[Progress of researches on the antiparasitic activity of antimicrobial peptide LL-37]

Parasitic diseases caused by protozoan and helminth infections are still widespread across the world, notably in tropical and subtropical areas, which threaten the children and adult health. Long-term use of anti-parasitic drugs may result in reduced drug susceptibility and even drug resistance. Antimicrobial peptides have been demonstrated to inhibit parasite growth and development, which has potential antiparasitic values. LL-37, the only human antimicrobial peptide in the cathelicidin family, has been widely investigated. This paper reviews the progress of researches on the antiparasitic activity of LL-37, and discusses the prospects of LL-37 in the research of parasites.

Single-Cell Transcriptomic Analysis of Dental Pulp and Periodontal Ligament Stem Cells

The regeneration of periodontal, periapical, and pulpal tissues is a complex process requiring the direct involvement of cells derived from pluripotent stem cells in the periodontal ligament and dental pulp. Dental pulp stem cells (DPSCs) and periodontal ligament stem cells (PDLSCs) are spatially distinct with the potential to differentiate into similar functional and phenotypic cells. We aimed to identify the cell heterogeneity of DPSCs and PDLSCs and explore the differentiation potentials of their specialized organ-specific functions using single-cell transcriptomic analysis. Our results revealed 7 distinct clusters, with cluster 3 showing the highest potential for differentiation. Clusters 0 to 2 displayed features similar to fibroblasts. The trajectory route of the cell state transition from cluster 3 to clusters 0, 1, and 2 indicated the distinct nature of cell differentiation. PDLSCs had a higher proportion of cells (78.6%) at the G1 phase, while DPSCs had a higher proportion of cells at the S and G2/M phases (36.1%), mirroring the lower cell proliferation capacity of PDLSCs than DPSCs. Our study suggested the heterogeneity of stemness across PDLSCs and DPSCs, the similarities of these 2 stem cell compartments to be potentially integrated for regenerative strategies, and the distinct features between them potentially particularized for organ-specific functions of the dental pulp and periodontal ligament for a targeted regenerative dental tissue repair and other regeneration therapies.

Modes and Mechanisms of Pacific Decadal-Scale Variability

The modes of Pacific decadal-scale variability (PDV), traditionally defined as statistical patterns of variance, reflect to first order the ocean's integration (i.e., reddening) of atmospheric forcing that arises from both a shift and a change in strength of the climatological (time-mean) atmospheric circulation. While these patterns concisely describe PDV, they do not distinguish among the key dynamical processes driving the evolution of PDV anomalies, including atmospheric and ocean teleconnections and coupled feedbacks with similar spatial structures that operate on different timescales. In this review, we synthesize past analysis using an empirical dynamical model constructed from monthly ocean surface anomalies drawn from several reanalysis products, showing that the PDV modes of variance result from two fundamental low-frequency dynamical eigenmodes: the North Pacific-central Pacific (NP-CP) and Kuroshio-Oyashio Extension (KOE) modes. Both eigenmodes highlight how two-way tropical-extratropical teleconnection dynamics are the primary mechanisms energizing and synchronizing the basin-scale footprint of PDV. While the NP-CP mode captures interannual- to decadal-scale variability, the KOE mode is linked to the basin-scale expression of PDV on decadal to multidecadal timescales, including contributions from the South Pacific.

Comparison of clinical diagnostic value of spiral CT with different dose in patients with early-stage peripheral lung cancer

PURPOSE

To compare the clinical diagnostic value of spiral CT scan with different dose in patients with early-stage peripheral lung cancer.

METHODS

A total of 163 cases of patients with early-stage peripheral lung cancer who came to People's Hospital of Rizhao for treatment from June 2014 to January 2017 were retrospectively analyzed. A total of 78 cases of patients who received low-dose CT scanning were the low-dose group, another 84 cases of patients who received routine dose CT scanning were the routine dose group. Multislice helical CT (MSCT) scanning was performed in both groups, with tube voltage of 120 kV. Tube current was 25 m A in the low-dose group and 250 m A in the routine dose group. In addition, a total of 80 patients with lobar pneumonia were added as the control group of diagnostic sensitivity, specificity and accuracy. Pathological diagnosis was taken as the gold standard to compare the diagnostic sensitivity, specificity and accuracy of the two groups.

RESULTS

The image quality, nodules and signs of the two groups were compared, and the results of radiation dose of the two groups were compared. The diagnostic sensitivity, specificity and accuracy of the low-dose group were 82.05%, 87.50% and 84.81%, respectively. The diagnostic sensitivity, specificity and accuracy of the routine dose group were 85.71%, 86.25% and 85.97%, respectively. The diagnostic value of the two groups was not statistically significant (p > 0.05). However, the radiation dose in the low-dose group was significantly lower than that in the routine group.

CONCLUSION

Low-dose MSCT scanning can meet the clinical requirements for imaging diagnosis of peripheral lung cancer, and can reduce the radiation dose of patients.

Coronavirus disease 2019: a bibliometric analysis and review

OBJECTIVE

On December 8, 2019, many cases of pneumonia with unknown etiology were first reported in Wuhan, China, subsequently identified as a novel coronavirus infection aroused worldwide concern. As the outbreak is ongoing, more and more researchers focused interest on the COVID-19. Therefore, we retrospectively analyzed the publications about COVID-19 to summarize the research hotspots and make a review, to provide reference for researchers in the world.

MATERIALS AND METHODS

We conducted a search in PubMed using the keywords "COVID-19" from inception to March 1, 2020. Identified and analyzed the data included title, corresponding author, language, publication time, publication type, research focus.

RESULTS

183 publications published from 2020 January 14 to 2020 February 29 were included in the study. The first corresponding authors of the publications were from 20 different countries. Among them, 78 (42.6%) from the hospital, 64 (35%) from the university and 39 (21.3%) from the research institution. All the publications were published in 80 different journals. Journal of Medical Virology published most of them (n=25). 60 (32.8%) were original research, 29 (15.8%) were review, 20 (10.9%) were short communications. 68 (37.2%) epidemiology, 49 (26.8%) virology and 26 (14.2%) clinical features.

CONCLUSIONS

According to our review, China has provided a large number of research data for various research fields, during the outbreak of COVID-19. Most of the findings play an important role in preventing and controlling the epidemic around the world. With research on the COVID-19 still booming, new vaccine and effective medicine for COVID-19 will be expected to come out in the near future with the joint efforts of researchers worldwide.

Interleukin-10 Protects Schwann Cells against Advanced Glycation End Products-Induced Apoptosis via NF-κB Suppression

Demyelination resulting from Schwann cell injury is a main pathological feature of diabetic neuropathy, and a key contributor to this process may be inflammation due to advanced glycation end products (AGEs). Therefore, protection by anti-inflammation agents is anticipated. In this study, we showed that interleukin-10 (IL-10), an anti-inflammatory cytokine, inhibits apoptosis of Schwann cells induced by AGEs in vitro. We isolated and cultured Schwann cells from rat sciatic nerves. As detected by flow cytometry, apoptosis of Schwann cells markedly increased following incubation with AGEs for 48 h. However, pretreatment with IL-10 inhibited AGE-induced apoptosis. The effect of IL-10 on NF-κB, which is a very important regulator of inflammation, was also evaluated, and results showed high levels of phospho-NF-κB and nuclear localization of NF-κB in cells incubated with AGEs but low levels of phospho-NF-κB and cytoplasmic localization in the cells incubated with IL-10, indicating the activation of NF-κB by AGEs and inhibition of NF-κB by IL-10. Moreover, incubating Schwann cells with an NF-κB inhibitor (caffeic acid phenethyl ester) for 30 min before adding AGEs mimicked IL-10, lowering the amount of reactive oxygen species and activity of caspase-3 and also decreasing apoptosis in Schwann cells. These results indicate that IL-10 may protect Schwann cells against AGE-induced apoptosis by attenuating oxidative stress via the inhibition of activation of NF-κB.

Numerical and experimental studies of water disinfection in UV reactors

Performance of UV reactors for water disinfection is investigated in this paper. Both experimental and numerical studies are performed on base reactor LP24. Enterobacteria phage MS2 is chosen as the challenge microorganism in the experiments. Experiments are conducted to evaluate the effect of different parameters, i.e. flow rate and UV transmission, on the reactor performance. Simulation is carried out based on the commercial software ANSYS FLUENT with user defined functions (UDFs) implemented. The UDF is programmed to calculate UV dose absorbed by different microorganisms along their flow trajectories. The effect with boundary layer mesh and without boundary layer mesh for LP24 is studied. The results show that the inclusion of boundary layer mesh does not have much effect on the reactor performance in terms of reduction equivalent dose (RED). The numerical results agree well with the experimental measurements, hence validating the numerical model. With this achieved, the numerical model is applied to study other scaled reactors: LP12, LP40, LP60 and LP80. Comparisons show that LP40 has the highest RED and log inactivation among all the reactors while LP80 has the lowest RED and log inactivation.

Protein kinase C and protein kinase A are involved in the protection of recombinant human glucagon-like peptide-1 on glomeruli and tubules in diabetic rats

AIMS/INTRODUCTION

Blockade or reversal the progression of diabetic nephropathy is a clinical challenge. The aim of the present study was to examine whether recombinant human glucagon-like peptide-1 (rhGLP-1) has an effect on alleviating urinary protein and urinary albumin levels in diabetic rats.

MATERIALS AND METHODS

Streptozotocin-induced diabetes rats were treated with rhGLP-1 insulin and saline. Using immunostaining, hematoxylin-eosin, electron microscopy and periodic acid-Schiff staining to study the pathology of diabetic nephropathy, and we carried out quantitative reverse transcription polymerase chain reaction, western blot and immunohistochemistry to identify the differentially expressed proteins. The mechanism was studied through advanced glycation end-products-induced tubular epithelial cells.

RESULTS

rhGLP-1 inhibits protein kinase C (PKC)-β, but increases protein kinase A (PKA), which reduces oxidative stress in glomeruli and in cultured glomerular microvascular endothelial cells. In tubules, rhGLP-1 increased the expression of two key proteins related to re-absorption - megalin and cubilin - which was accompanied by downregulation of PKC-β and upregulation of PKA. On human proximal tubular epithelial cells, rhGLP-1 enhanced the absorption of albumin, and this was blocked by a PKC activator or PKA inhibitor.

CONCLUSIONS

These findings suggest that rhGLP-1 can reverse diabetic nephropathy by protecting both glomeruli and tubules by inhibiting PKC and activating PKA.

A polymorphic MYC response element in KBTBD11 influences colorectal cancer risk, especially in interaction with an MYC-regulated SNP rs6983267

Background

MYC is a well-established cancer driver gene regulating the expression of numerous genes, indicating that polymorphisms in MYC response elements could affect tumorigenesis through altering MYC regulation. We performed integrative multistage study to evaluate the effects of variants in MYC response elements and colorectal cancer (CRC) risk.

Patients and methods

We systematically integrated ChIP-Seq, DNase-Seq and transcription factor motif data to screen variants with potential ability to affect the MYC binding affinity. Then, we conducted a two-stage case-control study, totally consisting of 4830 CRC cases and 4759 controls in Chinese population to identify risk polymorphisms and interactions. The effects of risk variants were confirmed by functional assays in CRC LoVo, SW480 and HCT15 cells.

Results

We identified a novel polymorphism rs11777210 in KBTBD11 significantly associated with CRC susceptibility (P = 2.43 × 10-12). Notably, we observed a significant interaction between rs11777210 and MYC nearby rs6983267 (P-multi = 0.003, P-add = 0.005), subjects carrying rs6983267 GG and rs11777210 CC genotypes showing higher susceptibility to CRC (2.83-fold) than those carrying rs6983267 TT and rs11777210 TT genotypes. We further demonstrated that rs6983267 T > G increased MYC expression, and MYC bound to and negatively regulated KBTBD11 expression when the rs11777210 C risk allele was present. KBTBD11 was downregulated in tumor tissues, and KBTBD11 knockdown promoted cell proliferation and inhibited cell apoptosis.

Conclusion

The rs11777210 is a potential predictive biomarker of CRC susceptibility, and KBTBD11 functions as a putative tumor suppressor in tumorigenesis. Our study highlighted the high CRC risk of people carrying rs6983267 G and rs11777210 C alleles, and provided possible biological mechanism of the interaction.

1,25-(OH)2D3 protects Schwann cells against advanced glycation end products-induced apoptosis through PKA-NF-κB pathway

AIMS

To explore the effect and mechanism of 1, 25-(OH)₂D₃ on Schwann cell apoptosis induced by advanced glycation end products.

MAIN METHODS

Schwann cells, isolated from rodent sciatic nerve were incubated with AGE-modified bovine serum albumin(AGE) to mimic diabetic conditions and 1,25-(OH)₂D₃ was used as protector. Cell apoptosis was detected by PI/Annexin-V staining, caspase 3 activity assay and western blotting for caspase 3 and PARP. The activation of protein kinase A (PKA) and nuclear factor kappa-B (NF-κB) was evaluated by western blot. Immunofluorescent staining was used for intercellular location of NF-κB. Cytokine secretion was evaluated by enzyme-linked immunosorbent assay.

KEY FINDINGS

Schwann cell apoptosis accelerated after incubating with AGE. However, if combining 1,25-(OH)₂D₃ with AGE, apoptosis decreased significantly. 1,25-(OH)₂D₃ enhanced PKA activity, but inhibited AGE-induced nuclear translocation of NF-κB. Furthermore, PKA activator (8-bromoadenoside cyclic adenoside monophosphate, 8-Br-cAMP) or NF-κB inhibitor (caffeic acid phenethyl ester, CAPE) could reduce the apoptosis, decreased cleaved caspase 3 and cleaved PARP, suggesting the involvement of PKA and NF-κB pathways in the protection of 1,25-(OH)₂D₃ on Schwann cells. Moreover, 8-Br-cAMP and CAPE could inhibit AGE-induced secretion of interleukin(IL)-1β, prostaglandin E2(PEG2) and cyclooxygenase 2(COX2). Interestingly, 8-Br-cAMP decreased phospho-NF-κB and inhibited nucleus translocation of NF-κB. It hinted at the regulation of PKA to NF-κB. Finally, a pre-treatment of H-89 (an inhibitor of PKA) could block the protection of 1,25-(OH)₂D₃ on cell apoptosis. In conclusion, 1,25-(OH)₂D₃ could protect Schwann cell against AGE-induced apoptosis through PKA/NF-κB pathway.

SIGNIFICANCE

These findings provide experimental rationales for using vitamin D for diabetic neuropathy.

Haemostatic Properties of Human Pulmonary and Cerebral Microvascular Endothelial Cells

Little is known on the haemostatic profiles of human microvascular endothelial cells (MVEC) from different tissues. In addition it is not known whether MVEC from patients display the same haemostatic pattern as MVEC coming from healthy controls. To address these questions MVEC from human lung and brain were isolated and stimulated with tumour necrosis factor α (TNF) and E. coli lipopolysaccharide (LPS) for 24 h. The level and the kinetics of procoagulant activity (PCA) and thrombomodulin (TM) expression were found to be different depending on the tissue of origin and on the agonist used. In particular, the inducible PCA was higher in lung than in brain MVEC, an observation that may be related to the frequency of lung involvement in septic shock. Differences were also observed for tissue plasminogen activator (t-PA) and plasminogen activator inhibitor 1 (PAI-1) with MVEC supernatants or cell lysates. These variables were then measured in lung MVEC purified from patients with acute respiratory distress syndrome (ARDS) and compared to controls. Cells from ARDS patients constitutively expressed more PCA and PAI-1 than controls. The fibrinolytic potential, expressed as t-PA/PAI-1 ratio, was lower in ARDS than in lung MVEC. It is concluded that MVEC display different haemostatic features depending on the tissue they come from and that lung MVEC from ARDS patients present a procoagulant profile when compared with those from controls.

Establishment of a Quantitative Polymerase Chain Reaction Assay for Monitoring Chimeric Antigen Receptor T Cells in Peripheral Blood

BACKGROUND

The chimeric antigen receptor (CAR) consists of an antigen recognition moiety from a monoclonal antibody fused to an intracellular signalling domain capable of activating T cells. The specific structure of the CAR molecule has been used in various basic research and clinical settings to detect CAR expression, but it is necessary to develop more specific and simpler monitoring methods to observe real-time changes.

MATERIALS AND METHODS

To develop a quantitative assay for the universal detection of DNA from anti-CD19 CAR-T cells, a TaqMan real-time quantitative polymerase chain reaction (qPCR) assay was developed using primers based on FMC63-28Z gene sequences. We identified the numbers of copies of CAR gene on T cells transduced with the CAR gene that were obtained from peripheral blood.

RESULTS

The assay had a minimum detection limit of 10 copies/μL and a strong linear standard curve (y = -3.3682x + 38.594; R² = 0.999) within the range of the input CAR gene (10-10⁷ copies/μL). The reproducibility test showed a coefficient of variation ranging from 0.63%-1.65%. Real-time qPCR is a highly sensitive, specific, reproducible, and universal method that can be used to detect anti-CD19 CAR-T cells in peripheral blood.

Human Proislet Peptide Promotes Pancreatic Progenitor Cells to Ameliorate Diabetes Through FOXO1/Menin-Mediated Epigenetic Regulation

We investigated how human proislet peptide (HIP) regulates differentiation of human fetus-derived pancreatic progenitor cells (HFPPCs) and explored the potential link between HIP signaling and the menin pathway, which is key to regulating pancreatic islet differentiation. The data show that HIP promoted expression of proislet transcription factors (TFs), including PDX-1, MAFA, and NKX6.1, as well as other maturation markers of β-cells, such as insulin, GLUT2, KIR6.2, SUR1, and VDCC. Moreover, HIP increased insulin content and promoted the ability of HFPPCs to normalize blood glucose in diabetic mice. HIP inhibited the TF FOXO1 by increasing AKT-mediated phosphorylation. HIP-induced repression of FOXO1 suppressed menin expression, leading to reducing menin binding to the promoter of the three key proislet TFs, decreasing recruitment of H3K9 methyltransferase SUV39H1, and thus reducing repressive H3K9me3 at the promoter. These coordinated actions lead to increased expression of the proislet TFs, resulting in induction of HFPPC differentiation. Consistently, constitutive activation of FOXO1 blocks HIP-induced transcription of these TFs. Together, these studies unravel the crucial role of the HIP/AKT/FOXO/menin axis in epigenetically controlling expression of proislet TFs, regulating the differentiation of HFPPCs, and normalizing blood glucose in diabetic mice.

Pseudo-hemorrhagic region formation in pancreatic neuroendocrine tumors is a result of blood vessel dilation followed by endothelial cell detachment

Aberrant blood vessel formation and hemorrhage may contribute to tumor progression and are potential targets in the treatment of several types of cancer. Pancreatic neuroendocrine tumors (PNETs) are highly vascularized, particularly when they are well-differentiated. However, the process of vascularization and endothelial cell detachment in PNETs is poorly understood. In the present study, 132 PNET clinical samples were examined and a special type of hemorrhagic region was observed in ~30% of the samples regardless of tumor subtype. These hemorrhagic regions were presented as blood-filled caverns with a smooth boundary and were unlined by endothelial cells. Based on the extensive endothelial cell detachment observed in the clinical samples, the formation process of these blood-filled caverns was hypothesized. Blood vessel dilation followed by detachment of endothelial cells from the surrounding tumor tissue was speculated. This was further supported using an INS-1 xenograft insulinoma model. As the formation process was distinct from the typical diffusive hemorrhage, it was named ‘pseudo-hemorrhage’. Furthermore, it was demonstrated that epithelial (E-) cadherin and β-catenin were overexpressed in tumor cells surrounding these pseudo-hemorrhagic regions. Therefore, even though no statistically significant association of pseudo-hemorrhage with clinical features (metastasis or disease recurrence) was identified, the high levels of E-cadherin and β-catenin expression may suggest that a number of features of normal islet cells are retained.

Recombinant human GLP-1(rhGLP-1) alleviating renal tubulointestitial injury in diabetic STZ-induced rats

GLP-1-based treatment improves glycemia through stimulation of insulin secretion and inhibition of glucagon secretion. Recently, more and more findings showed that GLP-1 could also protect kidney from diabetic nephropathy. Most of these studies focused on glomeruli, but the effect of GLP-1 on tubulointerstitial and tubule is not clear yet. In this study, we examined the renoprotective effect of recombinant human GLP-1 (rhGLP-1), and investigated the influence of GLP-1 on inflammation and tubulointerstitial injury using diabetic nephropathy rats model of STZ-induced. The results showed that rhGLP-1 reduced urinary albumin without influencing the body weight and food intake. rhGLP-1 could increased the serum C-peptide slightly but not lower fasting blood glucose significantly. In diabetic nephropathy rats, beside glomerular sclerosis, tubulointerstitial fibrosis was very serious. These lesions could be alleviated by rhGLP-1. rhGLP-1 decreased the expression of profibrotic factors collagen I, α-SMA, fibronectin, and inflammation factors MCP-1 and TNFα in tubular tissue and human proximal tubular cells (HK-2 cells). Furthermore, rhGLP-1 significantly inhibited the phosphorylation of NF-κB, MAPK in both diabetic tubular tissue and HK-2 cells. The inhibition of the expression of TNFα, MCP-1, collagen I and α-SMA in HK-2 cells by GLP-1 could be mimicked by blocking NF-κB or MAPK. These results indicate that rhGLP-1 exhibit renoprotective effect by alleviation of tubulointerstitial injury via inhibiting phosphorylation of MAPK and NF-κB. Therefore, rhGLP-1 may be a potential drug for treatment of diabetic nephropathy.

Transplantation of human fetal pancreatic progenitor cells ameliorates renal injury in streptozotocin-induced diabetic nephropathy

Background

Diabetic nephropathy (DN) is a severe complication of diabetes mellitus (DM). Pancreas or islet transplantation has been reported to prevent the development of DN lesions and ameliorate or reverse existing glomerular lesions in animal models. Shortage of pancreas donor is a severe problem. Islets derived from stem cells may offer a potential solution to this problem.

Objective

To evaluate the effect of stem cell-derived islet transplantation on DN in a rat model of streptozotocin-induced DM.

Methods

Pancreatic progenitor cells were isolated from aborted fetuses of 8 weeks of gestation. And islets were prepared by suspension culture after a differentiation of progenitor cells in medium containing glucagon-like peptide-1 (Glp-1) and nicotinamide. Then islets were transplanted into the liver of diabetic rats via portal vein. Blood glucose, urinary volume, 24 h urinary protein and urinary albumin were measured once biweekly for 16 weeks. Graft survival was evaluated by monitoring human C-peptide level in rat sera and by immunohistochemical staining for human mitochondrial antigen and human C-peptide in liver tissue. The effect of progenitor-derived islets on filtration membrane was examined by electron microscopy and real-time polymerase chain reaction (PCR). Immunohistochemical staining, real-time PCR and western blot were employed for detecting fibronectin, protein kinase C beta (PKCβ), protein kinase A (PKA), inducible nitric oxide synthase (iNOS) and superoxide dismutase (SOD).

Results

Islet-like clusters derived from 8th gestational-week human fetal pancreatic progenitors survived in rat liver. And elevated serum level of human C-peptide was detected. Blood glucose, 24 h urinary protein and urinary albumin were lower in progenitor cell group than those in DN or insulin treatment group. Glomerular basement membrane thickness and fibronectin accumulation decreased significantly while podocytes improved morphologically in progenitor cell group. Furthermore, receptor of advanced glycation end products and PKCβ became down-regulated whereas PKA up-regulated by progenitor cell-derived islets. And iNOS rose while SOD declined.

Conclusions

DN may be reversed by transplantation of human fetal pancreatic progenitor cell-derived islets. And fetal pancreatic progenitor cells offer potential resources for cell replacement therapy.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-017-1253-1) contains supplementary material, which is available to authorized users.

Dysfunction of the WT1-MEG3 signaling promotes AML leukemogenesis via p53-dependent and -independent pathways

Long non-coding RNAs (lncRNAs) play a pivotal role in tumorigenesis, exemplified by the recent finding that lncRNA maternally expressed gene 3 (MEG3) inhibits tumor growth in a p53-dependent manner. Acute myeloid leukemia (AML) is the most common malignant myeloid disorder in adults, and TP53 mutations or loss are frequently detected in patients with therapy-related AML or AML with complex karyotype. Here, we reveal that MEG3 is significantly downregulated in AML and suppresses leukemogenesis not only in a p53-dependent, but also a p53-independent manner. In addition, MEG3 is proven to be transcriptionally activated by Wilms’ tumor 1 (WT1), dysregulation of which by epigenetic silencing or mutations is causally involved in AML. Therefore MEG3 is identified as a novel target of the WT1 molecule. Ten–eleven translocation-2 (TET2) mutations frequently occur in AML and significantly promote leukemogenesis of this disorder. In our study, TET2, acting as a cofactor of WT1, increases MEG3 expression. Taken together, our work demonstrates that TET2 dysregulated WT1-MEG3 axis significantly promotes AML leukemogenesis, paving a new avenue for diagnosis and treatment of AML patients.

Forkhead Protein FoxO1 Acts as a Repressor to Inhibit Cell Differentiation in Human Fetal Pancreatic Progenitor Cells

Our colleagues have reported previously that human pancreatic progenitor cells can readily differentiate into insulin-containing cells. Particularly, transplantation of these cell clusters upon in vitro induction for 3-4 w partially restores hyperglycemia in diabetic nude mice. In this study, we used human fetal pancreatic progenitor cells to identify the forkhead protein FoxO1 as the key regulator for cell differentiation. Thus, induction of human fetal pancreatic progenitor cells for 1 week led to increase of the pancreatic β cell markers such as Ngn3, but decrease of stem cell markers including Oct4, Nanog, and CK19. Of note, FoxO1 knockdown or FoxO1 inhibitor significantly upregulated Ngn3 and insulin as well as the markers such as Glut2, Kir6.2, SUR1, and VDCC, which are designated for mature β cells. On the contrary, overexpression of FoxO1 suppressed the induction and reduced expression of these β cell markers. Taken together, these results suggest that FoxO1 may act as a repressor to inhibit cell differentiation in human fetal pancreatic progenitor cells.

Fabrication of HA/PEI-functionalized carbon dots for tumor targeting, intracellular imaging and gene delivery

Carbon quantum dots (CDs) as emerging carbon nano-materials have attracted tremendous attention in biomedical fields due to unique properties.

Tumor endothelial cells promote metastasis and cancer stem cell-like phenotype through elevated Epiregulin in esophageal cancer

Tumor endothelial cells have been found to be associated with metastasis and cancer progression. In this study, we reported that human esophageal cancer endothelial cells (HECEC), unlike corresponding human esophageal normal endothelial cells (HENEC) displayed several distinct feature couple with unique gene expression profile. Further studies showed that HECEC can enhance migration, invasion and self-renewal properties of esophageal carcinoma cell in vitro by a direct cell-cell interaction. In vivo assay demonstrated that HECEC could significantly enhance the invasion and lung metastasis of esophageal cancer cells. To elucidate the molecular mechanisms of HECEC in esophageal carcinoma progression, we employed the microarray to analyze the gene expression profiles before and after treating with HECEC, HENEC or conditioned meium from HECEC. Among the highly expressed HECEC-regulated genes, we focused on Epiregulin (EREG). Further studies demonstrated that overexpression of EREG in EC9706 or Kyse30 cells can induce actin reorganization, sphere formation ability and a significantly enrichment of CD44⁺ cancer stem-like cells. Moreover, up-regulation of EREG in esophageal cancer cells could enhance lung metastasis and decrease the survival time in vivo. Further study indicated that EREG could induce activation of the Src and FAK. In addition, all these effects could also be inhibited by the function-blocking anti-EREG antibody in a dose dependent manner. Immunohistochemical analysis revealed that high level of EREG was significantly correlated with lymph node metastases and poor prognosis. In summary, HECEC play key roles in enhancing the invasion, migration, cancer stem cell phenotype and metastatic potential of esophageal cancer cells through Epiregulin.

Effect of ozone on vascular endothelial growth factor (VEGF) and related inflammatory cytokines in rats with diabetic retinopathy

The aim of this study was to investigate the effect of ozone on inflammatory cytokines in diabetic retinopathy (DR) rats. Male rats (40) weighing 300-360 g were included in this study. Thirty rats were randomly divided into the model and ozone groups after DR was induced by streptozotocin. Ten rats served as the blank group. After the diabetic models were established for one month, the rats in the ozone group were treated with 50 mg/kg ozone coloclysis for one month (three times a week). After the rats were anesthetized by intraperitoneal injection, blood samples from the abdominal aorta were collected, and the supernatant was obtained by centrifugation. Vascular endothelial growth factor (VEGF) and inflammatory cytokine content in the serum was detected by enzyme linked immunosorbent assay. The values of VEGF, intercellular cell adhesion molecule-1, interleukin-1 beta, tumor necrosis factor-a, and IL-6 were significantly different among the three groups (P < 0.05). The cytokine levels in the model group were higher than those in the blank group (P < 0.05). The level of each cytokine in the ozone group was higher than that in the blank group. Compared with the model group, the cytokine levels in the ozone group were significantly reduced (P < 0.05). Ozone had no effect on the blood glucose of diabetic rats. Treatment with ozone coloclysis may effectively reduce the secretion of VEGF and inflammatory cytokines in diabetic retinopathy rats.

Resonant surface plasmon-exciton interaction in hybrid MoSe2@Au nanostructures

In this work we investigate the interaction between plasmonic and excitonic resonances in hybrid MoSe2@Au nanostructures. The latter were fabricated by combining chemical vapor deposition of MoSe2 atomic layers, Au disk processing by nanosphere lithography and a soft lift-off/transfer technique. The samples were characterized by scanning electron and atomic force microscopy. Their optical properties were investigated experimentally using optical absorption, Raman scattering and photoluminescence spectroscopy. The work is focused on a resonant situation where the surface plasmon resonance is tuned to the excitonic transition. In that case, the near-field interaction between the surface plasmons and the confined excitons leads to interference between the plasmonic and excitonic resonances that manifests in the optical spectra as a transparency dip. The plasmonic-excitonic interaction regime is determined using quantitative analysis of the optical extinction spectra based on an analytical model supported by numerical simulations. We found that the plasmonic-excitonic resonances do interfere thus leading to a typical Fano lineshape of the optical extinction. The near-field nature of the plasmonic-excitonic interaction is pointed out experimentally from the dependence of the optical absorption on the number of monolayer stacks on the Au nanodisks. The results presented in this work contribute to the development of new concepts in the field of hybrid plasmonics.

Prenatal Iron Deficiency and Auditory Brainstem Responses at 3 and 10 Months: A Pilot Study

PURPOSE

To examine whether prenatal iron deficiency delays auditory brainstem response (ABR) maturation in infancy.

METHODS

One hundred and fifteen full-term healthy Chinese infants with maternal and cord blood haemoglobin and serum ferritin determinations were recruited into this study. Forty-eight infants received ABR testing at 3 months, and 45 infants were tested at 10 months. Comparison of the ABR variables were made between infants with and those without evidence of prenatal iron deficiency (maternal 3rd trimester haemoglobin <110 g/L, cord blood ferritin <75 μg/L); or anaemia at 10 months (haemoglobin <110 g/L).

RESULTS

Latencies for wave V and wave III-V and I-V intervals were prolonged at 3 months in infants of anaemic mothers (effect sizes 1.02-1.19 SD). At 10 months, infants with low cord blood serum ferritin (indicating low iron stores at birth) showed longer wave I latency and possibly wave V latency also, besides demonstrating a smaller wave V amplitude (effect sizes 0.58-0.62 SD). Infants with low ferritin at birth and anemia at 10 months had longer wave III-V latency than other groups.

CONCLUSION

In full-term healthy infants, prenatal iron deficiency appears to have adverse effects on the developing central nervous system and auditory system as assessed by ABRs at 3 and/or 10 months.

Advanced Glycation End Products Impair Glucose-Stimulated Insulin Secretion of a Pancreatic β-Cell Line INS-1-3 by Disturbance of Microtubule Cytoskeleton via p38/MAPK Activation

Advanced glycation end products (AGEs) are believed to be involved in diverse complications of diabetes mellitus. Overexposure to AGEs of pancreatic β-cells leads to decreased insulin secretion and cell apoptosis. Here, to understand the cytotoxicity of AGEs to pancreatic β-cells, we used INS-1-3 cells as a β-cell model to address this question, which was a subclone of INS-1 cells and exhibited high level of insulin expression and high sensitivity to glucose stimulation. Exposed to large dose of AGEs, even though more insulin was synthesized, its secretion was significantly reduced from INS-1-3 cells. Further, AGEs treatment led to a time-dependent increase of depolymerized microtubules, which was accompanied by an increase of activated p38/MAPK in INS-1-3 cells. Pharmacological inhibition of p38/MAPK by SB202190 reversed microtubule depolymerization to a stabilized polymerization status but could not rescue the reduction of insulin release caused by AGEs. Taken together, these results suggest a novel role of AGEs-induced impairment of insulin secretion, which is partially due to a disturbance of microtubule dynamics that resulted from an activation of the p38/MAPK pathway.

Hyaluronic acid functionalized nitrogen-doped carbon quantum dots for targeted specific bioimaging

Schematic illustration of the preparation of HA-CQDs (A) and the following bioimaging application (B).

GSK-3β mediates dexamethasone-induced pancreatic β cell apoptosis

AIMS

Glucocorticoids, such as dexamethasone, are widely used anti-inflammatory drugs. Their use is frequently associated with the development of steroid- associated diabetes. Pancreatic β-cell dysfunction has been suggested to be one of the main causes of steroid-associated diabetes. However, the mechanism is not fully understood. Glycogen synthase kinase-3β (GSK-3β) is a multifunctional serine/threonine kinase and plays an important role in energy metabolism, cell growth and apoptosis. Therefore, the contribution of GSK-3β in dexamethasone-induced pancreatic β-cell apoptosis was determined in the present study.

MAIN METHODS

The effect of dexamethasone treatment on rat pancreatic β-cell line (INS-1) apoptosis (determined by TUNEL and Flow Cytometry), generation of reactive oxidative stress (ROS), and the phosphorylation status of GSK-3β was determined. The inhibitory effect of GSK-3β inhibitor-lithium chloride (LiCl) on dexamethasone-induced β-cell apoptosis was also evaluated.

KEY FINDINGS

Dexamethasone (0.1 μM) treatment induced INS-1 apoptosis, which was associated with increased GSK-3β activation and increased NOX4-derived ROS generation. Pretreatment of INS-1 with LiCl inhibited dexamethasone induced ROS generation and INS-1 apoptosis.

SIGNIFICANCE

This study provides a new mechanism of Dex induced pancreatic β cell apoptosis and may serve as a new therapeutic option for treating GC induced diabetes.

A meta analysis of cetuximab plus oxaliplatin based chemotherapy regimen for metastatic colorectal cancer

BACKGROUND

Oxaliplatin based chemotherapy regimen was one of the most used chemotherapy modality for metastatic colorectal cancer. The purpose of this meta-analysis was to assess the clinical activity and toxicities of cetuximab plus oxaliplatin-based chemotherapy regimen for metastatic colorectal Cancer.

METHODS

We searched the clinical studies about the cetuximab plus oxaliplatin-based chemotherapy regimen versus oxaliplatin-based chemotherapy alone for metastatic colorectal cancer in the databases of PubMed, EMBASE, Cochran, and CNKI. The data of response and toxicities were extracted and pooled by random or fixed effects model. And publication bias was evaluated by begg's funnel plot and egger's regression test.

RESULTS

Seven papers were included in this study. Adding cetuximab to oxaliplatin-based chemotherapy regime can significant increase response rate in K-RAS mutation metastatic colorectal patients (odds ratio [OR]: 1.45, 95% confidence interval [CI]: 1.17-1.80, Z = 3.38, P = 0.001) and metastatic colorectal patients without knowing the K-RAS status (OR: 1.36, 95% CI: 1.11-1.65, Z = 1.89, P = 0.003). But for patients with mutated K-RAS, the improvement for objective response rate was not statistical significant (OR: 0.70, 95% CI: 0.49-1.01, Z = 3.00, P = 0.058) when adding cetuximab to oxaliplatin-based chemotherapy regime. The pooled results indicating the rash and diarrhea risk was significantly increased in the combined treatment group (P < 0.05). The toxicity of peripheral neuritis was decreased by adding the cetuximab (P < 0.05). And other toxicities were not statistical different between the two groups (P > 0.05). Significant publication bias was found in toxicities evaluation.

CONCLUSION

Cetuximab plus oxaliplatin-based chemotherapy regimen significant increase the response rate for metastatic colorectal cancer. But the some toxicities such rash and diarrhea risk was also increased.

Colocalization of insulin and glucagon in insulinoma cells and developing pancreatic endocrine cells

A significant portion of human and rat insulinomas coexpress multiple hormones. This character termed as multihormonality is also observed in some early pancreatic endocrine cells which coexpress insulin and glucagon, suggesting an incomplete differentiation status of both cells. Here we demonstrate that insulinoma cells INS-1 and INS-1-derived single cell clone INS-1-15 coexpressed insulin and glucagon in a portion of cells. These two hormones highly colocalized in the intracellular vesicles within a cell. Due to the existence of both PC1/3 and PC2 in INS-1-derived cells, proglucagon could be processed into glucagon, GLP-1 and GLP-2. These glucagon-family peptides and insulin were secreted simultaneously corresponding to the elevating glucose concentrations. The coexpression and partial colocalization of insulin and glucagon was also observed in rat fetal pancreatic endocrine cells, but the colocalization rate was generally lower and more diverse, suggesting that in the developing pancreatic endocrine cells, insulin and glucagon may be stored in nonidentical pools of secreting vesicles and might be secreted discordantly upon stimulus.

Effect of different time phases of radionuclide hepatobiliary scintigraphy on the differential diagnosis of congenital biliary atresia

To investigate the value and essentiality of 6- and 24-h delay hepatobiliary scintigraphy in the differential diagnosis of biliary atresia (BA), we retrospectively analyzed 197 infants (121 boys/76 girls; age range, 3-205 days; average age, 63.9 days) admitted to Jiangxi Children's Hospital for persistent jaundice (> 2 weeks), hepatosplenomegaly, and abnormal liver function. After receiving anti-inflammatory treatment and cholagogic pre-treatment for 7-10 days without a clear diagnosis, the children underwent 99mTc-labeled diethylacetanilide-iminodiacetic acid hepatobiliary scintigraphy. BA and infant hepatitis syndrome were diagnosed in 107 and 90 infants, respectively after laparoscopic cholangiography, surgical pathology, or 6-month clinical follow-up. The diagnostic efficiencies of hepatobiliary scintigraphy for BA were evaluated within 50 min and at 6 and 24 h. The areas under the receiver operating characteristic curves within 50 min, at 6 and 24 h were 0.696, 0.829 , and 0.779 , suggesting poor diagnostic value within 50 min, but improvement at 6 and 24 h. The compliance rate of 6- and 24-h imaging for BA diagnosis was 89.34% (176/197; paired chi-square test Kappa value, 0.77; P > 0.05), signifying high consistency. The diagnostic efficiency values of 6-/24-h imaging for BA diagnosis were sensitivity (90.65/89.72%), specificity (74.44/78.89%), accuracy (83.25/84.77%), positive and negative predictive values (80.83/83.48% and 87.01/86.59%), with no significant difference (P > 0.05). To provide optimal treatment in early BA, the- 6-h hepatobiliary scintigraphy had practical value, especially when combined with tomographic or dynamic imaging; 24-h delay imaging was deemed unnecessary because it was not significantly superior.

Functionalized nanoscale micelles with brain targeting ability and intercellular microenvironment biosensitivity for anti-intracranial infection applications

Due to complication factors such as blood-brain barrier (BBB), integrating high efficiency of brain target ability with specific cargo releasing into one nanocarrier seems more important. A brain targeting nanoscale system is developed using dehydroascorbic acid (DHA) as targeting moiety. DHA has high affinity with GLUT1 on BBB. More importantly, the GLUT1 transportation of DHA represents a "one-way" accumulative priority from blood into brain. The artificial micelles are fabricated by a disulfide linkage, forming a bio-responsive inner barrier, which can maintain micelles highly stable in circulation and shield the leakage of entrapped drug before reaching the targeting cells. The designed micelles can cross BBB and be further internalized by brain cells. Once within the cells, the drug release can be triggered by high intracellular level of glutathione (GSH). Itraconazole (ITZ) is selected as the model drug because of its poor brain permeability and low stability in blood. It demonstrates that the functionalized nanoscale micelles can achieve highly effective direct drug delivery to targeting site. Based on the markedly increased stability in blood circulation and improved brain delivery efficiency of ITZ, DHA-modified micelles show highly effective in anti-intracranial infection. Therefore, this smart nanodevice shows a promising application for the treatment of brain diseases.

On-chip lithium cells for electrical and structural characterization of single nanowire electrodes

We present a transmission electron microscopy (TEM)-compatible, hybrid nanomachined, on-chip construct for probing the structural and electrical changes in individual nanowire electrodes during lithium insertion. We have assembled arrays of individual β-phase manganese dioxide (β-MnO2) nanowires (NWs), which are employed as a model material system, into functional electrochemical cells through a combination of bottom-up (dielectrophoresis) and top-down (silicon nanomachining) unit processes. The on-chip NWs are electrochemically lithiated inside a helium-filled glovebox and their electrical conductivity is studied as a function of incremental lithium loading during initial lithiation. We observe a dramatic reduction in NW conductivity (on the order of two to three orders in magnitude), which is not reversed when the lithium is extracted from the nanoelectrode. This conductivity change is attributed to an increase in lattice disorder within the material, which is observed from TEM images of the lithiated NWs. Furthermore, electron energy loss spectroscopy (EELS) was employed to confirm the reduction in valence state of manganese, which occurs due to the transformation of MnO2 to LixMnO2.

A bacteria deriving peptide modified dendrigraft poly-l-lysines (DGL) self-assembling nanoplatform for targeted gene delivery

Achieving effective gene therapy for glioma depends on gene delivery systems. The gene delivery system should be able to cross the blood-brain barrier (BBB) and further target glioma at its early stage. Active brain tumor targeted delivery can be achieved using the "Trojan horse" technology, which involves either endogenous ligands or extraneous substances that can recognize and bind to specific receptors in target sites. This method facilitates receptor-mediated endocytosis to cross the BBB and enter into glioma cells. Dendrigraft poly-l-lysines (DGLs), which are novel nonviral gene vectors, are conjugated to a peptide (sequence: EPRNEEK) derived from Streptococcus pneumonia, a pathogen causing meningitis. This process yields peptide-modified nanoparticles (NPs) after DNA loading. Cellular uptake and in vivo imaging results indicate that EPRNEEK peptide-modified NPs have a better brain tumor targeted effect compared with a pentapeptide derived from endogenous laminin after intravenous injection. The mechanism of this effect is further explored in the present study. Besides, EPRNEEK peptide-modified NPs also exhibited a prolonged median survival time. In conclusion, the EPRNEEK peptide-modified DGL NPs exhibit potential as a nonviral platform for efficient, noninvasive, and safe brain glioma dual-targeted gene delivery.

TRIB3 alters endoplasmic reticulum stress-induced β-cell apoptosis via the NF-κB pathway

OBJECTIVE

To examine the effect of TRIB3 on endoplasmic reticulum stress induced β-cell apoptosis and to investigate the mechanism with a specific emphasis on the role of NF-κB pathway.

MATERIALS/METHODS

We investigated the effect of TRIB3 on ER stress-induced β-cell apoptosis in INS-1 cells and primary rodent islets. The potential role of TRIB3 in ER stress inducer thapsigargin (Tg)-induced β-cell apoptosis was assessed using overexpression and siRNA knockdown approaches. Inducible TRIB3 β-cells, regulated by the tet-on system, were used for sub-renal capsule transplantation in streptozotocin (STZ)-diabetic mice, to study the effect of TRIB3 on ER stress-induced β-cell apoptosis in vivo. Apoptosis was determined by TUNEL staining both in vivo and in vitro, while the molecular mechanisms of NF-κB activation were investigated.

RESULTS

TRIB3 was induced in ER-stressed INS-1 cells and rodent islets, and its overexpression was accompanied by increased β-cell apoptosis. Specifically, TRIB3 overexpression enhanced Tg-induced INS-1 derived β-cell apoptosis both in vitro and in sub-renal capsular transplantation animal model. Additionally, knockdown of Trib3 blocked Tg-induced apoptosis. Mechanistically, the induction of TRIB3 during ER stress resulted in the activation of NF-κB and aggravated INS-1 derived β-cell apoptosis, while inhibiting the NF-κB pathway significantly abrogated this response and prevented β-cell apoptosis, both in vitro and in sub-renal capsular transplantation animal model.

CONCLUSION

TRIB3 mediated ER stress-induced β-cell apoptosis via the NF-κB pathway.

TRB3 is involved in free fatty acid-induced INS-1-derived cell apoptosis via the protein kinase C δ pathway

Chronic exposure to free fatty acids (FFAs) may induce β cell apoptosis in type 2 diabetes. However, the precise mechanism by which FFAs trigger β cell apoptosis is still unclear. Tribbles homolog 3 (TRB3) is a pseudokinase inhibiting Akt, a key mediator of insulin signaling, and contributes to insulin resistance in insulin target tissues. This paper outlined the role of TRB3 in FFAs-induced INS-1 β cell apoptosis. TRB3 was promptly induced in INS-1 cells after stimulation by FFAs, and this was accompanied by enhanced INS-1 cell apoptosis. The overexpression of TRB3 led to exacerbated apoptosis triggered by FFAs in INS-1-derived cell line and the subrenal capsular transplantation animal model. In contrast, cell apoptosis induced by FFAs was attenuated when TRB3 was knocked down. Moreover, we observed that activation and nuclear accumulation of protein kinase C (PKC) δ was enhanced by upregulation of TRB3. Preventing PKCδ nuclear translocation and PKCδ selective antagonist both significantly lessened the pro-apoptotic effect. These findings suggest that TRB3 was involved in lipoapoptosis of INS-1 β cell, and thus could be an attractive pharmacological target in the prevention and treatment of T2DM.

Quantitative analysis of the temperature dependency in Raman active vibrational modes of molybdenum disulfide atomic layers

Raman spectroscopy is utilized to quantify the temperature dependency of the vibrational modes in molybdenum disulfide (MoS2) atomic layers. These analyses are essential for understanding the structural properties and phononic behaviors of this two-dimensional (2D) material. We quantitatively analyze the temperature dependent shifts of the Raman peak positions in the temperature range from 300 to 550 K, and find that both planar and out-of-plane characteristic modes are highly sensitive to temperature variations. This temperature dependency is linear and can be fully explained by the first-order temperature coefficient. Using a semi-quantitative model, we evaluate the contributions of the material's thermal expansion and intrinsic temperature effects to this dependency. We reveal that the dominating source of shift in the peak position of planar mode E2g(1) for samples of all thicknesses investigated is the four-phonon process. In addition to the four-phonon process, thermal expansion plays a significant role in the temperature dependency of the out-of-plane mode, A1g. The thickness dependency of the temperature coefficient for MoS2 and a drastic change in behaviors of samples from bi- to single-layered are also demonstrated. We further explore the role of defects in the thermal properties of MoS2 by examining the temperature dependency of Raman modes in CVD-grown samples.

Humidity effects on anisotropic nanofriction behaviors of aligned carbon nanotube carpets

We evaluated the interfacial properties of vertically and transversely aligned multiwalled carbon nanotubes (CNTs) carpets using atomic force microscopy (AFM) under ambient (26%-52% relative humidity (RH)), mild (10% RH), and dry conditions (<3.3% RH). The frictional forces on a transversely aligned CNT (TAMWCNT) surface are lower than those on a vertically aligned CNT (VAMWCNT) surface, and they decrease as the relative humidity decreases for both TAMWCNT and VAMWCNT surfaces. Similar trends are found for adhesion forces on both surfaces. Contact mechanics theories are applied and compared in an attempt to better understand these results. The tribological behavior of CNT carpets unveiled in this paper is expected to inspire tunable friction surface engineering strategies.

Microwave frequency performance and high magnetic anisotropy of nanocrystalline Fe70Co30-B films prepared by composition gradient sputtering

The fabrication and high-frequency ferromagnetic performances of nanocrystalline Fe70Co30-B soft magnetic films were investigated. It is revealed that the composition gradient sputtering method dramatically improves the high-frequency soft magnetic properties of the as-prepared films. This method gives rise to almost a linearly-increased distribution of compositions and residual stress. As a result, a very high ferromagnetic resonance frequency up to 6.7 GHz, high uniaxial magnetic anisotropic field up to 450 Oe, and low magnetic loss were obtained in as-deposited samples, which are particularly in favor of the integration between magnetic films and microwave components.