Human Urinary Kallidinogenase Improves Outcome of Stroke Patients by Shortening Mean Transit Time of Perfusion Magnetic Resonance Imaging

Neuroprotective effect of apelin-13 and other apelin forms-a review

Neurodegenerative diseases, which occur when neurons begin to deteriorate, affect millions of people worldwide. These age-related disorders are becoming more common partly because the elderly population has increased in recent years. While no treatments are accessible, every year an increasing number of therapeutic and supportive options become available. Various substances that may have neuroprotective effects are currently being researched. One of them is apelin. This review aims to illustrate the results of research on the neuroprotective effect of apelin amino acid oligopeptide which binds to the apelin receptor and exhibits neuroprotective effects in the central nervous system. The collected data indicate that apelin can protect the central nervous system against injury by several mechanisms. More studies are needed to thoroughly investigate the potential neuroprotective effects of this peptide in neurodegenerative diseases and various other types of brain damage.

A rare incidence of acute ischaemic stroke with reversible middle cerebral artery occlusion in a methamphetamine addict: Case report

Background

Methamphetamine is an illegal drug that poses serious public health concerns worldwide. Previous studies have demonstrated a strong association between methamphetamine abuse and non-lethal haemorrhagic stroke. Ischaemic stroke after methamphetamine intake is less common than haemorrhagic stroke. The present study investigated the clinical features and potential pathogenesis in a young methylamphetamine addict that presented with acute ischaemic stroke and reversible middle cerebral artery (MCA) occlusion.

Methods

A retrospective data analysis was performed for the young methylamphetamine addict admitted to a hospital for acute ischaemic stroke followed by a literature review to explore the possible pathogenesis.

Results

The patient had been receiving methamphetamine for past 2 years. His recurrent headache occurred half an hour after each consumption and was relieved within a few hours. The patient was admitted for acute ischaemic stroke. Urine toxicology screening was positive for methamphetamine. Magnetic resonance angiography revealed occlusion of the right MCA. After discontinuing medication and routine treatment, digital subtraction angiography revealed normal blood flow in the right MCA, indicating reversible MCA occlusion.

Conclusion

For young patients with a stroke, a thorough investigation of the history of illicit drug use and toxicological screening of urine and serum samples should be performed. Young methamphetamine users need to be aware of the elevated risk of stroke as well as early signs and symptoms. Transient headaches in young methamphetamine users may be caused by cerebral vasospasms, suggesting the possibility of future catastrophic stroke events.

Efficacy of Urinary Kallidinogenase Plus Intravenous Recombinant Tissue Plasminogen Activator for Stroke Patients With Extended Window: A Retrospective Analysis

BACKGROUND

To assess the outcome of human urinary kallidinogenase (HUK) plus recombinant tissue plasminogen activator (rT-PA) intravenous thrombolysis for stroke patients with an extended time window(4.5 to 9 h).

METHODS

A total of 92 acute ischemic stroke patients who fulfilled the criteria were included in this study. All patients received basic treatment and intravenous rT-PA, and 49 patients received additional injections of HUK (HUK group) once a day for 14 consecutive days. Outcomes were indicated by the thrombolysis in cerebral infarction score as the primary endpoint and the National Institute of Health Stroke Scale, modified Rankin Scale, and Barthel Index as the secondary endpoints. The safety outcomes were the rate of symptomatic intracranial hemorrhage, bleeding, angioedema, and mortality.

RESULTS

The National Institute of Health Stroke Scale scores were significantly lower in the HUK group at hospital discharge (4.55 ± 3.78 vs 7.88 ± 7.31, P = 0.009) and day 90 (4.04 ± 3.51 vs 8.12 ± 9.53, P = 0.011). The improvements in the Barthel Index scores were more obvious in the HUK group. Patients in the HUK group achieved favorable functional independence (67.35% vs 46.51%; odds ratio: 2.37; 95% CI: 1.01-5.53) at 90 days. The recanalization rate of the HUK group was 64.10%, whereas that was 41.48% in the control group ( P = 0.050). The complete reperfusion rates were 42.9% and 23.3% in the HUK group and the control group, respectively. No significant differences were observed for adverse events between the two groups.

CONCLUSIONS

Combination therapy of HUK plus rT-PA in patients with acute ischemic stroke with an extended time window can safely improve their functional outcomes.

QHRD106 ameliorates ischemic stroke injury as a long-acting tissue kallikrein preparation

Ischemic stroke is the second leading cause of death worldwide, and there are limited effective treatment strategies. QHRD106, a polyethyleneglycol (PEG)-modified long-acting tissue kallikrein preparation, has not been reported previously. In this study, we aimed to investigate the therapeutic effect of QHRD106 in ischemic stroke and its possible mechanism. We found that QHRD106 treatment alleviated brain injury after stroke via bradykinin (BK) receptor B2 (B2R) instead of BK receptor B1 (B1R). Mechanistically, QHRD106 reduced high-mobility group box 1 (HMGB1)-induced apoptosis and inflammation after ischemic stroke in vivo and in vitro. Moreover, we confirmed that QHRD106 reduced the level of acetylated HMGB1 and reduced the binding between heat shock protein 90 alpha family class A member 1 (HSP90AA1) and HMGB1, thus inhibiting the translocation and release of HMGB1. In summary, these findings indicate that QHRD106 treatment has therapeutic potential for cerebral ischemic stroke.

Urinary Kallidinogenase plus rt-PA Intravenous Thrombolysis for Acute Ischemic Stroke: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Purpose

This research is aimed at systematically assessing the safety and effectiveness of intravenous thrombolysis (IVT) with rt-PA plus human urinary kallidinogenase (HUK) for acute ischemic stroke (AIS).

Methods

The data were obtained through rigorous searching of both domestic and foreign databases from inception to 2021.7.1. Randomized controlled trials (RCTs) were included for the comparison of the efficacy of IVT plus HUK. The Cochrane risk of bias (RoB) tool and Review Manager software 5.3 were responsible for RoB assessment and statistical analyses, respectively.

Results

A total of 18 articles were retrieved, including 2676 AIS patients treated with IVT within the time window. The control group used standardized rt-PA IVT, and the test group added HUK. After 14 days of combined application of HUK, the National Institute of Health Stroke Scale (NIHSS) score was significantly better in moderate stroke patients using the combination treatment versus those with IVT alone (mean difference (MD) = -3.13; 95% confidence intervals (CI): -3.40,-2.86; P < 0.00001); the NIHSS score was also statistically in severe stroke patients with combined treatment than in those with IVT alone, but the degree of recovery of patients varied greatly. After 90 days of treatment, the NIHSS (MD = -1.93; 95% CI: -2.51,-1.34; P < 0.00001) and Barthel index (BI) scores (MD = 22.23; 95% CI: 18.96, 25.49; P < 0.00001) of patients plus HUK were significantly better than those of patients with IVT alone, with fewer adverse events during treatment (Relative Risk (RR) = 0.66; 95% CI: 0.47, 0.92; P = 0.02).

Conclusions

For AIS patients with IVT within the time window, HUK plus rt-PA IVT could significantly improve the neurological function recovery after 14 days and the quality of life after 90 days and reduce the adverse reactions of IVT. This trial is registered with CRD42021226975.

Human urinary kallidinogenase may improve the prognosis of acute stroke patients with early neurological deterioration

OBJECTIVES

Some acute ischemic stroke (AIS) patients still suffer from early neurological deterioration (END) after receiving intravenous thrombolysis (IVT), and these patients often have a poor prognosis. The purpose of our study is to observe the efficacy and safety of human urinary kallidinogenase (HUK) treatment in patients with END.

METHODS

This was a retrospective analysis and 49 patients with END who met the inclusion criteria were divided into the observation group and the control group. All patients received routine treatment of AIS, while patients in the observation group were treated with HUK within 24 h after IVT and the other group without HUK.

RESULTS

There were 24 patients in the observation group and 25 patients in the control group. After treatment, favorable prognosis (mRS scores ≤2) at 3 months in the observation group with 13 cases (54.17%) was significantly better than that in the control group with four cases (16%) (p = .001), and there was no statistical difference between the two groups in any hemorrhagic complication.

CONCLUSION

HUK is considered to be safe and may improve the prognosis of AIS patients with END after IVT. More clinical trials are needed to validate these results in the future.

Human urinary kallidinogenase combined with edaravone in treating acute ischemic stroke patients: A meta-analysis

INTRODUCTION

Several studies have investigated the efficacy of human urinary kallidinogenase (HUK) combined with edaravone (Eda) in acute ischemic stroke (AIS) patients. Our aim was to provide the best available evidence for clinical practice and further research programs for stroke treatment.

METHODS

We searched the online database for paper published between January 2015 and April 2021. We calculated weighted mean difference (WMD) or odds risk (OR) and their corresponding 95% confidence interval (95% CI) of reported outcomes between HUK plus Eda and Eda groups for each study. The random-effect models or fixed-effect models were used to pool the analysis.

RESULTS

Thirteen studies with 1242 patients were included. In the pooled analysis, the scores of NIHSS in the HUK plus Eda group were significantly lower than that in patients receiving Eda (WMD = -3.92, 95% CI (-4.82, -3.02), p < .0001). The ADL scores in the HUK plus Eda group were significantly greater than that in patients receiving Eda (WMD = 14.13, 95% CI (10.67, 17.60), p < .0001). Furthermore, HUK plus Eda was associated with a higher rate of total efficacy (OR = 3.97, 95% CI (2.81, 5.59), p < .0001).

CONCLUSIONS

HUK combined with Eda provides potential clinical benefits as a treatment for AIS. Further high-quality, large-scale randomized trials are needed to confirm these results.

Increase in Blood-Brain Barrier Permeability is Modulated by Tissue Kallikrein via Activation of Bradykinin B1 and B2 Receptor-Mediated Signaling

Aim

Disruption of the blood–brain barrier (BBB) is a critical pathological feature after stroke. Although tissue kallikrein (TK) has used in the treatment of stroke in China, the role of TK in modulating BBB permeability is not clear.

Methods

We investigated the effect of different doses of TK on BBB by in vivo assessments of Evans blue (EB) and sodium-fluorescein isothiocyanate (FITC) leakage and in vitro assessments of the integrity of BBB and monolayers of microvascular endothelial cells (BMVECs). The expression of zonula occludens-1 (ZO-1) and bradykinin receptor-mediated signaling in BMVECs was detected.

Results

A significant increase in BBB permeability was observed in the mice treated with high dose of TK. However, standard and medium doses of TK could only enable sodium-FITC to enter the brain. The result of in vitro study indicated that high-doses of TK, but not standard and medium-dose of TK, reduced normal BBB integrity accompanied by a decreased expression of zonula occludens-1 (ZO-1), upregulated the mRNA levels of bradykinin 2 receptor (B2R) and endothelial nitric oxide synthase (eNOS) and the abundance of B2R. Moreover, standard-dose of TK exacerbated lipopolysaccharide-induced BBB hyperpermeability, upregulated the mRNA levels of bradykinin 1 receptor (B1R) and inducible nitric oxide synthase (iNOS), increased the abundance of B1R and reduced the abundance of ZO-1; these effects were inhibited by TK inhibitor.

Conclusion

TK can disrupt tight junctions and increase normal BBB permeability via B2R-dependent eNOS signaling pathway, aggravate impairment of BBB via B1R-dependent iNOS signaling pathway, and consequently serve as a useful adjunctive treatment for enhancing the efficacy of other neurotherapeutics.

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.

Matrix metallopeptidase 9 and placental growth factor may correlate with collateral status based on whole-brain perfusion combined with multiphase computed tomography angiography

OBJECTIVE

The aim of this study was to find out the relationship between serum biomarkers and cerebral collateral status in acute ischemic stroke with cerebral large artery atherosclerosis.

METHODS

We enrolled patients with ischemic stroke due to large artery atherosclerosis within 7 days of symptom onset, age 18-80 years, from August 2016 to December 2017. Twelve biomarkers representing different pathophysiological mechanisms were tested after admission. Whole-brain perfusion combined with multiphase computed tomography angiography was performed to assess cerebral collateral structure and function.

RESULTS

Fifty-two patients completed the test of candidate biomarkers and recruited in this study. The mean age was 55.0 (11.1) years, 42 (80.8%) patients were male, 20 (38.5%) had poor collateral, 36 (69.2%) patients had anterior circulation stenosis or occlusion. Compared with poor collateral group, the level of MMP-9 (135,475.00 pg/ml vs. 103,612.00 pg/ml, p = 0.040) and PGF (5.75 pg/ml vs. 3.46 pg/ml, p = 0.046) was significantly higher in good collateral group. The adjusted OR (95%CI) of MMP-9 and PGF were 5.533 (1.10-27.74, p = 0.038), 7.73 (1.41-42.39, p = 0.018), respectively. sTie-2 level had a positive correlation with proportion of Tmax 4-6 (r = 0.302, p = 0.033) and HMW-KGN had negative correlation with proportion of Tmax 6-8 (r = -0.338, p = 0.02). After adjustment, the correlation of sTie-2 level and proportion of Tmax 4-6 was statistically significant (p = 0.003), and correlation of HMW-KGN and Tmax6-8 was not statistically significant (p = 0.056).

DISCUSSION

Serum PGF and MMP-9 levels may correlate with collateral status based on MP-CTA in acute ischemic stroke patients with cerebral large artery atherosclerosis. Higher PGF and MMP-9 concentration associated with good collateral status.

Efficacy and safety of human urinary kallidinogenase for acute ischemic stroke: a meta-analysis

Objective

Human urinary kallidinogenase (HUK) is a glycoprotein extracted from human urine that is used to treat stroke by triggering positive regulation of the kallikrein–kinin system. Our aim was to evaluate the efficacy and safety of HUK treatment for acute ischemic stroke.

Methods

We searched the online databases PubMed, Embase, Cochrane Library, Google Scholar, and China National Knowledge Infrastructure (CNKI) for papers published between January 2015 and December 2019. The quality of each trial was assessed using the Cochrane Reviewers’ Handbook. Randomized controlled trials of HUK in patients with acute ischemic stroke were included.

Results

Sixteen trials with 1326 participants were included. The HUK injection groups had more neurological improvement than the control groups in National Institutes of Health Stroke Scale scores (mean difference, –1.65; 95% confidence interval [CI], –2.12 to –1.71) and clinical efficacy (1.30; 95% CI, 1.21 to 1.41). Subgroup analysis indicated that age may influence heterogeneity. Eleven trials reported adverse effects and there were no significant differences between the control and HUK groups (risk difference, 0.01; 95% CI, –0.02 to 0.04).

Conclusions

HUK ameliorates neurological symptoms in stroke patients with few adverse effects. Further high-quality, large-scale randomized trials are needed to confirm these results.

Human urinary kallidinogenase in treating acute ischemic stroke patients: analyses of pooled data from a randomized double-blind placebo-controlled phase IIb and phase III clinical trial

Objectives: Intravenous thrombolysis and thrombectomy are recommended for patients whose stroke onsets are within first 6 h, and very few options are available for patients whose stroke onset is more than 6 h, which includes most ischemic stroke patients. Human urinary kallidinogenase (HUK) showed potential clinical benefits in acute ischemic stroke patients. This study aims to investigate the safety and clinical benefits of HUK in ischemic stroke patients.Patients and methods: Patients were recruited for a multicenter double-blind, placebo-controlled phase II b and phase III trial. Neurophysiological outcomes were assessed by the European Stroke Scale (ESS) and the functional outcomes were assessed by the activity of daily living scale (ADL). Safety was monitored by recording adverse events.Results: The improvements in ESS scores and ADL scores in the HUK group were significantly greater than that in patients receiving placebo. Furthermore, HUK treatment was also associated with a lower rate of disable, according to ADL. HUK-related adverse events occurred at a low rate, in 1.73% of HUK-treated patients.Conclusion: HUK is safe and provides potential clinical benefits as a treatment for acute ischemic stroke. Further large post-marketing observational studies are needed.

The Protective Effects and Mechanisms of Apelin/APJ System on Ischemic Stroke: A Promising Therapeutic Target

The orphan receptor APJ and its endogenous ligand apelin, which are expressed in the brain, are the major components of the apelin/APJ system. Growing evidence shows that the apelin/APJ system plays a vital role in the pathophysiology of cerebral ischemic injury. Targeting the apelin/APJ system may have protective effects on cerebral ischemic injury. In this review, we sum up the latest research progress relating to the actions and therapeutic potential of the apelin/APJ system in ischemic stroke. An in-depth knowledge of the pathophysiological effects of the apelin/APJ system and the underlying mechanisms will help to develop novel therapeutic interventions for ischemic stroke.

Human urinary kallindinogenase therapy for acute ischemic stroke according to Chinese ischemic stroke subclassification: Clinical efficacy and risk factors

INTRODUCTION

To evaluate effectiveness of human urinary kallindinogenase (HUK) in patients with acute ischemic stroke (AIS) according to Chinese ischemic stroke subclassification (CISS) and analyzed risk factors of clinical efficacy.

METHODS

In this retrospective study, 134 patients received conventional therapy were enrolled to control group, and 132 patients received HUK treatment were enrolled to HUK group. National Institute of Health Stroke Scale (NIHSS) score was used to evaluate the clinical efficacy. Multivariate analysis of risk factors was performed by using logistic regression.

RESULTS

After treatment, NIHSS score of HUK group was significant lower than that of control group (p = .009). Effectiveness rate was 71.2% in HUK group, and 53.7% in control group, respectively (p = .003). The NIHSS of patients with large artery atherosclerosis (LAA) subtype in HUK group was significantly lower than that in control group (p = .005). The absence of HUK (OR = 2.75), homocysteine (OR = 0.15), and CS subtype (OR = 0.18) were risk factors for HUK clinical efficacy.

CONCLUSIONS

Human urinary kallindinogenase is an effective therapeutic approach for treatment of patients with AIS, especially in patients with LAA subtype. The absence of HUK, elevated homocysteine, and cardiogenic stroke subtype were risk factor for clinical efficacy of HUK.

Effects of Urinary Kallidinogenase on NIHSS score, mRS score, and fasting glucose levels in acute ischemic stroke patients with abnormal glucose metabolism: A prospective cohort study

Urinary kallidinogenase may assist recovery acute ischemic stroke. This study evaluated the effect of urinary kallidinogenase on National Institute of Health Stroke Scale (NIHSS) score, modified Rankin scale (mRS) score, and fasting glucose levels in patients with acute ischemic stroke (AIS) combined with diabetes mellitus and impaired fasting glucose.Patients with AIS and abnormal glucose metabolism were enrolled in this prospective cohort study and divided into 2 groups. The human urinary kallidinogenase (HUK) group were treated with urinary kallidinogenase and standard treatment; the control group received standard treatment. NIHSS scores, mRS scores, and fasting blood glucose were evaluated and compared.A total of 113 patients were included: 58 in the HUK group and 55 in the control group. NIHSS scores decreased with treatment in both groups (time effect P < .05), but were lower in the HUK group (main effect P = .026). The mRS score decreased in both groups from 10 until 90 days after treatment (time effect P < .05); the 2 groups were similar (main effect, P = .130). Blood glucose levels decreased in both groups 10 days after treatment (time effect, P < .05), but there was no significant treatment effect (main effect, P = .635). Multivariate analysis showed blood uric acid >420 μmol/L (odds ratio [OR]: 0.053, 95% confidence interval [CI]: 0.008-0.350; P = .002) and application of HUK (OR: 0.217, 95% CI: 0.049-0.954; P = .043) were associated with 90% NIHSS recovery. Baseline NIHSS score was independently associated with poor curative effect.Urinary kallidinogenase with conventional therapy significantly improved NIHSS scores in patients with AIS. Urinary kallidinogenase also showed a trend toward lower fasting blood glucose levels, although the level did not reach significance.

Human tissue kallikrein in the treatment of acute ischemic stroke

Acute ischemic stroke (AIS) remains a major cause of death and disability throughout the world. The most severe form of stroke results from large vessel occlusion of the major branches of the Circle of Willis. The treatment strategies currently available in western countries for large vessel occlusion involve rapid restoration of blood flow through removal of the offending blood clot using mechanical or pharmacological means (e.g. tissue plasma activator; tPA). This review assesses prospects for a novel pharmacological approach to enhance the availability of the natural enzyme tissue kallikrein (KLK1), an important regulator of local blood flow. KLK1 is responsible for the generation of kinins (bradykinin and kallidin), which promote local vasodilation and long-term vascularization. Moreover, KLK1 has been used clinically as a direct treatment for multiple diseases associated with impaired local blood flow including AIS. A form of human KLK1 isolated from human urine is approved in the People's Republic of China for subacute treatment of AIS. Here we review the rationale for using KLK1 as an additional pharmacological treatment for AIS by providing the biochemical mechanism as well as the human clinical data that support this approach.

The Combination of Human Urinary Kallidinogenase and Mild Hypothermia Protects Adult Rats Against Hypoxic-Ischemic Encephalopathy-Induced Injury by Promoting Angiogenesis and Regeneration

Objectives: Human Urinary Kallidinogenase (HUK) is a tissue kallikrein that plays neuroprotective role in ischemic conditions via different mechanisms. Mild hypothermia (MH) is another robust neuroprotectant that reduces mortality but does not profoundly ameliorate the neurological outcome in hypoxic-ischemic encephalopathy (HIE) patients. However, whether the combination of HUK and MH can be used as a promising neuroprotective treatment in HIE is unknown. Methods: One-hundred and forty-four adult Wistar rats were randomly divided into five groups: Sham, HIE, HUK, MH and a combination of HUK and MH treatment. The HIE rat model was established by right carotid dissection followed by hypoxia aspiration. The survival curve was created within 7 days, and the neurological severity scores (NSS) were assessed at days 0, 1, 3, and 7. Nissl staining, Terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL), immunofluorescent staining and western blotting were used to evaluate neuronal survival, apoptosis and necrosis, tight-junction proteins Claudin-1 and Zonula occludens-1 (ZO-1), vascular endothelial growth factor (VEGF), doublecortex (DCX), bradykinin receptor B1 (BDKRB1), BDKRB2 and Ki67 staining. Results: The combined treatment rescued all HIE rats from death and had a best survival curve compared to HIE. The Combination also reduced the NSS scores after HIE at days 7, better than HUK or MH alone. The combination of HUK and MH reserved more cells in Nissl staining and inhibited neuronal apoptosis and necrosis as well as significantly attenuated HIE-induced decreases in claudin-1, ZO-1, cyclin D1 and BDKRB1/B2 in comparison to HUK or MH treatment alone. Moreover, the combined treatment increased the expression of VEGF and DCX as well as the number of Ki67-labeled cells. Conclusions: This study demonstrates that both HUK and MH are neuroprotective after HIE insult; however, the combined therapy with HUK and MH enhanced the efficiency and efficacy of either therapy alone in the treatment of HIE, at least partially by promoting angiogenesis and regeneration and rescuing tight-junction loss. The combination of HUK and MH seems to be a feasible and promising clinical strategy to alleviate cerebral injury following HIE insult. Highlights: -The combination of HUK and MH distinctly reduces neurological dysfunction in HIE rats.-HUK enhances the neuroprotective effects of MH in HIE.-MH attenuates tight-junction disruption, upregulates the BDKR B1/2, DCX and cyclin D1.-The combination of MH and HUK enhances the expressions of MH/HUK mediated-BDKR B1/2, DCX, cyclin D1 and Ki67 positive cells.

Therapeutic Values of Human Urinary Kallidinogenase on Cerebrovascular Diseases

The term “tissue kallikrein” is used to describe a group of serine proteases shared considerable sequence homology and colocalize in the same chromosomal locus 19q13. 2–q13.4. It has been widely discovered in various tissues and has been proved to be involved in kinds of pathophysiological processes, such as inhibiting oxidative stress, inflammation, apoptosis, fibrosis and promoting angiogenesis, and neurogenesis. Human Urinary Kallidinogenase (HUK) extracted from human urine is a member of tissue kallikrein which could convert kininogen to kinin and hence improve the plasma kinin level. Medical value of HUK has been widely investigated in China, especially on acute ischemic stroke. In this review, we will summarize the therapeutic values of Human Urinary Kallidinogenase on acute ischemic stroke and its potential mechanisms.

Guidelines for evaluation and management of cerebral collateral circulation in ischaemic stroke 2017

Collateral circulation plays a vital role in sustaining blood flow to the ischaemic areas in acute, subacute or chronic phases after an ischaemic stroke or transient ischaemic attack. Good collateral circulation has shown protective effects towards a favourable functional outcome and a lower risk of recurrence in stroke attributed to different aetiologies or undergoing medical or endovascular treatment. Over the past decade, the importance of collateral circulation has attracted more attention and is becoming a hot spot for research. However, the diversity in imaging methods and criteria to evaluate collateral circulation has hindered comparisons of findings from different cohorts and further studies in exploring the clinical relevance of collateral circulation and possible methods to enhance collateral flow. The statement is aimed to update currently available evidence and provide evidence-based recommendations regarding grading methods for collateral circulation, its significance in patients with stroke and methods under investigation to improve collateral flow.

Intra-arterial human urinary kallidinogenase alleviates brain injury in rats with permanent middle cerebral artery occlusion through PI3K/AKT/FoxO1 signaling pathway

An urgent need exists to develop intra-arterial treatment for acute ischemic stroke in animal study. This study aimed to explore the beneficial effects of intra-arterial administration of human urinary kallidinogenase (HUK) on brain injury after permanent middle cerebral artery occlusion (pMCAO) in a rat model, and the potential underlying molecular mechanisms. Brain injury induced by pMCAO was evaluated through measuring neurological deficit scores, neuropathological changes, and inflammatory factors. Neurological deficits were observed 24 h after pMCAO and were alleviated by intra-arterial HUK treatment obviously. Inhibition of PI3K by LY294002 blocked the beneficial effect of HUK on neurological functions. In contrast to the pMCAO group, the intra-arterial HUK treatment group showed relatively more regularly arranged neurons and fewer pyknosis. Neurodegeneration, necrosis, infarct area and markers for brain injury were all ameliorated by intra-arterial HUK treatment. Moreover, a lower expression of inflammatory factors including interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α, and a higher expression of IL-10 were observed in the intra-arterial HUK treatment group than that in the pMCAO group. Additionally, when comparing with pMCAO group, a lower level of caspase-3, bax, and apoptotic rate, and a higher level of bcl-2, p-PI3K, p-AKT and p-FoxO1were observed in the pMCAO + HUK group. These results suggest that intra-arterial administration of HUK is a promising therapeutic strategy against pMCAO induced brain injury, and PI3K/AKT/FoxO1 signaling pathway may be involved in this process.

Prospective evaluation of the diagnostic value of plasma apelin 12 levels for differentiating patients with moyamoya and intracranial atherosclerotic diseases

Patients with moyamoya disease (MMD) or intracranial atherosclerotic disease (ICAD) experience similar cerebral ischaemic events. However, MMD patients show greater angiogenesis and arteriogenesis, which play crucial roles in collateral circulation development to enhance clinical prognosis and outcome. Apelins have been associated with angiogenesis and arteriogenesis. Therefore, the aim of the present study was to determine whether apelin levels were higher in patients with MMD than in patients with ICAD or in healthy controls. We compared plasma apelin levels in 29 patients with MMD, 82 patients with ICAD, and 25 healthy participants. Twelve-hour fasting blood samples were collected and analysed using commercially available kits. Univariate analyses indicated that compared with the ICAD and healthy control groups, the MMD group had higher apelin-12, apelin-13, apelin-36, and nitric oxide levels. Binary logistic regression analyses further showed that the plasma apelin-12 level was substantially higher in MMD patients than in ICAD patients. Patients with MMD were also differentiated from patients with ICAD by their mean ages, with the former being younger. Therefore, the plasma apelin-12 level is a potential diagnostic marker for differentiating MMD and ICAD and may provide a treatment strategy for enhancing collateral circulation development and clinical prognosis and outcome.

Apelin/APJ system: A novel promising therapy target for pathological angiogenesis

Apelin is the endogenous ligand of the G protein-coupled receptor APJ. Both Apelin and APJ receptor are widely distributed in various tissues such as heart, brain, limbs, retina and liver. Recent research indicates that the Apelin/APJ system plays an important role in pathological angiogenesis which is a progress of new blood branches developing from preexisting vessels via sprouting. In this paper, we review the important role of the Apelin/APJ system in pathological angiogenesis. The Apelin/APJ system promotes angiogenesis in myocardial infarction, ischemic stroke, critical limb ischemia, tumor, retinal angiogenesis diseases, cirrhosis, obesity, diabetes and other related diseases. Furthermore, we illustrate the detailed mechanism of pathological angiogenesis induced by the Apelin/APJ system. In conclusion, the Apelin/APJ system would be a promising therapeutic target for angiogenesis-related diseases.