Potential pathological and molecular mechanisms of temporomandibular joint osteoarthritis

Temporomandibular joint osteoarthritis (TMJ OA) is a progressive degenerative disease of the temporomandibular joint (TMJ). The unclear etiology and mechanisms of TMJ OA bring great difficulties to early diagnosis and effective treatment, causing enormous burdens to patients' life and social economics. In this narrative review, we summarized the main pathological changes of TMJ OA, including inflammatory responses, degeneration of extracellular matrix (ECM), abnormal cell biological behaviors (apoptosis, autophagy, and differentiation) in TMJ tissue, and aberrant angiogenesis. All pathological features are closely linked to each other, forming a vicious cycle in the process of TMJ OA, which results in prolonged disease duration and makes it difficult to cure. Various molecules and signaling pathways are involved in TMJ OA pathogenesis, including nuclear factor kappa-B (NF-κB), mitogen-activated protein kinases (MAPKs), extracellular regulated protein kinases (ERKs) and transforming growth factor (TGF)-β signaling pathways et al. One molecule or pathway can contribute to several pathological changes, and the crosstalk between different molecules and pathways can further lead to a complicated condition TMJ OA. TMJ OA has miscellaneous etiology, complex clinical status, depressed treatment results, and poor prognosis. Therefore, novel in-vivo and in-vitro models, novel medicine, materials, and approaches for therapeutic procedures might be helpful for further investigation of TMJ OA. Furthermore, the role of genetic factors in TMJ OA needs to be elucidated to establish more reasonable and effective clinical strategies for diagnosing and treating TMJ OA.

ITGA5 inhibition in pancreatic stellate cells re-educates the in vitro tumor-stromal crosstalk

The interaction between pancreatic cancer cells (PCCs) and pancreatic stellate cells (PSCs) promotes aggressive progression of pancreatic cancer, and disrupting the tumor-stromal crosstalk is a promising therapeutic strategy. Integrin α5 (ITGA5) is specifically overexpressed in pancreatic cancer stroma and activated PSCs. ITGA5 acts as a mediator in PCCs-PSCs interaction, but its role in regulating biological behaviors of PSCs and PCCs is still not quite clear. In this study, ITGA5 in PSCs was inhibited using its specific inhibitor AV3 peptide or siRNA knockdown technique. Pancreatic cancer SW1990 cells conditioned medium (SW1990-CM) and an indirect co-culture system were used to mimic the environment of the in vitro tumor-stromal crosstalk. Our results showed that ITGA5 inhibition impaired the proliferation and migration of PSCs, but enhanced autophagy. After co-culture with PSCs, SW1990 cells gained some cancer stem cells (CSCs)-like characteristics, such as increased drug resistance, migration and invasion ability, but PSCs with ITGA5 knockdown were incapable of producing these effects. The present results suggested that ITGA5 was involved in the development of the malignant biological behaviors of PSCs and PCCs, and ITGA5 inhibition in PSCs might benefit the treatment of pancreatic cancer by re-educating PCCs-PSCs interaction.

Effects of targeted-edited oncogenic insulin-like growth factor-1 receptor with specific-sgRNA on biological behaviors of HepG2 cells

BACKGROUND

Insulin-like growth factor-1 receptor (IGF-1R) is over-expressed in hepatocellular carcinoma (HCC). However, the relationship between IGF-1R activation and HCC progression remains unidentified.

AIM

To investigate the effects of editing IGF-1R on the biological features of HCC cells.

METHODS

Immunohistochemistry analyzed the expressions of IGF-1R and P-glyco protein (P-gp) in HCC tissues and their distal non-cancerous tissues (non-Ca). IGF-1R was edited with Crispr/Cas9 system, screened specific sgRNAs, and then transfected into HepG2 cells. CCK-8, scratch wound test detected cell proliferation, migration, invasion and transwell assays, respectively. Alterations of IGF-1R and P-gp were confirmed by Western blotting. Alterations of anti-cancer drug IC₅₀ values were analyzed at the cell level.

RESULTS

The positive rates of IGF-1R (93.6%, χ² = 63.947) or P-gp (88.2%, χ² = 58.448) were significantly higher (P < 0.001) in the HCC group than those (36.6% in IGF-1R or 26.9% in P-gp) in the non-Ca group. They were positively correlated between high IGF-1R and P-gp expression, and they were associated with hepatitis B virus infection and vascular invasion of HCC. Abnormal expressions of circulating IGF-1R and P-gp were confirmed and associated with HCC progression. Biological feature alterations of HCC cells transfected with specific sgRNA showed IGF-1R expression down-regulation, cell proliferation inhibition, cell invasion or migration potential decreasing, and enhancing susceptibility of HepG2 cells to anti-cancer drugs.

CONCLUSION

Edited oncogenic IGF-1R was useful to inhibit biological behaviors of HepG2 cells.

Circ-AK2 is associated with preeclampsia and regulates biological behaviors of trophoblast cells through miR-454-3p/THBS2

INTRODUCTION

Circ-AK2 has been found to be differentially expressed in PE placenta tissues, however, the role and the underlying molecular mechanisms of circ-AK2 in PE remain poorly known.

METHODS

The expression of circ-AK2, miR-454-3p, and THBS2 mRNA was detected using quantitative real-time polymerase chain reaction. Protein levels of CyclinD1, MMP-9 and THBS2 were measured using Western blot. Cell proliferation, migration, and invasion were analyzed by 3-(4, 5)-dimethylthiahiazo (-z-y1)-3, 5-di-phenytetrazoliumromide (MTT) assay and transwell assay. The interaction between miR-454-3p and circ-AK2 or THBS2 was analyzed by the dual-luciferase reporter assay.

RESULTS

Circ-AK2 was highly expressed in placental tissues of PE, and overexpression of circ-AK2 inhibited trophoblast cell proliferation, migration and invasion. Circ-AK2 directly bound to miR-454-3p, and miR-454-3p overexpression reversed the inhibitory action of circ-AK2 in biological functions of trophoblast cells. MiR-454-3p was lowly expressed in placental tissues of PE, and directly regulated THBS2 expression in a targeted manner. Silencing miR-454-3p suppressed the proliferating, migratory, and invasive abilities of trophoblast cells, while this condition was abolished by THBS2 knockdown. Besides, we also proved circ-AK2 could regulate THBS2 expression via miR-454-3p.

DISCUSSION

Circ-AK2 inhibited the proliferation, migration and invasion of trophoblast cells via targeting miR-454-3p/THBS2 axis, suggesting a novel insight into the etiology of PE and a potential therapeutic target for PE treatment.

HoxC6 Functions as an Oncogene and Isoform HoxC6-2 May Play the Primary Role in Gastric Carcinogenesis

PURPOSE

Based on previous researches of HoxC6, this study aims to investigate the expression levels of isoforms HoxC6-1 and HoxC6-2 and to explore their roles in gastric carcinogenesis as well as the possible molecular mechanism.

METHODS

We investigated expression levels of HoxC6, HoxC6-1, and HoxC6-2 in gastric cancer tissues, coupled with relevant data in TCGA dataset. In vitro, HoxC6, HoxC6-1, and HoxC6-2 knockdown by small interference RNA was carried for evaluating the changes of malignant biological behaviors of gastric cancer cells, such as proliferation, migration, invasion, apoptosis, and cell cycle alternation. Metastasis-related nucleotide lncRNA HOTAIR was selected by bioinformatics, and verification was carried out by in vitro researches.

RESULTS

Data suggested HoxC6-1 and HoxC6-2 were considerably over-expressed with different folds in gastric cancerous tissues. Decreased expression of HoxC6-2 was detected in well-differentiated type of gastric cancer. In vitro, the conclusion that HoxC6 functions as a tumor oncogene illuminated by previous studies was verified again. Additionally, down-regulating of HoxC6-2 significantly inhibited SGC-7901 and BGC-823 cells from proliferation, migration, invasion, apoptosis, while quite slight results or none statistically significant results were observed when HoxC6-1 was knockdown. Besides, over-expression of HOTAIR, which is relevant with HoxC6 during gastric carcinogenesis, was detected in gastric cancerous tissues. Restored expression of HoxC6 partially reversed the decreased migration caused by down-regulating HOTAIR in gastric cancer cells.

CONCLUSION

HoxC6 acts as an oncogene in gastric carcinogenesis and might be a promising therapeutic target. Isoform HoxC6-2 plays a primary carcinogenic role in gastric carcinogenesis. HOTAIR, over-expressed in gastric cancer, might regulate HoxC6 on the protein level in promoting migration of gastric cells.

Advanced oxidation protein products change biological behaviors of rat endometrial epithelial cells by activating ERK/P38 signaling pathways

Advanced oxidation protein products (AOPPs) are a family of oxidized protein compounds and could induce oxidative stress and inflammatory lesion in various cells. The accumulation of AOPPs was associated with female reproductive diseases such as polycystic ovary syndrome (PCOS), leiomyoma and endometriosis. However, the relationship between AOPPs and endometrial cells is unclear. To explore the effects of accumulated AOPPs on endometrial cells, we treated normal rat endometrial epithelial cells (rEECs) and endometriosis model rats with AOPPs. Primary rEECs were collected from 8-week-old female Wistar rats. Increasing the amount of AOPPs in the media of rEECs enhanced rEEC proliferation and migration, and inhibited apoptosis. Moreover, AOPPs triggered the production of reactive oxygen species and nitrite along with activated ERK and P38 signal and this, in turn, led to an upregulation of proliferation and migration. With the treatment of antioxidants or the inhibitors of ERK and P38, the above effects of AOPPs on rEECs were attenuated. Additionally, in an endometriosis rat model, a similar phenomenon was observed in that the growth of endometriotic implants were promoted by AOPPs and EECs were significantly increased. This study indicated that the accumulation of AOPPs could promote rEEC proliferation and migration through ERK and P38 signal both in vivo and in vitroThis article has an associated First Person interview with the first author of the paper.

Effects of statherin on the biological properties of titanium metals subjected to different surface modification

The failure of dental implants is usually caused by bacteria infection, poor bioactivity and biocompatibility. It is a common phenomenon clinically. Statherin, a salivary protein, plays a crucial role of mediator between materials and cells/bacteria. However, the conformation of statherin might be changed by the implants in vivo. In this study, we investigated the effects of statherin on the bioactivities, antibacterial abilities and biocompatibilities of the titanium metals and the reaction mechanism. We found that the conformation of statherin was mainly influenced by surface composition, surface structure, surface roughness, surface hydrophilia and Ti-OH groups of materials. Statherin could decrease the cell biocompatibility of the titanium metals including pure titanium (PT), anodic oxidation (AO), sandblasting and etching (SLA) and plasma spraying hydroxyapatite (HA) coating in HGF cell experiments, regulate the bio-mineralization ability of HA coating in SBF, and enhance the antibacterial properties of PT and HA coating. This study revealed that surface properties of materials could change the conformation of statherin, which influenced the bioactivities, antibacterial properties and biocompatibilities of the materials in return.

microRNA-27a-3p Down-regulation Inhibits Malignant Biological Behaviors of Ovarian Cancer by Targeting BTG1

Ovarian cancer is the most deadly malignant tumor. MicroRNA-27a-3p (miR-27a-3p) was a tumor oncogene in various cancers. However, the role and mechanism of miR-27a-3p in ovarian cancer are still unknown. In this study, we found that miR-27a-3p over-expression could significantly promote the viability of SK-OV-3 cells, enhance cell migration and invasion, and reduce cell apoptosis. Besides, results from western blot assay showed that miR-27a-3p over-expression could increase Bcl-2 protein expression and decrease Bax protein expression. Furthermore, TargetScan and the dual luciferase reporter gene assay revealed that BTG anti-proliferation factor 1 (BTG1) was a direct target of miR-27a-3p. In addition, we found that miR-27a-3p down-regulation suppressed SK-OV-3 cell viability, migration and invasion, and promoted cell apoptosis. All the effects of miR-27a-3p down-regulation on SK-OV-3 cells were reversed by BTG1-siRNA. Therefore, miR-27a-3p/BTG1 axis may be a new potential target for the treatment of ovarian cancer.

[Effects of MTA1 on biological behaviors of gastric cancer cells]

Objective: To study the effects of metastasis associated 1 (MTA1) on biological characteristics such as migration, invasion and proliferation of gastric cancer (GC) cells. Methods: pSilencer3.1-MTA1-siRNA vector was used to establish human gastric cancer BGC-823 cell lines with constitutive MTA1-knockdown. Boyden, wound healing, clony forming assay and 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2H tetrazolium bromide (MTT) assay were performed to identify the effects of MTA1-deficiency on the biological behaviors of BGC-823 cells in vitro. Simultaneously, MTA1 overexpressed BGC-823 cell line was established by pcDNA3-MTA1 plasmid transfection for reverse verification. In addition, the role of MTA1 in the tumorigenicity of gastric cancer BGC823 cells in vivo was examined by subcutaneous injection of BGC-823 cells expressing different MTA1 levels into nude mice. Reverse transcription-polymerase chain reaction (RT-PCR) and western blot were used to detect the expression levels of integrin β1, cyclin D1 and uPAR in pSilencer3.1-MTA1-siRNA, pcDNA3-MTA1 transfected cells and control cells. Results: MTA1 knocked down or upregulated BGC-823 cell lines were successfully generated by transfecting pSilencer3.1-MTA1-siRNA or pcDNA3-MTA1 vector with lipofectamine 2000, respectively. The Boyden and wound healing experiments showed metastasis and invasion ability in MTA1 knocked down cells (25±2, 12±1) were significantly decreased when compared with those of control (78±2, 50±2) and MTA1-overexpressed groups (218±2, 269±3; P<0.05). The results of MTT assay and colony forming assay were significantly decreased when compared with those of showed that MTA1 overexpressed cells grew more rapidly and formed more colonies in vitro and induced worse malignant tumors in vivo, while MTA1 knocked down cells presented the reversed phenotype[control group (1 482.41±511.90) mm(3,) (1.39±0.29)g; MTA1 overexpressed group [(3 158.73±1 823.22) mm(3,) (2.23±0.51)g; MTA1-downregulated group (711.32±284.30)mm(3,) (0.87±0.21) g ; P<0.05)]. In addition, RT-PCR result showed that the expression level of MTA1 was positively correlated with the known metastasis-related genes (integrinβ1, cyclinD1, uPAR). Conclusions: MTA1 promotes the invasion, migration and proliferation of human gastric cancer BGC-823 cells. On the contrary, down-regulation of MTA1 significantly inhibits tumorigenicity of BGC-823 cells and induces favorable phenotypes. MTA1 may promote the malignant phenotype of BGC-23 cells via regulating the expressions of integrinβ1, cyclinD1 and uPAR.

Regulating the surface poly(ethylene glycol) density of polymeric nanoparticles and evaluating its role in drug delivery in vivo

Poly(ethylene glycol) (PEG) is usually used to protect nanoparticles from rapid clearance in blood. The effects are highly dependent on the surface PEG density of nanoparticles. However, there lacks a detailed and informative study in PEG density and in vivo drug delivery due to the critical techniques to precisely control the surface PEG density when maintaining other nano-properties. Here, we regulated the polymeric nanoparticles' size and surface PEG density by incorporating poly(ε-caprolactone) (PCL) homopolymer into poly(ethylene glycol)-block-poly(ε-caprolactone) (PEG-PCL) and adjusting the mass ratio of PCL to PEG-PCL during the nanoparticles preparation. We further developed a library of polymeric nanoparticles with different but controllable sizes and surface PEG densities by changing the molecular weight of the PCL block in PEG-PCL and tuning the molar ratio of repeating units of PCL (CL) to that of PEG (EG). We thus obtained a group of nanoparticles with variable surface PEG densities but with other nano-properties identical, and investigated the effects of surface PEG densities on the biological behaviors of nanoparticles in mice. We found that, high surface PEG density made the nanoparticles resistant to absorption of serum protein and uptake by macrophages, leading to a greater accumulation of nanoparticles in tumor tissue, which recuperated the defects of decreased internalization by tumor cells, resulting in superior antitumor efficacy when carrying docetaxel.

Changes in biological behaviors of rat dermal fibroblasts induced by high expression of MMP9

BACKGROUND

The high level of matrix metalloproteinase 9 (MMP9) is thought to slow down the healing of diabetic foot ulcers. Whether it can influence the biological behaviors of skin fibroblasts and affect wound healing is still unclear. The present study aimed to observe changes in the biological behaviors of rat dermal fibroblasts induced by high expression of MMP9 and to clarify the possible mechanisms of wound healing for diabetic foot.

METHODS

A cell model of skin fibroblast with high expression of MMP9 was established by co-culture of high glucose (22.0 mmol/L) and homocysteine (100 μmol/L). A control group was incubated with normal glucose (5.5 mmol/L). Realtime PCR, ELISA and gelatin zymography were used to detect the MMP9 mRNA, protein expression and activity of MMP9. Flow cytometry, CCK-8, ELISA assay, scratch test and transwell were used to detect cell proliferation, viability, collagen (hydroxyproline) secretion, horizontal migration and vertical migration of cells. The data were expressed as mean±SD. P value less than 0.05 was considered statistically significant.

RESULTS

The expression of MMP9 mRNA, protein levels and the activity of MMP9 were much higher in the high MMP9 group than in the control group (7.05±1.02 vs. 1.00±0.00, 206.9±33.6 pg/mL vs. 40.4±5.9 pg/mL, and 1.47±0.13 vs. 0.57±0.12, respectively, P<0.01). The proportion of S-phase cells, proliferation index, cell viability, collagen (hydroxyproline) secretion, horizontal migration rate and the number of vertical migration cells were lower in the high MMP9 group than in the control group (P<0.01).

CONCLUSION

Fibroblasts with a high expression of MMP9 decreased proliferation, activity, secretion and migration of collagens, suggesting that MMP9 may inhibit the biological behaviors of fibroblasts.