The association between activation of the ERK1/2-NF-κB signaling pathway by TIMP2 expression and chronic renal allograft dysfunction in the CRAD rat model

PURPOSE

The tissue inhibitor of metalloproteinase 2 (TIMP2), a natural inhibitor of matrix metalloproteinase (MMP), regulates inflammation, fibrosis, and cell proliferation. Chronic renal allograft dysfunction (CRAD) is a primary factor affecting the long-term survival of renal allografts. We assessed whether up-regulation of TIMP2 expression may affect the ERK1/2-NF-κB signaling pathway and CRAD development.

METHODS

Lewis rats received orthotopic F344 kidney allografts to establish the classical CRAD model. The treatment group was injected with a lentivirus encoding a TIMP2-targeting small hairpin (sh)RNA (LTS) at 5 × 108 TU/ml monthly after kidney transplantation. A second CRAD group was injected with a lentivirus TIMP2-control vector (LTC). After 12 weeks, blood, urine, and kidney tissue were harvested to evaluate renal function and pathological examinations. Hematoxylin and eosin staining, Masson staining, and Periodic acid-Schiff staining were performed for renal histopathological evaluation according to the Banff criteria. TIMP2, phospho (p)-ERK1/2, p-p65 (NF-κB) expression levels were measured via immunohistochemical and Western blot analyses.

RESULTS

Compared to the F344 and Lewis control groups, the expression of TIMP2, p-ERK1/2, and p-p65 were significantly higher in the CRAD and CRAD+LTC renal tissues (p < 0.05). There were also increased levels of serum creatinine, nitrogen, and 24 h urinary protein in these two groups (p < 0.05). Typical histopathological changes of CRAD were observed in the CRAD and CRAD+LTC groups. Administration of LTS effectively decreased the expression of TIMP2, p-ERK1/2, and p-P65, and reduced interstitial fibrosis and macrophage infiltration in the treatment group (p < 0.05). Additionally, MCP1 and ICAM-1, which are downstream cytokines of the NF-κB pathway, were also inhibited in the renal rat kidney from the LTS group (p < 0.05). Furthermore, renal function was well preserved in the LTS group compared to the CRAD group and CRAD+LTC group.

CONCLUSION

A decrease of TIMP2 can alleviate the progression of inflammation in CRAD via inhibition of the ERK1/2-NF-κB signaling pathway.

Urinary TIMP-2*IGFBP-7 to diagnose acute kidney injury in children receiving cisplatin

BACKGROUND

Cisplatin is associated with acute kidney injury (AKI) and electrolyte abnormalities. Urine tissue inhibitor of metalloproteinase 2 (TIMP-2) and insulin-like growth factor-binding protein 7 (IGFBP-7) may be early cisplatin-AKI biomarkers.

METHODS

We conducted a 12-site prospective cohort study with pediatric patients treated with cisplatin (May 2013-December 2017). Blood and urine (measured for TIMP-2, IGFBP-7) were collected pre-cisplatin, 24-h post-cisplatin, and near hospital discharge during the first or second cisplatin cycle (early visit (EV)) and during second-to-last or last cisplatin cycle (late visit (LV)).

PRIMARY OUTCOME

serum creatinine (SCr)-defined AKI (≥ stage 1).

RESULTS

At EV (median (interquartile (IQR)) age: 6 (2-12) years; 78 (50%) female), 46/156 (29%) developed AKI; at LV, 22/127 (17%) experienced AKI. At EV, TIMP-2, IGFBP-7, and TIMP-2*IGFBP-7 pre-cisplatin infusion concentrations were significantly higher in participants with vs. those without AKI. At EV and LV, biomarker concentrations were significantly lower in participants with vs. those without AKI at post-infusion and near-hospital discharge. Biomarker values normalized to urine creatinine were higher in patients with AKI compared to without (LV post-infusion, median (IQR): TIMP-2*IGFBP-7: 0.28 (0.08-0.56) vs. 0.04 (0.02-0.12) (ng/mg creatinine)2/1000; P < .001). At EV, pre-infusion biomarker concentrations had the highest area under the curves (AUC) (range: 0.61-0.62) for AKI diagnosis; at LV, biomarkers measured post-infusion and near discharge yielded the highest AUCs (range: 0.64-0.70).

CONCLUSIONS

TIMP-2*IGFBP-7 were poor to modest at detecting AKI post-cisplatin. Additional studies are needed to determine whether raw biomarker values or biomarker values normalized to urinary creatinine are more strongly associated with patient outcomes. A higher resolution version of the Graphical abstract is available as Supplementary information.

Urinary cell cycle biomarkers for the prediction of renal non-recovery in patients with septic acute kidney injury: a prospective study

BACKGROUND

Poor prognosis has been associated with the absence of renal recovery after acute kidney injury (AKI). This study aimed to investigate whether urinary biomarkers at 0 and 24 h could be used independently or in conjunction with a clinical model to predict renal non-recovery in septic AKI.

METHODS

A prospective observational study was conducted to measure the urinary levels of insulin-like growth factor-binding protein 7 (IGFBP7) and tissue inhibitor of metalloproteinase-2 (TIMP-2) at the time of AKI diagnosis (0 h) and 24 h later. Renal non-recovery within 7 days was defined as the outcome. The predictive value of urinary biomarkers for renal non-recovery in septic AKI was assessed using the area under the curve (AUC).

RESULTS

A total of 198 individuals with septic AKI were included in the final analysis. Among them, 38.9% (n = 77) did not experience renal recovery within 7 days. The combination of urinary IGFBP7 and TIMP-2 at the initial time point demonstrated prognostic value for non-recovery of renal function, with an AUC of 0.782. When [TIMP-2]*[IGFBP7] was measured at 0 h, the clinical prognostic model, incorporating AKI stage 2-3 and the non-renal sequential organ failure assessment score, showed an improved AUC of 0.822 (with a sensitivity of 88.3% and specificity of 59.5%).

CONCLUSIONS

The combination of urinary [TIMP-2]*[IGFBP7] at 0 h exhibited moderate predictive ability for renal non-recovery in cases of septic AKI. However, there is potential to enhance the prognostic capabilities of the [TIMP-2]*[IGFBP7]-clinical prediction model.

Combination of biomarker with clinical risk factors for prediction of severe acute kidney injury in critically ill patients

Background

Acute kidney injury (AKI) occurs commonly in the intensive care unit (ICU). Insulin-like growth factor-binding protein 7 (IGFBP7) and tissue inhibitor of metalloproteinase-2 (TIMP-2), known as [TIMP-2] x [IGFBP7] (NephroCheck), have been identified as novel biomarkers for the prediction of AKI risk. However, the effective use of disease biomarkers is indispensable from an appropriate clinical context. We conducted a retrospective cohort study to find risk factors and assess the performance of the combination of NephroCheck with risk factors, so as to provide feasible information for AKI prediction.

Methods

All patients who were admitted in the ICU (from June 2016 to July 2017) participated in the study. The primary outcome was the detection of severe AKI within the first 7 days after patients being admitted to the ICU. The predictors were separated into three categories: chronic risk factors, acute risk factors and biochemical indicators.

Results

The study included 577 patients. 96 patients developed to severe AKI (16.6%) within 7 days. In addition to NephroCheck (+) (OR = 2.139, 95% CI (1.260–3.630), P = 0.005), age > 65 years (OR = 1.961, 95% CI (1.153–3.336), P = 0.013), CKD (OR = 2.573, 95% CI (1.319–5.018), P = 0.006) and PCT (+)(OR = 3.223, 95% CI (1.643–6.321), P = 0.001) were also the independent predictors of severe AKI within 7 days. Compared to NephroCheck (+) only (AUC = 0.66, 95% CI:0.60–0.72), the combination of NephroCheck (+) and risk factors (age > 65 years, CKD and PCT positive) (AUC = 0.75, 95% CI:0.70–0.81) led to a significant increase in the area under ROC curve for severe AKI prediction within 7 days.

Conclusions

Although NephroCheck is an effective screening tool for recognizing high-risk patients, we found that combination with biomarker and risk factors (age > 65 years, CKD, procalcitonin positive) for risk assessment of AKI has the greatest significance to patients with uncertain disease trajectories.

Tissue inhibitor of metalloproteinase-2 (TIMP-2) from red seabream (Pagrus major): Molecular cloning and biochemical characterization of highly expressed recombinant protein

The tissue inhibitor of metalloproteinase-2 (TIMP-2) is originally characterized as an endogenous inhibitor of matrix metalloproteinases (MMPs) to response collagenolysis associated with immune challenge. In this study, the cDNA encoding TIMP-2a gene from red seabream (Pagrus major) muscle was cloned. It was 585 bp encoding a putative protein of 194 amino acids, which comprised all recognized functional domains and showed the high identity to TIMP-2as from other teleost fishes, revealing it belongs to TIMP-2a family. Soluble rTIMP-2a was efficiently expressed using a new constructed pPIC9K-rTIMP-2a vector with high inhibitory activity against to MMP-2 and MMP-9. The recombinant TIMP-2a tagged with 6 histidine residues showed the molecular mass of 23 kDa and isoelectric point of 6.50. Furthermore, the 6 disulfide bonds formed by 12 conserved cysteine residues were identified as functional motifs for its structural stability. In addition, rTIMP-2a possessed the high inhibitory activity against gelatinolytic hydrolysis and degradation of type I collagen which induced by endogenous MMPs in muscle. The results revealed the properties and inhibitory function of rTIMP-2a, which may be a pivotal role in regulation gelatinolytic MMPs metabolization during defense mechanism.

Effects of glucocorticoid on the eye development in guinea pigs

Glucocorticoid (GC) has been widely used in clinic. However, the effect of GC on normal and myopic development of eyes is still unknown. In this study, 3-week-old guinea pigs were randomly divided into four groups: No-Lens (control), GC+No-Lens, negative lens-induced myopia (LIM), and GC+LIM. To induce myopia, right eyes were covered with a -10 D lens in GC+LIM and LIM groups. GC+No-Lens and GC+LIM groups received intraperitoneal injections of hydrocortisone (10 mg/kg) once daily for 2 weeks, and then received intragastric hydrocortisone (32.5 mg/kg) every other day for the next 4 weeks, while No-Lens (control) and LIM groups were injected intraperitoneally with saline for 2 weeks, and then given saline by intragastric administertion for the next 4 weeks. Several parameters were assessed: ocular axial length and refractive error, sclera thickness, matrix metalloprotein-2 (MMP-2) and tissue inhibitor metalloprotease-2 (TIMP-2) expressions and localization of the posterior sclera, plasma concentrations of free triiodothyronine (FT3), free thyroxine (FT4), testosterone (T), and oestradiol (E2). Results indicated that: (1) in normal eye development, hydrocortisone could inhibit both the axial elongation and the myopic shift; whereas (2) in LIM eye development, hydrocortisone (a) enhanced the axial elongation, myopic shift and sclera thinning; (b) enhanced the MMP-2 expression and decreased TIMP-2 expression, and (c) elevated the plasma concentration of E2 but decreased the levels of FT3, FT4, and T. In conclusion, glucocorticoid may influence both normal and LIM eye development. The balance of the hormones is fundamental for the eye development.

MMP-2 and TIMP-2 in Patients with Heart Failure and Chronic Kidney Disease

The aim of the study was to assess MMP-2 (matrix metalloproteinase-2) and TIMP-2 (tissue inhibitor of metalloproteinase-2) serum levels in patients with diverse types of heart failure (HF) and chronic kidney disease (CKD).

101 patients with chronic HF were enrolled. Each patient has assessed the serum levels of MMP-2, TIMP-2, and NT-proBNP. Patients were initially classified into 2 groups based on their LVEF. 43 patients were classified into the HFREF group (HF with Reduced Ejection Fraction) and 58 characterized as HFPEF (HF with Preserved Ejection Fraction). Next, all patients were subdivided into 4 groups according to the degree of diastolic dysfunction.

38 patients with CKD were classified into HF/CKD(+) group. The HF/CKD(-) (HF without CKD) group comprised 61 patients.

This study provides original data on positive correlation between ejection fraction and MMP-2 levels in all patients with heart failure. Elevated levels of MMP-2 and TIMP-2 were found in serum from patients with chronic kidney disease; in addition, serum levels of MMP-2 were correlated with the degree of kidney failure. In all groups of patients there was positive correlation between MMP-2 and TIMP-2. Among patients with heart failure etiology was not related to MMP-2 and TIMP-2 serum levels.

Prognostic value of cell cycle arrest biomarkers in patients at high risk for acute kidney injury: A systematic review and meta-analysis

Urinary tissue inhibitor of metalloproteinase-2 (TIMP-2) and insulin-like growth factor binding protein 7 (IGFBP7) are G1 cell cycle arrest biomarkers. This systematic review aimed to evaluate the prognostic value of urinary [TIMP-2]·[IGFBP7] in patients at high risk for AKI. The MEDLINE (via PubMed), Ovid, EMBASE and Cochrane Library databases were systematically searched from inception to December 25, 2016. Original clinical studies which met the eligibility criteria were included in this study. The prognostic accuracy of urinary [TIMP-2]·[IGFBP7] for assessing the need for renal replacement therapy (RRT) and mortality was evaluated by pooled sensitivity, specificity, diagnostic odds ratio, and summary receiver operating characteristic curves. A total of four prospective cohort studies evaluating 277 patients were included. The estimated area under the receiver operating characteristic curve (AUC) of urinary [TIMP-2]·[IGFBP7] for predicting the need for RRT in patients at high risk for AKI was 0.915 (standard error [SE] = 0.040). Pooled sensitivity and specificity with corresponding 95% confidence intervals (CI) were 0.69 (95% CI 0.53-0.82) and 0.81 (95% CI 0.75-0.86), respectively. Urinary [TIMP-2]·[IGFBP7] for mortality prediction in patients at high risk for AKI was assessed by qualitative description. Based on the above data, urinary [TIMP-2]·[IGFBP7] performs well in predicting the need for RRT and mortality in patients at high risk for AKI. However, further meta-analyses are warranted as more data become available.

The Impact of Preexisting Chronic Kidney Disease on the Severity and Recovery of Acute Kidney Injury

BACKGROUND

Recent observational studies have shown that in chronic kidney disease (CKD) patients, a significantly smaller percentage of patients with an episode of acute kidney injury (AKI) have full recovery of renal function compared to those without CKD. However, precise mechanisms involved in the incomplete repair after AKI with preexisting CKD have not been completely ascertained. Here, we assessed the impact of preexisting CKD on the severity and recovery of AKI in a mouse model of 5/6 nephrectomy.

METHODS

Male CD-1 mice underwent 5/6 nephrectomy (Nx). Six weeks post surgery, ischemia reperfusion injury (IRI) or a sham operation was performed and functional, histological, and various molecular parameters were compared between them.

RESULTS

Serum creatinine level on day 1 after IRI was comparable between control and Nx mice. However, serum creatinine remained significantly higher throughout the recovery phase in Nx mice compared to control mice. mRNA and protein expression of the cell cycle regulatory proteins were persistently elevated in Nx mice and this was associated with significantly increased levels of the G1 cell cycle arrest markers. Treatment with a p53 inhibitor following IRI resulted in not only decreased expression of G1 arrest markers but also decreased fibrosis, suggesting that prolonged epithelial G1 cell cycle arrest might be partially responsible for impaired recovery from superimposed AKI on CKD.

CONCLUSION

Taken together, reduced nephron mass have a negative effect on the repair process that is partially mediated by the disruption of the cell cycle regulation.

Diagnostic value of urinary tissue inhibitor of metalloproteinase-2 and insulin-like growth factor binding protein 7 for acute kidney injury: a meta-analysis

Background

Tissue inhibitor of metalloproteinase-2 (TIMP-2) and insulin-like growth factor binding protein 7 (IGFBP7), inducers of G₁ cell cycle arrest, are two recently discovered good biomarkers for early diagnosis of acute kidney injury (AKI). To obtain a more robust performance measurement, the present meta-analysis was performed, pooling existing studies.

Methods

Literature in the MEDLINE (via PubMed), Ovid, Embase, and Cochrane Library databases was systematically searched from inception to 12 October 2016. Studies that met the set inclusion and exclusion criteria were identified by two independent investigators. The diagnostic value of urinary [TIMP-2] × [IGFBP7] for AKI was evaluated by pooled sensitivity, specificity, likelihood ratio (LR), diagnostic odds ratio (DOR), and summary receiver operating characteristic (SROC) curve analyses. The causes of heterogeneity were explored by sensitivity and subgroup analyses.

Results

A total of nine published and eligible studies assessing 1886 cases were included in this meta-analysis. Early diagnostic value of urinary [TIMP-2] × [IGFBP7] for AKI was assessed using a random-effects model. Pooled sensitivity and specificity with corresponding 95% CIs were 0.83 (95% CI 0.79–0.87, heterogeneity I² = 68.8%) and 0.55 (95% CI 0.52–0.57, I² = 92.9%), respectively. Pooled positive LR, negative LR, and DOR were 2.37 (95% CI 1.87–2.99, I² = 82.6%), 0.30 (95% CI 0.21–0.41, I² = 43.4%), and 9.92 (95% CI 6.09–16.18, I² = 38.5%), respectively. The AUC estimated by SROC was 0.846 (SE 0.027) with a Q* value of 0.777 (SE 0.026). Sensitivity analysis indicated that one study significantly affected the stability of pooled results. Subgroup analysis showed that population setting and AKI threshold were the key factors causing heterogeneity in pooled sensitivity and specificity.

Conclusions

On the basis of recent evidence, urinary [TIMP-2] × [IGFBP7] is an effective predictive factor of AKI.

Trial registration

PROSPERO registration number: CRD42016051186. Registered on 10 November 2016.

Clinical Implication of Aortic Wall Biopsy in Aortic Valve Disease with Bicuspid Valve Pathology

Background

Although unique aortic pathology related to bicuspid aortic valve (BAV) has been previously reported, clinical implications of BAV to aortopathy risk have yet to be investigated. We looked for potential differences in matrix protein expressions in the aortic wall in BAV patients.

Methods

Aorta specimens were obtained from 31 patients: BAV group (n=27), tricuspid aortic valve (TAV) group (n=4). The BAV group was categorized into three subgroups: left coronary sinus-right coronary sinus (R+L group; n=13, 42%), right coronary sinus-non-coronary sinus (R+N group; n=8, 26%), and anteroposterior (AP group; n=6, 19%). We analyzed the expression of endothelial nitric oxide synthase (eNOS), matrix metalloproteinase (MMP)-9, and tissue inhibitor of matrix metalloproteinase (TIMP)-2.

Results

Based on the mean value of the control group, BAV group showed decreased expression of eNOS in 72.7% of patients, increased MMP-9 in 82.3%, and decreased TIMP in 79.2%. There was a higher tendency for aortopathy in the BAV group: eNOS (BAV:TAV)= 53%±7%:57%±11%, MMP-9 (BAV:TAV)=48%±10%:38%±1%. The AP group showed lower expression of eNOS than the fusion (R+L, R+N) group did; 48%±5% vs. 55%±7% (p=0.081).

Conclusion

Not all patients with BAV had expression of aortopathy; however, for patients who had a suspicious form of bicuspid valve, aortic wall biopsy could be valuable to signify the presence of aortopathy.

Hyperhomocysteinemia induced by excessive methionine intake promotes rupture of cerebral aneurysms in ovariectomized rats

Background

Hyperhomocysteinemia (HHcy) is associated with inflammation and a rise in the expression of matrix metalloproteinase-9 (MMP-9) in the vascular wall. However, the role of HHcy in the growth and rupture of cerebral aneurysms remains unclear.

Methods

Thirteen-week-old female Sprague-Dawley rats were subject to bilateral ovariectomy and ligation of the right common carotid artery and fed an 8 % high-salt diet to induce cerebral aneurysms. Two weeks later, they underwent ligation of the bilateral posterior renal arteries. They were divided into two groups and methionine (MET) was or was not added to their drinking water. In another set of experiments, the role of folic acid (FA) against cerebral aneurysms was assessed.

Results

During a 12-week observation period, subarachnoid hemorrhage due to aneurysm rupture was observed at the anterior communicating artery (AcomA) or the posterior half of the circle of Willis. HHcy induced by excessive MET intake significantly increased the incidence of ruptured aneurysms at 6–8 weeks. At the AcomA of rats treated with MET, we observed the promotion of aneurysmal growth and infiltration by M1 macrophages. Furthermore, the mRNA level of MMP-9, the ratio of MMP-9 to the tissue inhibitor of metalloproteinase-2, and the level of interleukin-6 were higher in these rats. Treatment with FA abolished the effect of MET, suggesting that the inflammatory response and vascular degradation at the AcomA is attributable to HHcy due to excessive MET intake.

Conclusions

We first demonstrate that in hypertensive ovariectomized rats, HHcy induced by excessive MET intake may be associated with the propensity of the aneurysm wall to rupture.

Electronic supplementary material

The online version of this article (doi:10.1186/s12974-016-0634-3) contains supplementary material, which is available to authorized users.

The influence of type 2 diabetes mellitus on the expression of inflammatory mediators and tissue inhibitor of metalloproteinases-2 in human chronic periodontitis

PURPOSE

The purpose of this study was to compare and quantify the expression of C-reactive protein (CRP), matrix metalloproteinase (MMP)-14, and tissue inhibitor of metalloproteinases (TIMP)-2 in gingival tissues of patients with chronic periodontitis accompanied with inflammatory reaction related to alveolar bone resorption with or without type 2 diabetes mellitus (DM).

METHODS

Twelve patients with type 2 DM and chronic periodontitis (group 3), twelve patients with chronic periodontitis (group 2), and twelve healthy individuals (group 1) were included in the study. Gingival tissue biopsies were collected from each patient and from healthy individuals at the time of periodontal surgery (including surgical crown lengthening) or tooth extraction. The concentrations of cytokines were determined by a western blot analysis.

RESULTS

The expression levels of CRP and MMP-14 increased in group 2 and 3, and they were highest in group 3. The expressions of TIMP-2 also increased in group 2 and 3.

CONCLUSIONS

This study demonstrated that the expression levels of CRP, MMP-14, and TIMP-2 might be inflammatory markers in periodontal inflamed tissue. It can be assumed that CRP, MMP-14, and TIMP-2 may be partly involved in the progression of periodontal inflammation associated to type 2 DM.

Effects of rosiglitazone on matrix metalloproteinase-2 in mice with schistosomiasis and liver fibrosis

AIM: To study the effects of rosiglitazone, a peroxisome proliferator-activator receptor (gamma) ligand, on serum levels of matrix metalloproteinase-2 (MMP-2) and the tissue inhibitor of metalloproteinase-2 (TIMP-2), along with the hepatic expression of MMP-2 and TIMP-2 mRNA in mice with liver fibrosis caused by Schistosoma japonicum infection.

METHODS: Fifty mice were divided into five groups: one uninfected group (A), and four schistosomiasis groups (B-E): without any treatment (B), praziquantel treatment (C), rosiglitazone treatment (D), and rosiglitazone and praziquantel treatment (E). Serum levels of MMP-2 and TIMP-2 were measured by ELISA. Hepatic expression of MMP-2 and TIMP-2 mRNA were determined by real-time quantitative PCR.

RESULTS: Serum level and hepatic mRNA expression of MMP-2 were markedly higher in groups D and E [306.0 ± 62.3 mg/L, 312.0 ± 54.3 mg/L; -19.123 ± (-5.965), -20.375 ± (-6.189)] than in group A [221.3 ± 39.2 mg/L, -26.324 ± (-5.314); P < 0.05], but were lower than in group B [411.3 ± 57.5 mg/L, -12.227 ± (-4.426), P < 0.05] and group C [402.9 ± 57.2 mg/L, -12.804 ± (-4.036), P < 0.05]. Serum level and hepatic mRNA expression of TIMP-2 was markedly increased in the four schistosomiasis groups compared to the normal group [209.3 ± 60.5 mg/L, -20.516 ± (-4.716); 213.5 ± 66.0 mg/L, -19.944 ± (-5.052); 223.6 ± 65.3 mg/L, -18.767 ± (-5.509); 224.5 ± 64.4 mg/L, -19.676 ± (-4.320) vs 150.4 ± 46.5 mg/L, -27.186 ± (-5.985), P < 0.05]; however, there was no significant difference among the schistosomiasis groups (P > 0.05).

CONCLUSION: MMP-2 plays a role in promoting liver fibrosis. Rosiglitazone can relieve liver fibrosis because it down-regulates the expression of MMP-2 in mice with schistosomiasis and liver fibrosis.

Expression of hMSH2, hMLH1, transforming growth factor β receptor type Ⅱ, matrix metalloproteinase-7, tissue inhibitor of metalloproteinase-2 and their correlations with the biological behaviors of hereditary nonpolyposis colorectal cancer

AIM: To investigate the correlation of hMSH2, hMLH1, transforming growth factor β receptor type Ⅱ (TβRⅡ), matrix metalloproteinase-7 (MMP-7) and tissue inhibitor of metalloprotei-nase-2 (TIMP-2) expression with the biological behaviours of human hereditary nonpolyposis colorectal cancer (HNPCC).

METHODS: Immunohistochemical staining was used to detect the expression of hMSH2, hMLH1, TβRⅡ, MMP-7 and TIMP-2 protein in 30 cases of sporadic colorectal cancer (SCRC), 30 cases of HNPCC and 8 cases of normal colorectal mucosa, and their corresponding clinical datas were studied retrospectively.

RESULTS: The positive rates of hMSH2, hMLH1, TβRⅡ, MMP-7 and TIMP-2 expression were significantly related to the depth of invasion and lymph node metastasis, but not to the sex of patients and the size or position of tumors. The positive rates of hMSH2, hMLH1, TβRⅡ, MMP-7 and TIMP-2 expression were remarkably different between SCRC and HNPCC (P < 0.05). The expression of hMSH2 had a positive correlation with hMLH1 (r = 0.835, P < 0.01); The expression of TβRⅡ had positive correlations with hMSH2 (r = 0.592, P < 0.01), hMLH1 (r = 0.472, P < 0.01) and MMP-7 (r = 0.735, P < 0.01), while the expression of MMP-7 had negative correlations with TβRⅡ(r = -0.582, P < 0.01), TIMP-2 (r = -0.421, P < 0.01) in HNPCC.

CONCLUSION: The mutations of hMSH2 and hMLH1 beget the inactivation of TβRⅡ in HNPCC, which induces down-regulated expression of MMP-7 and up-regulated expression of TIMP-2. This might be one reason for the special biological behaviours of HNPCC.

Expression of transforming growth factor β receptor Type Ⅱ, matrix metalloproteinase-7 and tissue inhibitor of metalloproteinase-2 and their roles in the invasion and metastasis of hereditary nonpolyposis colorectal cancer

AIM: To investigate the roles of transforming growth factor β receptor Type Ⅱ (TβRⅡ), matrix metalloproteinase-7 (MMP-7) and tissue inhibitor of metalloproteinase-2 (TIMP-2) expression in the invasion and metastasis of human hereditary nonpolyposis colorectal cancer (HNPCC).

METHODS: Immunohistochemical staining was used to detect the expressions of TβRⅡ, MMP-7 and TIMP-2 protein in 30 cases of sporadic colorectal cancer (sporadic CRC) and 30 cases of HNPCC, and their corresponding clinical data were analyzed retrospectively.

RESULTS: The positive rates of TβRⅡ, MMP-7 and TIMP-2 expression in HNPCC were 40.0%, 46.7% and 63.3% respectively, while in sporadic CRC, the rates were 73.3%, 86.7% and 20.0% respectively. The ratio of MMP-7(+~++) to TIMP-2(-) in sporadic CRC was higher while that of MMP-7(-) to TIMP-2(+~++) was lower significantly than that in HNPCC. TβRⅡ, MMP-7 and TIMP-2 expression were closely related to the depth of invasion and lymph node metastasis, but not to the sex of patients, tumor size and position. The positive rate of MMP-7 expression was significantly increased in tissues with extra-chorion invasion and metastasis, but the expression of TβRⅡ and TIMP-2 were markedly decreased (P < 0.05). In HNPCC and sporadic CRC, positive correlation was found between TβRⅡ and MMP-7 expression (r = 0.735, P = 0.000; r = 0.792, P = 0.000), while negative correlation existed between TIMP-2 and TβRⅡ expression (r = -0.582, P = 0.001; r = -0.394, P = 0.031) as well as between TIMP-2 and MMP-7 expression (r = -0.473, P = 0.008; r = -0.388, P = 0.034).

CONCLUSION: TβRⅡ, MMP-7 and TIMP-2 are differently expressed in HNPCC and sporadic CRC. The expression rates and intensities of TβRⅡ and MMP-7 are obviously higher in sporadic CRC than those in HNPCC, while the positive expression of TIMP-2 was a reverse situation. So the imbalance of MMP-7/TIMP-2 is increased in sporadic CRC. Down-regulated expression of MMP-7, TβRⅡ and up-regulated expression of TIMP-2 may play important roles in the invasion and metastasis of HNPCC.

Effects of chemically modified small interfering RNA targeting tissue inhibitor of metalloproteinase-2 on carbon tetrachloride-induced liver fibrosis in rats

AIM: To probe the effects of chemically modified small interfering RNA (siRNA) targeting tissue inhibitor of metalloproteinase-2 (TIMP-2) on liver fibrosis as well as its possible mechanism in rats.

METHODS: A total of 42 male rats were randomly and averagely divided into 7 groups: a normal group, a negative control group, a sham-operated group, a model group and three siRNA-treated groups (treated with 0.05, 0.1, and 0.2 mg/kg siRNA via portal vain, respectively). Carbon tetrachloride (CCl₄) was used to induce liver cirrhosis. All the rats were sacrificed at 8 wk to collect liver tissue specimens, and the portal vein pressure (PVP) was measured. The pathological changes of liver tissues were observed after HE and Van Gieson (VG) staining. The levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), hyaluronic acid (HA), laminin (LN), procolagen type Ⅲ (PCⅢ), collagen type Ⅳ (CIV) and hydroxyproline (Hyp) were measured. The mRNA expression of TIMP-2, collagen type I (COLI), collagen type Ⅲ (COLⅢ) and a-smooth muscle actin (a-SMA) were detected by quantitative real-time polymerase chain reaction (QRT-PCR). The protein expression of TIMP-2, a-SMA and MMP-2 were analyzed by Western blott or gelatin zymography.

RESULTS: In comparison with those in the model group, the pathological changes in the three siRNA-treated groups (treated with 0.05, 0.1, and 0.2 mg/kg siRNA, respectively) were markedly attenuated, and the levels of PVP (2.2 ± 0.1, 1.9 ± 0.1, 1.6 ± 0.1 kPa vs 2.7 ± 0.1 kPa, P < 0.05), ALT (2089.3 ± 154.5, 1869.8 ± 138.0, 1422.5 ± 139.7 nkat/L vs 2717.2 ± 193.8 nkat/L, P < 0.05), AST (3634.1 ± 242.7, 2739.4 ± 141.3, 2286.6 ± 145.5 nkat/L vs 4067.5 ± 251.5 nkat/L, P < 0.05), HA (176.0 ± 10.2, 160.6 ± 9.3, 109.9 ± 9.4 mg/L vs 206.3 ± 17.0 mg/L, P < 0.05), LN (93.1 ± 8.2, 71.4 ± 7.5, 55.9 ± 7.3 mg/L vs 116.6 ± 10.8 mg/L, P < 0.05), PCⅢ(71.2 ± 6.1, 64.1 ± 5.1, 53.6 ± 4.3 mg/L vs 91.2 ± 8.9 mg/L, P < 0.05), CIV (64.3 ± 5.4, 50.7 ± 5.8, 41.6 ± 4.4 mg/L vs 80.3 ± 6.8 mg/L, P < 0.05) and Hyp (328.7 ± 17.6, 279.7 ± 16.3, 230.4 ± 16.1 mg/g vs 380.7 ± 20.6 mg/g, P < 0.05) were significantly lowered. QRT-PCR showed that the mRNA expression of TIMP-2, COLI, COLⅢ and a-SMA in the three siRNA-treated groups were decreased significantly as compared with those in the model group (7.53 ± 0.83, 5.04 ± 0.75, 1.30 ± 0.49 vs 23.23 ± 2.14, P < 0.05; 33.38 ± 2.85, 22.80 ± 2.48, 11.45 ± 1.27 vs 43.18 ± 3.32, P < 0.05; 19.23 ± 1.95, 13.21 ± 1.35, 10.11 ± 1.09 vs 25.90 ± 2.23, P < 0.05; 23.76 ± 2.06, 15.33 ± 1.25, 10.53 ± 1.02 vs 34.85 ± 3.16, P < 0.05). Western blot or gelatin zymography showed that the protein expression of TIMP-2, MMP-2 and a-SMA in the three siRNA-treated groups were also decreased significantly as compared with those in the model group (23.27 ± 3.06, 14.13 ± 1.86, 9.16 ± 1.33 vs 44.83 ± 5.45, P < 0.05; 23.80 ± 2.14, 15.58 ± 1.52, 9.52 ± 0.93 vs 39.90 ± 3.23, P < 0.05; 24.58 ± 2.59, 19.29 ± 2.31, 13.40 ± 1.98 vs 57.19 ± 7.07, P < 0.05).

CONCLUSION: Chemically modified siRNA targeting TIMP-2 can down-regulate the expression of TIMP-2, decrease the contents of extracellular matrix, and inhibit the activation of hepatic stellate cells.

Antisense oligonucleotides-based inhibition of gene and protein expression of tissue inhibitor of metalloproteinase-2 on experimental liver fibrosis in rats

AIM: To investigate the inhibitory effect of tissue inhibitor of metalloproteinase-2 (TIMP-2) targeted antisense oligonucleotide (asON) on the progress of experimental liver fibrosis in rats.

METHODS: Twenty-two rats were divided into asON treatment (n = 6), model (n = 6), and normal control group (n = 10). The liver fibrosis model was induced by human serum albumin (HSA). During modeling, the rats were treated with antisense oligonucleotides via tail vein. The level of TIMP-2 expression was detected by reverse transcription polymerase chain reaction (RT-PCR), in situ hybridization, immunohistochemical staining and enzyme linked immunosorbent assay (ELISA). The effect of asON on liver fibrosis was analyzed by histopathological exami-nation, immunohistochemical staining of collagenⅠand Ⅳ, and special staining of collagen fiber as well as electron microscopy.

RESULTS: The pathological grading was notably im-proved in asON group than that in model group (u = 2.071, P <0.05). The serum and tissue expression of TIMP-2 were lower in asON group than those in model group (T = 55, P <0.05; t = 3.332, P <0.05), but higher than those in the control (T = 55, P <0.05; t = 5.550, P <0.05). Image quantitative analysis for immunohistochemical staining of collagen Ⅳ showed that the value was significant decreased in asON group as compared with that in model group (t = 2.310, P <0.05), but still higher than that in the control (t = 3.623, P <0.05); The value for collagenⅠwas also decreased in asON group as compared with that in model group (t = 2.845, P <0.05). Less collagen deposition was found in the hepatic sinusoid of asON group, which was not significantly different from that of model group.

CONCLUSION: TIMP-2 targeted asON can inhibit the progress of experimental liver fibrosis in rats.