Matrix metalloproteinase-cleavable nanocapsules for tumor-activated drug release

In the war against cancer, nanotechnology-based drug delivery systems may play a significant role by enhancing the efficacy of conventional therapies. Here, we tried to address some major limitations plaguing anticancer drugs, namely, poor water solubility and off-target toxicity. The systems we propose are cross-linked polyelectrolyte nanocapsules based on an oil-core and a matrix metalloproteinase-2 (MMP-2)-cleavable shell. They can load hydrophobic drugs, prevent their systemic leakage, and release their payload upon an endogenous stimulus. Both the stability enhancement and the stimuli-responsive drug release mechanisms were achieved by cross-linking the nanocapsule shell with an MMP-2-sensitive peptide. On the basis of this strategy, the system maintained its stability in PBS up to one month. Further, when tested on 3D tumor and healthy spheroid models, the nanocapsules were able to disrupt their integrity preferentially in the tumor-like microenvironment. The high level of MMP-2 enzymes expressed by tumor spheroids, indeed, catalyzed the disassembly of the nanocapsules, which ultimately leads to drug release. Therefore, this device holds great potential as a smart system that allows for the safe transport of hydrophobic drugs and for a spatially controlled release upon an endogenous stimulus coming from the very nature of the tumor itself. STATEMENT OF SIGNIFICANCE: The performance of nanoparticle-based therapeutic approaches is often hindered by some intrinsic limitations typically including laborious drug loading methods, synthetic routes of preparation and stability issues. In this work, we implemented for the first time a smart drug delivery strategy into oil-core multilayer nanocapsules, which represent an ideal family of nanocarriers. To this aim, we developed a robust method enabling the use of soft matters like oil-core nanocapsules combined with a microenvironmentally triggered release mechanism. The efficacy of nanocapsules was tested on tumor and healthy spheroids. Results clearly demonstrate their selective drug release, triggered by a stimulus intrinsically present in tumor microenvironment. We believe this study is of particular interest for cancer research and paves the way for the use of these robust stimuli-responsive nanocapsules in vivo.

MGF enhances tenocyte invasion through MMP-2 activity via the FAK-ERK1/2 pathway

Tendon regeneration and healing requires tenocytes to move to the repair site followed by proliferation and synthesis of the extracellular matrix. A novel synthetic growth factor, mechano-growth factor (MGF), has been discovered to have positive roles in tissue repair through the improvement of cell proliferation and migration and the protection of cells against injury-induced apoptosis. However, it remains unclear whether MGF has the potential to accelerate tendon repair. In this study, using a transwell system, we found that MGF-C25E (a synthetic mechano-growth factor E peptide) significantly promotes tenocyte invasion, which was accompanied by the increased phosphorylation of focal adhesion kinase (FAK) and extracellular signal regulated kinase1/2 (ERK1/2) as well as the increased activity of matrix metalloproteinases-2 (MMP-2). The MMP-2 inhibitor OA-Hy blocked MGF-C25E-promoted tenocyte invasion. Inhibitors of FAK or ERK1/2 blocked MGF-C25E-promoted tenocyte invasion and MMP-2 activity as well. These results indicate that MGF-C25E promotes tenocyte invasion by increasing MMP-2 activity via the FAK-ERK1/2 signaling pathway. Taken together, our findings provide the first evidence that MGF-C25E enhances tenocyte invasion and indicate that it may serve as a potential repair material for promoting the healing and regeneration of injured tendons.

Platelet-Derived Growth Factor Receptor-α and β are Involved in Fluid Shear Stress Regulated Cell Migration in Human Periodontal Ligament Cells

Introduction

Fluid shear stress (FSS) is the most common stress produced by mastication, speech, or tooth movement. However, how FSS regulates human periodontal ligament (PDL) cell proliferation and migration as well as the underlying mechanism remains unknown.

Methods

FSS (6 dyn/cm²) was produced in a flow chamber. Cell proliferation was tested by the 5-ethynyl-2'-deoxyuridine assay. Cell migration was tested by the wound healing assay. Gene and protein expression of platelet-derived growth factors (PDGFs) and matrix metalloproteinase (MMP)-2 were measured by reverse transcription-polymerase chain reaction and western blot analyses.

Results

We investigated the effect of 4 h of 6 dyn/cm² FSS on proliferation and migration of PDL cells. FSS promoted PDL cell proliferation but inhibited migration. The gene and protein expression of PDGF receptor (PDGFR)-α and β both decreased in response to FSS. Activating and inhibiting the PDGFRs did not affect the FSS-induced increase in cell proliferation. However, activating PDGFRs with PDGF-BB, which bound both PDGFR-α and β, and PDGF-CC and DD, which had high affinities for PDGFR-α and PDGFR-β, individually rescued FSS-inhibited migration. FSS also inhibited MMP-2 gene expression, which was the most important factor for matrix turnover and migration of PDLs. PDGF-BB, CC, and DD increased the FSS-induced decline in MMP-2 expression. These results indicate that MMP-2 is regulated by FSS and contributes to the FSS-induced decrease in cell migration.

Conclusions

Our study suggests a role for PDGFR-α and β in short-term FSS-regulated cell proliferation and migration. These results will help provide the scientific foundation for revealing the mechanisms clinical tooth movement and PDL regeneration.

Relationship between metalloproteinase-2 and -9 levels in plasma and vaginal secretion with preterm birth

OBJECTIVE

To study the association of plasma and vaginal levels of matrix metalloproteinases 2 (MMP-2) and 9 (MMP-9), determined between 20⁺⁰ and 25⁺⁶ weeks of gestation, with preterm birth and its predictive value.

STUDY DESIGN

All 129 cases of preterm birth (cases) and 258 randomly selected term patients (control group) were included in a cohort study with a nested case-control design. Inclusion criteria were living in Ribeirão Preto, Brazil, and gestational age 20⁺⁰ to 25⁺⁶ at enrollment. Exclusion criteria were multiple fetuses, congenital malformations or chromosome syndromes, and loss to follow-up. Maternal age, parity, smoking, and previous preterm birth were included as covariates. A blood sample and vaginal secretion were obtained for the determination of MMP-2 and MMP-9; the patients were screened for urinary tract infection and bacterial vaginosis, and cervical length was measured by ultrasound. The cut-off values for matrix metalloproteinases were calculated using receiver operating characteristic (ROC) curves for logistic regression analysis (crude and adjusted odds ratios).

RESULTS

According to the WHO, in this study, preterm subtypes included 3.8 % extremely preterm, 6.9 % very preterm, and 89.2 % late preterm births. The plasma MMP-9 cut-off was 63.25 ng/mL and the area under the ROC curve was 0.725 (standard error 0.03; 95 % confidence interval, 0.677-0.769). The cut-off for plasma MMP-2 was 239.4 ng/mL and the area under the ROC curve was 0.585 (standard error 0.03, 95 % confidence interval, 0.521-0.649). Crude odds ratios showed an increased risk of preterm birth associated with plasma MMP-2 (odds ratio, 1.75; 95 % confidence interval, 1.14-2.68) and plasma MMP-9 (odds ratio, 3.26, 95 % confidence interval, 2.09-5.07); no association was detected for vaginal MMP-2 or 9. For plasma, adjusted odds ratios were 1.42 (95 % confidence interval, 0.80-2.53) for MMP-2 and 2.71 (95 % confidence interval, 1 .52-4.83) for MMP-9, along with an increased risk in other covariates.

CONCLUSION

Elevated plasma MMP-9 levels and decreased MMP-2 levels were positively associated with preterm birth. Plasma MMP-9 level increased nearly three times the preterm risk.

Expression of matrix metalloproteinases-2 and -9 in esophageal carcinoma and their relationship with trace elements

AIM: To explore the role of matrix metalloproteinase-2 (MMP-2), MMP-9 and trace elements in the occurrence, growth, invasion and metastasis of esophageal carcinoma.

METHODS: The expression of MMP-2 and MMP-9 in 49 esophageal carcinoma specimens and 16 carcinoma-adjacent esophageal tissue specimens was detected by immunohistochemistry. The correlation of MMP-2 and MMP-9 expression with tumor grade, differentiation, lymph node metastasis, and patients' gender and age was analyzed. The content of trace elements in esophageal carcinoma was measured using a Shimadzu AA-670 atomic absorption spectrophotometer.

RESULTS: The positive rates of MMP-2 and MMP-9 expression in esophageal carcinoma were higher than that in carcinoma-adjacent esophageal tissue (69.3% vs 12.5% and 71.4% vs 6.25%, respectively, both P < 0.05). The positive rates of MMP-2 and MMP-9 expression were significantly higher in esophageal carcinoma patients with lymph node metastasis than in those without lymph node metastasis (85.7% vs 47.6% and 82.1% vs 52.3%, respectively, both P < 0.05). The positive rates of MMP-2 and MMP-9 expression were not correlated with tumor differentiation, pathologic type, and patients' age and gender (all P > 0.05). The average content of zinc (Zn) and the ratio of Zn to copper (Cu) in esophageal carcinoma were significantly lower than those in carcinoma-adjacent tissue (8.13 μg/g ± 3.08 μg/g vs 11.63 μg/g ± 3.49 μg/g; 7.50 ± 3.65 vs 15.40 ± 6.84; both P < 0.05). The Zn/Cu ratio in adenocarcinoma was significantly lower than that in squamous cell carcinoma (4.48 ± 3.52 vs 8.02 ± 3.45, P < 0.05). The average content of selenium (Se) in adenocarcinoma was significantly higher than that in squamous cell carcinoma (0.91 μg/g ± 1.72 μg/g vs 0.29 μg/g ± 0.28 μg/g, P < 0.05). The average content of Zn in esophageal carcinoma and the Zn/Cu ratio in patients with lymph node metastasis were significantly lower than those in esophageal carcinoma tissue and patients without lymph node metastasis, respectively (7.72 μg/g ± 3.03 μg/g vs 9.59 μg/g ± 3.06 μg/g; 6.91 ± 3.86 vs 9.93 ± 4.81; both P < 0.05). The content of trace elements in esophageal carcinoma was not correlated with tumor differentiation, pathologic type, and patients' age and gender.

CONCLUSION: MMP-2 and MMP-9 expression, Zn content, and Zn/Cu ratio are closely correlated with the occurrence, growth and metastasis of esophageal carcinoma. Combined detection of trace element content and MMP-2 and MMP-9 expression may provide an objective indicator to estimate the biological behavior and prognosis of esophageal carcinoma.

Expression of matrix Metalloproteinases-2 and aquaporin-1 in corneoscleral junction after angle-closure in rabbits

Background

To investigate the expression of Matrix Metalloproteinases 2 and aquaporin-1 in corneoscleral junction and explore the mechanism of trabecular damageafter angle-closure.

Methods

Thirty New Zealand white rabbits were randomly assigned into 2 groups, theexperimental group (Group 1) including twenty five rabbits and the control group (Group 2) including 5 rabbits. The rabbits in the experimental group were used to establish angle-closure models, and the rabbits in the control group were not subjected to any operation. All the rabbits were followed by slit lamp microscopy, Tonopen tonometer, and anterior segment optical coherent tomography (AS-OCT). The expressions of metalloproteinase MMP-2, aquaporin-1, and tissue inhibitors of metalloproteinase-2 in corneoscleral junctionwere evaluatedin both groups byimmunofluorescence, quantitative reverse-transcription polymerase chain reaction (qRT-PCR), and enzyme-linked immunosorbent assay (ELISA).

Results

Slit-lamp examination showed that angle-closure model was successfully established in twenty rabbits. The extent of angle-closure was about 2 to 4 clock hours in all the rabbit models, but the intraocular pressure (IOP) of the rabbits distributed from 8.57 to 15.25 mmHg and no significant high IOP was found in the follow-up period. The AQP-1-positive cells mainly located in Schlemm’s canal, the inner surface of trabecular meshwork (TM), and the surface of iris, which began to decline on 1 month after angle-closure. MMP2 staining was diffuse in trabecular meshwork and iris. Immunofluorescence signal of MMP2 was strong within 1 month after angle-closure, and subsequently became weak. qRT-PCR and ELISA showed that the expression of MMP-2 and TIMP-2 increased within 1 month after angle-closure and then declined gradually. The AQP-1 levels showed slightly declined on 1 month after angle-closure.

Conclusions

Altered levels of MMPs, TIMPs, and AQP-1 were found in the area of angle-closure, which may be involved in the damage of TM and Schlemm’s canal after angle-closure.

Antisense Deoxyoligonucleotides Inhibit Activities of Matrix Metalloproteinase-2 in Human Fibrosarcoma HT1080 Cells

PURPOSE

MMP-2, 72 kDa-type IV collagenase, plays a major role in the migration and growth of tumor cells, a process that requires the disintegration of basement membrane. Activation of MMP-2 is correlated with the invasiveness of various tumors. The aim of this study was to determine the sequence-specific phosphorothioated oligodeoxynucleotides (ODNs) inhibiting the translation of MMP-2 mRNA and the subsequent invasiveness of tumor cells.

MATERIALS AND METHODS

Eight types of antisense ODNs were designed and each (8micro gram/ml) were transfected into HT1080 cells. The effects of these antisense ODNs on MMP expression were examined by gelatin zymography, Western blot, Northern blot and matrigel assay.

RESULTS

Antisense-5 (+904~923), antisense-6 (+1274~+1293) and antisense-7 (+1646~+1665) reduced the MMP-2 activity of the culture supernatant in HT1080 fibrosarcoma cells. Treatment with antisense-6 showed inhibition of MMP-2 mRNA and protein, and in vitro invasion in a dose-dependent manner.

CONCLUSION

Antisense-6 might be one of the therapeutic candidates for tumor invasion and metastasis.

Association between elevated serum matrix metalloproteinase-2 and tumor necrosis factor-α, and clinical symptoms in male patients with treatment-resistant and chronic medicated schizophrenia

BACKGROUND

Inflammation has an important role in the pathogenesis of schizophrenia. The aim of this study was to investigate the levels of tumor necrosis factor (TNF) and matrix metalloproteinase-2 (MMP-2) in male patients with treatment-resistant schizophrenia (TRS) and chronic medicated schizophrenia (CMS), and the relationship with psychopathology.

METHODS

The study enrolled 31 TRS and 49 cm male patients, and 53 healthy controls. Serum MMP-2 and TNF-α levels were measured by the Luminex liquid suspension chip detection method. Positive and Negative Syndrome Scale (PANSS) scores were used to evaluate symptom severity and Repeatable Battery for the Assessment of Neuropsychological Status was used to assess cognitive function.

RESULTS

Serum TNF-α and MMP-2 levels differed significantly between TRS, CMS and healthy control patients (F = 4.289, P = 0.016; F = 4.682, P = 0.011, respectively). Bonferroni correction demonstrated that serum TNF-α levels were significantly elevated in CMS patients (P = 0.022) and MMP-2 levels were significantly higher in TRS patients (P = 0.014) compared to healthy controls. In TRS patients, TNF-α was negatively correlated with age (r=-0.435, P = 0.015) and age of onset (r=-0.409, P = 0.022). In CMS patients, MMP-2 and TNF-α were negatively correlated with PANSS negative and total scores, and TNF-α was negatively correlated with PANSS general psychopathology scores (all P < 0.05). MMP-2 levels were positively correlated with TNF-α levels (P < 0.05), but not with cognitive function (P > 0.05).

CONCLUSION

The results indicate the involvement of inflammation in the etiology of TRS and CMS. Further studies are warranted.