Maternal diabetes modulates offspring cell proliferation and apoptosis during odontogenesis via the TLR4/NF-κB signalling pathway

Sodium Glucose Transporter-2 Inhibitors (SGLT2Is)-TLRs Axis Modulates Diabetes

Diabetes affects millions of people worldwide and is mainly associated with impaired insulin function. To date, various oral anti-diabetic drugs have been developed, of which, the sodium glucose transporter-2 inhibitors (SGLT2Is) are of the most recent classes that have been introduced. They differ from other classes in terms of their novel mechanism of actions and unique beneficial effects rather than just lowering glucose levels. SGLT2Is can protect body against cardiovascular events and kidney diseases even in non-diabetic individuals. SGLT2Is participate in immune cell activation, oxidative stress reduction, and inflammation mediation, thereby, moderating diabetic complications. In addition, toll like receptors (TLRs) are the intermediators of the immune system and inflammatory process, thus it's believed to play crucial roles in diabetic complications, particularly the ones that are related to inflammatory reactions. SGLT2Is are also effective against diabetic complications via their anti-inflammatory and oxidative properties. Given the anti-inflammatory properties of TLRs and SGLT2Is, this review investigates how SGLT2Is can affect the TLR pathway, and whether this could be favorable toward diabetes.

Involvement of IGF1 in endoplasmic reticulum stress contributes to cataract formation through regulating Nrf2/NF-κB signaling

Endoplasmic reticulum (ER) stress is reportedly involved in the development of ophthalmic diseases. This study aimed to investigate the role and potential mechanism of insulin-like growth factor 1 (IGF1) in ER stress. A mouse cataract model was constructed by subcutaneous injection of sodium selenite, and sh-IGF1 was used to evaluate the effect of silencing IGF1 on cataract progression. Slit-lamp and histological examination of the lens were performed to examine lens damage. The regulatory effects of IGF1 on inflammatory responses, oxidative stress, and ER stress were evaluated using ELISA, reverse transcription-quantitative PCR (RT-qPCR), and immunoblotting analysis. Tunicamycin was used to induce ER stress in the lens of epithelial cells. The NF-E2 related factor-2 (Nrf2) inhibitor ML385 and nuclear factor-κB (NF-κB) agonist diprovocim were used to confirm whether IGF1 regulates inflammation and ER stress through Nrf2/NF-κB signaling. Silencing IGF1 alleviated lens damage and reduced lens turbidity in the cataract mice. Silencing IGF1 inhibited inflammatory response, oxidative stress and ER stress response. Meanwhile, IGF1 was highly expressed in sodium selenite-treated lens epithelial cells. The ER stress agonist tunicamycin suppressed cell viability as well as induced ER stress, oxidative stress and inflammation. Silencing IGF1 increased cell viability, EdU-positive rate and migration. Also, silencing of IGF1 reduced inflammation and ER stress via regulating Nrf2/NF-κB pathway. This study reveals silencing IGF1 attenuated cataract through regulating Nrf2/NF-κB signaling, which shares novel insights into the underlying mechanism of cataract and provides potential therapeutic target for cataract.

Long-term outcomes and potential mechanisms of offspring exposed to intrauterine hyperglycemia

Diabetes mellitus during pregnancy, which can be classified into pregestational diabetes and gestational diabetes, has become much more prevalent worldwide. Maternal diabetes fosters an intrauterine abnormal environment for fetus, which not only influences pregnancy outcomes, but also leads to fetal anomaly and development of diseases in later life, such as metabolic and cardiovascular diseases, neuropsychiatric outcomes, reproduction malformation, and immune dysfunction. The underlying mechanisms are comprehensive and ambiguous, which mainly focus on microbiota, inflammation, reactive oxygen species, cell viability, and epigenetics. This review concluded with the influence of intrauterine hyperglycemia on fetal structure development and organ function on later life and outlined potential mechanisms that underpin the development of diseases in adulthood. Maternal diabetes leaves an effect that continues generations after generations through gametes, thus more attention should be paid to the prevention and treatment of diabetes to rescue the pathological attacks of maternal diabetes from the offspring.

Heat Shock Proteins in Tooth Development and Injury Repair

Heat shock proteins (HSPs) are a class of molecular chaperones with expression increased in response to heat or other stresses. HSPs regulate cell homeostasis by modulating the folding and maturation of intracellular proteins. Tooth development is a complex process that involves many cell activities. During tooth preparation or trauma, teeth can be damaged. The damaged teeth start their repair process by remineralizing and regenerating tissue. During tooth development and injury repair, different HSPs have different expression patterns and play a special role in odontoblast differentiation and ameloblast secretion by mediating signaling pathways or participating in protein transport. This review explores the expression patterns and potential mechanisms of HSPs, particularly HSP25, HSP60 and HSP70, in tooth development and injury repair.

Maxillary and dental development in the offspring of protein-restricted female rats

Nutritional restriction during developmental periods impairs organ physiology. Female rats were subjected to protein restriction during pregnancy and lactation to analyze dental and maxillary development. Four exposure groups were considered: normal-protein diet during pregnancy and lactation (NP, 17% casein), low-protein diet during lactation (LP-L, 6% casein), low-protein diet during pregnancy and lactation (LP), and low-protein diet during pregnancy (LP-G). Maxillae from 15-day-old male pups were collected. All protein-restricted groups presented increased dentin thickness and reduced alveolar bone area. When protein restriction was applied during both gestation and lactation (LP), harmful effects were observed in the form of loss of protective OPG (osteoprotegerin) in tooth epithelium-mesenchyme, due to higher RANKL expression, delay in odontoblast maturation, less dental pulp vascularity, reduction in amount of alveolar bone, and less matrix mineralization. In the LP-L group, effects of protein restriction seemed less harmful, and despite less alveolar bone, the enhancement in BMP-7, VEGF, and RANKL seems a compensatory signal to maintain maxillary osteogenesis. In LP-G animals, Dspp expression was higher, suggesting a delay in odontoblast maturation or expression recuperation. In conclusion, maternal protein restriction affects dental and maxillary development. A low-protein diet only in gestation allows for normal development. A low-protein diet during gestation-lactation results in impaired odontogenesis that may increase susceptibility of dental anomalies.

S-methyl cysteine sulfoxide ameliorates duodenal morphological alterations in streptozotocin-induced diabetic rats

Diabetes mellitus (DM) is a metabolic disease associated with several intestinal disorders. S-methyl cysteine sulfoxide (SMCS) ​​is an amino acid present in Allium cepa L with hypoglycemic effects. However, the effects of SMCS on diabetic intestinal changes are unknown. Thus, we aimed to investigate the effects of SMCS on duodenal morphology and immunomodulatory markers in diabetic rats. Twenty-six rats were divided into three groups: control (C), diabetic (D) and diabetic +200 mg/kg SMCS (DSM). DM was induced by intraperitoneal injection of streptozotocin (50 mg/kg). After 30 days, duodenum samples were processed to assess histopathological and stereological alterations in volume, villus length, and immunohistochemical expression of NF-kB, IL-10, BCL-2, and caspase-3. SMCS reduced hyperglycemia and mitigated the increase in total reference volume of the duodenum, the absolute volume of the mucosa, and the length of the intestinal crypts in the DMS group when compared to D. IL-10 immunostaining was reduced in D when compared to C, while NF-kB was increased in D in comparison to the other groups. SMCS ​​supplementation could decrease the NF-kB immunostaining observed in D. Positive staining for BCL-2 and caspase-3 were not statistically different between groups. In summary, SMCS decreased hyperglycemia and mitigated the morphological changes of the duodenum in diabetic animals, and these beneficial effects can be partially explained by NF-kB modulation.

Interaction of M2 macrophages and endometrial cells induces downregulation of GRIM-19 in endometria of adenomyosis

RESEARCH QUESTION

Does the aggregation of M2 macrophages affect the expression of gene associated with retinoid-interferon-induced mortality 19 (GRIM-19) in adenomyosis?

DESIGN

Endometrial tissues were collected from patients with (n = 15) and without (n = 15) adenomyosis. Tissues were analysed for GRIM-19 and toll-like receptor 4 (TLR4) expression by immunohistochemistry and western blotting. Apoptosis was analysed by TdT (terminal deoxynucleotidyl transferase)-mediated dUDP nick-end labelling (TUNEL) assay. Human endometrial stromal cells (HESC) were transfected with GRIM-19 small interfering RNA (SiRNA) to knockdown GRIM-19 expression. The HESC were co-cultured with M2 macrophages to detect the influence of M2 macrophages in HESC cells. Analyses included GRIM-19, caspase-3 and TLR4 expression by western blotting, and GRIM-19 and TLR4 by quantitative real-time polymerase chain reaction. Apoptosis was measured by flow cytometry and TUNEL assay. Cell proliferation (Cell Counting Kit-8 assay) and migration assays were carried out.

RESULTS

The expression of GRIM-19 was significantly lower in adenomyosis lesions compared with controls (P < 0.001). Deficiency of GRIM-19 induced by siRNA decreased apoptosis and increased proliferation and migration in HESC. A significant decrease in GRIM-19 expression occurred in HESC after co-culture with M2 macrophages (P = 0.018). After co-culture with M2 macrophage, apoptosis decreased and proliferation and cell invasion in HESC increased. Protein (P = 0.006) and mRNA (P = 0.013) expression of TLR4 in HESC also reduced after this co-culture. Up-regulation of GRIM-19 occurred in HESC treated with the activator TLR4 (P = 0.016). Up-regulation of GRIM-19 was significantly reversed in cells treated with the TLR4 inhibitor (P = 0.011).

CONCLUSION

M2 macrophages may be involved in regulating the expression of GRIM-19 partly through the TLR4 signalling axis in adenomyosis.

Molecular Insight into Odontogenesis in Hyperglycemic Environment: A Systematic Review

Diabetes mellitus is an endocrinal disorder affecting worldwide and the disease incidence is rising alarmingly high. The effects of diabetes on tooth development are explored by limited studies and their molecular insights are very rarely studied. This systematic review is aimed to provide the best scientific literature source on the molecular insights into odontogenesis in hyperglycemic environment caused by diabetes mellitus or by maternal diabetes on the offspring. The literature search was conducted on the databases, namely PubMed, PubMed Central, Cochrane, and Scopus. The original studies exploring the alterations in the molecular pathways of odontogenesis in diabetes mellitus were selected. Data were extracted, chosen, and evaluated by two independent researchers. At the end of thorough data search, four articles were eligible for the review. Three articles brought out the molecular pathways involved in the offspring of gestational diabetes through animal models. Fourth article was an in vitro study, which treated the stem cells in hyperglycemic environment and drafted the molecular pathway. The altered molecular pathways in dental epithelial stem cells (DESCs), dental papilla cells (DPCs), and stem cells from apical papilla were studied and empowered with statistical analysis. Thus with this systematic review, we conclude that apurinic/apyrimidinic endonuclease1 downregulation causing deoxyribonucleic acid hypermethylation and Oct4, Nanog gene silencing, activation of toll-like receptor-4/nuclear factor kappa B (TLR4/NF-κB) pathway are involved in suppressing cell proliferation and accelerated apoptosis in DESCs in high glucose environment. DPCs are suppressed from odonto differentiation by activation of TLR4 signaling and resulting inhibition of SMAD1/5/9 phosphorylation in diabetic condition. NF-κB pathway activation causes decreased cell proliferation and enhanced differentiation in apical papilla stem cells in hyperglycemia. Further studies targeting various stages of odontogenesis can reveal more molecular insight.

Vitamin C alleviates the senescence of periodontal ligament stem cells through inhibition of Notch3 during long-term culture

Periodontal ligament stem cells (PDLSCs), as potential "seed cells" for periodontal tissue repair and regeneration, require to be expanded in vitro for a large scale. Senescence of PDLSCs occurred during long-term culture may compromise the therapeutic effects of PDLSCs. Medium supplements may be useful in antisenescence. However, the effects and mechanisms of vitamin C (Vc) treatment on PDLSCs during long-term culture are still unclear. In this study, we identified that Vc-treated PDLSCs cells maintained a slender morphology, higher growth rate and migration capacity, stemness, and osteogenic differentiation capability during a long-term culture. Moreover, we also identified that Notch3 was significantly upregulated during the cell senescence, and Vc treatment alleviated the senescence of PDLSCs through inhibition of Notch3 during long-term culture. In summary, Vc treatment suppressed PDLSCs senescence by reducing the expression of Notch3 and might be a simple and useful strategy to inhibit cellular senescence during the cell long-term culture.

Exosome-like vesicles derived from Hertwig's epithelial root sheath cells promote the regeneration of dentin-pulp tissue

Background: The formation of dentin-pulp involves complex epithelial-mesenchymal interactions between Hertwig's epithelial root sheath cells (HERS) and dental papilla cells (DPCs). Earlier studies have identified some of the regulatory molecules participating in the crosstalk between HERS and DPCs and the formation of dentin-pulp. In the present study we focused on the role of HERS-secreted exosomes in DPCs and the formation of dentin-pulp. Specifically, we hypothesized that exosome-like vesicles (ELVs) might mediate the function of HERS and trigger lineage-specific differentiation of dental mesenchymal cells. To test our hypothesis, we evaluated the potential of ELVs derived from a HERS cell line (ELVs-H1) in inducing in vitro and in vivo differentiation of DPCs. Methods: ELVs-H1 were characterized using transmission electron microscopy and dynamic light scattering. The proliferation, migration, and odontoblast differentiation of DPCs after treatment with ELVs-H1, was detected by CCK8, transwell, ALP, and mineralization assays, respectively. Real time PCR and western blotting were used to detect gene and protein expression. For in vivo studies, DPC cells were mixed with collagen gel combined with or without ELVs and transplanted into the renal capsule of rats or subcutaneously into nude mice. HE staining and immunostaining were used to verify the regeneration of dentin-pulp and expression of odontoblast differentiation markers. Results: ELVs-H1 promoted the migration and proliferation of DPCs and also induced odontogenic differentiation and activation of Wnt/β-catenin signaling. ELVs-H1 also contributed to tube formation and neural differentiation in vitro. In addition, ELVs-H1 attached to the collagen gel, and were slowly released and endocytosed by DPCs, enhancing cell survival. ELVs-H1 together with DPCs triggered regeneration of dental pulp-dentin like tissue comprised of hard (reparative dentin-like tissue) and soft (blood vessels and neurons) tissue, in an in vivo tooth root slice model. Conclusion: Our data highlighted the potential of ELVs-H1 as biomimetic tools in providing a microenvironment for specific differentiation of dental mesenchymal stem cells. From a developmental perspective, these vesicles might be considered as novel mediators facilitating the epithelial-mesenchymal crosstalk. Their instructive potency might be exploited for the regeneration of dental pulp-dentin tissues.

The NF-κB/miR-425-5p/MCT4 axis: A novel insight into diabetes-induced endothelial dysfunction

Endothelial cells (ECs) primarily rely on glycolysis for their energy metabolism, and the final product of glycolysis-lactate-is transferred out of cells via monocarboxylate transporter 4 (MCT4). We previously showed that MCT4 downregulation is involved in diabetic endothelial injury. However, the underlying regulatory mechanisms of MCT4 in diabetes remain unclear. This study showed that miR-425-5p was significantly upregulated in diabetic patients and human umbilical vein endothelial cells (HUVECs) treated with high glucose (HG) and interleukin-1β (IL-1β). MCT4 was shown to be a direct target gene of miR-425-5p, and miR-425-5p expression led to MCT4 downregulation, lactate accumulation and increased apoptosis in HUVECs. Furthermore, the results indicated that NF-κB signaling activation increased miR-425-5p levels and induced MCT4 downregulation, lactate accumulation and apoptosis in HUVECs. In conclusion, NF-κB/miR-425-5p/MCT4 axis activation plays a crucial role in the EC injury induced by HG and IL-1β.

Chronic Toxic Effects of Flutolanil on the Liver of Zebrafish ( Danio rerio)

Flutolanil is a broad-spectrum amide fungicide that is widely used to prevent fungal pathogens in agriculture. However, its usage may have a potential environmental impact on organisms. So far, few literatures have investigated the chronic toxicity of flutolanil at concentrations relevant to environmental conditions in the nontarget aquatic organisms. This study was aimed at evaluating whether the long-term exposure of flutolanil affects oxidative stress, immune response, and apoptosis in the liver of zebrafish ( Danio rerio). The results showed that the activity of catalase (CAT) was significantly decreased in the liver in all flutolanil-treated groups. Interestingly, the malondialdehyde (MDA) contents were remarkably increased following the flutolanil exposure. Deoxyribonucleic acid (DNA) damage was increased with a concentration-dependent manner. The transcription level of genes involved in apoptosis and the immune system were significantly altered following flutolanil chronic exposure in zebrafish liver. Furthermore, the caspase-3 enzyme activity was significantly increased. Taken together, this study demonstrated that the resulting effects on oxidative stress, immune toxicity, and apoptosis may be responsible for the pathological alterations in zebrafish liver after flutolanil exposure at concentrations relevant to environmental conditions, advancing the knowledge of pesticide environmental risk assessment.

Development of immortalized Hertwig's epithelial root sheath cell lines for cementum and dentin regeneration

Background

Hertwig’s epithelial root sheath (HERS) is important in guiding tooth root formation by differentiating into cementoblasts through epithelial–mesenchymal transition (EMT) and inducing odontoblastic differentiation of dental papilla through epithelial–mesenchymal interaction (EMI) during the tooth root development. Thus, HERS cells are critical for cementum and dentin formation and might be a potential cell source to achieve tooth root regeneration. However, limited availability and lifespan of primary HERS cells may represent an obstacle for biological investigation and therapeutic use of tooth tissue engineering. Therefore, we constructed, characterized, and tested the functionality of immortalized cell lines in order to produce a more readily available alternative to HERS cells.

Methods

Primary HERS cells were immortalized via infection with lentivirus vector containing the gene encoding simian virus 40 Large T Antigen (SV40LT). Immortalized HERS cell subclones were isolated using a limiting dilution method, and subclones named HERS-H1 and HERS-C2 cells were isolated. The characteristics of HERS-H1 and HERS-C2 cells, including cell proliferation, ability of epithelial–mesenchymal transformation and epithelial–mesenchymal interaction, were determined by CCK-8 assay, immunofluorescence staining, and real-time PCR. The cell differentiation into cementoblast-like cells or periodontal fibroblast-like cells was confirmed in vivo. And the inductive influence of the cell lines on dental papilla cells (DPCs) was also confirmed in vivo.

Results

HERS-H1 and HERS-C2 cells share some common features with primary HERS cells such as epithelial-like morphology, positive expression of CK14, E-Cadherin, and Vimentin, and undergoing EMT in response to TGF-beta. HERS-C2 cells showed the EMT characteristics and could differentiate into cementum-forming cells in vitro and generate cementum-like tissue in vivo. HERS-H1 could induce the differentiation of DPCs into odontoblasts in vitro and generation of dentin-like tissue in vivo.

Conclusions

We successfully isolated and characterized novel cell lines representing two key features of HERS cells during the tooth root development and which were useful substitutes for primary HERS cells, thereby providing a biologically relevant, unlimited cell source for studies on cell biology, developmental biology, and tooth root regeneration.

Electronic supplementary material

The online version of this article (10.1186/s13287-018-1106-8) contains supplementary material, which is available to authorized users.

Tumor-secreted factors induce IL-1β maturation via the glucose-mediated synergistic axis of mTOR and NF-κB pathways in mouse macrophages

Macrophages are one of the major cell types that produce IL-1β. IL-1β maturation occurs via inflammasome activation, and mature IL-1β is then released from the cell. Secreted IL-1β mediates inflammatory reactions in various pathological environments, such as those in infectious, autoimmune, and cancerous diseases. Although the mechanism of IL-1β production has been discovered in infectious and autoimmune diseases, its production mechanism in the tumor microenvironment is unclear. Therefore, the mechanism of IL-1β production in macrophages in the tumor microenvironment was investigated in this study. First, bone marrow-derived macrophages obtained from C57BL/6 mice were treated with B16F10 tumor-conditioned media (TCM) in vitro. TCM increased the levels of IL-1β via glucose-mediated activation of the inflammasome. Moreover, TCM enhanced the activation of both NF-κB and mTOR pathways in a glucose-dependent manner. In particular, the expression levels of mTORC1 component proteins were dependent on the TCM-induced activation of NF-κB signaling. In addition, TCM affected ASC-ASC interactions through increasing intracellular reactive oxygen species levels. Finally, glucose inhibition by inoculation with 2-deoxy-D-glucose in vivo decreased the IL-1β levels in both the blood and tumor region of B16F10-bearing C57BL/6 mice relative to those in PBS-injected tumor-bearing mice. These results suggest that glucose supplied from blood vessels might be important for IL-1β production in tumor-associated macrophages via the integrated signals of the NF-κB and mTOR pathways in the tumor microenvironment.

Ursolic acid alleviates inflammation and against diabetes‑induced nephropathy through TLR4‑mediated inflammatory pathway

Ursolic acid (UA) is a triterpenoid isolated from Chinese herbal medicine. It is extensively distributed in the plant kingdom in at least 63 Chinese herbal medicines of 26 families. UA has multiple bioactivities, including anti‑viral hepatitis, antitumor, anti‑oxidation, anti‑bacterium and anti‑inflammation. The aim of this in vitro study was to examine the effects of UA on diabetes‑induced nephropathy and its possible mechanism. In mice with diabetes‑induced nephropathy, UA increased the body weight, reduced kidney/body weight index, protected kidney cells, alleviated inflammation [tumor necrosis factor (TNF)‑α, interleukin (IL)‑1β, IL‑6 and IL‑18 levels] and kidney cell damage. It was also indicated that UA suppressed Toll‑like receptor 4 (TLR4), myeloid differentiation factor 88 and nuclear factor‑κB protein expression in mice with diabetes‑induced nephropathy. The inhibition of TLR4 increased the anti‑inflammation of UA on inflammation in rat with diabetes‑induced nephropathy through the TLR4 signaling pathway. In conclusion, UA alleviates inflammation and inhibits diabetes‑induced nephropathy through a TLR4‑mediated inflammatory pathway. The present findings indicated that UA may be a possible therapeutic agent against diabetic nephropathy.

Hispidulin alleviates high-glucose-induced podocyte injury by regulating protective autophagy

OBJECTIVES

Diabetic nephropathy (DN) is one of the most common complications in patients with diabetes, and the discovery of novel targeted therapeutic approaches for DN treatment still faces severe challenges. In the current study, we aimed to discover a novel natural product for potential DN treatment and determine its molecular mechanisms.

MATERIALS AND METHODS

Methylthiazoltetrazolium (MTT) assay was employed to evaluate cell viability. Transmission electron microscopy, GFP-LC3 fluorescence fusion plasmid, and Annexin V/PI apoptosis assay were carried out to determine cellular autophagy and apoptosis. Moreover, quantitative proteomics and bioinformatics analysis, Western blotting, and RNA interference were performed to investigate potential molecular mechanisms.

RESULTS

Hispidulin displayed protective capacity on the high-glucose-induced podocyte injury models by activating autophagy and inhibiting apoptosis. The mechanism for hispidulin-induced autophagy was associated to Pim1 inhibition and the regulation of Pim1-p21-mTOR signaling axis. Moreover, quantitative proteomics and bioinformatics analysis revealed that the hispidulin-regulated Pim1 inhibition was associated to RAB18, NRas, PARK7, and FIS1.

CONCLUSIONS

These results indicate that hispidulin induces autophagy and inhibits apoptosis induced by high glucose in murine podocytes. This study will illuminate future developments in DN-targeted therapy.

Schistosoma japonicum attenuates dextran sodium sulfate-induced colitis in mice via reduction of endoplasmic reticulum stress

AIM

To elucidate the impact of Schistosoma (S.) japonicum infection on inflammatory bowel disease by studying the effects of exposure to S. japonicum cercariae on dextran sodium sulfate (DSS)-induced colitis.

METHODS

Infection was percutaneously established with 20 ± 2 cercariae of S. japonicum, and colitis was induced by administration of 3% DSS at 4 wk post infection. Weight change, colon length, histological score (HS) and disease activity index (DAI) were evaluated. Inflammatory cytokines, such as IL-2, IL-10 and IFN-γ, were tested by a cytometric bead array and real-time quantitative polymerase chain reaction (RT-PCR). Protein and mRNA levels of IRE1α, IRE1β, GRP78, CHOP, P65, P-P65, P-IκBα and IκBα in colon tissues were examined by Western blot and RT-PCR, respectively. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling positive cells, cleaved-caspase 3 expression and Bcl2/Bax were investigated to assess the apoptosis in colon tissues.

RESULTS

Mice infected with S. japonicum cercariae were less susceptible to DSS. Mice infected with S. japonicum cercariae and treated with DSS showed decreased weight loss, longer colon, and lower HS and DAI compared with mice treated with DSS alone. A substantial decrease in Th1/Th2/Th17 response was observed after infection with S. japonicum. Endoplasmic reticulum (ER) stress and the nuclear factor-kappa B (NF-κB) pathway were reduced in mice infected with S. japonicum cercariae and treated with DSS, along with ameliorated celluar apoptosis, in contrast to mice treated with DSS alone.

CONCLUSION

Exposure to S. japonicum attenuated inflammatory response in a DSS-induced colitis model. In addition to the Th1/Th2/Th17 pathway and NF-κB pathway, ER stress was shown to be involved in mitigating inflammation and decreasing apoptosis. Thus, ER stress is a new aspect in elucidating the relationship between helminth infection and inflammatory bowel disease (IBD), which may offer new therapeutic methods for IBD.

Metabolic reprogramming by HIF-1 activation enhances survivability of human adipose-derived stem cells in ischaemic microenvironments

OBJECTIVES

Poor cell survival severely limits the beneficial effect of adipose-derived stem cell (ADSC)-based therapy for disease treatment and tissue regeneration, which might be caused by the attenuated level of hypoxia-inducible factor-1 (HIF-1) in these cells after having been cultured in 21% ambient oxygen in vitro for weeks. In this study, we explored the role of pre-incubation in dimethyloxalylglycine (DMOG, HIF-1 activator) in the survivability of human ADSCs in a simulated ischaemic microenvironment in vitro and in vivo. The underlying mechanism and angiogenesis were also studied.

MATERIALS AND METHODS

Survivability of ADSCs was determined in a simulated ischaemic model in vitro and a nude mouse model in vivo. Cell metabolism and angiogenesis were investigated by tube formation assay, flow cytometry, fluorescence staining and real-time polymerase chain reaction (RT-PCR) after DMOG treatment.

RESULTS

The results of the experimental groups showed significant enhancement of ADSC survivability in a simulated ischaemic microenvironment in vitro and transplanted model in vivo. Study of the underlying mechanisms suggested that the improved cell survival was regulated by HIF-1-induced metabolic reprogramming including decreased reactive oxygen species, increased intracellular pH, enhanced glucose uptake and increased glycogen synthesis. Tube formation assay revealed higher angiogenic ability in the DMOG-treated group than that in control group.

CONCLUSIONS

The promotion of HIF-1 level in ADSCs induced by DMOG preconditioning suggests a potential strategy for improving the outcome of cell therapy due to increased survival and angiogenic ability.

Maternal diabetes modulates offspring cell proliferation and apoptosis during odontogenesis via the TLR4/NF-κB signalling pathway

OBJECTIVES

Maternal gestational diabetes leads to an adverse in utero environment and increases the risk of malformations during embryo organogenesis. In the present study, we analysed the effects of maternal diabetes on tooth germ cell proliferation and apoptosis in offspring, and investigated their underlying mechanisms.

MATERIALS AND METHODS

A rat model of maternal diabetes was induced by intraperitoneal injection of streptozotocin and the pregnant rats were divided into three groups: controls, the diabetic group and diabetic group with insulin treatment. Offspring of the three groups were collected and cell proliferation and apoptosis in tooth germs were analysed. Primary dental papilla cells and dental epithelial stem cells were isolated and treated with high glucose in vitro, in an attempt to simulate maternal diabetes-induced hyperglycaemia in vivo.

RESULTS

Maternal diabetes significantly affected cell proliferation and apoptosis in offspring tooth germs. The TLR4/NF-ĸB signalling pathway was activated in the tooth germs of offspring of diabetic dams. High glucose treatment activated the TLR4/NF-ĸB signalling pathway in primary dental papilla cells and dental epithelial stem cells in vitro, resulting in suppression of cell proliferation and enhancement of apoptosis. TLR4 knockdown significantly reduced adverse effects induced by high glucose treatment.

CONCLUSIONS

Maternal gestational diabetes significantly impaired dental epithelial and mesenchymal cell proliferation and apoptosis in offspring, possibly by activation of the TLR4/NF-ĸB signalling pathway.