Weight regain, but not weight loss exacerbates hepatic fibrosis during multiple weight cycling events in male mice

PURPOSE

Weight cycling is a phenomenon characterized by fluctuating body weight that is commonly observed in individuals employing intentional weight loss methods. Despite its prevalence, the impact of weight cycling on health remains equivocal. The current investigation aimed to examine the effects of weight cycling on liver health.

METHODS

The weight cycling model was established by switching the feeding method of mice between ad libitum (AL) and restricted intake (DR or 60% of AL) of the breeding diet to cause weight gain and weight loss, respectively. The weight cycling model comprised two and a half cycles, with one group terminating the experience during the weight-gain period (S-AL) and the other during the weight-loss period (S-DR). Liver tissue was collected to investigate morphology alterations, apoptosis, lipid metabolism, and mitochondrial homeostasis.

RESULTS

The results demonstrated that the termination point of weight cycling affected body weight and hepatic steatosis. All parameters examined in the S-DR mice exhibited a comparable trend to those observed in the DR mice. Notably, S-AL mice showed a significant increase in lipid metabolism-related proteins in the liver compared to AL-fed mice, along with reduced lipid droplets. Moreover, hepatic apoptosis and fibrosis were exacerbated in the S-AL mice compared to AL mice, whereas mitochondrial fusion, biogenesis, and mitophagy were decreased in the S-AL mice.

CONCLUSION

Weight cycling ending in weight gain exacerbated hepatic fibrosis, potentially by inducing apoptosis or disrupting mitochondrial homeostasis. Conversely, weight cycling ending in weight loss demonstrated beneficial effects on hepatic health.

Histone Trimethylations and HDAC5 Regulate Spheroid Subpopulation and Differentiation Signaling of Human Adipose-Derived Stem Cells

Human adipose-derived stem cells (ASCs) have shown immense potential for regenerative medicine. Our previous work demonstrated that chitosan nano-deposited surfaces induce spheroid formation and differentiation of ASCs for treating sciatic nerve injuries. However, the underlying cell fate and differentiation mechanisms of ASC-derived spheroids remain unknown. Here, we investigate the epigenetic regulation and signaling coordination of these therapeutic spheroids. During spheroid formation, we observed significant increases in histone 3 trimethylation at lysine 4 (H3K4me3), lysine 9 (H3K9me3), and lysine 27 (H3K27me3), accompanied by increased histone deacetylase (HDAC) activities and decreased histone acetyltransferase activities. Additionally, HDAC5 translocated from the cytoplasm to the nucleus, along with increased nuclear HDAC5 activities. Utilizing single-cell RNA sequencing (scRNA-seq), we analyzed the chitosan-induced ASC spheroids and discovered distinct cluster subpopulations, cell fate trajectories, differentiation traits, and signaling networks using the 10x Genomics platform, R studio/language, and the Ingenuity Pathway Analysis (IPA) tool. Specific subpopulations were identified within the spheroids that corresponded to a transient reprogramming state (Cluster 6) and the endpoint cell state (Cluster 3). H3K4me3 and H3K9me3 were discovered as key epigenetic regulators by IPA to initiate stem cell differentiation in Cluster 6 cells, and confirmed by qPCR and their respective histone methyltransferase inhibitors: SNDX-5613 (a KMT2A inhibitor for H3K4me3) and SUVi (an SUV39H1 inhibitor for H3K9me3). Moreover, H3K9me3 and HDAC5 were involved in regulating downstream signaling and neuronal markers during differentiation in Cluster 3 cells. These findings emphasize the critical role of epigenetic regulation, particularly H3K4me3, H3K9me3, and HDAC5, in shaping stem cell fate and directing lineage-specific differentiation.

An efficient approach for identifying important biomarkers for biomedical diagnosis

In this paper, we explore the challenges associated with biomarker identification for diagnosis purpose in biomedical experiments, and propose a novel approach to handle the above challenging scenario via the generalization of the Dantzig selector. To improve the efficiency of the regularization method, we introduce a transformation from an inherent nonlinear programming due to its nonlinear link function into a linear programming framework under a reasonable assumption on the logistic probability range. We illustrate the use of our method on an experiment with binary response, showing superior performance on biomarker identification studies when compared to their conventional analysis. Our proposed method does not merely serve as a variable/biomarker selection tool, its ranking of variable importance provides valuable reference information for practitioners to reach informed decisions regarding the prioritization of factors for further investigations.

An efficient swarm intelligence approach to the optimization on high-dimensional solutions with cross-dimensional constraints, with applications in supply chain management

Introduction

The Swarm Intelligence Based (SIB) method has widely been applied to efficient optimization in many fields with discrete solution domains. E-commerce raises the importance of designing suitable selling strategies, including channel- and direct sales, and the mix of them, but researchers in this field seldom employ advanced metaheuristic techniques in their optimization problem due to the complexities caused by the high-dimensional problems and cross-dimensional constraints.

Method

In this work, we introduce an extension of the SIB method that can simultaneously tackle these two challenges. To pursue faster computing, CPU parallelization techniques are employed for algorithm acceleration.

Results

The performance of the SIB method is examined on the problems of designing selling schemes in different scales. It outperforms the Genetic Algorithm (GA) in terms of both the speed of convergence and the optimized capacity as measured using improvement multipliers.

Discovery of HDAC6, HDAC8, and 6/8 Inhibitors and Development of Cell-Based Drug Screening Models for the Treatment of TGF-β-Induced Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis is incurable, and its progression is difficult to control and thus can lead to pulmonary deterioration. Pan-histone deacetylase inhibitors such as SAHA have shown potential for modulating pulmonary fibrosis yet with off-target effects. Therefore, selective HDAC inhibitors would be beneficial for reducing side effects. Toward this goal, we designed and synthesized 24 novel HDAC6, HDAC8, or dual HDAC6/8 inhibitors and established a two-stage screening platform to rapidly screen for HDAC inhibitors that effectively mitigate TGF-β-induced pulmonary fibrosis. The first stage consisted of a mouse NIH-3T3 fibroblast prescreen and yielded five hits. In the second stage, human pulmonary fibroblasts (HPFs) were used, and four out of the five hits were tested for caco-2 permeability and liver microsome stability to give two potential leads: J27644 (15) and 20. This novel two-stage screen platform will accelerate the discovery and reduce the cost of developing HDAC inhibitors to mitigate TGF-β-induced pulmonary fibrosis.

Adipose-derived stem cells modulate neuroinflammation and improve functional recovery in chronic constriction injury of the rat sciatic nerve

Introduction

Compressive neuropathy, a common chronic traumatic injury of peripheral nerves, leads to variable impairment in sensory and motor function. Clinical symptoms persist in a significant portion of patients despite decompression, with muscle atrophy and persistent neuropathic pain affecting 10%-25% of cases. Excessive inflammation and immune cell infiltration in the injured nerve hinder axon regeneration and functional recovery. Although adipose-derived stem cells (ASCs) have demonstrated neural regeneration and immunomodulatory potential, their specific effects on compressive neuropathy are still unclear.

Methods

We conducted modified CCI models on adult male Sprague-Dawley rats to induce irreversible neuropathic pain and muscle atrophy in the sciatic nerve. Intraneural ASC injection and nerve decompression were performed. Behavioral analysis, muscle examination, electrophysiological evaluation, and immunofluorescent examination of the injured nerve and associated DRG were conducted to explore axon regeneration, neuroinflammation, and the modulation of inflammatory gene expression. Transplanted ASCs were tracked to investigate potential beneficial mechanisms on the local nerve and DRG.

Results

Persistent neuropathic pain was induced by chronic constriction of the rat sciatic nerve. Local ASC treatment has demonstrated robust beneficial outcomes, including the alleviation of mechanical allodynia, improvement of gait, regeneration of muscle fibers, and electrophysiological recovery. In addition, locally transplanted ASCs facilitated axon remyelination, alleviated neuroinflammation, and reduced inflammatory cell infiltration of the injured nerve and associated dorsal root ganglion (DRG). Trafficking of the transplanted ASC preserved viability and phenotype less than 7 days but contributed to robust immunomodulatory regulation of inflammatory gene expression in both the injured nerve and DRG.

Discussion

Locally transplanted ASC on compressed nerve improve sensory and motor recoveries from irreversible chronic constriction injury of rat sciatic nerve via alleviation of both local and remote neuroinflammation, suggesting the promising role of adjuvant ASC therapies for clinical compressive neuropathy.

Early-onset caloric restriction alleviates ageing-associated steatohepatitis in male mice via restoring mitochondrial homeostasis

Non-alcoholic fatty liver disease is associated with ageing, and impaired mitochondrial homeostasis is the main cause for hepatic ageing. Caloric restriction (CR) is a promising therapeutic approach for fatty liver. The purpose of the present study was to investigate the possibility of early-onset CR in decelerating the progression of ageing-related steatohepatitis. The putative mechanism associated with mitochondria was further determined. C57BL/6 male mice at 8 weeks of age were randomly assigned to one of three treatments: Young-AL (AL, ad libitum), Aged-AL, or Aged-CR (60% intake of AL). Mice were sacrificed when they were 7 months old (Young) or 20 months old (Aged). Aged-AL mice displayed the greatest body weight, liver weight, and liver relative weight among treatments. Steatosis, lipid peroxidation, inflammation, and fibrosis coexisted in the aged liver. Mega mitochondria with short, randomly organized crista were noticed in the aged liver. The CR ameliorated these unfavourable outcomes. The level of hepatic ATP decreased with ageing, but this was reversed by CR. Ageing caused a decrease in mitochondrial-related protein expressions of respiratory chain complexes (NDUFB8 and SDHB) and fission (DRP1), but an increase in proteins related to mitochondrial biogenesis (TFAM), and fusion (MFN2). CR reversed the expression of these proteins in the aged liver. Both Aged-CR and Young-AL revealed a comparable pattern of protein expression. To summarize, this study demonstrated the potential of early-onset CR in preventing ageing-associated steatohepatitis, and maintaining mitochondrial functions may contribute to CR's protection during hepatic ageing.

Autologous Platelet-Rich Growth Factor Reduces M1 Macrophages and Modulates Inflammatory Microenvironments to Promote Sciatic Nerve Regeneration

The failure of peripheral nerve regeneration is often associated with the inability to generate a permissive molecular and cellular microenvironment for nerve repair. Autologous therapies, such as platelet-rich plasma (PRP) or its derivative platelet-rich growth factors (PRGF), may improve peripheral nerve regeneration via unknown mechanistic roles and actions in macrophage polarization. In the current study, we hypothesize that excessive and prolonged inflammation might result in the failure of pro-inflammatory M1 macrophage transit to anti-inflammatory M2 macrophages in large nerve defects. PRGF was used in vitro at the time the unpolarized macrophages (M0) macrophages were induced to M1 macrophages to observe if PRGF altered the secretion of cytokines and resulted in a phenotypic change. PRGF was also employed in the nerve conduit of a rat sciatic nerve transection model to identify alterations in macrophages that might influence excessive inflammation and nerve regeneration. PRGF administration reduced the mRNA expression of tumor necrosis factor-α (TNFα), interleukin-1β (IL-1β), and IL-6 in M0 macrophages. Increased CD206 substantiated the shift of pro-inflammatory cytokines to the M2 regenerative macrophage. Administration of PRGF in the nerve conduit after rat sciatic nerve transection promoted nerve regeneration by improving nerve gross morphology and its targeted gastrocnemius muscle mass. The regenerative markers were increased for regrown axons (protein gene product, PGP9.5), Schwann cells (S100β), and myelin basic protein (MBP) after 6 weeks of injury. The decreased expression of TNFα, IL-1β, IL-6, and CD68⁺ M1 macrophages indicated that the inflammatory microenvironments were reduced in the PRGF-treated nerve tissue. The increase in RECA-positive cells suggested the PRGF also promoted angiogenesis during nerve regeneration. Taken together, these results indicate the potential role and clinical implication of autologous PRGF in regulating inflammatory microenvironments via macrophage polarization after nerve transection.

Sodium phenylbutyrate inhibits Schwann cell inflammation via HDAC and NFκB to promote axonal regeneration and remyelination

Background

Epigenetic regulation by histone deacetylases (HDACs) in Schwann cells (SCs) after injury facilitates them to undergo de- and redifferentiation processes necessary to support various stages of nerve repair. Although de-differentiation activates the synthesis and secretion of inflammatory cytokines by SCs to initiate an immune response during nerve repair, changes in either the timing or duration of prolonged inflammation mediated by SCs can affect later processes associated with repair and regeneration. Limited studies have investigated the regulatory processes through which HDACs in SCs control inflammatory cytokines to provide a favorable environment for peripheral nerve regeneration.

Methods

We employed the HDAC inhibitor (HDACi) sodium phenylbutyrate (PBA) to address this question in an in vitro RT4 SC inflammation model and an in vivo sciatic nerve transection injury model to examine the effects of HDAC inhibition on the expression of pro-inflammatory cytokines. Furthermore, we assessed the outcomes of suppression of extended inflammation on the regenerative potential of nerves by assessing axonal regeneration, remyelination, and reinnervation.

Results

Significant reductions in lipopolysaccharide (LPS)-induced pro-inflammatory cytokine (tumor necrosis factor-α [TNFα]) expression and secretion were observed in vitro following PBA treatment. PBA treatment also affected the transient changes in nuclear factor κB (NFκB)-p65 phosphorylation and translocation in response to LPS induction in RT4 SCs. Similarly, PBA mediated long-term suppressive effects on HDAC3 expression and activity. PBA administration resulted in marked inhibition of pro-inflammatory cytokine secretion at the site of transection injury when compared with that in the hydrogel control group at 6-week post-injury. A conducive microenvironment for axonal regrowth and remyelination was generated by increasing expression levels of protein gene product 9.5 (PGP9.5) and myelin basic protein (MBP) in regenerating nerve tissues. PBA administration increased the relative gastrocnemius muscle weight percentage and maintained the intactness of muscle bundles when compared with those in the hydrogel control group.

Conclusions

Suppressing the lengthened state of inflammation using PBA treatment favors axonal regrowth and remyelination following nerve transection injury. PBA treatment also regulates pro-inflammatory cytokine expression by inhibiting the transcriptional activation of NFκB-p65 and HDAC3 in SCs in vitro.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12974-021-02273-1.

More than causing (epi)genomic instability: emerging physiological implications of transposable element modulation

Transposable elements (TEs) initially attracted attention because they comprise a major portion of the genomic sequences in plants and animals. TEs may jump around the genome and disrupt both coding genes as well as regulatory sequences to cause disease. Host cells have therefore evolved various epigenetic and functional RNA-mediated mechanisms to mitigate the disruption of genomic integrity by TEs. TE associated sequences therefore acquire the tendencies of attracting various epigenetic modifiers to induce epigenetic alterations that may spread to the neighboring genes. In addition to posting threats for (epi)genome integrity, emerging evidence suggested the physiological importance of endogenous TEs either as cis-acting control elements for controlling gene regulation or as TE-containing functional transcripts that modulate the transcriptome of the host cells. Recent advances in long-reads sequence analysis technologies, bioinformatics and genetic editing tools have enabled the profiling, precise annotation and functional characterization of TEs despite their challenging repetitive nature. The importance of specific TEs in preimplantation embryonic development, germ cell differentiation and meiosis, cell fate determination and in driving species specific differences in mammals will be discussed.

Variants in Maternal Effect Genes and Relaxed Imprinting Control in a Special Placental Mesenchymal Dysplasia Case with Mild Trophoblast Hyperplasia

Placental mesenchymal dysplasia (PMD) and partial hydatidiform mole (PHM) placentas share similar characteristics, such as placental overgrowth and grape-like placental tissues. Distinguishing PMD from PHM is critical because the former can result in normal birth, while the latter diagnosis will lead to artificial abortion. Aneuploidy and altered dosage of imprinted gene expression are implicated in the pathogenesis of PHM and also some of the PMD cases. Diandric triploidy is the main cause of PHM, whereas mosaic diploid androgenetic cells in the placental tissue have been associated with the formation of PMD. Here, we report a very special PMD case also presenting with trophoblast hyperplasia phenotype, which is a hallmark of PHM. This PMD placenta has a normal biparental diploid karyotype and is functionally sufficient to support normal fetal growth. We took advantage of this unique case to further dissected the potential common etiology between these two diseases. We show that the differentially methylated region (DMR) at NESP55, a secondary DMR residing in the GNAS locus, is significantly hypermethylated in the PMD placenta. Furthermore, we found heterozygous mutations in NLRP2 and homozygous variants in NLRP7 in the mother’s genome. NLRP2 and NLRP7 are known maternal effect genes, and their mutation in pregnant females affects fetal development. The variants/mutations in both genes have been associated with imprinting defects in mole formation and potentially contributed to the mild abnormal imprinting observed in this case. Finally, we identified heterozygous mutations in the X-linked ATRX gene, a known maternal–zygotic imprinting regulator in the patient. Overall, our study demonstrates that PMD and PHM may share overlapping etiologies with the defective/relaxed dosage control of imprinted genes, representing two extreme ends of a spectrum.

Timing Does Matter: Nerve-Mediated HDAC1 Paces the Temporal Expression of Morphogenic Genes During Axolotl Limb Regeneration

Sophisticated axolotl limb regeneration is a highly orchestrated process that requires highly regulated gene expression and epigenetic modification patterns at precise positions and timings. We previously demonstrated two waves of post-amputation expression of a nerve-mediated repressive epigenetic modulator, histone deacetylase 1 (HDAC1), at the wound healing (3 days post-amputation; 3 dpa) and blastema formation (8 dpa onward) stages in juvenile axolotls. Limb regeneration was profoundly inhibited by local injection of an HDAC inhibitor, MS-275, at the amputation sites. To explore the transcriptional response of post-amputation axolotl limb regeneration in a tissue-specific and time course-dependent manner after MS-275 treatment, we performed transcriptome sequencing of the epidermis and soft tissue (ST) at 0, 3, and 8 dpa with and without MS-275 treatment. Gene Ontology (GO) enrichment analysis of each coregulated gene cluster revealed a complex array of functional pathways in both the epidermis and ST. In particular, HDAC activities were required to inhibit the premature elevation of genes related to tissue development, differentiation, and morphogenesis. Further validation by Q-PCR in independent animals demonstrated that the expression of 5 out of 6 development- and regeneration-relevant genes that should only be elevated at the blastema stage was indeed prematurely upregulated at the wound healing stage when HDAC1 activity was inhibited. WNT pathway-associated genes were also prematurely activated under HDAC1 inhibition. Applying a WNT inhibitor to MS-275-treated amputated limbs partially rescued HDAC1 inhibition, resulting in blastema formation defects. We propose that post-amputation HDAC1 expression is at least partially responsible for pacing the expression timing of morphogenic genes to facilitate proper limb regeneration.

Transcriptome Analysis of Dnmt3l Knock-Out Mice Derived Multipotent Mesenchymal Stem/Stromal Cells During Osteogenic Differentiation

Multipotent mesenchymal stem/stromal cells (MSCs) exhibit great potential for cell-based therapy. Proper epigenomic signatures in MSCs are important for the maintenance and the subsequent differentiation potential. The DNA methyltransferase 3-like (DNMT3L) that was mainly expressed in the embryonic stem (ES) cells and the developing germ cells plays an important role in shaping the epigenetic landscape. Here, we report the reduced colony forming ability and impaired in vitro osteogenesis in Dnmt3l-knockout-mice-derived MSCs (Dnmt3l KO MSCs). By comparing the transcriptome between undifferentiated Dnmt3l KO MSCs and the MSCs from the wild-type littermates, some of the differentially regulated genes (DEGs) were found to be associated with bone-morphology-related phenotypes. On the third day of osteogenic induction, differentiating Dnmt3l KO MSCs were enriched for genes associated with nucleosome structure, peptide binding and extracellular matrix modulation. Differentially expressed transposable elements in many subfamilies reflected the change of corresponding regional epigenomic signatures. Interestingly, DNMT3L protein is not expressed in cultured MSCs. Therefore, the observed defects in Dnmt3l KO MSCs are unlikely a direct effect from missing DNMT3L in this cell type; instead, we hypothesized them as an outcome of the pre-deposited epigenetic signatures from the DNMT3L-expressing progenitors. We observed that 24 out of the 107 upregulated DEGs in Dnmt3l KO MSCs were hypermethylated in their gene bodies of DNMT3L knock-down ES cells. Among these 24 genes, some were associated with skeletal development or homeostasis. However, we did not observe reduced bone development, or reduced bone density through aging in vivo. The stronger phenotype in vitro suggested the involvement of potential spreading and amplification of the pre-deposited epigenetic defects over passages, and the contribution of oxidative stress during in vitro culture. We demonstrated that transient deficiency of epigenetic co-factor in ES cells or progenitor cells caused compromised property in differentiating cells much later. In order to facilitate safer practice in cell-based therapy, we suggest more in-depth examination shall be implemented for cells before transplantation, even on the epigenetic level, to avoid long-term risk afterward.

[Clinical characteristics and related factors of acute tubular necrosis in patients with minimal change disease]

Objective: To investigate the clinical characteristics and related factors of acute tubular necrosis (ATN) in patients with minimal change disease (MCD). Methods: Patients from Chinese PLA General Hospital who were pathologically diagnosed with MCD and had clinical manifestations of nephrotic syndrome from January 1, 2013 to December 31, 2019 were included. The clinical and pathological data of patients were retrospectively analyzed. Meanwhile, the incidence and clinical characteristics of ATN in different age groups were compared. The risk factors for ATN were assessed using binary logistic regression. Results: A total of 525 patients were included, with a gender ratio of 1.56∶1 (male: female), aged 33 (21, 48) years old. ATN occurred in 49 (9.3%) of 525 patients, of which 34 were male and 15 were female. The incidence of ATN increased with age in MCD patients of different age groups (χ(2)=31.442, P<0.001). The incidence of ATN in groups of age≤20 years, 21-40 years, 41-60 years, and >60 years was 2.4% (3/123), 5.2% (10/192), 13.2% (20/152) and 27.6% (16/58), respectively. Elevations of alanine aminotransferase (ALT), aspartate aminotransferase (AST), γ-glutamyl transpeptidase (GGT) and serum IgE occurred in 92 patients (17.5%), 53 patients (10.1%), 99 patients (18.9%), and 303 patients (57.7%), respectively. There were significant differences in age, ALT, serum creatinine, serum urea nitrogen, history of diabetes and history of hypertension between non-ATN group and ATN group (all P<0.05). The results of logistic regression analysis showed that>40 years old (OR=6.283, 95% CI: 2.695-14.649, P<0.001) and serum albumin (OR=0.924, 95% CI: 0.857-0.997, P=0.040) was independently associated with ATN in MCD patients. Conclusion: Age>40 years is an independent risk factor and serum albumin is a protective factor for ATN in MCD patients.

Transient DNMT3L Expression Reinforces Chromatin Surveillance to Halt Senescence Progression in Mouse Embryonic Fibroblast

Global heterochromatin reduction, which is one of the hallmarks of senescent cells, is associated with reduced transposable element repression and increased risk of chromatin instability. To ensure genomic integrity, the irreparable cells in a population exit permanently from the cell cycle, and this process is termed "senescence." However, senescence only blocks the expansion of unwanted cells, and the aberrant chromatin of senescent cells remains unstable. Serendipitously, we found that the transient ectopic expression of a repressive epigenetic modulator, DNA methyltransferase 3-like (DNMT3L) was sufficient to delay the premature senescence progression of late-passage mouse embryonic fibroblasts (MEFs) associated with a tightened global chromatin structure. DNMT3L induces more repressive H3K9 methylation on endogenous retroviruses and downregulates the derepressed transposons in aging MEFs. In addition, we found that a pulse of ectopic DNMT3L resulted in the reestablishment of H3K27me3 on polycomb repressive complex 2 (PRC2)-target genes that were derepressed in old MEFs. We demonstrated that ectopic DNMT3L interacted with PRC2 in MEFs. Our data also suggested that ectopic DNMT3L might guide PRC2 to redress deregulated chromatin regions in cells undergoing senescence. This study might lead to an epigenetic reinforcement strategy for overcoming aging-associated epimutation and senescence.

In vitro culture and characterization of duck primordial germ cells

This study aimed to isolate, culture, and characterize duck primordial germ cells (PGCs) and to compare these cells with chicken PGCs. We first cultured Muscovy duck (Cairina moschata) circulating PGCs and gonadal PGCs (gPGCs) in the modified serum-containing medium used to amplify chicken PGCs. gPGCs were found to proliferate better in serum-free chemically defined medium than in serum-containing medium. Thereafter, gPGCs were similarly isolated from 2 other duck breeds, the Pekin duck (Anas platyrhynchos) and the hybrid mule duck (C. moschata × A. platyrhynchos), and amplified for a limited period of time in the chemically defined culture condition, but sufficiently to be characterized and transplanted. Cultured gPGCs of all 3 duck breeds were characterized by Periodic acid-Schiff staining, immunocytochemical staining, and expression analysis of germline-specific and pluripotency genes. Cultured duck gPGCs colonized the gonads after being genetically labeled and injected into recipient embryos. Taken together, these results demonstrate that duck PGCs retain their germline characteristics after being isolated, expanded in vitro, and genetically modified. Further studies are required to establish the optimal conditions for long-term culture of duck PGCs, which may involve supplementing the culture medium with other growth factors or compounds.

Nerve-mediated expression of histone deacetylases regulates limb regeneration in axolotls

Axolotls have amazing abilities to regenerate their lost limbs. Nerve and wound epidermis have great impacts on this regeneration. Histone deacetylases (HDACs) have been shown to play roles in the regeneration of amphibian tails and limbs. In this study, a bi-phasic up-regulation of HDAC1 was noted before early differentiation stage of axolotl limb regeneration. Limb regeneration was delayed in larvae incubated with an HDAC inhibitor MS-275. Local injection of MS-275 or TSA, another HDAC inhibitor, into amputation sites of the juveniles did not interfere with wound healing but more profoundly inhibited local HDAC activities and blastema formation/limb regeneration. Elevation of HDAC1 expression was more apparent in wound epidermis than in mesenchyme. Prior denervation prohibited this elevation and limb regeneration. Supplementation of nerve factors BMP7, FGF2, and FGF8 in the stump ends after amputation on denervated limbs not only enabled HDAC1 up-regulation but also led to more extent of limb regeneration. In conclusion, nerve-mediated HDAC1 expression is required for blastema formation and limb regeneration.

Analysis of experience-regulated transcriptome and imprintome during critical periods of mouse visual system development reveals spatiotemporal dynamics

Visual system development is light-experience dependent, which strongly implicates epigenetic mechanisms in light-regulated maturation. Among many epigenetic processes, genomic imprinting is an epigenetic mechanism through which monoallelic gene expression occurs in a parent-of-origin-specific manner. It is unknown if genomic imprinting contributes to visual system development. We profiled the transcriptome and imprintome during critical periods of mouse visual system development under normal- and dark-rearing conditions using B6/CAST F1 hybrid mice. We identified experience-regulated, isoform-specific and brain-region-specific imprinted genes. We also found imprinted microRNAs were predominantly clustered into the Dlk1-Dio3 imprinted locus with light experience affecting some imprinted miRNA expression. Our findings provide the first comprehensive analysis of light-experience regulation of the transcriptome and imprintome during critical periods of visual system development. Our results may contribute to therapeutic strategies for visual impairments and circadian rhythm disorders resulting from a dysfunctional imprintome.

Dlk1-Dio3 locus-derived lncRNAs perpetuate postmitotic motor neuron cell fate and subtype identity

The mammalian imprinted Dlk1-Dio3 locus produces multiple long non-coding RNAs (lncRNAs) from the maternally inherited allele, including Meg3 (i.e., Gtl2) in the mammalian genome. Although this locus has well-characterized functions in stem cell and tumor contexts, its role during neural development is unknown. By profiling cell types at each stage of embryonic stem cell-derived motor neurons (ESC~MNs) that recapitulate spinal cord development, we uncovered that lncRNAs expressed from the Dlk1-Dio3 locus are predominantly and gradually enriched in rostral motor neurons (MNs). Mechanistically, Meg3 and other Dlk1-Dio3 locus-derived lncRNAs facilitate Ezh2/Jarid2 interactions. Loss of these lncRNAs compromises the H3K27me3 landscape, leading to aberrant expression of progenitor and caudal Hox genes in postmitotic MNs. Our data thus illustrate that these lncRNAs in the Dlk1-Dio3 locus, particularly Meg3, play a critical role in maintaining postmitotic MN cell fate by repressing progenitor genes and they shape MN subtype identity by regulating Hox genes.

When a gene is active, its DNA sequence is ‘transcribed’ to form a molecule of RNA. Many of these RNAs act as templates for making proteins. But for some genes, the protein molecules are not their final destinations. Their RNA molecules instead help to control gene activity, which can alter the behaviour or the identity of a cell. For example, experiments performed in individual cells suggest that so-called long non-coding RNAs (or lncRNAs for short) guide how stem cells develop into different types of mature cells. However, it is not clear whether lncRNAs play the same critical role in embryos.

Yen et al. used embryonic stem cells to model how motor neurons develop in the spinal cord of mouse embryos. This revealed that motor neurons produce large amounts of a specific group of lncRNAs, particularly one called Meg3. Further experiments showed that motor neurons in mouse embryos that lack Meg3 do not correctly silence a set of genes called the Hox genes, which are crucial for laying out the body plans of many different animal embryos. These neurons also incorrectly continue to express genes that are normally active in an early phase of the stem-like cells that make motor neurons.

There is wide interest in how lncRNAs help to regulate embryonic development. With this new knowledge of how Meg3 regulates the activity of Hox genes in motor neurons, research could now be directed toward investigating whether lncRNAs help other tissues to develop in a similar way.

Stage-dependent piRNAs in chicken implicated roles in modulating male germ cell development

Background

The PIWI/piRNA pathway is a conserved machinery important for germ cell development and fertility. This piRNA-guided molecular machinery is best known for repressing derepressed transposable elements (TE) during epigenomic reprogramming. The extent to which piRNAs are involved in modulating transcripts beyond TEs still need to be clarified, and it may be a stage-dependent event. We chose chicken germline as a study model because of the significantly lower TE complexity in the chicken genome compared to mammalian species.

Results

We generated high-confidence piRNA candidates in various stages across chicken germline development by 3′-end-methylation-enriched small RNA sequencing and in-house bioinformatics analysis. We observed a significant developmental stage-dependent loss of TE association and a shifting of the ping-pong cycle signatures. Moreover, the stage-dependent reciprocal abundance of LINE retrotransposons, CR1-C, and its associated piRNAs implicated the developmental stage-dependent role of piRNA machinery. The stage dependency of piRNA expression and its potential functions can be better addressed by analyzing the piRNA precursors/clusters. Interestingly, the new piRNA clusters identified from embryonic chicken testes revealed evolutionary conservation between chickens and mammals, which was previously thought to not exist.

Conclusions

In this report, we provided an original chicken RNA resource and proposed an analytical methodology that can be used to investigate stage-dependent changes in piRNA compositions and their potential roles in TE regulation and beyond, and also revealed possible conserved functions of piRNAs in developing germ cells.

Electronic supplementary material

The online version of this article (10.1186/s12864-018-4820-9) contains supplementary material, which is available to authorized users.

Comparative global immune-related gene profiling of somatic cells, human pluripotent stem cells and their derivatives: implication for human lymphocyte proliferation

Human pluripotent stem cells (hPSCs), including embryonic stem cells (ESCs) and induced PSCs (iPSCs), represent potentially unlimited cell sources for clinical applications. Previous studies have suggested that hPSCs may benefit from immune privilege and limited immunogenicity, as reflected by the reduced expression of major histocompatibility complex class-related molecules. Here we investigated the global immune-related gene expression profiles of human ESCs, hiPSCs and somatic cells and identified candidate immune-related genes that may alter their immunogenicity. The expression levels of global immune-related genes were determined by comparing undifferentiated and differentiated stem cells and three types of human somatic cells: dermal papilla cells, ovarian granulosa cells and foreskin fibroblast cells. We identified the differentially expressed genes CD24, GATA3, PROM1, THBS2, LY96, IFIT3, CXCR4, IL1R1, FGFR3, IDO1 and KDR, which overlapped with selected immune-related gene lists. In further analyses, mammalian target of rapamycin complex (mTOR) signaling was investigated in the differentiated stem cells following treatment with rapamycin and lentiviral transduction with specific short-hairpin RNAs. We found that the inhibition of mTOR signal pathways significantly downregulated the immunogenicity of differentiated stem cells. We also tested the immune responses induced in differentiated stem cells by mixed lymphocyte reactions. We found that CD24- and GATA3-deficient differentiated stem cells including neural lineage cells had limited abilities to activate human lymphocytes. By analyzing the transcriptome signature of immune-related genes, we observed a tendency of the hPSCs to differentiate toward an immune cell phenotype. Taken together, these data identify candidate immune-related genes that might constitute valuable targets for clinical applications.

Endothelial-derived extracellular matrix ameliorate the stemness deprivation during ex vivo expansion of mouse bone marrow-derived mesenchymal stem cells

Mesenchymal stem cells (MSCs) hold great potential in cell therapies by virtue of the regenerative effects and immunomodulatory properties, but the scarce nature of MSCs makes ex vivo expansion indispensable prior to transplantation purposes. However, potential loss of stemness ensuing culture expansion has hindered the advancements in MSCs-based treatments. In principle, stemness could be preserved by reconstructing the stem cell niche. To test whether the endothelial cells (ECs) participate in the constitution of the stem cell niche for mesenchymal stem cells (MSCs), ECs derivatives including extracellular matrix (ECM) and conditioned medium (CM) prepared from aortic endothelial cells (AECs) and Mile Sven 1 endothelial cell line (MS1) were investigated for the potential to maintain MSCs stemness. MSCs expanded on endothelial ECMs, especially on MS1-ECM, possessed a more juvenile morphology and showed delayed proliferation, when compared with untreated MSCs and MSCs on MSC-ECM and in CMs. Once induced, MS1-ECM group showed better tri-lineage differentiations indicating that MS1-ECM could better preserve MSC stemness. MSCs on MS1-ECM showed stronger immune-modulatory potential and had significantly higher H3K27me3 with lower Kdm6b expression. Taken together, MS1-ECM shapes an inhibitory chromatin signature and retains MSCs stemness. Our work provided supportive evidence that MSCs can reside in a perivascular niche, and a feasible novel approach for MSCs expansion.

Dnmt3l-knockout donor cells improve somatic cell nuclear transfer reprogramming efficiency

Nuclear transfer (NT) is a technique used to investigate the development and reprogramming potential of a single cell. DNA methyltransferase-3-like, which has been characterized as a repressive transcriptional regulator, is expressed in naturally fertilized egg and morula/blastocyst at pre-implantation stages. In this study, we demonstrate that the use of Dnmt3l-knockout (Dnmt3l-KO) donor cells in combination with Trichostatin A treatment improved the developmental efficiency and quality of the cloned embryos. Compared with the WT group, Dnmt3l-KO donor cell-derived cloned embryos exhibited increased cell numbers as well as restricted OCT4 expression in the inner cell mass (ICM) and silencing of transposable elements at the blastocyst stage. In addition, our results indicate that zygotic Dnmt3l is dispensable for cloned embryo development at pre-implantation stages. In Dnmt3l-KO mouse embryonic fibroblasts, we observed reduced nuclear localization of HDAC1, increased levels of the active histone mark H3K27ac and decreased accumulation of the repressive histone marks H3K27me3 and H3K9me3, suggesting that Dnmt3l-KO donor cells may offer a more permissive epigenetic state that is beneficial for NT reprogramming.

Epigenetic factors in the regulation of prospermatogonia and spermatogonial stem cells

Appropriate regulation of epigenome within cells is crucial for the determination of cell fate and contributes to the lifelong maintenance of tissue homeostasis. Epigenomic re-establishment during embryonic prospermatogonia development and fine-tune of the epigenetic landscape in postnatal spermatogonial stem cells (SSCs) are two key processes required for functional male germ cell formation. Repression of re-activated transposons and male germline-specific epigenome establishment occur in prospermatogonia, whereas modulations of the epigenetic landscape is important for SSC self-renewal and differentiation to maintain the stem cell pool and support long-term sperm production. Here, we describe the impact of epigenome-related regulators and small non-coding RNAs as well as the influence of epigenome modifications that result from extrinsic signaling for controlling the decision between self-renewal, differentiation and survival in mouse prospermatogonia and SSCs. This article provides a review of epigenome-related molecules involved in cell fate determination in male germ cells and discusses the intriguing questions that arise from these studies.

Emergence of differentially regulated pathways associated with the development of regional specificity in chicken skin

Background

Regional specificity allows different skin regions to exhibit different characteristics, enabling complementary functions to make effective use of the integumentary surface. Chickens exhibit a high degree of regional specificity in the skin and can serve as a good model for when and how these regional differences begin to emerge.

Results

We used developing feather and scale regions in embryonic chickens as a model to gauge the differences in their molecular pathways. We employed cosine similarity analysis to identify the differentially regulated and co-regulated genes. We applied low cell techniques for expression validation and chromatin immunoprecipitation (ChIP)-based enhancer identification to overcome limited cell availabilities from embryonic chicken skin.

We identified a specific set of genes demonstrating a high correlation as being differentially expressed during feather and scale development and maturation. Some members of the WNT, TGF-beta/BMP, and Notch family known to be involved in feathering skin differentiation were found to be differentially regulated. Interestingly, we also found genes along calcium channel pathways that are differentially regulated. From the analysis of differentially regulated pathways, we used calcium signaling pathways as an example for further verification. Some voltage-gated calcium channel subunits, particularly CACNA1D, are expressed spatio-temporally in the skin epithelium. These calcium signaling pathway members may be involved in developmental decisions, morphogenesis, or epithelial maturation. We further characterized enhancers associated with histone modifications, including H3K4me1, H3K27ac, and H3K27me3, near calcium channel-related genes and identified signature intensive hotspots that may be correlated with certain voltage-gated calcium channel genes.

Conclusion

We demonstrated the applicability of cosine similarity analysis for identifying novel regulatory pathways that are differentially regulated during development. Our study concerning the effects of signaling pathways and histone signatures on enhancers suggests that voltage-gated calcium signaling may be involved in early skin development. This work lays the foundation for studying the roles of these gene pathways and their genomic regulation during the establishment of skin regional specificity.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-014-1202-9) contains supplementary material, which is available to authorized users.

Loss of non-coding RNA expression from the DLK1-DIO3 imprinted locus correlates with reduced neural differentiation potential in human embryonic stem cell lines

INTRODUCTION

Pluripotent stem cells are increasingly used to build therapeutic models, including the transplantation of neural progenitors derived from human embryonic stem cells (hESCs). Recently, long non-coding RNAs (lncRNAs), including delta-like homolog 1 gene and the type III iodothyronine deiodinase gene (DLK1-DIO3) imprinted locus-derived maternally expressed gene 3 (MEG3), were found to be expressed during neural development. The deregulation of these lncRNAs is associated with various neurological diseases. The imprinted locus DLK1-DIO3 encodes abundant non-coding RNAs (ncRNAs) that are regulated by differential methylation of the locus. We aim to study the correlation between the DLK1-DIO3-derived ncRNAs and the capacity of hESCs to differentiate into neural lineages.

METHODS

We classified hESC sublines into MEG3-ON and MEG3-OFF based on the expression levels of MEG3 and its downstream microRNAs as detected by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). A cDNA microarray was used to analyze the gene expression profiles of hESCs. To investigate the capacity of neural differentiation in MEG3-ON and MEG3-OFF hESCs, we performed neural lineage differentiation followed by neural lineage marker expression and neurite formation analyses via qRT-PCR and immunocytochemistry, respectively. MEG3-knockdown via small interfering RNA (siRNA) and small hairpin RNA (shRNA) was used to investigate the potential causative effect of MEG3 in regulating neural lineage-related gene expression.

RESULTS

DLK1-DIO3-derived ncRNAs were repressed in MEG3-OFF hESCs compared with those in the MEG3-ON hESCs. The transcriptome profile indicated that many genes related to nervous system development and neural-type tumors were differentially expressed in MEG3-OFF hESCs. Three independent MEG3-knockdown assays using different siRNA and shRNA constructs consistently resulted in downregulation of some neural lineage genes. Lower expression levels of stage-specific neural lineage markers and reduced neurite formation were observed in neural lineage-like cells derived from MEG3-OFF-associated hESCs compared with those in the MEG3-ON groups at the same time points after differentiation.

CONCLUSIONS

Repression of ncRNAs derived from the DLK1-DIO3 imprinted locus is associated with reduced neural lineage differentiation potential in hESCs.

DNMT3L promotes quiescence in postnatal spermatogonial progenitor cells

The ability of adult stem cells to reside in a quiescent state is crucial for preventing premature exhaustion of the stem cell pool. However, the intrinsic epigenetic factors that regulate spermatogonial stem cell quiescence are largely unknown. Here, we investigate in mice how DNA methyltransferase 3-like (DNMT3L), an epigenetic regulator important for interpreting chromatin context and facilitating de novo DNA methylation, sustains the long-term male germ cell pool. We demonstrated that stem cell-enriched THY1(+) spermatogonial stem/progenitor cells (SPCs) constituted a DNMT3L-expressing population in postnatal testes. DNMT3L influenced the stability of promyelocytic leukemia zinc finger (PLZF), potentially by downregulating Cdk2/CDK2 expression, which sequestered CDK2-mediated PLZF degradation. Reduced PLZF in Dnmt3l KO THY1(+) cells released its antagonist, Sal-like protein 4A (SALL4A), which is associated with overactivated ERK and AKT signaling cascades. Furthermore, DNMT3L was required to suppress the cell proliferation-promoting factor SALL4B in THY1(+) SPCs and to prevent premature stem cell exhaustion. Our results indicate that DNMT3L is required to delicately balance the cycling and quiescence of SPCs. These findings reveal a novel role for DNMT3L in modulating postnatal SPC cell fate decisions.

Cell-autonomous heparanase modulates self-renewal and migration in bone marrow-derived mesenchymal stem cells

Background

Stem cell-fate is highly regulated by stem cell niche, which is composed of a distinct microenvironment, including neighboring cells, signals and extracellular matrix. Bone marrow-derived mesenchymal stem cells (BM-MSCs) are multipotent stem cells and are potentially applicable in wide variety of pathological conditions. However, the niche microenvironment for BM-MSCs maintenance has not been clearly characterized. Accumulating evidence indicated that heparan sulfate glycosaminoglycans (HS-GAGs) modulate the self-renewal and differentiation of BM-MSCs, while overexpression of heparanase (HPSE1) resulted in the change of histological profile of bone marrow. Here, we inhibited the enzymatic activity of cell-autonomous HPSE1 in BM-MSCs to clarify the physiological role of HPSE1 in BM-MSCs.

Results

Isolated mouse BM-MSCs express HPSE1 as indicated by the existence of its mRNA and protein, which includes latent form and enzymatically active HPSE1. During in vitro osteo-differentiations, although the expression levels of Hpse1 fluctuated, enzymatic inhibition did not affect osteogenic differentiation, which might due to increased expression level of matrix metalloproteinase 9 (Mmp9). However, cell proliferation and colony formation efficiency were decreased when HPSE1 was enzymatically inhibited. HPSE1 inhibition potentiated SDF-1/CXCR4 signaling axis and in turn augmented the migratory/anchoring behavior of BM-MSCs. We further demonstrated that inhibition of HPSE1 decreased the accumulation of acetylation marks on histone H4 lysine residues suggesting that HPSE1 also modulates the chromatin remodeling.

Conclusions

Our findings indicated cell-autonomous HPSE1 modulates clonogenicity, proliferative potential and migration of BM-MSCs and suggested the HS-GAGs may contribute to the niche microenvironment of BM-MSCs.

Potential modulation on P-glycoprotein and CYP3A by soymilk and miso: in vivo and ex-vivo studies

P-glycoprotein (P-gp) and CYP3A4 both play very important roles in drug bioavailability, resistance and interactions. Our in vitro studies indicated that P-gp function was activated by many isoflavones. This study investigated the in vivo effects of soymilk and miso, isoflavone-rich soy foods, on P-gp and CYP3A by tracing the pharmacokinetics of cyclosporine (CSP), a probe drug of P-gp. Rats were orally administered CSP with and without soymilk or miso. A specific monoclonal fluorescence polarisation immunoassay was used to determine the blood concentration of CSP. The results showed that soymilk and miso significantly decreased the C(max) of CSP by 64.5% and 78.3%, and reduced the AUC(0-540) by 64.9% and 78.3%, respectively. Mechanism studies revealed that the activities of P-gp and CYP3A4 were induced by soymilk and miso. In conclusion, ingestion of soymilk and miso significantly activated the functions of P-gp and CYP3A.

Involvement of the serine protease inhibitor, SERPINE2, and the urokinase plasminogen activator in cumulus expansion and oocyte maturation

The serpin peptidase inhibitor, clade E, member 2 (SERPINE2) inhibits urokinase-type plasminogen activator (PLAU) and tissue-type plasminogen activator. Higher SERPINE2 expression levels were detected in cumulus cells of human immature oocytes than in those of mature oocytes. The objective of this study was to evaluate whether high SERPINE2 levels in cumulus cells are associated with oocyte immaturity. Using the mouse cumulus–oocyte complex as an experimental model, the effects of elimination and overexpression of SERPINE2 in cumulus cells on cumulus expansion and oocyte maturation were assayed by in vitro maturation. Serpine2 and PLAU transcripts were the most highly expressed serpins and plasminogen activators, respectively. Their expression was coordinately regulated in cumulus cells during gonadotropin-induced oocyte maturation. Silencing of Serpine2 expression using small interfering RNAs or blockage of SERPINE2 protein using a specific antibody had no effect on oocyte maturation. However, overexpression of Serpine2 or exogenous supplementation with high levels of SERPINE2 impaired cumulus expansion and oocyte maturation, probably by decreasing hyaluronan synthase 2 (Has2) and versican (Vcan) mRNA expression. Amiloride, a specific PLAU inhibitor, also suppressed these processes. PLAU supplementation of the oocyte in vitro maturation medium caused earlier and more extensive expansion of cumulus cells and oocyte maturation that may be mediated by increased Has2 mRNA expression. However, these effects were neutralized by coincubation with SERPINE2 or amiloride and PLAU. In conclusion, SERPINE2 and PLAU are involved in cumulus expansion and oocyte maturation. High SERPINE2 levels impair these processes, probably by decreasing cumulus matrix gene expression as well as reducing cumulus hyaluronan contents and inhibiting PLAU activity. These findings may explain why cumulus cells surrounding immature human oocytes express high SERPINE2 levels.

Functions of DNA methyltransferase 3-like in germ cells and beyond

DNA methyltransferase 3-like (DNMT3L) is one of the key players in de novo DNA methylation of imprinting control elements and retrotransposons, which occurs after genome-wide epigenetic erasure during germ cell development. In this review, we summarise the biochemical properties of DNMT3L and discuss the possible mechanisms behind DNMT3L-mediated imprinting establishment and retrotransposon silencing in germ cells. We also discuss possible connections between DNMT3L and non-coding RNA-mediated epigenetic remodelling, the roles of DNMT3L in germ cell development and the implications in stem cell and cancer research.

14-3-3σ regulates β-catenin-mediated mouse embryonic stem cell proliferation by sequestering GSK-3β

BACKGROUND

Pluripotent embryonic stem cells are considered to be an unlimited cell source for tissue regeneration and cell-based therapy. Investigating the molecular mechanism underlying the regulation of embryonic stem cell expansion is thus important. 14-3-3 proteins are implicated in controlling cell division, signaling transduction and survival by interacting with various regulatory proteins. However, the function of 14-3-3 in embryonic stem cell proliferation remains unclear.

METHODOLOGY AND PRINCIPAL FINDINGS

In this study, we show that all seven 14-3-3 isoforms were detected in mouse embryonic stem cells. Retinoid acid suppressed selectively the expression of 14-3-3σ isoform. Knockdown of 14-3-3σ with siRNA reduced embryonic stem cell proliferation, while only 14-3-3σ transfection increased cell growth and partially rescued retinoid acid-induced growth arrest. Since the growth-enhancing action of 14-3-3σ was abrogated by β-catenin knockdown, we investigated the influence of 14-3-3σ overexpression on β-catenin/GSK-3β. 14-3-3σ bound GSK-3β and increased GSK-3β phosphorylation in a PI-3K/Akt-dependent manner. It disrupted β-catenin binding by the multiprotein destruction complex. 14-3-3σ overexpression attenuated β-catenin phosphorylation and rescued the decline of β-catenin induced by retinoid acid. Furthermore, 14-3-3σ enhanced Wnt3a-induced β-catenin level and GSK-3β phosphorylation. DKK, an inhibitor of Wnt signaling, abolished Wnt3a-induced effect but did not interfere GSK-3β/14-3-3σ binding.

SIGNIFICANCE

Our findings show for the first time that 14-3-3σ plays an important role in regulating mouse embryonic stem cell proliferation by binding and sequestering phosphorylated GSK-3β and enhancing Wnt-signaled GSK-3β inactivation. 14-3-3σ is a novel target for embryonic stem cell expansion.

Isolation and characterization of novel murine epiphysis derived mesenchymal stem cells

Background

While bone marrow (BM) is a rich source of mesenchymal stem cells (MSCs), previous studies have shown that MSCs derived from mouse BM (BMMSCs) were difficult to manipulate as compared to MSCs derived from other species. The objective of this study was to find an alternative murine MSCs source that could provide sufficient MSCs.

Methodology/Principal Findings

In this study, we described a novel type of MSCs that migrates directly from the mouse epiphysis in culture. Epiphysis-derived MSCs (EMSCs) could be extensively expanded in plastic adherent culture, and they had a greater ability for clonogenic formation and cell proliferation than BMMSCs. Under specific induction conditions, EMSCs demonstrated multipotency through their ability to differentiate into adipocytes, osteocytes and chondrocytes. Immunophenotypic analysis demonstrated that EMSCs were positive for CD29, CD44, CD73, CD105, CD166, Sca-1 and SSEA-4, while negative for CD11b, CD31, CD34 and CD45. Notably, EMSCs did not express major histocompatibility complex class I (MHC I) or MHC II under our culture system. EMSCs also successfully suppressed the proliferation of splenocytes triggered by concanavalin A (Con A) or allogeneic splenocytes, and decreased the expression of IL-1, IL-6 and TNF-α in Con A-stimulated splenocytes suggesting their anti-inflammatory properties. Moreover, EMSCs enhanced fracture repair, ameliorated necrosis in ischemic skin flap, and improved blood perfusion in hindlimb ischemia in the in vivo experiments.

Conclusions/Significances

These results indicate that EMSCs, a new type of MSCs established by our simple isolation method, are a preferable alternative for mice MSCs due to their better growth and differentiation potentialities.

Meiotic competent human germ cell-like cells derived from human embryonic stem cells induced by BMP4/WNT3A signaling and OCT4/EpCAM (epithelial cell adhesion molecule) selection

The establishment of an effective germ cell selection/enrichment platform from in vitro differentiating human embryonic stem cells (hESCs) is crucial for studying the molecular and signaling processes governing human germ cell specification and development. In this study, we developed a germ cell-enriching system that enables us to identify signaling factors involved in germ cell-fate induction from differentiating hESCs in vitro. First, we demonstrated that selection through an OCT4-EGFP reporter system can successfully increase the percentage of meiotic-competent, germ cell-like cells from spontaneously differentiating hESCs. Furthermore, we showed that the pluripotency associated surface marker, epithelial cell adhesion molecule (EpCAM), is also expressed in human fetal gonads and can be used as an effective selection marker for germ cell enrichment from differentiating hESCs. Combining OCT4 and EpCAM selection can further enrich the meiotic-competent germ cell-like cell population. Also, with the percentage of OCT4(+)/EpCAM(+) cells as readout, we demonstrated the synergistic effect of BMP4/pSMAD1/5/8 and WNT3A/β-CATENIN in promoting hESCs toward the germline fate. Combining BMP4/WNT3A induction and OCT4/EpCAM selection can significantly increase the putative germ cell population with meiotic competency. Co-transplantation of these cells with dissociated mouse neonatal ovary cells into SCID mice resulted in a homogenous germ cell cluster formation in vivo. The stepwise platform established in this study provides a useful tool to elucidate the molecular mechanisms of human germ cell development, which has implications not only for human fertility research but regenerative medicine in general.

Identification of a missense mutation of c.3064G>A, Gly1022Ser in exon 43 of COL1A1 gene in a girl with osteogenesis imperfecta type III

Osteogenesis imperfecta (OI) types I-V have been inherited in an autosomal dominant pattern. OI type I is associated with mutations in COL1A1 mostly due to a null allele. OI types II-IV are associated with mutations in COL1A1 or COL1A2 and mostly are due to glycine substitutions. It has been suggested that the effect of glycine substitutions is position specific, and the substitution of glycine by serine has much less lethal effect than the substitutions by valine, aspartic acid, glutamic acid, arginine and cysteine. We report identification of c.3064G>A, GGT>AGT, Gly1022Ser (Gly(844) --> Ser844 in triple helix) in exon 43 of the COL1A1 gene in an 8-year-old girl with OI type III. Our report provides evidence that at triple helix glycine residue 844 (p.Gly1022), a glycine substitution by serine can result in OI type III but not a lethal outcome.

Partial monosomy 3p (3p26.2 --> pter) and partial trisomy 5q (5q34 --> qter) in a girl with coarctation of the aorta, congenital heart defects, short stature, microcephaly and developmental delay

A 1-year-and-3-month-old girl presented with psychomotor retardation, developmental delay, clinodactyly of the thumb, coarctation of the aorta, patent ductus arteriosus, peripheral pulmonary stenosis, atrial septal defect, microcephaly, brachycephaly, a small oval face, almond-shaped eyes, a down-turned mouth, a widened nasal bridge, hypertelorism, epicanthic folds, long philtrum, low-set large ears and but no craniosynostosis. Oligonucleotide-based array comparative genomic hybridization revealed a -4.79-Mb deletion of 3p26.2 --> pter encompassing CHL1 and CNTN4, and a -19.56-Mb duplication of 5q34 --> qter encompassing MSX2, NKX2-5 and NSD1. The karyotype of the girl was 46,XX,der(3)t(3;5)(p26.2;q34) pat. The present case adds distal 5q duplication to the list of chromosome aberrations associated with coarctation of the aorta.

Clinical imaging findings in a girl with Hutchinson-Gilford progeria syndrome

We report an 82-year-old girl with premature aging, a karyotype of 46,XX and a de novo c.1824C>T mutation encoding p.G608G in the lamin A gene. The clinical features of accelerated aging and the molecular finding were consistent with the diagnosis of Hutchinson-Gilford progeria syndrome (HGPS). In this presentation, we demonstrate the radiological imaging findings of skeletal, oral and craniofacial phenotypes of abnormalities associated with HGPS. The oral and craniofacial abnormalities caused dental caries, severe malocclusion, and swallowing, feeding and speech problems. Dural calcification, and granulation in the ear drum and external ear canal were additionally observed.

Discriminant analysis for anaesthetic decision-making: an intelligent recognition system for epidural needle insertion

BACKGROUND

Incorrect placement of epidural catheters causes medical complications. We used linear discriminant analysis (LDA) to develop an intelligent recognition system (i-RS) in order to guide epidural placement and reduce physician error.

METHODS

We analysed real-time dual-wavelength fibreoptic data recorded from the end of an epidural needle in a live porcine model. Two categories of tissue layers were necessary for correct placement of catheter: epidural space and ligamentum flavum. The data were tested using linear, quadratic and logistic parametric analysis to identify which method could distinguish the two anatomical structures.

RESULTS

LDA was the best fit for our model. There was ∼80% sensitivity and specificity for correct anatomical identification. Error rates based on cross-validation were 17.0% for the epidural space and 18.6% for ligamentum flavum. Error rates were greater with the 532 nm compared with 650 nm wavelength.

CONCLUSIONS

The sensitivity and specificity of LDA for identifying the correct anatomical structure was similar to a physician who is an expert in epidural placement. Overall performance of an i-RS could be improved by expanding the database for decision-making and adding a category of uncertainty. This would reduce complications caused by incorrect epidural placement.

Strategic management of behavioural change in type 2 diabetic patients

OBJECTIVES

To investigate the key factors in and gap between perception and performance of daily blood glucose monitoring, regular exercise and diet control in individuals with type 2 diabetes, and to help develop patient-centric healthcare management strategies.

STUDY DESIGN

Cross-sectional study.

METHODS

A focus group interview was conducted and questionnaires were collected from outpatients with type 2 diabetes. Paired sample t-tests, importance-performance gap analysis and regression analysis were performed.

RESULTS

Perseverance was the key factor affecting blood glucose monitoring and regular exercise; the association was stronger in men than women. The critical factor in diet control was the desire to eat. Patients' perceived severity of diabetes and limited daily activities due to diabetes correlated with regular exercise, patients' compliance correlated with glucose monitoring, and perceived health status correlated with diet control.

CONCLUSIONS

The cultivation of perseverance and strengthening psychological coping is critical. Health professionals should design tailored services, avoid didactic intervention education programmes, and develop a 'meaning-centred' rather than a 'message-centred' philosophy of exercise. Such a campaign may help to improve self-management and promote health behaviours for people with type 2 diabetes.

Mosaic supernumerary r(1)(p13.2q23.3) in a 10-year-old girl with epilepsy facial asymmetry psychomotor retardation kyphoscoliosis dermatofibrosarcoma and multiple exostoses

We report molecular cytogenetic characterization of mosaic supernumerary r(1)(p13.2q23.3) in a 10-year-old girl with epilepsy, facial asymmetry, psychomotor retardation, kyphoscoliosis, dermatofibrosarcoma and multiple exostoses. The supernumerary r(1) is associated with gene dosage increase of CHRNB2, ADAR and KCNJ10 in the pericentromeric area of 1q, and a breakpoint within CTTNBP2NL at 1p13.2. We speculate that the gene dosage increase of CHRNB2, ADAR and KCNJ10 is most likely responsible for epilepsy, and the breakpoint at 1p13.2 in the supernumerary r(1) is most likely responsible for the development of multiple exostoses and osteochondroma in this patient.

A 24.2-Mb deletion of 4q12 --> q21.21 characterized by array CGH in a 131/2-year-old girl with short stature, mental retardation, developmental delay, hyperopia, exotropia, enamel defects, delayed tooth eruption and delayed puberty

We report molecular and cytogenetic characterization of proximal deletion of chromosome 4q, del(4)(q12 --> q21.21) in a 131/2-year-old girl with short stature, mental retardation, developmental delay, hyperopia, exotropia, enamel defects, delayed tooth eruption and delayed puberty. We speculate that haploinsufficiency of the AMTN, ENAM and AMBN genes is most likely responsible for dental disorders, haploinsufficiency of the BMP2K genes is most likely responsible for ocular disorders, and haploinsufficiency of the EREG, AREG and BTC genes is most likely responsible for delayed puberty in this patient.