[Predictive value of serum Gal-13, GLP-1 and VEGF levels in adverse pregnancy outcomes of gestational diabetes mellitus]

To explore the application value of serum Gal-13, GLP-1 and VEGF in the prevention and guidance of adverse pregnancy outcomes in gestational diabetes (GDM). A retrospective study with case-control method was used to select 1 012 GDM patients from Haikou Maternal and Child Health Hospital from January 2019 to December 2022 as the study objects, and they were divided into poor pregnancy outcome group (n=342) and good pregnancy outcome group (n=670) according to whether they had adverse pregnancy outcomes. The medical records of 521 healthy women with normal glucose metabolism were selected as the control group. Serum Gal-13 and GLP-1 were detected by enzyme-linked immunosorbent assay and VEGF was determined by IAMMGE specific protein analyzer. After comparing the differences of the above factors among the three groups, multivariate logistic regression model was used to analyze the influencing factors of adverse pregnancy outcomes in GDM patients, and ROC curve was drawn to analyze the predictive value of serum Gal-13, GLP-1 and VEGF levels on adverse pregnancy outcomes in GDM patients. The results showed that Fasting blood glucose (FPG), glycosylated hemoglobin (HbA1c) and fasting insulin (FINS) in the adverse pregnancy outcome group were 5.92(4.98, 6.41) mmol/L, 5.32(4.96, 5.47)%, 62.56(49.21,99.50) pmol/L, VEGF was 495.47(389.14, 567.13) ng/L, TSH was 1.48(1.34, 1.58) mIU/L, right ventricular myocardial work index (Tei index) was 0.59(0.45, 0.67), 89 cases of elderly parturients; FPG was 4.45(4.16, 5.03) mmol/L, HbA1c was 5.04(4.86, 5.29)%, FINS was 57.41(46.90, 74.08) pmol/L, VEGF was 405.84(348.02, 462.68) ng/L, TSH was 1.42(1.25, 1.50) mIU/L, Tei index was 0.50(0.47, 0.64), there were 142 cases of old women. In the control group, FPG was 4.33(4.05, 4.75) mmol/L, HbA1c was 5.01(4.13, 5.18)%, FINS was 38.48(36.76, 41.72) pmol/L and VEGF was 302.45(283.14, 336.56) ng/L, TSH was 1.32(1.24, 1.47)mIU/L, Tei index was 0.48(0.39, 0.59), and there were 106 elderly parturiencies. The levels of FPG, HbA1c, FINS, VEGF, TSH and Tei index in the adverse pregnancy outcome group and the good pregnancy outcome group were higher than those in the control group, and the proportion of elderly parturients was higher than that in the control group, and the adverse pregnancy outcome group was higher than that in the good pregnancy outcome group. The differences were statistically significant (H=8.620, P<0.001, H=2.616, P=0.014, H=6.156, P<0.001, H=3.051, P<0.001, H=4.892, P=0.044, χ2=2.548, P=0.045). In the adverse pregnancy outcome group, Gal-13 was 15.27(8.35, 24.45)pg/ml, GLP-1 was 9.27(8.26, 12.35) pmol/L and FT4 was 11.59(9.67, 13.48) pmol/L. In the group with good pregnancy outcome, Gal-13 was 25.34(20.14, 29.73) pg/ml, GLP-1 was 12.38(10.25, 15.63) pmol/L and FT4 was 13.86(10.67, 15.10) pmol/L. In the control group, Gal-13 was 31.21(27.48, 34.45) pg/ml, GLP-1 was 11.34(10.40, 14.37) pmol/L and FT4 was 14.15(10.75, 15.43)pmol/L. The levels of Gal-13, GLP-1 and FT4 in the adverse pregnancy outcome group and the good pregnancy outcome group were significantly lower than those in the control group, and the adverse pregnancy outcome group was lower than that in the good pregnancy outcome group. The differences were statistically significant (H=6.458, P=0.011, H=8.445, P<0.001, H=5.694, P<0.001). The levels of Gal-13 and GLP-1 in normal blood glucose recovery group were higher than those in non-normal blood glucose recovery group, and the levels of VEGF were lower than those in non-normal blood glucose recovery group (P<0.05).In multivariate logistic regression analysis, Gal-13, GLP-1, VEGF, TSH, FT4 and Tei indexes were independent influencing factors for adverse pregnancy outcomes with GDM (P<0.05). ROC curve analysis showed that the AUC of Gal-13, GLP-1 and VEGF alone in predicting adverse pregnancy were 0.779, 0.761 and 0.615, respectively. The value of the combined diagnosis was the highest (AUC=0.912), the sensitivity was 90.1%, and the specificity was 80.0%. In conclusion, Gal-13, GLP-1 and VEGF may be independent influencing factors for adverse pregnancy outcomes in GDM patients, and the combined detection of the three may help to improve the auxiliary diagnostic efficacy for predicting adverse pregnancy outcomes.

Retraction: Bio-inspired terpolymers containing dopamine, cations and MPC: a versatile platform to construct a recycle antibacterial and antifouling surface

Retraction of 'Bio-inspired terpolymers containing dopamine, cations and MPC: a versatile platform to construct a recycle antibacterial and antifouling surface' by B. L. Wang et al., J. Mater. Chem. B, 2015, 3, 5501-5510, https://doi.org/10.1039/C5TB00597C.

Stress induces behavioral abnormalities by increasing expression of phagocytic receptor MERTK in astrocytes to promote synapse phagocytosis

Childhood neglect and/or abuse can induce mental health conditions with unknown mechanisms. Here, we identified stress hormones as strong inducers of astrocyte-mediated synapse phagocytosis. Using in vitro, in vivo, and human brain organoid experiments, we showed that stress hormones increased the expression of the Mertk phagocytic receptor in astrocytes through glucocorticoid receptor (GR). In post-natal mice, exposure to early social deprivation (ESD) specifically activated the GR-MERTK pathway in astrocytes, but not in microglia. The excitatory post-synaptic density in cortical regions was reduced in ESD mice, and there was an increase in the astrocytic engulfment of these synapses. The loss of excitatory synapses, abnormal neuronal network activities, and behavioral abnormalities in ESD mice were largely prevented by ablating GR or MERTK in astrocytes. Our work reveals the critical roles of astrocytic GR-MERTK activation in evoking stress-induced abnormal behaviors in mice, suggesting GR-MERTK signaling as a therapeutic target for stress-induced mental health conditions.

Arginine 65 methylation of Neurogenin 3 by PRMT1 is required for pancreatic endocrine development of hESCs

Neurogenin 3 (NGN3) is a key transcription factor in the cell fate determination of endocrine progenitors (EPs) in the developing pancreas. Previous studies have shown that the stability and activity of NGN3 are regulated by phosphorylation. However, the role of NGN3 methylation is poorly understood. Here, we report that protein arginine methyltransferase-1 (PRMT1)-mediated arginine 65 methylation of NGN3 is required for the pancreatic endocrine development of human embryonic stem cells (hESCs) in vitro. We found that inducible PRMT1-knockout (P-iKO) hESCs did not differentiate from EPs into endocrine cells (ECs) in the presence of doxycycline. Loss of PRMT1 caused NGN3 accumulation in the cytoplasm of EPs and decreased the transcriptional activity of NGN3. We found that PRMT1 specifically methylates NGN3 arginine 65 and that this modification is a prerequisite for ubiquitin-mediated degradation. Our findings demonstrate that arginine 65 methylation of NGN3 is a key molecular switch in hESCs permitting their differentiation into pancreatic ECs.

Light-stimulated insulin secretion from pancreatic islet-like organoids derived from human pluripotent stem cells

Optogenetic techniques permit non-invasive, spatiotemporal, and reversible modulation of cellular activities. Here, we report a novel optogenetic regulatory system for insulin secretion in human pluripotent stem cell (hPSC)-derived pancreatic islet-like organoids using monSTIM1 (monster-opto-Stromal interaction molecule 1), an ultra-light-sensitive OptoSTIM1 variant. The monSTIM1 transgene was incorporated at the AAVS1 locus in human embryonic stem cells (hESCs) by CRISPR-Cas9-mediated genome editing. Not only were we able to elicit light-induced intracellular Ca2+ concentration ([Ca2+]i) transients from the resulting homozygous monSTIM1+/+-hESCs, but we also successfully differentiated them into pancreatic islet-like organoids (PIOs). Upon light stimulation, the β-cells in these monSTIM1+/+-PIOs displayed reversible and reproducible [Ca2+]i transient dynamics. Furthermore, in response to photoexcitation, they secreted human insulin. Light-responsive insulin secretion was similarly observed in monSTIM1+/+-PIOs produced from neonatal diabetes (ND) patient-derived induced pluripotent stem cells (iPSCs). Under LED illumination, monSTIM1+/+-PIO-transplanted diabetic mice produced human c-peptide. Collectively, we developed a cellular model for the optogenetic control of insulin secretion using hPSCs, with the potential to be applied to the amelioration of hyperglycemic disorders.

Fasudil alleviates the vascular endothelial dysfunction and several phenotypes of Fabry disease

Fabry disease (FD), a lysosomal storage disorder, is caused by defective α-galactosidase (GLA) activity, which results in the accumulation of globotriaosylceramide (Gb3) in endothelial cells and leads to life-threatening complications such as left ventricular hypertrophy (LVH), renal failure, and stroke. Enzyme replacement therapy (ERT) results in Gb3 clearance; however, because of a short half-life in the body and the high immunogenicity of FD patients, ERT has a limited therapeutic effect, particularly in patients with late-onset disease or progressive complications. Because vascular endothelial cells (VECs) derived from FD-induced pluripotent stem cells display increased thrombospondin-1 (TSP1) expression and enhanced SMAD2 signaling, we screened for chemical compounds that could downregulate TSP1 and SMAD2 signaling. Fasudil reduced the levels of p-SMAD2 and TSP1 in FD-VECs and increased the expression of angiogenic factors. Furthermore, fasudil downregulated the endothelial-to-mesenchymal transition (EndMT) and mitochondrial function of FD-VECs. Oral administration of fasudil to FD mice alleviated several FD phenotypes, including LVH, renal fibrosis, anhidrosis, and heat insensitivity. Our findings demonstrate that fasudil is a novel candidate for FD therapy.

[Observation of the efficacy of autologous mucosal transplantation to prevent esophageal stricture after near-circumferential endoscopic submucosal dissection for early esophageal cancer]

Objective: To investigate the efficacy of autologous mucosal transplantation to prevent esophageal stricture after near-circumferential endoscopic submucosal dissection (ESD) for early esophageal cancer. Methods: The case data of 33 patients, who underwent near-circumferential ESD for early esophageal cancer and were followed up regularly in the First Affiliated Hospital of Zhengzhou University from April 2017 to July 2022, were analyzed retrospectively, including 14 males and 19 females, aged (66.4±7.4) (47-77) years. According to the different treatment methods, they were divided into 4 groups: group A (6 cases) were treated with autologous mucosa transplantation and fully covered metal stent implantation, combined with oral, intravenous and local injection of hormone; Group B (8 cases) were treated with autologous mucosa transplantation and fully covered metal stent implantation; Group C (11 cases) were treated with fully covered metal stent implantation combined with oral or intravenous hormone; Group D (8 cases) were treated with fully covered metal stent implantation. After the operation, the growth of the transplanted mucosa, esophageal stricture and surgical complications were observed by endoscopy, so as to understand the efficacy of automucosa transplantation in preventing esophageal stricture after near-circumferential ESD for early esophageal cancer. Results: The gastroscopic operation was successful in 33 patients. The times of expansion in groups B, C and D were more than that in group A, and the times of expansion [M(Q₁,Q₃)] in group A were 0(0, 1.8) times, while the times of expansion in group B, C and D were 5.5(4.3, 6.8), 4.0(4.0, 7.0) and 5.5(3.5, 10.8) times, respectively, with statistical significance (all P<0.05). There was no significant difference in times of expansion among groups B, C and D (all P>0.05). The stent placement time [M(Q₁,Q₃)] in group B [7.5(6.3, 8.8) days] was shorter than that in group A [64.5(41.5, 75.5) days] (P=0.006). There was no significant difference in stent placement time between group C [38.0(28.0, 50.0) days] and group D [31.5(27.3, 66.3) days] and group A (both P>0.05). The stent placement time in group C was longer than that in group B (P<0.05).There was no significant difference in stent placement time between group B, C and D (all P>0.05). There was no significant difference in the incidence of complications among the groups (all P>0.05). Conclusions: Autologous mucosal transplantation is safe and effective in preventing stenosis after near-circumferential ESD for early esophageal cancer. The effect of autologous mucosal transplantation combined with fully covered metal stent placement, systemic and local steroid application in preventing esophageal stricture after near-circumferential ESD for early esophageal cancer is better than that of single application.

ECM Architecture-Mediated Regulation of β-Cell Differentiation from hESCs via Hippo-Independent YAP Activation

Changes in the extracellular matrix (ECM) influence stem cell fate. When hESCs were differentiated on a thin layer of Matrigel coated onto PDMS (Matrigel__PDMS), they exhibited a substantial increase in focal adhesion and focal adhesion-associated proteins compared with those cultured on Matrigel coated onto TCPS (Matrigel__TCPS), resulting in YAP/TEF1 activation and ultimately promoting the transcriptional activities of pancreatic endoderm (PE)-associated genes. Interestingly, YAP activation in PE cells was mediated through integrin α3-FAK-CDC42-PP1A signaling rather than the typical Hippo signaling pathway. Furthermore, pancreatic islet-like organoids (PIOs) generated on Matrigel__PDMS secreted more insulin than those generated from Matrigel__TCPS. Electron micrographs revealed differential Matrigel architectures depending on the underlying substrate, resulting in varying cell-matrix anchorage resistance levels. Accordingly, the high apparent stiffness of the unique mucus-like network structure of Matrigel__PDMS was the critical factor that directly upregulated focal adhesion, thereby leading to better maturation of the pancreatic development of hESCs in vitro.

Generation of a CRISPR/Cas9-corrected-hiPSC line (DDLABi001-A) from Fabry disease (FD)-derived iPSCs having α-galactosidase (GLA) gene mutation (c.803_806del)

Fabry disease (FD) is a lysosomal storage disorder caused by mutations in GLA gene. Here, GLA mutation (1268fs*1 (c.803_806del)) of FD iPSCs was corrected using the CRISPR-Cas9 gene editing system. The corrected (cor) FD-iPSCs retained normal morphology, karyotype, expression of pluripotency-associated markers, trilineage differentiation potential, and GLA activity. Thus, FD(cor)-iPSCs can be used as valuable tools to study the mechanism how GLA mutation^1268fs*1 induces various pathophysiologic phenotypes in FD patients.

[The mid-term effect of corneal collagen cross-linking for progressive keratoconus and the changes in rigid gas permeable contact lens fitting parameters]

Objective: To investigate the effect of corneal collagen cross-linking (CXL) for progressive keratoconus and to evaluate changes in the parameters of rigid gas permeable contact lens (RGPCL) fitting after surgery. Methods: It was a prospective cohort study. Fifty-three eyes of 41 keratoconus patients received accelerated CXL in Qingdao Eye Hospital of Shandong First Medical University from May to December 2018. There were 31 males and 10 females, aged (20.46±4.15) years. According to the corneal thickness, de-epithelial CXL (33 eyes) or trans-epithelial CXL (20 eyes) was performed. The best spectacle-corrected visual acuity, refractive power and the thinnest corneal thickness at baseline and at 6 weeks were compared. Corneal topography was performed at baseline and at 6 weeks, 3, 6 and 12 months postoperatively. Rose K RGPCLs were used before and 6 weeks after surgery, and the fitting status was monitored until 12 months after surgery. The t test was performed to analyze the difference before and after the operation. Results: The best spectacle-corrected visual acuity, refractive power, and the thinnest corneal thickness were not significantly changed over 6 weeks of follow-up, but the Kf, Ks and Kmax values were significantly increased in all patients (all P<0.05). In the de-epithelial group, the Kmax values before the operation, at 3, 6 and 12 months after the operation were (55.00±5.51) diopters (D), (54.73±5.34) D, (54.58±6.15) D and (54.20±5.49) D, respectively, and the decrease at 12 months was significant [(0.80±2.05) D; t=2.25, P=0.001]. In the trans-epithelial group, the Kmax values were (59.43±8.98) D, (57.97±8.79) D, (58.19±8.37) D and (56.94±7.19) D at the four time points, respectively, and the decreases at 3, 6 and 12 months were all significant [(1.46±2.09) D, (1.25±1.82) D, (2.49±3.64) D; t=3.12, 3.06, 3.50; P=0.006, 0.006, 0.007]. The best RGPCL-corrected visual acuity, the diameter and the average diopters of RGPCLs showed no significant change in both groups. The RGPCL base curve decreased by 0.07 mm in the de-epithelial group and by 0.13 mm in the trans-epithelial group (both P<0.05). The design of edge lifting was used in 10 eyes postoperatively in the de-epithelial group compared with 8 eyes preoperatively, and in 4 eyes postopratively in the trans-epithelial group compared with 7 eyes preoperatively. The number of eyes using the toric peripheral design of the lens was increased to 3 compared with 2 preoperatively in the de-epithelial group and from 1 to 4 in the trans-epithelial group. The acceptance rate of RGPCL fitting in both groups increased at 6 and 12 months after surgery compared to 6 weeks after surgery. Conclusions: The corneal curvature became steep slightly at 6 weeks after CXL and gradually recovered and flattened. The Kmax in the trans-epithelial group decreased earlier and more than that in the de-epithelial group. The base curve of the RGPCLs was slightly reduced after 6 weeks, and the toric peripheral design was increasingly needed, but the requirement for the design of the lifted edge was different between the two groups. A good RGPCL fitting can be achieved within 1 year after CXL.

Association between ARID2 and RAS-MAPK pathway in intellectual disability and short stature

BACKGROUND

ARID2 belongs to the Switch/sucrose non-fermenting complex, in which the genetic defects have been found in patients with dysmorphism, short stature and intellectual disability (ID). As the phenotypes of patients with ARID2 mutations partially overlap with those of RASopathy, this study evaluated the biochemical association between ARID2 and RAS-MAPK pathway.

METHODS

The phenotypes of 22 patients with either an ARID2 heterozygous mutation or haploinsufficiency were reviewed. Comprehensive molecular analyses were performed using somatic and induced pluripotent stem cells (iPSCs) of a patient with ARID2 haploinsufficiency as well as using the mouse model of Arid2 haploinsufficiency by CRISPR/Cas9 gene editing.

RESULTS

The phenotypic characteristics of ARID2 deficiency include RASopathy, Coffin-Lowy syndrome or Coffin-Siris syndrome or undefined syndromic ID. Transient ARID2 knockout HeLa cells using an shRNA increased ERK1 and ERK2 phosphorylation. Impaired neuronal differentiation with enhanced RAS-MAPK activity was observed in patient-iPSCs. In addition, Arid2 haploinsufficient mice exhibited reduced body size and learning/memory deficit. ARID2 haploinsufficiency was associated with reduced IFITM1 expression, which interacts with caveolin-1 (CAV-1) and inhibits ERK activation.

DISCUSSION

ARID2 haploinsufficiency is associated with enhanced RAS-MAPK activity, leading to reduced IFITM1 and CAV-1 expression, thereby increasing ERK activity. This altered interaction might lead to abnormal neuronal development and a short stature.

Graphene Nanocoating: High Quality and Stability upon Several Stressors

Titanium implants present 2 major drawbacks-namely, the long time needed for osseointegration and the lack of inherent antimicrobial properties. Surface modifications and coatings to improve biomaterials can lose their integrity and biological potential when exposed to stressful microenvironments. Graphene nanocoating (GN) can be deposited onto actual-size dental and orthopedic implants. It has antiadhesive properties and can enhance bone formation in vivo. However, its ability to maintain structural integrity and quality when challenged by biologically relevant stresses remains largely unknown. GN was produced by chemical vapor deposition and transferred to titanium via a polymer-assisted transfer technique. GN has high inertness and did not increase expression of inflammatory markers by macrophages, even in the presence of lipopolysaccharides. It kept high coverage at the top tercile of tapered dental implant collars after installation and removal from bone substitute and pig maxilla. It also resisted microbiologically influenced corrosion, and it maintained very high coverage area and quality after prolonged exposure to biofilms and their removal by different techniques. Our findings show that GN is unresponsive to harsh and inflammatory environments and that it maintains a promising level of structural integrity on the top tercile of dental implant collars, which is the area highly affected by biofilms during the onset of implant diseases. Our findings open the avenues for the clinical studies required for the use of GN in the development of implants that have higher osteogenic potential and are less prone to implant diseases.

Dysregulated ECM remodeling proteins lead to aberrant osteogenesis of Costello syndrome iPSCs

Costello syndrome (CS) is an autosomal dominant disorder caused by mutations in HRAS. Although CS patients have skeletal abnormalities, the role of mutated HRAS in bone development remains unclear. Here, we use CS induced pluripotent stem cells (iPSCs) undergoing osteogenic differentiation to investigate how dysregulation of extracellular matrix (ECM) remodeling proteins contributes to impaired osteogenesis. Although CS patient-derived iPSCs develop normally to produce mesenchymal stem cells (MSCs), the resulting CS MSCs show defective osteogenesis with reduced alkaline phosphatase activity and lower levels of bone mineralization. We found that hyperactivation of SMAD3 signaling during the osteogenic differentiation of CS MSCs leads to aberrant expression of ECM remodeling proteins such as MMP13, TIMP1, and TIMP2. CS MSCs undergoing osteogenic differentiation also show reduced β-catenin signaling. Knockdown of TIMPs permits normal differentiation of CS MSCs into osteoblasts and enhances β-catenin signaling in a RUNX2-independent manner. Thus, this study demonstrates that enhanced TIMP expression induced by hyperactivated SMAD3 signaling impairs the osteogenic development of CS MSCs via an inactivation of β-catenin signaling.

SHP2 mutations induce precocious gliogenesis of Noonan syndrome-derived iPSCs during neural development in vitro

Background

Noonan syndrome (NS) is a developmental disorder caused by mutations of Src homology 2 domain-containing protein tyrosine phosphatase 2 (SHP2). Although NS patients have diverse neurological manifestations, the mechanisms underlying the involvement of SHP2 mutations in neurological dysfunction remain elusive.

Methods

Induced pluripotent stem cells generated from dermal fibroblasts of three NS-patients (NS-iPSCs) differentiated to the neural cells by using two different culture systems, 2D- and 3D-cultured systems in vitro.

Results

Here we represent that SHP2 mutations cause aberrant neural development. The NS-iPSCs exhibited impaired development of EBs in which BMP and TGF-β signalings were activated. Defective early neuroectodermal development of NS-iPSCs recovered by inhibition of both signalings and further differentiated into NPCs. Intriguingly, neural cells developed from NS-NPCs exhibited abundancy of the glial cells, neurites of neuronal cells, and low electrophysiological property. Those aberrant phenotypes were also detected in NS-cerebral organoids. SHP2 inhibition in the NS-NPCs and NS-cerebral organoids ameliorated those anomalies such as biased glial differentiation and low neural activity.

Conclusion

Our findings demonstrate that SHP2 mutations contribute to precocious gliogenesis in NS-iPSCs during neural development in vitro.

Clinical significance of perioperative EMT-CTC in rectal cancer patients receiving open/laparoscopic surgery

The objective of this study was to explore the clinical significance of perioperative CTCs (circulating tumor cells) counts and EMT-CTCs (epithelial-mesenchymal transition-CTCs) in rectal cancer patients. A total of 30 patients with rectal cancer who underwent radical resection of rectal cancer at the Guangxi Zhuang Autonomous Region People's hospital were enrolled. Five ml peripheral blood was withdrawn from 30 patients with rectal cancer before the operation and seven days after the operation and at the corresponding time also from 20 healthy volunteers. CanPatrol™ CTC detection technique was used to enrich and identify CTCs and IER3 expression simultaneously. We found out that the preoperative total CTCs were correlated with lymph node metastasis (p=0.008) and tumor size, and mixed CTCs were closely correlated with lymph node metastasis (p=0.009). The number of IER3-positive total CTCs and mesenchymal CTCs were statistically associated with tumor size, p=0.034 and 0.043, respectively. The number of CTCs varied significantly before and after the operation in all patients (p=0.049). There were significant differences in CTCs variations between the open operation group and the laparoscopic operation group. In the laparoscopic operation group, the average number of single-cell CTCs was 6.9 before operation and 3.5 after the operation (p=0.013). In the open operation group, the average number of single-cell CTCs was 5.9 before operation and 4.2 after the operation. To conclude, surgery is associated with a decrease of CTCs in rectal cancer patients, especially in patients receiving laparoscopic surgery. The number of CTCs before the operation in rectal cancer patients is related to the size of tumors and regional lymph node metastasis. CTCs detection and characterization may be useful for clinical staging and lymph node dissection during operation.

Enhanced thrombospondin-1 causes dysfunction of vascular endothelial cells derived from Fabry disease-induced pluripotent stem cells

BACKGROUND

Fabry disease (FD) is a recessive X-linked lysosomal storage disorder caused by α-galactosidase A (GLA) deficiency. Although the mechanism is unclear, GLA deficiency causes an accumulation of globotriaosylceramide (Gb3), leading to vasculopathy.

METHODS

To explore the relationship between the accumulation of Gb3 and vasculopathy, induced pluripotent stem cells generated from four Fabry patients (FD-iPSCs) were differentiated into vascular endothelial cells (VECs). Genome editing using CRISPR-Cas9 system was carried out to correct the GLA mutation or to delete Thrombospondin-1 (TSP-1). Global transcriptomes were compared between wild-type (WT)- and FD-VECs by RNA-sequencing analysis.

FINDINGS

Here, we report that overexpression of TSP-1 contributes to the dysfunction of VECs in FD. VECs originating from FD-iPSCs (FD-VECs) showed aberrant angiogenic functionality even upon treatment with recombinant α-galactosidase. Intriguingly, FD-VECs produced more p-SMAD2 and TSP-1 than WT-VECs. We also found elevated TSP-1 in the peritubular capillaries of renal tissues biopsied from FD patients. Inhibition of SMAD2 signaling or knock out of TSP-1 (TSP-1-/-) rescues normal vascular functionality in FD-VECs, like in gene-corrected FD-VECs. In addition, the enhanced oxygen consumption rate is reduced in TSP-1-/- FD-VECs.

INTERPRETATION

The overexpression of TSP-1 secondary to Gb3 accumulation is primarily responsible for the observed FD-VEC dysfunction. Our findings implicate dysfunctional VEC angiogenesis in the peritubular capillaries in some of the complications of Fabry disease.

FUNDING

This study was supported by grant 2018M3A9H1078330 from the National Research Foundation of the Republic of Korea.

Inhibiting Corrosion of Biomedical-Grade Ti-6Al-4V Alloys with Graphene Nanocoating

The identification of metal ions and particles in the vicinity of failed implants has raised the concern that biomedical titanium alloys undergo corrosion in healthy and infected tissues. Various surface modifications and coatings have been investigated to prevent the deterioration and biocorrosion of titanium alloys but so far with limited success. Graphene is a cytocompatible atom-thick film made of carbon atoms. It has a very high surface area and can be deposited onto metal objects with complex shapes. As the carbon lattice has a very small pore size, graphene has promising impermeability capacity. Here, we show that graphene coating can effectively protect Ti-6Al-4V from corrosion. Graphene nanocoatings were produced on Ti-6Al-4V grade 5 and 23 discs and subjected to corrosive challenge (0.5M NaCl supplemented with 2-ppm fluoride, pH of 2.0) up to 30 d. The linear polarization resistance curves and electrochemical impedance spectroscopy analysis showed that the graphene-coated samples presented higher corrosion resistance and electrochemical stability at all time points. Moreover, the corrosion rate of the graphene-coated samples was very low and stable (~0.001 mm/y), whereas that of the uncoated controls increased up to 16 and 5 times for grade 5 and 23 (~0.091 mm/y) at the end point, respectively. The surface oxidation, degradation (e.g., crevice defects), and leaching of Ti, Al, and V ions observed in the uncoated controls were prevented by the graphene nanocoating. The Raman mappings confirmed that the graphene nanocoating presented high structural stability and resistance to mechanical stresses and chemical degradation, keeping >99% of coverage after corrosion challenge. Our findings open the avenues for the use of graphene as anticorrosion coatings for metal biomedical alloys and implantable devices.

Dietary threonine prevented stress-related mucosal diseases in rats

Stress-related mucosal disease (SRMD), or stress ulceration, is a group of conditions ranging from stress-related superficial gastric mucosal damage to deep gastric ulcers that are primarily correlated with mucosal ischemia, and pharmacologic interventions that optimize tissue perfusion or preserve defensive mucus aim to decrease the occurrence of conditions, such as gastric acidity, or enhance gastric defenses. However, the identification of multifactorial pathogenesis may be effective in preventing SMRD, and the use of stress prophylaxis is generally preferred. Since threonine is a component in the polymerization and synthesis of gastric mucin and possibly enhanced defense actions and lignin may provide structural support for defense and antioxidative function, we hypothesized that dietary intake of threonine and/or lignin can enhance defense against SRMD. The water immersion-restraint stress (WIRS) was used in rats and additional groups were pretreated with threonine alone or the combination of threonine and lignin. Based on gross and microscopic evaluations, threonine alone or the combination of threonine and lignin, a natural antioxidant, significantly reduced the development of SRMD (P < 0.05). According to molecular explorations, the levels of inflammatory mediators, such as interleukin (IL)-8, IL-6, IL-1β, inducible nitric oxide synthase (iNOS), tumor necrosis factor alpha (TNF-α), and interferon gamma (IFN-γ), all of which are mediators that play a significant role in controlling WIRS, significantly decreased in the groups pretreated with either threonine alone or the combination of threonine and lignin (P < 0.01). WIRS significantly increased apoptosis in the stomach. However, the apoptotic index significantly decreased with threonine pretreatment. According to periodic acid Schiff staining results, the expression of gastric mucin was significantly preserved in groups pretreated with threonine but remarkedly decreased in the WIRS group. The gastric heme oxygenase-1 levels significantly increased in the group treated with threonine. In conclusion, the dietary intake of threonine or the combination of threonine and lignin is effective in preventing SRMD.

Host nuclear factor erythroid 2-related factor-2 defense system determines the outcome of dextran sulfate sodium-induced colitis in mice

Administration of dextran sulfate sodium (DSS) in drinking water led to significant bout of colitis simulating ulcerative colitis of human. However, colitis usually developed 5 - 7 days after DSS administration. Therefore, we hypothesized host defense system might protect colitis up to 5 days of DSS administration. 2.5% DSS-induced colitis were administered to C57BL/6 mice and sequential measurements of pathology, cyclooxygenase-2 (COX-2), nuclear factor-κB (NF-κB), heme oxygenase-1 (HO-1), NADPH quinone oxidoreductase-1 (NQO1), γ-glutamylcysteine synthetase (γ-GCS), nuclear factor erythroid 2-related factor-2 (Nrf2), and keap1 were done at 2, 6, 12, 24, 48, 96, 120, and 168 hour of DSS administration, respectively. DSS-induced colitis was repeated in either COX-2^-/- or Nrf2^-/- mice. On serial pathological analysis, significant colitis was noted after 120 h of DSS administration, during which both activations of COX-2/NF-κB and HO-1/Nrf2 were noted. Nrf2 activations after keap1 inactivation led to significant increases in HO-1 after 168 hours of DSS administration, when NF-κB nuclear translocation was noted. Significantly attenuated colitis was noted in DSS-challenged COX-2^-/- mice, in which the levels of HO-1 were significantly decreased compared to DSS-challenged WT littermates (p < 0.01), while the levels of NQO1 were significantly increased. On DSS administration to Nrf2^-/- mice, colitis was significantly aggravated (p < 0.01), in which the expressions of COX-2 as well as expressions of HO-1 and γ-GCS were significantly increased (p < 0.01). Reciprocal activations of inflammatory and antioxidative defense signaling after DSS administration might be prerequisite to make intestinal homeostasis and host defense Nrf2 system can determine colitis.

Prediction of drug-induced immune-mediated hepatotoxicity using hepatocyte-like cells derived from human embryonic stem cells

Drug-induced liver injury (DILI) is a leading cause of liver disease and a key safety factor during drug development. In addition to the initiation events of drug-specific hepatotoxicity, dysregulated immune responses have been proposed as major pathological events of DILI. Thus, there is a need for a reliable cell culture model with which to assess drug-induced immune reactions to predict hepatotoxicity for drug development. To this end, stem cell-derived hepatocytes have shown great potentials. Here we report that hepatocyte-like cells derived from human embryonic stem cells (hES-HLCs) can be used to evaluate drug-induced hepatotoxic immunological events. Treatment with acetaminophen significantly elevated the levels of inflammatory cytokines by hES-HLCs. Moreover, three human immune cell lines, Jurkat, THP-1, and NK92MI, were activated when cultured in conditioned medium obtained from acetaminophen-treated hES-HLCs. To further validate, we tested thiazolidinedione (TZD) class, antidiabetic drugs, including troglitazone withdrawn from the market because of severe idiosyncratic drug hepatotoxicity. We found that TZD drug treatment to hES-HLCs resulted in the production of pro-inflammatory cytokines and eventually associated immune cell activation. In summary, our study demonstrates for the first time the potential of hES-HLCs as an in vitro model system for assessment of drug-induced as well as immune-mediated hepatotoxicity.

Lineage-specific Expression of miR-200 Family in Human Embryonic Stem Cells during In Vitro Differentiation

Although microRNAs have emerged as key regulators in diverse cellular processes, the roles of microRNAs are poorly understood in human embryonic stem cells (hESCs) during differentiation into specialized cell types. In this study, we used a microRNA array with 799 human microRNA probes to examine the expression profiles of microRNAs in hESCs during differentiation into endodermal and mesodermal lineages in vitro. Among the microRNAs analyzed, 7 and 20 microRNAs were enriched in the developmental process of hESCs into mesodermal and endodermal lineages, respectively. In particular, the expression levels of miR-200 family, which is known to regulate the epithelial to mesenchymal transition (EMT), gradually increased in hESCs during differentiation into hepatocytes while they gradually decreased during differentiation into vascular endothelial cells. Downregulation of ZEB1, a direct target of miR-200 family, and E-CADHERIN, a target protein of ZEB1, was observed in hESCs during differentiation into endodermal and mesodermal lineages, respectively. These results indicate that miR-200 family has an important role in determining the cell fate between endodermal and mesodermal lineages from the pluripotent state.

Exosome-mediated activation of toll-like receptor 3 in stellate cells stimulates interleukin-17 production by γδ T cells in liver fibrosis

During liver injury, hepatocytes secrete exosomes that include diverse types of self-RNAs. Recently, self-noncoding RNA has been recognized as an activator of Toll-like receptor 3 (TLR3). However, the roles of hepatic exosomes and TLR3 in liver fibrosis are not yet fully understood. Following acute liver injury and early-stage liver fibrosis induced by a single or 2-week injection of carbon tetrachloride (CCl4 ), increased interleukin (IL)-17A production was detected primarily in hepatic γδ T cells in wild-type (WT) mice. However, liver fibrosis and IL-17A production by γδ T cells were both significantly attenuated in TLR3 knockout (KO) mice compared with WT mice. More interestingly, IL-17A-producing γδ T cells were in close contact with activated hepatic stellate cells (HSCs), suggesting a role for HSCs in IL-17A production by γδ T cells. In vitro treatments with exosomes derived from CCl4 -treated hepatocytes significantly increased the expression of IL-17A, IL-1β, and IL-23 in WT HSCs but not in TLR3 KO HSCs. Furthermore, IL-17A production by γδ T cells was substantially increased upon coculturing with exosome-treated WT HSCs or conditioned medium from TLR3-activated WT HSCs. However, similar increases were not detected when γδ T cells were cocultured with exosome-treated HSCs from IL-17A KO or TLR3 KO mice. Using reciprocal bone marrow transplantation between WT and TLR3 KO mice, we found that TLR3 deficiency in HSCs contributed to decreased IL-17A production by γδ T cells, as well as liver fibrosis.

CONCLUSION

In liver injury, the exosome-mediated activation of TLR3 in HSCs exacerbates liver fibrosis by enhancing IL-17A production by γδ T cells, which might be associated with HSC stimulation by unknown self-TLR3 ligands from damaged hepatocytes. Therefore, TLR3 might be a novel therapeutic target for liver fibrosis. (Hepatology 2016;64:616-631).

Malfunction in Mitochondrial β-Oxidation Contributes to Lipid Accumulation in Hepatocyte-Like Cells Derived from Citrin Deficiency-Induced Pluripotent Stem Cells

Citrin deficiency (CD) is a recessive genetic disorder caused by mutations in the citrin gene SLC25A13. CD causes various symptoms related to nutrient metabolism such as urea cycle failure, abnormal amino acid levels, and fatty liver. To understand the pathophysiology of CD, the molecular phenotypes were investigated using induced pluripotent stem cells derived from fibroblasts of CD patient (CD-iPSCs). In this study, we demonstrate that aberrant mitochondrial β-oxidation may lead to fatty liver in CD patients. CD-iPSCs normally differentiated into hepatocytes, similar to wild-type iPSCs (WT-iPSCs). However, hepatocytes derived from CD-iPSCs (CD-HLCs) did not exhibit ureogenesis. Cellular triglyceride and lipid granule levels were significantly increased in CD-HLCs compared with WT-HLCs. Peroxisome proliferator-activated receptor-α (PPAR-α) and its target genes which are involved in mitochondrial β-oxidation were downregulated in CD-HLCs, and treatment with a PPAR-α agonist partially reduced the lipid accumulation in CD-HLCs. In addition, the mitochondria in CD-HLCs exhibited abnormal morphologies. Based on these observations, we conclude that the lipid accumulation in CD-HLCs results from dysfunctional mitochondrial β-oxidation and abnormal mitochondrial structure.

Enhanced SMAD1 Signaling Contributes to Impairments of Early Development in CFC-iPSCs

Cardio-facio-cutaneous (CFC) syndrome is a developmental disorder caused by constitutively active ERK signaling manifesting mainly from BRAF mutations. Little is known about the role of elevated ERK signaling in CFC syndrome during early development. Here, we show that both SMAD1 and ERK signaling pathways may contribute to the developmental defects in CFC syndrome. Induced pluripotent stem cells (iPSCs) derived from dermal fibroblasts of a CFC syndrome patient (CFC-iPSCs) revealed early developmental defects in embryoid body (EB) development, β-catenin localization, and neuronal differentiation. Both SMAD1 and ERK signalings were significantly activated in CFC-iPSCs during EB formation. Most of the β-catenin was dissociated from the membrane and preferentially localized into the nucleus in CFC-EBs. Furthermore, activation of SMAD1 signaling recapitulated early developmental defects in wild-type iPSCs. Intriguingly, inhibition of SMAD1 signaling in CFC-iPSCs rescued aberrant EB morphology, impaired neuronal differentiation, and altered β-catenin localization. These results suggest that SMAD1 signaling may be a key pathway contributing the pathogenesis of CFC syndrome during early development.

Reconstruction of atmospheric soot history in inland regions from lake sediments over the past 150 years

Historical reconstruction of atmospheric black carbon (BC, in the form of char and soot) is still constrained for inland areas. Here we determined and compared the past 150-yr records of BC and polycyclic aromatic compounds (PACs) in sediments from two representative lakes, Huguangyan (HGY) and Chaohu (CH), in eastern China. HGY only receives atmospheric deposition while CH is influenced by riverine input. BC, char, and soot have similar vertical concentration profiles as PACs in both lakes. Abrupt increases in concentrations and mass accumulation rates (MARs) of soot have mainly occurred since ~1950, the establishment of the People’s Republic of China, when energy usage changed to more fossil fuel contributions reflected by the variations in the concentration ratios of char/soot and individual PACs. In HGY, soot MARs increased by ~7.7 times in the period 1980–2012 relative to the period 1850–1950. Similar increases (~6.7 times) were observed in CH. The increase in soot MARs is also in line with the emission inventory records in the literature and the fact that the submicrometer-sized soot particles can be dispersed regionally. The study provides an alternative method to reconstruct the atmospheric soot history in populated inland areas.

The expression of osteopontin in breast cancer tissue and its relationship with p21ras and CD44V6 expression

OBJECTIVE

This study aimed to investigate the expression of osteopontin (OPN), p2lras, and CD44V6 in breast cancer tissues, and to analyze the relationships between their expression and a patient's clinicopathological characteristics and five-year survival rate.

MATERIALS AND METHODS

Streptavidin-peroxidase immunohistochemistry was used to detect the expression of OPN, p2lras, and CD44V6 in tissue samples from 96 breast cancer patients, and the multivariate Cox proportional hazards model (mCOX-PHM) was used to analyze the factors that affect prognosis.

RESULTS

Among the 96 breast cancer patients studied, positive staining for OPN, CD44V6, and p21ras was observed in 54.2%, 58.3%, and 43.8% of samples, respectively. The expression of OPN and CD44V6 were positively correlated (r = 0.58), and the expression of OPN and p21ras were also positively correlated (r = 0.25). Coexpression OPN, CD44V6, and p21ras was negatively correlated with a patient's five-year survival rate (p < 0.05). Kaplan-Meier analysis indicated that a patient without OPN, CD44V6, or p21ras expression had an improved survival (p < 0.05). Results from the mCOX-PHM analysis indicated that CD44V6 expression, the degree of tumor differentiation, and lymph node metastasis were all independent factors that indicate prognosis. The combined detection of OPN, CD44V6, and p21ras could contribute to a more accurate assessment of the biological behavior of breast cancers, and could help to indicate the prognosis of breast cancer patients.

Mitochondrial Respiratory Defect Causes Dysfunctional Lactate Turnover via AMP-activated Protein Kinase Activation in Human-induced Pluripotent Stem Cell-derived Hepatocytes

A defective mitochondrial respiratory chain complex (DMRC) causes various metabolic disorders in humans. However, the pathophysiology of DMRC in the liver remains unclear. To understand DMRC pathophysiology in vitro, DMRC-induced pluripotent stem cells were generated from dermal fibroblasts of a DMRC patient who had a homoplasmic mutation (m.3398T→C) in the mitochondrion-encoded NADH dehydrogenase 1 (MTND1) gene and that differentiated into hepatocytes (DMRC hepatocytes) in vitro. DMRC hepatocytes showed abnormalities in mitochondrial characteristics, the NAD(+)/NADH ratio, the glycogen storage level, the lactate turnover rate, and AMPK activity. Intriguingly, low glycogen storage and transcription of lactate turnover-related genes in DMRC hepatocytes were recovered by inhibition of AMPK activity. Thus, AMPK activation led to metabolic changes in terms of glycogen storage and lactate turnover in DMRC hepatocytes. These data demonstrate for the first time that energy depletion may lead to lactic acidosis in the DMRC patient by reduction of lactate uptake via AMPK in liver.

Impaired osteogenesis in Menkes disease-derived induced pluripotent stem cells

Introduction

Bone abnormalities, one of the primary manifestations of Menkes disease (MD), include a weakened bone matrix and low mineral density. However, the molecular and cellular mechanisms underlying these bone defects are poorly understood.

Methods

We present in vitro modeling for impaired osteogenesis in MD using human induced pluripotent stem cells (iPSCs) with a mutated ATP7A gene. MD-iPSC lines were generated from two patients harboring different mutations.

Results

The MD-iPSCs showed a remarkable retardation in CD105 expression with morphological anomalies during development to mesenchymal stem cells (MSCs) compared with wild-type (WT)-iPSCs. Interestingly, although prolonged culture enhanced CD105 expression, mature MD-MSCs presented with low alkaline phosphatase activity, reduced calcium deposition in the extracellular matrix, and downregulated osteoblast-specific genes during osteoblast differentiation in vitro. Knockdown of ATP7A also impaired osteogenesis in WT-MSCs. Lysyl oxidase activity was also decreased in MD-MSCs during osteoblast differentiation.

Conclusions

Our findings indicate that ATP7A dysfunction contributes to retardation in MSC development and impairs osteogenesis in MD.

Electronic supplementary material

The online version of this article (doi:10.1186/s13287-015-0147-5) contains supplementary material, which is available to authorized users.

SET7/9 methylation of the pluripotency factor LIN28A is a nucleolar localization mechanism that blocks let-7 biogenesis in human ESCs

LIN28-mediated processing of the microRNA (miRNA) let-7 has emerged as a multilevel program that controls self-renewal in embryonic stem cells. LIN28A is believed to act primarily in the cytoplasm together with TUT4/7 to prevent final maturation of let-7 by Dicer, whereas LIN28B has been suggested to preferentially act on nuclear processing of let-7. Here, we find that SET7/9 monomethylation in a putative nucleolar localization region of LIN28A increases its nuclear retention and protein stability. In the nucleoli of human embryonic stem cells, methylated LIN28A sequesters pri-let-7 and blocks its processing independently of TUT4/7. The nuclear form of LIN28A regulates transcriptional changes in MYC-pathway targets, thereby maintaining stemness programs and inhibiting expression of early lineage-specific markers. These findings provide insight into the molecular mechanism underlying the posttranslational methylation of nuclear LIN28A and its ability to modulate pluripotency by repressing let-7 miRNA expression in human embryonic stem cells.

Bio-inspired terpolymers containing dopamine, cations and MPC: a versatile platform to construct a recycle antibacterial and antifouling surface

A new kind of bio-inspired terpolymer was synthesized by a conventional free radical terpolymerization of dopamine methacrylamide (DMA), 2-(dimethylamino)-ethyl methacrylate (DMAEMA) and 2-methacryloyloxyethyl phosphorylcholine (MPC) with azobisisobutyronitrile (AIBN) as an initiator. DMA consists of a biomimetic adhesive side chain covalently linked to a polymerizable methacrylate monomer. 1H NMR and gel permeation chromatography confirmed the successful synthesis of P(DMA-co-MPC-co-DMAEMA). The terpolymer could self-assemble on the macroscopic planar substrates with DMA as an anchor. After being quaternized by 1-bromo-heptane, terpolymers of P(DMA-co-MPC-co-DMAEMA+) with bactericidal function were obtained. The self-assembly terpolymer on the substrate was confirmed by X-ray photoelectron spectroscopy, water contact angle, spectroscopic ellipsometry and atomic force microscopy. The hydrophilicity and antifouling properties of the self-assembly coating increased greatly against bacteria, protein and cells with the increase of MPC content. As the existence of bactericidal cations for electrostatic targeting of bacteria as well as membrane lysis, the terpolymer coating showed excellent bactericidal function against E. coli and S. aureus. Biofilm inhibition assay showed that terpolymer coating was very efficient to resist bacterial adhesion and biofilm formation in a nutrient environment. Bacteria could be continuously "captured" and killed by the terpolymer coating, and then bacteria corpse was released into the solution. Importantly, this work provides a versatile strategy for the fabrication of a recycle antibacterial and antifouling surface to modify biomaterials.

Differences in the Epigenetic Regulation of Cytochrome P450 Genes between Human Embryonic Stem Cell-Derived Hepatocytes and Primary Hepatocytes

Human pluripotent stem cell-derived hepatocytes have the potential to provide in vitro model systems for drug discovery and hepatotoxicity testing. However, these cells are currently unsuitable for drug toxicity and efficacy testing because of their limited expression of genes encoding drug-metabolizing enzymes, especially cytochrome P450 (CYP) enzymes. Transcript levels of major CYP genes were much lower in human embryonic stem cell-derived hepatocytes (hESC-Hep) than in human primary hepatocytes (hPH). To verify the mechanism underlying this reduced expression of CYP genes, including CYP1A1, CYP1A2, CYP1B1, CYP2D6, and CYP2E1, we investigated their epigenetic regulation in terms of DNA methylation and histone modifications in hESC-Hep and hPH. CpG islands of CYP genes were hypermethylated in hESC-Hep, whereas they had an open chromatin structure, as represented by hypomethylation of CpG sites and permissive histone modifications, in hPH. Inhibition of DNA methyltransferases (DNMTs) during hepatic maturation induced demethylation of the CpG sites of CYP1A1 and CYP1A2, leading to the up-regulation of their transcription. Combinatorial inhibition of DNMTs and histone deacetylases (HDACs) increased the transcript levels of CYP1A1, CYP1A2, CYP1B1, and CYP2D6. Our findings suggest that limited expression of CYP genes in hESC-Hep is modulated by epigenetic regulatory factors such as DNMTs and HDACs.

Elemental carbon and polycyclic aromatic compounds in a 150-year sediment core from Lake Qinghai, Tibetan Plateau, China: influence of regional and local sources and transport pathways

Elemental carbon (EC) and polycyclic aromatic compounds (PACs) are potential proxies for the reconstruction of change in human activities and the origin of air masses in historic times. In this study, the historic deposition of char and soot (the two subtypes of EC) and PACs in a 150-year sediment core from different topographic subbasins of Lake Qinghai on the Qinghai Tibetan Plateau (QTP) were reconstructed. The objective was to explore how the variations in the concentrations of EC and PACs, in the ratios of char to soot and of oxygenated polycyclic aromatic hydrocarbons (OPAHs) to parent PAHs, and in the composition of the PAC mixtures reflect historical changes in climate and human activity and the origin of air masses arriving at the QTP. The deposition fluxes of soot in the different subbasins were similar, averaging 0.18 (range of 0.15-0.25) and 0.16 (0.13-0.23) g m(-2) year(-1), respectively, but they varied for char (averaging 0.11 and 0.22 g m(-2) year(-1), respectively), suggesting ubiquitous atmospheric deposition of soot and local river inputs of char. The different vertical distributions of the char/soot ratios in the different subbasins can be interpreted in terms of the different transport mechanisms of char and soot. An abrupt increase in soot concentrations since 1980 coincides with results from the QTP ice cores that were interpreted to be indicative of soot transport from South Asia. Similar concentration patterns of PAHs with soot and 9,10-anthraquinone/anthracene (9,10-AQ/ANT) ratios all >2.0 suggest regional PAC sources. Increasing PAH/soot ratios and decreasing 9,10-AQ/ANT ratios since the beginning of the 1970s indicate increasing local emissions. The historical trends of these diagnostic ratios indicate an increase in the fossil-fuel contribution since the beginning of the 1970s. The increase of perylene concentrations with increasing core depth and the ratio of perylene to its penta-aromatic isomers indicate that perylene originates mainly from in situ biogenic diagenesis. We demonstrate that the concentrations of EC, char, soot, and PACs in sediments can be used to reconstruct local, regional, and remote sources and transport pathways of pollutants to the QTP.

Stronger association of polycyclic aromatic hydrocarbons with soot than with char in soils and sediments

The knowledge of the association of polycyclic aromatic hydrocarbons (PAHs) with organic matter and carbonaceous materials is critical for a better understanding of their environmental transport, fate, and toxicological effects. Extensive studies have been done with regard to the relationship of PAHs with total organic carbon (TOC) and elemental carbon (EC) in different environmental matrices. The relationship between PAHs and the two subtypes of EC, char (combustion residues) and soot (produced via gas-to-particle conversion) also has been tested in field and laboratory experiments using reference materials. However, a direct comparison of associations of PAHs between with char and with soot in real environmental matrices has to our knowledge not yet been reported because of a lack of methodology to differentiate them. In this study, char and soot were measured using the IMPROVE method to test their associations with 12 EPA priority PAHs measured in topsoil samples (N=22, top 10 cm) collected from the Guanzhong Plain and in surface sediment samples (N=32, top 5 cm) from the Wei River (central China). In both soils and sediments, ∑12PAHs were more strongly associated with soot than with char, mainly due to the fact that soot and PAHs were produced in the same gas phase during combustion, had a strong affinity for each other, and were transported and deposited together, while char, the combustion residue, was transported differently to PAHs due to its large particle size. Stronger correlations between PAHs and the different carbon fractions (TOC, soot, and char) in sediments than in soils were observed, which is associated with the redistribution of PAHs among the organic matter pools in water because of the processes during soil erosion and sedimentation in the river.

DUSP4 regulates neuronal differentiation and calcium homeostasis by modulating ERK1/2 phosphorylation

Protein tyrosine phosphatases have been recognized as critical components of multiple signaling regulators of fundamental cellular processes, including differentiation, cell death, and migration. In this study, we show that dual specificity phosphatase 4 (DUSP4) is crucial for neuronal differentiation and functions in the neurogenesis of embryonic stem cells (ESCs). The endogenous mRNA and protein expression levels of DUSP4 gradually increased during mouse development from ESCs to postnatal stages. Neurite outgrowth and the expression of neuron-specific markers were markedly reduced by genetic ablation of DUSP4 in differentiated neurons, and these effects were rescued by the reintroduction of DUSP4. In addition, DUSP4 knockdown dramatically enhanced extracellular signal-regulated kinase (ERK) activation during neuronal differentiation. Furthermore, the DUSP4-ERK pathway functioned to balance calcium signaling, not only by regulating Ca(2+)/calmodulin-dependent kinase I phosphorylation, but also by facilitating Cav1.2 expression and plasma membrane localization. These data are the first to suggest a molecular link between the MAPK-ERK cascade and calcium signaling, which provides insight into the mechanism by which DUSP4 modulates neuronal differentiation.

Transcriptional Profiles of Imprinted Genes in Human Embryonic Stem Cells During In vitro Differentiation

BACKGROUND AND OBJECTIVES

Genomic imprinting is an inheritance phenomenon by which a subset of genes are expressed from one allele of two homologous chromosomes in a parent of origin-specific manner. Even though fine-tuned regulation of genomic imprinting process is essential for normal development, no other means are available to study genomic imprinting in human during embryonic development. In relation with this bottleneck, differentiation of human embryonic stem cells (hESCs) into specialized lineages may be considered as an alternative to mimic human development.

METHODS AND RESULTS

In this study, hESCs were differentiated into three lineage cell types to analyze temporal and spatial expression of imprinted genes. Of 19 imprinted genes examined, 15 imprinted genes showed similar transcriptional level among two hESC lines and two human induced pluripotent stem cell (hiPSC) lines. Expressional patterns of most imprinted genes were varied in progenitors and fully differentiated cells which were derived from hESCs. Also, no consistence was observed in the expression pattern of imprinted genes within an imprinting domain during in vitro differentiation of hESCs into three lineage cell types.

CONCLUSIONS

Transcriptional expression of imprinted genes is regulated in a cell type- specific manner in hESCs during in vitro differentiation.

Autophagy regulates homeostasis of pluripotency-associated proteins in hESCs

The pluripotency of embryonic stem cells (ESCs) is maintained by intracellular networks of many pluripotency-associated (PA) proteins such as OCT4, SOX2, and NANOG. However, the mechanisms underlying the regulation of protein homeostasis for pluripotency remain elusive. Here, we first demonstrate that autophagy acts together with the ubiquitin-proteasome system (UPS) to modulate the levels of PA proteins in human ESCs (hESCs). Autophagy inhibition impaired the pluripotency despite increment of PA proteins in hESCs. Immunogold-electron microscopy confirmed localization of OCT4 molecules within autophagosomes. Also, knockdown of LC3 expression led to accumulation of PA proteins and reduction of pluripotency in hESCs. Interestingly, autophagy and the UPS showed differential kinetics in the degradation of PA proteins. Autophagy inhibition caused enhanced accumulation of both cytoplasmic and nuclear PA proteins, whereas the UPS inhibition led to preferentially degrade nuclear PA proteins. Our findings suggest that autophagy modulates homeostasis of PA proteins, providing a new insight in the regulation of pluripotency in hESCs.

Differentiation of human pluripotent stem cells into nephron progenitor cells in a serum and feeder free system

Objectives

Kidney disease is emerging as a critical medical problem worldwide. Because of limited treatment options for the damaged kidney, stem cell treatment is becoming an alternative therapeutic approach. Of many possible human stem cell sources, pluripotent stem cells are most attractive due to their self-renewal and pluripotent capacity. However, little is known about the derivation of renal lineage cells from human pluripotent stem cells (hPSCs). In this study, we developed a novel protocol for differentiation of nephron progenitor cells (NPCs) from hPSCs in a serum- and feeder-free system.

Materials and Methods

We designed step-wise protocols for differentiation of human pluripotent stem cells toward primitive streak, intermediate mesoderm and NPCs by recapitulating normal nephrogenesis. Expression of key marker genes was examined by RT-PCR, real time RT-PCR and immunocytochemistry. Each experiment was independently performed three times to confirm its reproducibility.

Results

After modification of culture period and concentration of exogenous factors, hPSCs can differentiate into NPCs that markedly express specific marker genes such as SIX2, GDNF, HOXD11, WT1 and CITED1 in addition to OSR1, PAX2, SALL1 and EYA1. Moreover, NPCs possess the potential of bidirectional differentiation into both renal tubular epithelial cells and glomerular podocytes in defined culture conditions. In particular, approximately 70% of SYN-positive cells were obtained from hPSC-derived NPCs after podocytes induction. NPCs can also form in vitro tubule-like structures in three dimensional culture systems.

Conclusions

Our novel protocol for hPSCs differentiation into NPCs can be useful for producing alternative sources of cell replacement therapy and disease modeling for human kidney diseases.

Dual modulation of the mitochondrial permeability transition pore and redox signaling synergistically promotes cardiomyocyte differentiation from pluripotent stem cells

Background

Cardiomyocytes that differentiate from pluripotent stem cells (PSCs) provide a crucial cellular resource for cardiac regeneration. The mechanisms of mitochondrial metabolic and redox regulation for efficient cardiomyocyte differentiation are, however, still poorly understood. Here, we show that inhibition of the mitochondrial permeability transition pore (mPTP) by Cyclosporin A (CsA) promotes cardiomyocyte differentiation from PSCs.

Methods and Results

We induced cardiomyocyte differentiation from mouse and human PSCs and examined the effect of CsA on the differentiation process. The cardiomyogenic effect of CsA mainly resulted from mPTP inhibition rather than from calcineurin inhibition. The mPTP inhibitor NIM811, which does not have an inhibitory effect on calcineurin, promoted cardiomyocyte differentiation as much as CsA did, but calcineurin inhibitor FK506 only slightly increased cardiomyocyte differentiation. CsA‐treated cells showed an increase in mitochondrial calcium, mitochondrial membrane potential, oxygen consumption rate, ATP level, and expression of genes related to mitochondrial function. Furthermore, inhibition of mitochondrial oxidative metabolism reduced the cardiomyogenic effect of CsA while antioxidant treatment augmented the cardiomyogenic effect of CsA.

Conclusions

Our data show that mPTP inhibition by CsA alters mitochondrial oxidative metabolism and redox signaling, which leads to differentiation of functional cardiomyocytes from PSCs.

The AMPK-PPARGC1A pathway is required for antimicrobial host defense through activation of autophagy

AMP-activated protein kinase (AMPK) is a crucial energy sensor and plays a key role in integration of cellular functions to maintain homeostasis. Despite this, it is largely unknown whether targeting the AMPK pathway can be used as a therapeutic strategy for infectious diseases. Herein, we show that AMPK activation robustly induces antibacterial autophagy, which contributes to antimicrobial defense against Mycobacterium tuberculosis (Mtb). AMPK activation led to inhibition of Mtb-induced phosphorylation of the mechanistic target of rapamycin (MTOR) in macrophages. In addition, AMPK activation increased the genes involved in oxidative phosphorylation, mitochondrial ATP production, and biogenesis in Mtb-infected macrophages. Notably, peroxisome proliferator-activated receptor-gamma, coactivator 1α (PPARGC1A) was required for AMPK-mediated antimicrobial activity, as well as enhancement of mitochondrial function and biogenesis, in macrophages. Further, the AMPK-PPARGC1A pathway was involved in the upregulation of multiple autophagy-related genes via CCAAT/enhancer binding protein (C/EBP), β (CEBPB). PPARGC1A knockdown inhibited the AMPK-mediated induction of autophagy and impaired the fusion of phagosomes with MAP1LC3B (LC3B) autophagosomes in Mtb-infected macrophages. The link between autophagy, mitochondrial function, and antimicrobial activity was further demonstrated by studying LysMCre-mediated knockout of atg7, demonstrating mitochondrial ultrastructural defects and dysfunction, as well as blockade of antimicrobial activity against mycobacteria. Collectively, our results identify the AMPK-PPARGC1A axis as contributing to autophagy activation leading to an antimicrobial response, as a novel host defense mechanism.

The reprogramming factor nuclear receptor subfamily 5, group A, member 2 cannot replace octamer-binding transcription factor 4 function in the self-renewal of embryonic stem cells

Although octamer-binding transcription factor 4 (Oct-4) is one of the most intensively studied factors in mammalian development, no cellular genes capable of replacing Oct-4 function in embryonic stem (ES) cells have been found. Recent data show that nuclear receptor subfamily 5, group A, member 2 (Nr5a2) is able to replace Oct-4 function in the reprogramming process; however, it is unclear whether Nr5a2 can replace Oct-4 function in ES cells. In this study, the ability of Nr5a2 to maintain self-renewal and pluripotency in ES cells was investigated. Nr5a2 localized to the nucleus in ES cells, similarly to Oct-4. However, expression of Nr5a2 failed to rescue the stem cell phenotype or to maintain the self-renewal ability of ES cells. Furthermore, as compared with Oct-4-expressing ES cells, Nr5a2-expressing ES cells showed a reduced number of cells in S-phase, did not expand normally, and did not remain in an undifferentiated state. Ectopic expression of Nr5a2 in ES cells was not able to activate transcription of ES cell-specific genes, and gene expression profiling demonstrated differences between Nr5a2-expressing and Oct-4-expressing ES cells. In addition, Nr5a2-expressing ES cells were not able to form teratomas in nude mice. Taken together, these results strongly suggest that the gene regulation properties of Nr5a2 and Oct-4 and their abilities to confer self-renewal and pluripotency of ES cells differ. The present study provides strong evidence that Nr5a2 cannot replace Oct-4 function in ES cells.

Comparative receptor tyrosine kinase profiling identifies a novel role for AXL in human stem cell pluripotency

The extensive molecular characterization of human pluripotent stem cells (hPSCs), human embryonic stem cells (hESCs) and human-induced pluripotent stem cells (hiPSCs) is required before they can be applied in the future for personalized medicine and drug discovery. Despite the efforts that have been made with kinome analyses, we still lack in-depth insights into the molecular signatures of receptor tyrosine kinases (RTKs) that are related to pluripotency. Here, we present the first detailed and distinct repertoire of RTK characteristic for hPSC pluripotency by determining both the expression and phosphorylation profiles of RTKs in hESCs and hiPSCs using reverse transcriptase-polymerase chain reaction with degenerate primers that target conserved tyrosine kinase domains and phospho-RTK array, respectively. Among the RTKs tested, the up-regulation of EPHA1, ERBB2, FGFR4 and VEGFR2 and the down-regulation of AXL, EPHA4, PDGFRB and TYRO3 in terms of both their expression and phosphorylation levels were predominantly related to the maintenance of hPSC pluripotency. Notably, the specific inhibition of AXL was significantly advantageous in maintaining undifferentiated hESCs and hiPSCs and for the overall efficiency and kinetics of hiPSC generation. Additionally, a global phosphoproteomic analysis showed that ∼30% of the proteins (293 of 970 phosphoproteins) showed differential phosphorylation upon AXL inhibition in undifferentiated hPSCs, revealing the potential contribution of AXL-mediated phosphorylation dynamics to pluripotency-related signaling networks. Our findings provide a novel molecular signature of AXL in pluripotency control that will complement existing pluripotency-kinome networks.

Transcription elongation factor Tcea3 regulates the pluripotent differentiation potential of mouse embryonic stem cells via the Lefty1-Nodal-Smad2 pathway

Self-renewal and pluripotency are hallmark properties of pluripotent stem cells, including embryonic stem cells (ESCs) and iPS cells. Previous studies revealed the ESC-specific core transcription circuitry and showed that these core factors (e.g., Oct3/4, Sox2, and Nanog) regulate not only self-renewal but also pluripotent differentiation. However, it remains elusive how these two cell states are regulated and balanced during in vitro replication and differentiation. Here, we report that the transcription elongation factor Tcea3 is highly enriched in mouse ESCs (mESCs) and plays important roles in regulating the differentiation. Strikingly, altering Tcea3 expression in mESCs did not affect self-renewal under nondifferentiating condition; however, upon exposure to differentiating cues, its overexpression impaired in vitro differentiation capacity, and its knockdown biased differentiation toward mesodermal and endodermal fates. Furthermore, we identified Lefty1 as a downstream target of Tcea3 and showed that the Tcea3-Lefty1-Nodal-Smad2 pathway is an innate program critically regulating cell fate choices between self-replication and differentiation commitment. Together, we propose that Tcea3 critically regulates pluripotent differentiation of mESCs as a molecular rheostat of Nodal-Smad2/3 signaling.

Nonsteroidal anti-inflammatory drugs (NSAID) sparing effects of glucosamine hydrochloride through N-glycosylation inhibition; strategy to rescue stomach from NSAID damage

Gastrointestinal or cardiovascular complications limit nonsteroidal anti-inflammatory drugs (NSAID) prescription. Glucosamine hydrochloride (GS-HCl) alternatively chosen, but debates still exist in its clinical efficiency. COX-2 instability through inhibiting COX-2 N-glycosylation of GS-HCl raised the possibility of NSAID sparing effect. Study was done to determine whether combination treatment of glucosamine and NSAID contributes to gastric safety through NSAID sparing effect. IEC-6 cells were stimulated with TNF-α and compared the expressions of inflammatory mediators after indomethacin alone or combination of indomethacin and GS-HCl by Western blotting and RT-PCR. C57BL/6 mice injected with type II collagen to induce arthritis were treated with indomethacin alone or combination of reduced dose of indomethacin and GS-HCl after 3 weeks. TNF-α increased the expression of COX-2, iNOS and inflammatory cytokines, but GS-HCl significantly attenuated TNF-α-induced COX-2 expression. Decreased COX-2 after GS-HCl was caused by N-glycosylation inhibition as much as tunicamycin. Combination of reduced dose of indomethacin and GS-HCl significantly reduced the expressions of ICAM-1, VCAM-1, IL-8, IL-1β, MMP-2, MMP-7, MMP-9, and MMP-11 mRNA as well as NF-κB activation better than high dose indomethacin alone. These NSAID sparing effect of GS-HCl was further proven in collagen-induced arthritis model. Combination of GS-HCl and 2.5 mg/kg indomethacin showed significant protection from gastric damages as well as efficacious anti-arthritic effect. Taken together, COX-2 N-glycosylation inhibition by GS-HCl led to indomethacin sparing effects, based on which combination of GS-HCl and reduced dose of NSAID can provide the strategy to secure stomach from NSAID-induced gastric damage as well as excellent anti-arthritic effects.

Generation of human induced pluripotent stem cells from osteoarthritis patient-derived synovial cells

OBJECTIVE

This study was undertaken to generate and characterize human induced pluripotent stem cells (PSCs) from patients with osteoarthritis (OA) and to examine whether these cells can be developed into disease-relevant cell types for use in disease modeling and drug discovery.

METHODS

Human synovial cells isolated from two 71-year-old women with advanced OA were characterized and reprogrammed into induced PSCs by ectopic expression of 4 transcription factors (Oct-4, SOX2, Klf4, and c-Myc). The pluripotency status of each induced PSC line was validated by comparison with human embryonic stem cells (ESCs).

RESULTS

We found that OA patient-derived human synovial cells had human mesenchymal stem cell (MSC)-like characteristics, as indicated by the expression of specific markers, including CD14-, CD19-, CD34-, CD45-, CD44+, CD51+, CD90+, CD105+, and CD147+. Microarray analysis of human MSCs and human synovial cells further determined their unique and overlapping gene expression patterns. The pluripotency of established human induced PSCs was confirmed by their human ESC-like morphology, expression of pluripotency markers, gene expression profiles, epigenetic status, normal karyotype, and in vitro and in vivo differentiation potential. The potential of human induced PSCs to differentiate into distinct mesenchymal cell lineages, such as osteoblasts, adipocytes, and chondrocytes, was further confirmed by positive expression of markers for respective cell types and positive staining with alizarin red S (osteoblasts), oil red O (adipocytes), or Alcian blue (chondrocytes). Functional chondrocyte differentiation of induced PSCs in pellet culture and 3-dimensional polycaprolactone scaffold culture was assessed by chondrocyte self-assembly and histology.

CONCLUSION

Our findings indicate that patient-derived synovial cells are an attractive source of MSCs as well as induced PSCs and have the potential to advance cartilage tissue engineering and cell-based models of cartilage defects.