromosome analysis was performed on lymphocytes obtained from both the male and his parents. Cytogenomic studies were performed by fluorescent in situ hybridisation and the CytoScan(™)  HD array analysis to detect Y chromosomal rearrangements and copy number mutations. Semen analysis showed severe oligozoospermia. Numerous spermatogenic cells were observed in the semen, and approximately 60% of the cells examined in semen were primary spermatocytes, showing spermatogenic arrest at the primary spermatocyte level. Cytogenomic studies of blood revealed his karyotype which was 46,X,i(Y) (p11.32) (Yqter→Yp11.32::Yp11.32→Yqter).ish (DYZ3++, SRY++, SHOX-). array (PLCXD1→SHOX) ×1,(SRY →GOLGA2P3Y)×2, (DHRSX→ ASMT, SPRY3 →IL9R)×3. The rearrangement Y chromosome is de novo. This is the first case reported with a nonmosaic 46,X, i (Y) (p11.32), which will be useful to estimate the infertility phenotype-molecular karyotype correlation. Haploinsufficiency of short stature homeobox-containing gene is primarily responsible for the short stature. Aberrations in pseudoautosomal region 1 on the rearranged Y chromosome may result in the deficiency of X-Y pairing or recombination, ultimately lead to the spermatogenic failure.

Notch ligand Delta-like 1 promotes the metastasis of melanoma by enhancing tumor adhesion

Notch signaling plays a vital role in tumorigenicity and tumor progression by regulating proliferation, invasion, and the tumor microenvironment. Previous research by our group indicated that Notch ligand Delta-like 1 (Dll1) is involved in angiogenesis in melanoma, and we noticed that it took a longer time to trypsinize Dll1-expressing B16 melanoma cells than the control cells. In this article, we extended our study to investigate the effects of Dll1 on tumor cell adhesion and metastasis. Dll1 overexpression activated Notch signaling in B16 tumor cells and significantly enhanced the adhering capacity of B16 tumor cells both in vitro and in vivo. B16-Dll1 cells also had a higher metastatic potential than their counterpart in the mouse model of lung metastasis. Along with increased Dll1 expression, N-cadherin, but not E-cadherin, was upregulated in B16-Dll1 cells. These data suggested that Notch ligand Dll1 may enhance the adhesion and metastasis of melanoma cells by upregulation of N-cadherin.

Rapid, high-resolution, whole-brain, susceptibility-based MRI of multiple sclerosis

BACKGROUND

Susceptibility-based MRI offers a unique opportunity to study neurological diseases such as multiple sclerosis (MS). In this work, we assessed a three-dimensional segmented echo-planar-imaging (3D-EPI) sequence to rapidly acquire high-resolution T2 -weighted and phase contrast images of the whole brain. We also assessed if these images could depict important features of MS at clinical field strength, and we tested the effect of a gadolinium-based contrast agent (GBCA) on these images.

MATERIALS AND METHODS

The 3D-EPI acquisition was performed on four healthy volunteers and 15 MS cases on a 3T scanner. The 3D sagittal images of the whole brain were acquired with a voxel size of 0.55 × 0.55 × 0.55 mm(3) in less than 4 minutes. For the MS cases, the 3D-EPI acquisition was performed before, during, and after intravenous GBCA injection.

RESULTS

Both T2-weighted and phase-contrast images from the 3D-EPI acquisition were sensitive to the presence of lesions, parenchymal veins, and tissue iron. Conspicuity of the veins was enhanced when images were obtained during injection of GBCA.

CONCLUSIONS

We propose this rapid imaging sequence for investigating, in a clinical setting, the spatiotemporal relationship between small parenchymal veins, iron deposition, and lesions in MS patient brains.

P2X1-initiated p38 signalling enhances thromboxane A2-induced platelet secretion and aggregation

ATP released by activated platelets can serve as a positive feedback machinery to amplify platelet responses by activating P2X1 receptors. It has, however, not been defined how P2X1 activities influence thromboxane A2 (TXA2)-stimulated platelet functional responses. Our aim was to elaborate the molecular mechanisms of P2X1 engagements in TXA2-induced platelet secretion and aggregation. P2X1 inhibition by 1 µM NF449 inhibited platelet P-selectin expression induced by a low concentration of the TXA2 analogue U46619 (0.3 µM) (32.0 ± 2.0% vs 43.4 ± 3.0%; n=5; p<0.05). p38 inhibition by SB203580, but not ERK inhibition by U0126, elicited a similar inhibition by NF499. The combination of NF449 and SB203580 provided, however, no additive effects. U46619-induced platelet aggregation was similarly decreased by NF449 and SB203580 alone or in combination, and by P2X1 pre-desensitisation with α,β-Me-ATP. U46619 caused rapid and reversible P2X1-dependent p38 phosphorylation. However, the P2X1-p38 pathway mainly enhanced mild platelet activation by U46619, because α,β-Me-ATP supplementation or p38 blockade had no effect on intense platelet activation induced by a higher concentration of U46619 (3 µM). In conclusion, P2X1 activation, via p38 signalling, potentiates platelet activation initiated by low doses of U46619. Hence, the P2X1-induced p38 signalling promotes more robust platelet activation in response to mild platelet stimuli.

Alpha-1-fucosidase as a prognostic indicator for hepatocellular carcinoma following hepatectomy: a large-scale, long-term study

Background:

Preoperative alpha-L-fucosidase (AFU) has been used as a diagnostic biomarker for hepatocellular carcinoma (HCC), but its role as a prognostic predictor after partial hepatectomy has not been well defined. The study aimed to investigate the prognostic significance of preoperative serum AFU for HCC patients after hepatic resection.

Methods:

A retrospective training data set and a prospective validation data set were used to evaluate the prognosis of HCC after partial hepatectomy. A total of 669 patients with histopathologically confirmed HCC were enrolled. Univariate and multivariate analyses were used to identify the prognostic significance of preoperative serum AFU.

Results:

The retrospective training data set showed a preoperative AFU>35 u l⁻¹ should be used. The prospective validation data set showed preoperative AFU was an independent prognostic factor of overall survival (OS) (P=0.008; hazard ratio: 2.333; 95% confidence interval: 1.249–4.369). Patients with a preoperative AFU>35 u l⁻¹ had a lower recurrence-free survival rate and an OS rate than those with AFU⩽35 u l⁻¹, and they have a higher tendency to form macrovascular invasion. Furthermore, the prognostic significance of AFU>35 u l⁻¹ could also be applied to patients with alpha-fetoprotein levels of ⩽400 ng ml⁻¹.

Conclusions:

Preoperative serum AFU is a prognostic predictor of HCC.

Promyelocytic leukaemia zinc finger maintains self-renewal of male germline stem cells (mGSCs) and its expression pattern in dairy goat testis

OBJECTIVES

Previous studies have shown that promyelocytic leukaemia zinc finger (PLZF) is a spermatogonia-specific transcription factor in the testis, required to regulate self-renewal and maintenance of the spermatogonia stem cell. Up to now, expression and function of PLZF in the goat testis has not been known. The objectives of this study were to investigate PLZF expression pattern in the dairy goat and its effect on male goat germline stem cell (mGSC) self-renewal and differentiation.

MATERIALS AND METHODS

Testis development and expression patterns of PLZF in the dairy goat were analysed by haematoxylin and eosin staining, immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR). Furthermore, effects of PLZF overexpression on mGSC self-renewal and differentiation were evaluated by quantitative RT-PCR (QRT-PCR), immunofluorescence and BrdU incorporation assay.

RESULTS

Promyelocytic leukaemia zinc finger was essential for dairy goat testis development and expression of several proliferation and pluripotency-associated proteins including OCT4, C-MYC were upregulated by PLZF overexpression. The study demonstrated that PLZF played a key role in maintaining self-renewal of mGSCs and its overexpression enhanced expression of proliferation-associated genes.

CONCLUSIONS

Promyelocytic leukaemia zinc finger could function in the dairy goat as well as in other species in maintaining self-renewal of germline stem cells and this study provides a model to study the mechanism on self-renewal and differentiation of mGSCs in livestock.

HIF-2α as a prognostic marker for breast cancer progression and patient survival

Malignant cells show increased invasion potency in vitro and in vivo. This process is considered to be mediated by matrix-metalloproteases (MMPs). Hypoxia-inducible factor-2α (HIF-2α) may upregulate MMP-2 expression; however, little is known about the correlation between HIF-2α and MMP-2 expressions in breast cancer. The current study investigated this correlation immunohistochemically according to various clinical and pathological features in 102 paraffin-embedded archival tissue block specimens from patients with breast cancer. HIF-2α and MMP-2 expression was detected in 60.8% (62/102) and 65.7% (67/102) of tumor samples, respectively. HIF-2α expression was significantly correlated with tumor size (P = 0.019), lymph node involvement (P = 0.035), and metastasis (P = 0.035). MMP-2 expression was significantly associated with lymph node involvement (P = 0.043) and metastasis (P = 0.003). Univariate analyses revealed that HIF-2α (P = 0.001) and MMP-2 (P = 0.000) expressions were significantly associated with a poorer survival rate, as well as tumor size, lymph node invasion, and distant metastasis. Multivariate analysis revealed that HIF-2α (P = 0.003) and the T-stage (P = 0.000) were independent prognostic factors of overall survival. Spearman correlation analysis revealed that HIF-2α and MMP-2 expressions were significantly correlated (r = 0.990; P = 0.041). These results suggest that high HIF- 2α expression is associated with poor overall survival in patients with breast cancer, indicating that HIF-2α could be a valuable marker of breast cancer progression.

Associations of high sensitivity C-reactive protein levels with the prevalence of asymptomatic intracranial arterial stenosis

BACKGROUND AND PURPOSE

High sensitivity C-reactive protein (hs-CRP), an inflammatory biomarker, has been demonstrated to contribute to the process of atherosclerosis and artery stenosis. The aim of this study was to evaluate whether hs-CRP level is associated with asymptomatic intracranial artery stenosis (ICAS).

METHODS

A random sample of 5440 participants aged 40 years or older (40.1% women) were enrolled in the Asymptomatic Polyvascular Abnormalities Community study in 2010-2011. Information on the potential risk factors for ICAS was collected and the presence of ICAS was assessed by transcranial Doppler in 5309 participants. Participants were stratified into three groups according to hs-CRP levels. A multivariate logistic regression was used to examine the association between hs-CRP levels and asymptomatic ICAS.

RESULTS

The prevalence of asymptomatic ICAS was 13.2% in this cohort. The median of hs-CRP levels was positively associated with the increasing numbers of ICASs. After adjusting for possible risk factors, hs-CRP ≥ 3 mg/l remained significantly associated with asymptomatic ICAS (odds ratio 1.28, 95% confidence interval 1.02-1.61).

CONCLUSIONS

In this large community-based study, subjects with higher hs-CRP levels showed a mild increase in the prevalence of asymptomatic ICAS, independent of traditional vascular risk factors. hs-CRP is an independent predictor of asymptomatic ICAS and intracranial atherosclerotic burden.

Observation of a charged (DD*)± mass peak in e+ e- → πDD* at sqrt[s] = 4.26 GeV

We report on a study of the process e+ e- → π± (DD*)∓ at sqrt[s] = 4.26  GeV using a 525 pb(-1) data sample collected with the BESIII detector at the BEPCII storage ring. A distinct charged structure is observed in the (DD*)∓ invariant mass distribution. When fitted to a mass-dependent-width Breit-Wigner line shape, the pole mass and width are determined to be Mpole = (3883.9±1.5(stat)±4.2(syst))  MeV/c2 and Γpole = (24.8±3.3(stat)±11.0(syst))  MeV. The mass and width of the structure, which we refer to as Zc(3885), are 2σ and 1σ, respectively, below those of the Zc(3900) → π± J/ψ peak observed by BESIII and Belle in π+ π- J/ψ final states produced at the same center-of-mass energy. The angular distribution of the πZc(3885) system favors a JP = 1+ quantum number assignment for the structure and disfavors 1- or 0-. The Born cross section times the DD* branching fraction of the Zc(3885) is measured to be σ(e+ e- → π± Zc(3885)∓)×B(Zc(3885)∓ → (DD*)∓) = (83.5±6.6(stat)±22.0(syst))   pb. Assuming the Zc(3885) → DD* signal reported here and the Zc(3900) → πJ/ψ signal are from the same source, the partial width ratio (Γ(Zc(3885) → DD*)/Γ(Zc(3900) → πJ/ψ)) = 6.2±1.1(stat)±2.7(syst) is determined.