Human urinary kallidinogenase in acute ischemic stroke: A single-arm, multicenter, phase IV study (RESK study).

AIMS: Human urinary kallidinogenase (HUK) has shown favorable efficacies in acute ischemic stroke (AIS) treatment. We sought confirmation of the safety and efficacy of HUK for AIS in a large population. METHODS: RESK study enrolled patients with AIS of anterior circulation to receive HUK infusion. The primary endpoint was the incidence of treatment-emergent adverse events (AEs). Secondary endpoints assessed neurological and functional improvements and stroke recurrent rate. RESULTS: Of 1206 eligible patients, 1202 patients received at least one dose of HUK infusion and 983 (81.5%) completed the study. The incidence of treatment-emergent AEs and serious AEs were 55.99% and 2.41%, respectively. Pre-specified AEs of special interest occurred in 21.71% of patients, but the majority were mild and unrelated to therapy. Hypertension, age, treatment time, and drug combination were identified to be associated with drug-related blood pressure reduction. Neurological and functional evaluations revealed favorable outcomes from baseline to post-treatment assessment. The cumulative recurrence rate of stroke was 2.50% during the 90-day assessment. CONCLUSION: HUK had an acceptable safety and tolerability profile in AIS patients. Besides, HUK demonstrated the neurological and functional improvements in AIS, further confirming its clinical efficacy in a real-world large population.

N-Butylphthalide vs. Human Urinary Kallidinogenase for the Treatment of Acute Ischemic Stroke: Functional Outcome and Impact on Serum VEGF and TNF-α Expressions.

OBJECTIVE: To compare the e!cacy and functional outcomes of dl-3-n-Butylphthalide (NBP) and human urinary kallidinogenase (HUK) on ischemic stroke patients and to determine their effects on serum tumor necrosis factor-alpha (TNF-α) and vascular endothelial growth factor (VEGF). METHODS: A prospective study was conducted on 57 ischemic stroke patients. Functional outcomes were assessed by the National Institute Health Stroke Scale (NIHSS), the modified Rankin Scale (mRS), and the activities of daily living score (ADL), whereas TNF-α and VEGF expressions were measured by enzyme-linked immunosorbent assay (ELISA). RESULTS: TNF-α was significantly down-regulated in the NBP group and upregulated in the control group two weeks after treatment (p=0.017 and p=0.047, respectively). A significant difference in VEGF expressions was observed between the two groups (330.25±120.64 vs. 437.15±137.68, p=0.041) two weeks after treatment. Both groups showed significant improvement in NIHSS and ADL scores three months after treatment (p<0.001), with the NBP group exhibiting improvement in NIHSS scores as early as two weeks after treatment (p=0.008). The three-month NIHSS scores of the two groups were significantly lower than those of the control group (p=0.010 and p=0.008, respectively). Both the NBP and HUK groups showed a significant decline in mRS scores two weeks and three months after treatment (p<0.05). CONCLUSIONS: Both treatments are effective and can significantly promote recovery in stroke patients. Additionally, both options have similar effects in promoting long-term recovery, with NBP exerting a greater impact on serum VEGF and TNF-α expressions.

Influence of butyphthalide combined with urinary kallikrein in ACI treatment on neuro-cytokines and vascular endothelial function and its clinical effect.

Objective: To study the influence of butyphthalide combined with urinary kallikrein in acute cerebral infarction (ACI) treatment on neuro-cytokines and indicators of vascular endothelial function, observe the curative effect and adverse effects, and discuss its safety and feasibility.Method: 110 ACI patients were chosen as the objects, and classified into observation group (55 cases) and control group (55 cases) according to the method of random number table. Butyphthalide injection combined with urinary kallikrein was adopted for the observation group based on conventional treatment, while cinepazide maleate injection combined with alprostadil injection was applied for the control group based on conventional treatment. The following indicators of both groups were compared before and after treatment: neurotrophic factor (NTF), nerve growth factor (NGF), neuron specific enolase (NSE); content of CXC chemotactic factor ligand 16 (CXCL16), soluble CD ligand (CD40L), Fibulin-5 and high mobility group box B1 (HMGB1); the content of indicators of vascular endothelial function including plasma endothelin -1 (ET-1) and no therapeutic effects and adverse effects were recorded.Results: NSE of both groups after treatment decreased obviously, and the content of NTF and NGF increased obviously. NSE content of observation group was lower than that of control group. NTF content and NGF content of observation group were higher than those of control group. The differences had statistical significance (p < 0.05). The levels of CXCL16, CD40L, Fibulin-5 and HMGB1 declined obviously, compared with pre-treatment, and the levels of observation groups were significantly lower than those of control grip. The differences had statistical significance (p < 0.05). ET-1 level rose significantly after treatment, and NO level declined obviously after treatment. ET-1 level of observation group was significantly higher than that of control group, and NO level of observation group was significantly lower than that of control group. The difference had statistical significance (p < 0.05). Clinical effect of observation group was significantly higher than that of control group. The difference had statistical significance (p < 0.05). The comparison difference of both groups in the occurrence rate of adverse effects had no statistical significance (p > 0.05).Conclusion: The application of butyphthalide combined with urinary kallikrein in ACI treatment can effectively inhibit secretion and release of neuro-cytokines, and improve patients' vascular endothelial function, with significant treatment effect and high safety. Therefore, it deserves to be promoted clinically.

Superoxide Dismutase 3 Inhibits LL-37/KLK-5-Mediated Skin Inflammation through Modulation of EGFR and Associated Inflammatory Cascades.

The expressions of LL-37 and KLK-5 were found to be altered in various dermatoses, including atopic dermatitis, psoriasis, and rosacea. However, the downstream inflammatory effect of LL-37 and KLK-5 is not as well studied. In addition, there is little high-quality evidence for the treatment of LL-37- and KLK-5-mediated inflammation. In this study, we investigated the effect of superoxide dismutase 3 (SOD3) on LL-37- or KLK-5-induced skin inflammation in vitro and in vivo and its underlying anti-inflammatory mechanisms. Our data showed that SOD3 significantly reduced both LL-37- and KLK-5-induced expression of pro-inflammatory mediators and suppressed the activation of EGFR, protease-activated receptor 2, nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3, and p38/extracellular signal-regulated kinase signaling pathways in human keratinocytes. Moreover, SOD3 suppressed LL-37-induced expression of inflammatory mediators, reactive oxygen species production, and p38/extracellular signal-regulated kinase activation in mast cells. In addition, subcutaneous injection of KLK-5 in SOD3 knockout mice exhibited erythema with increased epidermal thickness, mast cell and neutrophil infiltration, expression of inflammatory mediators, and activation of EGFR, protease-activated receptor 2, nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3, and downstream mitogen-activated protein kinase pathways. However, treatment with SOD3 in SOD3 knockout mice rescued KLK-5-induced inflammatory cascades. Similarly, KLK-5-induced inflammation in wild-type mice was also ameliorated when treated with SOD3. Taken together, our data suggest that SOD3 is a potentially effective therapy for both LL-37-and KLK-5-induced skin inflammation.

The Pyk2/MCU pathway in the rat middle cerebral artery occlusion model of ischemic stroke.

Mitochondrial dysfunction caused by Ca2+ overload plays an important role in ischemia-induced brain damage. Mitochondrial calcium uniporter (MCU), located on the mitochondrial inner membrane, is the major channel responsible for mitochondrial Ca2+ uptake. Activated proline-rich tyrosine kinase 2 (Pyk2) can directly phosphorylate MCU, which enhances mitochondrial Ca2+ uptake in cardiomyocytes. It has been suggested that the Pyk2/MCU pathway may be a novel therapeutic target in stress-induced cellular apoptosis. In this study, we explored the role of the Pyk2/MCU pathway in the ischemic brain following a stroke injury. We found that the Pyk2/MCU pathway is activated in a rat cerebral ischemia model, and is responsible for mitochondrial dysfunction and neuronal apoptosis. Inhibiting the Pyk2/MCU pathway with a Pyk2 inhibitor (PF-431396) prevented mitochondrial Ca2+ overload, mitochondrial injury, proapoptotic protein release, and cell death. Interestingly, human urinary kallidinogenase (HUK) alleviated neuronal ischemic injury by inhibiting the Pyk2/MCU pathway, suggesting that the Pyk2/MCU pathway may be a protective target for ischemic stroke treatment.

Ultrasound-Mediated Kallidinogenase-Loaded Microbubble Targeted Therapy for Acute Cerebral Infarction.

BACKGROUND: The neuroprotective effects of kallidinogenase against acute cerebral infarction have been demonstrated, and the use of microbubbles has been suggested as a therapeutic mechanism for drug delivery. This study was designed to investigate the optimal parameters for preparing kallidinogenase-loaded microbubbles (KLMs) and to evaluate the effects of KLM-targeted therapy on neurogenesis and angiogenesis following experimental acute cerebral infarction in rats. MATERIALS AND METHODS: KLMs were prepared by mechanical shaking. Male Wistar rats were randomly divided into an ultrasound-mediated KLM-treated group and 4 control groups. Treatments were administered via daily tail vein injection on 6 consecutive days, starting at 24 hours after middle cerebral artery occlusion (MCAO). The ultrasound-treated groups were subjected to a 2-MHz pulse of ultrasonic irradiation on the lateral skull of the ischemic side for 10 minutes during injection. Cell proliferation was examined using a 5-bromo-2-deoxyuridine assay. Infarct volume and neurological function were evaluated on days 3 and 7 after MCAO. RESULTS: The ultrasound-mediated KLM and kallidinogenase treatments significantly increased the numbers of doublecortin-immunoreactive cells in the subventricular zone (SVZ) and laminin+ cells in the peri-infarction region on day 7 after MCAO, compared with the other 3 groups (all P <.05). The neurological function scores of the ultrasound-mediated KLM-treated group were significantly better than those of rats treated with kallidinogenase alone or with the other treatments (all P <.05). CONCLUSIONS: Treatment with the ultrasound-mediated KLMs promoted the proliferation of SVZ neuroblasts and vascular regeneration, which contributed to functional improvement after stroke. These findings provide a novel therapy for ischemic stroke.

The Therapeutic Effect of Pancreatic Kininogenase on Treatment of Diabetic Peripheral Neuropathy in Patients with Type 2 Diabetes.

Background: To determine the therapeutic efficacy and cost-effective of pancreatic kininogenase (PKase) on treatment of diabetic peripheral neuropathy (DPN) compared with Prostaglandin E1 (PGE1) in patients with type 2 diabetes. Methods: 104 patients with DPN receiving standard glucose control therapy were randomly assigned into 3 groups: Group-A received PKase treatment, Group-B received PGE1 treatment, and Group-C received only standard glucose control therapy. Michigan neuropathy screening instrument (MNSI) score, neurophysiology examination, and nerve conduction velocity were measured. Results: Standard glucose control therapy significantly reduced hyperglycemia to a similar level in all groups. Questionnaire grading and neurophysiology examination both indicated that no significant difference was found at the end of treatment between Groups -A and -B. Except for the ulnar nerve sensory conduction velocity that was significantly improved in Group-B, the remaining nerve conduction velocity (regardless of sensory or motor nerve conduction velocities) was improved to a similar level in Groups -A and -B. Group-A had significantly reduced questionnaire grading and better improvement in motor nerve conduction velocity of the common peroneal nerve, ulnar nerve, and sensory nerve conduction velocity of the sural nerve as compared with Group-C. However, the medical cost of PKase was only 18.9% of that of PGE1 during one course of treatment. Conclusions: PKase has the similar therapeutic efficacy as PGE1 on treatment of DPN in patients with type 2 diabetes. However, the medical cost of PKase is one fifth of that of PGE1. Thus, PKase is a cost-effective drug for treatment of DPN.

Human urine kininogenase attenuates balloon-induced intimal hyperplasia in rabbit carotid artery through transforming growth factor ß1/Smad2/3 signaling pathway.

OBJECTIVE: Effective treatments against restenosis after percutaneous transluminal angioplasty and stenting are largely lacking. Human tissue kallikrein gene transfer has been shown to be able to attenuate neointima formation induced by balloon catheter. As a tissue kallikrein in vivo, human urinary kininogenase (HUK) is widely used to prevent ischemia-reperfusion injury. However, the effects of HUK on neointima formation have not been explored. We therefore investigated whether HUK could alleviate balloon catheter-induced intimal hyperplasia in rabbits fed with high-fat diets. METHODS: The effects of HUK on neointima and atherosclerosis formation were analyzed by hematoxylin-eosin staining and immunohistochemical staining in balloon-injured carotid arteries of rabbits. Local inflammatory response was evaluated by detecting the gene expression of tumor necrosis factor α and interleukin 1ß with real-time quantitative polymerase chain reaction plus the invasion of macrophages with immunohistochemical staining. Western blotting was employed to investigate the effects of HUK on activities of endothelial nitric oxide synthase (eNOS), transforming growth factor ß1 (TGF-ß1), and Smad signaling pathway. The long-term effect of HUK on intimal hyperplasia of the injured carotid artery was assessed by angiography. RESULTS: Quantitative image analysis showed that intravenous administration of HUK for 14 days significantly decreased the intimal areas and intima area/media area ratios (day 14, 54% decrease in intimal area and 58% decrease in intima area/media area ratios; day 28, 63% and 85%). Significant decreases were also noted in macrophage foam cell-positive area after 7-day or 14-day administration of HUK (day 7, 69% decrease in intimal area and 78% decrease in media area; day 14, 79% and 60%; day 28, 68% and 44%). Actin staining for smooth muscle cells in neointima at 2 months showed similar results (vascular smooth muscle cell-positive area of neointima, 28.21% ± 5.58% vs 43.78% ± 8.36%; P < .05). Real-time quantitative polymerase chain reaction or Western blot analysis showed that HUK reduced expression of tumor necrosis factor α, interleukin 1ß, TGF-ß1, and p-Smad2/3 but increased the expression of p-eNOS. Angiography analysis showed that 14-day administration of HUK significantly decreased the degree of stenosis (26.8% ± 7.1% vs 47.9% ± 5.7%; P < .01) at 2 months after balloon injury. CONCLUSIONS: Our results indicate that HUK is able to attenuate atherosclerosis formation and to inhibit intimal hyperplasia by downregulating TGF-ß1 expression and Smad2/3 phosphorylation, upregulating eNOS activity. HUK may be a potential therapeutic agent to prevent stenosis after vascular injury.

Study on the effect of urinary kallidinogenase after thrombolytic treatment for acute cerebral infarction.

OBJECTIVE: To evaluate the safety and efficacy of urinary kallidinogenase for recombinant tissue-type plasminogen activator (rt-PA) intravenous thrombolytic treatment in patients with acute cerebral infarction. PATIENTS AND METHODS: All 200 patients with acute cerebral infarction were randomized 1:1 into an experimental group (100 cases) and a control group (100 cases). Patients in the control group were administrated rt-PA (0/9 mg/kg) while patients in the experimental group were given urinary kallidinogenase by intravenous drip (0.15 PNAU/d, for 7 days) after rt-PA intravenous thrombolytic treatment (0.9 mg/kg). The main evaluation index was NIHSS and BI. RESULTS: Compared to the control group, the NIHSS scores were significantly lower 7 and 90 days after thrombolytic therapy (t = 2.391, 2.714; p < 0.05). BI scores were obviously higher at 90 days after thrombolytic therapy in the experimental group (t = 2.675, p < 0.05). CONCLUSIONS: Urinary kallidinogenase may improve the treatment effect for rt-PA intravenous thrombolytic treatment in patients with acute cerebral infraction.

Induction of complement C3a receptor responses by kallikrein-related peptidase 14.

Activation of the complement system is primarily initiated by pathogen- and damage-associated molecular patterns on cellular surfaces. However, there is increasing evidence for direct activation of individual complement components by extrinsic proteinases as part of an intricate crosstalk between physiological effector systems. We hypothesized that kallikrein-related peptidases (KLKs), previously known to regulate inflammation via proteinase-activated receptors, can also play a substantial role in innate immune responses via complement. Indeed, KLKs exemplified by KLK14 were efficiently able to cleave C3, the point of convergence of the complement cascade, indicating a potential modulation of C3-mediated functions. By using in vitro fragmentation assays, mass spectrometric analysis, and cell signaling measurements, we pinpointed the generation of the C3a fragment of C3 as a product with potential biological activity released by the proteolytic action of KLK14. Using mice with various complement deficiencies, we demonstrated that the intraplantar administration of KLK14 results in C3-associated paw edema. The edema response was dependent on the presence of the receptor for C3a but was not associated with the receptor for the downstream complement effector C5a. Our findings point to C3 as one of the potential substrates of KLKs during inflammation. Given the wide distribution of the KLKs in tissues and biological fluids where complement components may also be expressed, we suggest that via C3 processing, tissue-localized KLKs can play an extrinsic complement-related role during activation of the innate immune response.

Prospective multicenter study of visual outcomes following three different treatments for macular edema associated with branch retinal vein occlusion: a study by the Japanese BRVO study group.

PURPOSE: To evaluate the visual outcomes of three different treatments for macular edema associated with a branch retinal vein occlusion. METHODS: A 1-year, non-randomized study was conducted at 21 ophthalmological institutes in Japan. All of the patients received one of three treatments: medication per-oral (PO), photocoagulation (PC) or pars plana vitrectomy (PPV). Retinal hemorrhage that was lower than that shown in reference photographs was considered an inclusion criteria. RESULTS: Ninety-eight patients were studied. Twenty-six (26.5%) patients were in the PO, 37 (37.8%) in the PC and 35 (35.7%) in the PPV group. The mean best-corrected visual acuity (BCVA) improved significantly after 1 year in all groups (P < 0.001). There was no significant difference among those groups in the degree of the BCVA improvement. However, the BCVA in the PPV group improved significantly at 6 months, significantly earlier than in the other two groups. The BCVA at entry in the PPV group was significantly worst among patients whose eyes had a BCVA of ≥ 0.7 at 1 year (P < 0.05). CONCLUSIONS: PPV had a slight advantage over PC and PO, although the improvement to the BCVA did not differ significantly following any of the three treatments.

Change in blood kinin and plasma porcine pancreatic kallikrein concentrations after oral administration of kallikrein formulation in dog.

Oral formulation of tissue kallikrein consists primarily of porcine pancreatic kallikrein (PPK) and is used to improve peripheral circulation, menopausal symptoms, and impaired chorioretinal circulation. Although gastrointestinal absorption of tissue kallikrein after oral administration has been reported in nonclinical and clinical studies, the increase in the concentration of pharmacologically active kinins, which are produced from kininogens by tissue kallikrein, has not been investigated. In this study, kallikrein formulation was orally administered to dogs and an increase in PPK in plasma was confirmed, along with an increase in the blood kinin level. After oral administration of kallikrein formulation (10 U/kg or 20 U/kg PPK) to dogs, PPK concentration in plasma reached maximum 3 h after administration, and then decreased time-dependently. The maximum concentration was 6.01 ± 1.44 pg/ml in the 10 U/kg group and 10.88 ± 3.59 pg/ml in the 20 U/kg group (mean ± S.E.M, n = 5). After oral administration of kallikrein formulation (40 U/kg PPK) to dogs, the blood kinin concentration in the PPK-treated group was significantly increased 2 h after administration as compared to the purified water-treated group (before administration: 48.8 ± 2.1 ng/ml vs. 48.1 ± 1.9 ng/ml, 2 h after administration: 55.5 ± 1.6 ng/ml vs. 49.6 ± 1.4 ng/ml; mean ± S.E.M, n = 4, p < 0.05). In conclusion, PPK was considered to be absorbed after oral administration and to exert its pharmacological action via kinins produced by kininogen degradation in dogs.

HER-2 targeted treatment of osteosarcoma: the challenges of developing targeted therapy and prognostic factors for rare malignancies.

IMPORTANCE OF THE FIELD: Despite the substantial success realized treating osteosarcoma with chemotherapy, metastatic disease or refractory/recurrent disease continue to frustrate patients and clinicians. The failure to improve outcomes with treatment intensification indicates the need for new approaches, such as the introduction of targeted therapy. The application of trastuzumab (Herceptin((R))) in the setting of HER-2 positive osteosarcoma is reflective of this concept. AREAS COVERED IN THIS REVIEW: This review summarizes reports from 1996 to the present which focus on HER-2 expression and its prognostic relevance in the setting of osteosarcoma. WHAT THE READER WILL GAIN: The prognostic value of HER-2 remains controversial, and both standard methodologies for assessing expression and the effectiveness of HER-2 directed therapy in this patient population have yet to be established. TAKE HOME MESSAGE: The relative rarity of the disease makes larger prospective studies difficult in terms of both time and coordination. The feasibility of defining therapy specifically for a subpopulation of patients afflicted with a rare cancer, such as osteosarcoma, can be conceptually questioned.

B2 kinin receptor activation is the predominant mechanism by which trypsin mediates endothelium-dependent relaxation in bovine coronary arteries.

The roles of kinin and protease-activated receptors (PAR) in endothelium-dependent relaxations to the serine protease, trypsin, were examined in rings of bovine left anterior descending coronary artery (LAD). Trypsin (0.01-30 U/ml) caused biphasic, endothelium-dependent relaxations-a high potency (0.01-0.3 U/ml), low efficacy relaxation [maximum relaxation (R (max)), 9.0 +/- 5.1%] followed by a lower potency (1-30 U/ml) but high efficacy (R (max), 90.4 +/- 5.5%) relaxation, which was abolished by aprotinin. Captopril (10 microM) caused an approximately 10-fold leftward shift of the second phase response such that the first phase was masked. The second phase relaxation to trypsin was inhibited in a concentration-dependent, non-surmountable manner by the B2 antagonist, HOE-140. At 3 nM HOE-140, the second phase response to trypsin was abolished unmasking the first phase. Kallikrein (0.0003-0.3 U/ml) caused monophasic, endothelium-dependent relaxations (R (max), 33.7 +/- 14.6%), which were potentiated by captopril (R (max), 94.2 +/- 1.0%) and abolished by HOE-140. In the presence of captopril, the second phase relaxation to trypsin was only minimally inhibited by either N(G)-nitro-L: -arginine (100 microM) or 67 mM [K(+)](o) alone but markedly reduced when these two treatments were combined (R (max), 26.1 +/- 11.6% versus 98.6 +/- 2.9% in controls). The PAR1-activating peptide, SFLLRN (0.1-30 microM), but not the PAR2-activating peptide, SLIGRL, caused concentration-dependent relaxations (pEC(50), 5.9 +/- 0.0%; R (max), 43.3 +/- 8.3%). In conclusion, trypsin causes endothelium-dependent relaxations in the bovine LAD predominantly via release of endogenous BK, which in turn activates endothelial B2 receptors. Only a minor role for PAR1-like receptors was evident in this tissue.

Exogenous kallikrein enhances neurogenesis and angiogenesis in the subventricular zone and the peri-infarction region and improves neurological function after focal cortical infarction in hypertensive rats.

Kallikrein, a serine proteinase, has been identified as an angiogenic growth factor recently. We investigated whether delayed treatment with exogenous kallikrein enhances neurogenesis and angiogenesis after focal cortical infarction in stroke-prone renovascular hypertensive rats. Human tissue kallikrein (1.6 x 10(-2) PNAU/kg) or vehicle was given through a tail vein daily for 6 consecutive days starting 24 h after distal middle cerebral artery occlusion (MCAO). Cell proliferation was examined by using 5'-bromo-2'-deoxyuridine (BrdU, 50 mg/kg). Rats were sacrificed at 3, 7, 14 or 28 d after MCAO, respectively. Treatment with kallikrein significantly increased the number of BrdU(+) cells in the subventricular zone (SVZ) and the peri-infarction region initiating 3 d after MCAO compared with the vehicle group (all p<0.05). Kallikrein significantly increased the number of BrdU(+)/DCX(+) cells and BrdU(+)/nestin(+) cells in the SVZ as well as vascular density in the peri-infarction region compared with the vehicle group (all p<0.05), which increased at 3 d, peaked at 7-14 d after MCAO, and then gradually decreased. Kallikrein markedly increased the number of BrdU(+)/NeuN(+) cells in the peri-infarction region compared with the vehicle group at 14 d and 28 d after MCAO (all p<0.05). The kallikrein group showed better functional improvement after stroke (all p<0.05). Our study demonstrates that delayed administration of kallikrein at 24 h after cortical infarction promotes the SVZ neuroblasts proliferation, migration, and selective differentiation. Moreover, kallikrein enhanced endogenous neurogenesis is associated with angiogenesis, both attributing to functional improvement after stroke. Therefore, kallikrein may have a potential therapeutic perspective on ischemic stroke.

Kallikrein gene delivery improves cardiac reserve and attenuates remodeling after myocardial infarction.

In this study, we used the somatic gene delivery approach to explore the role of the kallikrein-kinin system (KKS) in cardiac remodeling and apoptosis after myocardial infarction (MI). Rats were subjected to coronary artery ligation to induce MI, and adenovirus carrying the human tissue kallikrein or luciferase gene was injected into the tail vein at 1 week after surgery. Cardiac output gradually decreased from 2 to 6 weeks after MI, whereas delivery of the kallikrein gene prevented this decrease. Cardiac responses to dobutamine-induced stress were improved in rats receiving kallikrein gene as compared with rats receiving control virus at 6 weeks after MI. Kallikrein significantly improved cardiac remodeling by decreasing collagen density, cardiomyocyte size, and left ventricular internal perimeter and increasing capillary density in the heart at 6 weeks after MI. Kallikrein gene transfer attenuated myocardial apoptosis, which was positively correlated with remodeling parameters in the heart at 2 weeks after MI. Endothelial dysfunction, characterized by increased vascular resistance, decreased left ventricular blood flow, and decreased cardiac nitric oxide levels, existed in remodeled hearts at 2 weeks after MI, whereas kallikrein gene transfer improved these parameters. Kallikrein gene delivery improved cell survival parameters as shown by increased phospho-Akt and reduced caspase-3 activation at 2 weeks after MI. This study indicates that the kallikrein-kinin system plays an important role in preventing the progression of heart failure by attenuating cardiac hypertrophy and fibrosis, improving endothelial function, and inhibiting myocardial apoptosis through the Akt-mediated signaling pathway.

Turnover of 125I-labelled tissue kallikrein following intraduodenal or intravenous administration.

UNLABELLED: Tissue kallikrein is released in the body both physiologically and in many inflammatory disorders. Little is, however, known about the turnover of released tissue kallikrein in humans. Approximately 1 mg of tissue kallikrein (mol wt 43,000 Da) was purified from 85 L human urine by: (1) ultracentrifugation, (2) filtration through an aprotinin-coupled Sepharose 4B column, followed by (3) gel filtration over a Sephadex G-75 column. The elimination, after intraduodenal or intravenous administration of purified tissue kallikrein radiolabelled with 125I, was followed by collecting serial samples of plasma, urine and faeces from three volunteers. Within 72 h, about 96% of the intraduodenally administered radioactivity had been excreted in urine, and approximately 5.4% in faeces, mainly as 125I. No intact 125I-tissue kallikrein was found in plasma, urine or faeces after the intraduodenal instillation of the protein. The plasma half-life of 125I-tissue kallikrein up to 3 h after intravenous injection was 9 min and, thereafter, 20 h. The 125I-tissue kallikrein was quickly bound to a plasma protein with a mol wt of about 67 kDa, but some of the radioiodinated tissue kallikrein was still unbound 15 min after injection, judged by gel filtration on Sephadex G-200 columns. Most of the radioactivity was excreted in the urine as 125I, but about 4-6% was recovered as free 125I-tissue kallikrein. CONCLUSION: The use of tissue kallikrein as an oral drug appears, therefore, to be useless. Tissue kallikrein released into plasma seems to be quickly bound to a protein with a mol wt of 67 kDa, probably kallistatin or Protein C inhibitor, but some tissue kallikrein seems to be unbound and may have some physiological or pathophysiological action. The unbound tissue kallikrein is, at least partly, cleared from the circulation by the kidneys, and tissue kallikrein in the urine may partly be derived from plasma.

Adenovirus-mediated human tissue kallikrein gene delivery induces angiogenesis in normoperfused skeletal muscle.

We investigated whether local delivery of the tissue kallikrein gene induces angiogenesis in normoperfused mouse hindlimb muscles. Intramuscular injection of adenovirus containing the human tissue kallikrein gene under the control of a cytomegalovirus enhancer/promoter sequence resulted in local production and release of recombinant human tissue kallikrein, whereas transgene expression was absent in muscles of the contralateral hindlimb. Angiogenesis in infected muscles was documented by histological evidence of increased capillary density. In contrast, no angiogenic effect was seen either in the ipsilateral gastrocnemius or contralateral hindlimb muscles. Neovascularization was associated with a transient increase in muscular blood flow as determined by laser Doppler flowmetry. We also investigated the mechanisms of kallikrein-induced angiogenesis. We found that the angiogenic response to kallikrein was abolished by chronic blockade of the kinin B(1) or B(2) receptor or by inhibition of nitric oxide synthase. In addition, inhibition of cyclooxygenase-2 by nimesulide significantly reduced kallikrein-induced effects. These results indicate that (1) human tissue kallikrein acts as an angiogenic factor in normoperfused skeletal muscle and (2) nitric oxide and prostacyclin are essential mediators of kallikrein-induced angiogenesis. Our findings provide new insights into the role of the tissue kallikrein-kinin system in vascular biology.

Plasma-kallikrein clearance during liver regeneration after partial hepatectomy in the rat.

AIMS/BACKGROUND: The liver clears circulating plasma-kallikrein through a receptor-mediated endocytosis process: an initial fast phase is followed by a slow exponential phase. METHODS: To determine whether the clearance rate of plasma-kallikrein is affected during liver regeneration, we perfused isolated rat livers with rat plasma-kallikrein (rPK) at 0, 1, 2, 3 and 7 days after partial hepatectomy or sham operation. RESULTS: Liver regeneration was followed by the expression of the proliferating-cell nuclear antigen (PCNA) labeling index. The serum concentration of alpha2-macroglobulin, an acute phase protein in rats, was measured. At day 1, the fast phase of rPK clearance rate increased in hepatectomized rats when compared with day 0 (4.9+/-0.4 and 3.7+/-0.4 mU/g liver min, p<0.05). However, at day 2, the rPK fast phase clearance rate dropped significantly (2.6+/-0.2, p<0.05), when compared with day 1. No difference was found among the sham groups at different days of hepatectomy. These changes seem to be independent of the acute phase reaction. The regenerative liver weight increased continuously during the observation period. PCNA expression increased significantly after hepatectomy, with maximal PCNA-labeling indices at days 1 and 2, declining thereafter. CONCLUSION: The rPK fast phase clearance rate changes during liver regeneration, with a zenith occurring when PCNA labeling index is maximal (day 1) and a nadir occurring at the mitotic phase (day 2).

Kallikrein gene therapy: a new strategy for hypertensive diseases.

The tissue kallikrein-kinin system has been postulated to play a role in blood pressure homeostasis and the pathogenesis of clinical hypertension. To demonstrate the potential therapeutic effects of somatic gene delivery in treating hypertension, we used spontaneously hypertensive rats (SHR) as a model. The gene encoding the human tissue kallikrein was used because of its powerful hypotensive action. The human kallikrein DNA constructs were placed under the control of the metallothionein metal response element, the cytomegalovirus promoter/enhancer or the Rous sarcoma virus 3'-LTR. The human tissue kallikrein DNA constructs were incorporated into adenoviral vectors via homologous recombination. The naked plasmid DNA constructs or adenovirus containing the kallikrein gene were first introduced into kidney 293 cells and the expression of human tissue kallikrein was identified by ELISA. The kallikrein gene was delivered into SHR via intramuscular, intravenous, portal vein, intraperitoneal, and intracerebroventricular routes. A single injection of naked human kallikrein DNA constructs caused a prolonged reduction of high blood pressure for up to 8 weeks. Adenoviral-mediated gene delivery results in high efficiency of human tissue kallikrein expression. Immunoreactive human kallikrein was detected in rat serum at the highest level at 1 day post gene delivery. Portal vein delivery of a reporter gene, AdCMV-LacZ, results in intense staining of beta-galactosidase in rat liver, suggesting that recombinant kallikrein is mainly produced in liver and secreted into the circulation. These results show that kallikrein gene delivery causes a sustained reduction of blood pressure in genetically hypertensive rats and provide important information for a potential gene therapy approach to human hypertension and related diseases.