Circulating miRNA profiles and the risk of hemorrhagic transformation after thrombolytic treatment of acute ischemic stroke: a pilot study.

Background: Hemorrhagic transformation (HT) in acute ischemic stroke is likely to occur in patients treated with intravenous thrombolysis (IVT) and may lead to neurological deterioration and symptomatic intracranial hemorrhage (sICH). Despite the complex inclusion and exclusion criteria for IVT and some useful tools to stratify HT risk, sICH still occurs in approximately 6% of patients because some of the risk factors for this complication remain unknown. Objective: This study aimed to explore whether there are any differences in circulating microRNA (miRNA) profiles between patients who develop HT after thrombolysis and those who do not. Methods: Using qPCR, we quantified the expression of 84 miRNAs in plasma samples collected prior to thrombolytic treatment from 10 individuals who eventually developed HT and 10 patients who did not. For miRNAs that were downregulated (fold change (FC) <0.67) or upregulated (FC >1.5) with p < 0.10, we investigated the tissue specificity and performed KEGG pathway annotation using bioinformatics tools. Owing to the small patient sample size, instead of multivariate analysis with all major known HT risk factors, we matched the results with the admission NIHSS scores only. Results: We observed trends towards downregulation of miR-1-3p, miR-133a-3p, miR-133b and miR-376c-3p, and upregulation of miR-7-5p, miR-17-3p, and miR-296-5p. Previously, the upregulated miR-7-5p was found to be highly expressed in the brain, whereas miR-1, miR-133a-3p and miR-133b appeared to be specific to the muscles and myocardium. Conclusion: miRNA profiles tend to differ between patients who develop HT and those who do not, suggesting that miRNA profiling, likely in association with other omics approaches, may increase the current power of tools predicting thrombolysis-associated sICH in acute ischemic stroke patients. This study represents a free hypothesis-approach pilot study as a continuation from our previous work. Herein, we showed that applying mathematical analyses to extract information from raw big data may result in the identification of new pathophysiological pathways and may complete standard design works.

Case report: First treatment of acute ischaemic stroke in a patient on active rivaroxaban therapy using andexanet alfa and rtPA combined with early complete recovery.

Patients with non-large vessel occlusion acute ischemic stroke (NL-AIS) on oral anticoagulants (OAC) constitute the biggest portion among those who cannot receive any potential-reperfusion treatment even if they appear early in the hospital. We present the first case of therapy for NL-AIS in a patient with active anti-Xa anticoagulation, combining andexanet alfa and rtPA, who was recruited for STRoke On AntiCoagulants for Thrombolysis (acronym: STROACT), an ongoing therapeutic trial for non-LVO ischemic stroke on a DOAC. This is also the first report of the use of andexanet alfa-rtPA for AIS in a patient on rivaroxaban, which is the most frequently used non-vitamin K antagonist oral anticoagulant. The patient received the intravenous bolus of 800 mg of andexanet (contralateral arm), followed by a bolus of rtPA (10% of the calculated dose; ipsilateral arm), then a continuous infusion of andexanet at 8 mg/min for 120 min (contralateral arm), and rtPA (90% of the calculated dose; ipsilateral arm)-both stopped after completion of 38.9 and 74% of infusion dose, respectively, due to the severe adverse event related to the administration of rtPA. In this schema, both infusions are ongoing concurrently for approximately 60 min, and then andexanet is administered alone until the completion of the dose (altogether lasting approximately 3 h). The therapy was spectacularly effective, with early and complete improvement in NIHSS from 8 to 0 points in 70 min from the initiation of the therapy; mRS = 0. Obviously, a single case cannot drive any standard therapeutic decisions, but the experience we share in this article may help manage selected special clinical problems, especially when a patient's expected outcome is poor and there is no other way to help than experimentally. Additionally, it seems a valuable addition to recent meta-data on thrombolysis in anticoagulated patients. Trial registration: https://www.clinicaltrialsregister.eu. Identifier: 2020-004898-41. Date of registration: March 31, 2021.

Genotype-Dependent Effect of Silencing of TaCKX1 and TaCKX2 on Phytohormone Crosstalk and Yield-Related Traits in Wheat.

The influence of silenced TaCKX1 and TaCKX2 on coexpression of other TaCKX gene family members (GFMs), phytohormone regulation and yield-related traits was tested in awned-spike cultivar. We documented a strong feedback mechanism of regulation of TaCKX GFM expression in which silencing of TaCKX1 upregulated expression of TaCKX2 genes and vice versa. Additionally, downregulation of TaCKX2 highly upregulated the expression of TaCKX5 and TaNAC2-5A. In contrast, expression of these genes in silenced TaCKX1 was downregulated. Silenced TaCKX1 T2 lines with expression decreased by 47% had significantly higher thousand grain weight (TGW) and seedling root mass. Silenced TaCKX2 T2 lines with expression of TaCKX2.2.1 and TaCKX2.2.2 decreased by 33% and 30%, respectively, had significantly higher chlorophyll content in flag leaves. TaCKX GFM expression, phytohormone metabolism and phenotype were additionally modified by Agrobacterium-mediated transformation. Two novel phytohormones, phenylacetic acid (PAA) and topolins, lack of gibberellic acid (GA) and changed phytohormone contents in the 7 days after pollination (DAP) spikes of the awned-spike cultivar compared to a previously tested, awnless one, were detected. We documented that major mechanisms of coregulation of the expression of TaCKX GFMs were similar in different spring wheat cultivars, but, depending on content and composition of phytohormones, regulation of yield-related traits was variously impacted.

SWATH-MS for prospective identification of protein blood biomarkers of rtPA-associated intracranial hemorrhage in acute ischemic stroke: a pilot study.

Intravenous recombinant tissue plasminogen activator (rtPA) is, besides mechanical thrombectomy, the highest class evidence based reperfusion treatment of acute ischemic stroke (AIS). The biggest concern of the therapy is symptomatic intracranial hemorrhage (sICH), which occurs in 3-7% of all treated patients, and is associated with worse functional outcome. Finding a method of the powerful identification of patients at highest risk of sICH, in order to increase the percentage of stroke patients safely treated with rtPA, is one of the most important challenges in stroke research. To address this problem, we designed a complex project to identify blood, neuroimaging, and clinical biomarkers combined for prospective assessment of the risk of rtPA-associated ICH. In this paper we present results of blood proteomic and peptide analysis of pilot 41 AIS patients before rtPA administration (the test ICH group, n = 9 or the controls, without ICH, n = 32). We demonstrated that pre-treatment blood profiles of 15 proteins differ depending on whether the patients develop rtPA-associated ICH or not. SWATH-MS quantification of serum or plasma proteins might allow for robust selection of blood biomarkers to increase the prospective assessment of rtPA-associated ICH over that based solely on clinical and neuroimaging characteristics.

TaCKX2.2 Genes Coordinate Expression of Other TaCKX Family Members, Regulate Phytohormone Content and Yield-Related Traits of Wheat.

TaCKX gene family members (GFMs) play essential roles in the regulation of cytokinin during wheat development and significantly influence yield-related traits. However, detailed function of most of them is not known. To characterize the role of TaCKX2.2 genes we silenced all homoeologous copies of both TaCKX2.2.1 and TaCKX2.2.2 by RNAi technology and observed the effect of silencing in 7 DAP spikes of T1 and T2 generations. The levels of gene silencing of these developmentally regulated genes were different in both generations, which variously determined particular phenotypes. High silencing of TaCKX2.2.2 in T2 was accompanied by slight down-regulation of TaCKX2.2.1 and strong up-regulation of TaCKX5 and TaCKX11, and expression of TaCKX1, TaCKX2.1, and TaCKX9 was comparable to the non-silenced control. Co-ordinated expression of TaCKX2.2.2 with other TaCKX GFMs influenced phytohormonal homeostasis. Contents of isoprenoid, active cytokinins, their conjugates, and auxin in seven DAP spikes of silenced T2 plants increased from 1.27 to 2.51 times. However, benzyladenine (BA) and abscisic acid (ABA) contents were significantly reduced and GA3 was not detected. We documented a significant role of TaCKX2.2.2 in the regulation of thousand grain weight (TGW), grain number, and chlorophyll content, and demonstrated the formation of a homeostatic feedback loop between the transcription of tested genes and phytohormones. We also discuss the mechanism of regulation of yield-related traits.

Efficacy and Safety of Intravenous rtPA in Ischemic Strokes Due to Small-Vessel Occlusion: Systematic Review and Meta-Analysis.

Intravenous recombinant tissue plasminogen activator (iv-rtPA) has been routinely used to treat ischemic stroke for 25 years, following large clinical trials. However, there are few prospective studies on the efficacy and safety of this therapy in strokes attributed to cerebral small vessel disease (SVD). We evaluated functional outcome (modified Rankin scale, mRS) and symptomatic intracerebral hemorrhage (sICH) using all available data on the effects of iv-rtPA in SVD-related ischemic stroke (defined either using neuroimaging, clinical features, or both). Using fixed-effect and random-effects models, we calculated the pooled effect estimates with regard to excellent and favorable outcomes (mRS=0-1 and 0-2 respectively, at 3 months), and the rate of sICH. Twenty-three studies fulfilled the eligibility criteria, 11 of which were comparative, and there were only 3 randomized clinical trials. In adjusted analyses, there was an increased odds of excellent outcome (adjusted OR=1.53, 95% CI: 1.29-1.82, I2: 0%) or favorable outcome (adjusted OR=1.68, 95% CI: 1.31-2.15,I2: 0%) in patients who received iv-rtPA compared with placebo. Across the six studies which reported it, the incidence of sICH was higher in the treatment group (M-H RR = 8.83, 95% CI: 2.76-28.27). The pooled rate of sICH in patients with SVD administered iv-rtPA was only 0.72% (95% CI: 0.12%-1.64%). We conclude that when ischemic stroke attributed to SVD is considered separately, available data on the effects of iv-rtPA therapy are insufficient for the highest level of recommendation, but it seems to be safe. Although further therapeutic trials in SVD-related ischemic stroke appear to be justified, our findings should not prevent its continued use for this group of patients in clinical practice.

New Remote Cerebral Microbleeds on T2*-Weighted Echo Planar MRI After Intravenous Thrombolysis for Acute Ischemic Stroke.

BACKGROUND: The main and well-defined complication of intravenous administration of recombinant tissue plasminogen activator (tPA) in patients with acute ischemic stroke (AIS) is symptomatic intracranial hemorrhage (sICH). However, rtPA might also be connected with the formation of cerebral microbleeds (CMBs), located remotely from the ischemic lesions, that may remain clinically silent. This association might be important because the load of CMBs has been associated with cognitive impairment. We investigated whether administration of rtPA in AIS results in the appearance of new CMBs and if the initial load of CMBs is associated with hemorrhagic transformation. METHODS: A total of fifty-nine consecutive patients with AIS treated with rtPA underwent MRI including T2*-weighted Echo Planar Imaging (T2*-EPI) shortly before and 7-9 days after rtPA administration. We calculated the load of new CMBs located outside the MR diffusion restriction area in the follow-up imaging and assessed hemorrhagic transformation with ECASS-II scoring. RESULTS: A total of forty-nine patients were included for the final analysis. On initial T2*-EPI-GRE, 37 baseline microbleeds (CMBs) were observed in 14 patients (28.6%). On follow-up T2*-EPI-GRE amount of CMBs increased to a total number of 103. New CMBs were found in 5 (14.3%) of 35 patients without and in 9 (64.3%) of 14 with any baseline CMBs. Multiple logistic regression analysis indicated that presence of baseline CMBs (risk ratio [RR] 5.95, 95% CI 2.69-13.20, p < 0.001) and lower platelets level (risk ratio [RR] 0.992, 95% CI 0.986-0.998, p = 0.007) were independently associated with new CMBs. The baseline load of CMBs was not associated with the risk of hemorrhagic transformation. CONCLUSION: In this study, new CMBs were found in nearly 30% of patients with AIS on the 7-9 days after rtPA treatment. Baseline CMBs correlated with a higher risk of new CMBs appearing after the rtPA treatment, independently of other factors. At the same time, in our sample, baseline CMBs did not correlate with an increased risk of hemorrhagic transformation. Since the associations between the CMBs load and cognitive impairment have already been proved, further studies are warranted to investigate possible associations between the thrombolytic treatment of patients with AIS, mainly those with baseline CMBs, and the risk of earlier cognitive decline.

Silencing of TaCKX1 Mediates Expression of Other TaCKX Genes to Increase Yield Parameters in Wheat.

TaCKX, Triticum aestivum (cytokinin oxidase/dehydrogenase) family genes influence the development of wheat plants by the specific regulation of cytokinin content in different organs. However, their detailed role is not known. The TaCKX1, highly and specifically expressed in developing spikes and in seedling roots, was silenced by RNAi-mediated gene silencing via Agrobacterium tumefaciens and the effect of silencing was investigated in 7 DAP (days after pollination) spikes of T1 and T2 generations. Various levels of TaCKX1 silencing in both generations influence different models of co-expression with other TaCKX genes and parameters of yield-related traits. Only a high level of silencing in T2 resulted in strong down-regulation of TaCKX11 (3), up-regulation of TaCKX2.1, 2.2, 5, and 9 (10), and a high yielding phenotype. This phenotype is characterized by a higher spike number, grain number, and grain yield, but lower thousand grain weight (TGW). The content of most of cytokinin forms in 7 DAP spikes of silenced T2 lines increased from 23% to 76% compared to the non-silenced control. The CKs cross talk with other phytohormones. Each of the tested yield-related traits is regulated by various up- or down-regulated TaCKX genes and phytohormones. The coordinated effect of TaCKX1 silencing on the expression of other TaCKX genes, phytohormone levels in 7 DAP spikes, and yield-related traits in silenced T2 lines is presented.

Changes of augmentation index early after ischaemic stroke predict functional outcome.

Purpose: Outcome after ischaemic stroke (AIS) depends on multiple factors, including values of blood pressure (BP) and arterial stiffness (AS) in the early phase. It is also known that stroke outcome is affected by BP variability; however, the influence of AS oscillations in the early phase of stroke on its prognosis is unknown. The aim of our study was to assess the relationship between changes of AS markers and stroke outcome.Materials and methods: Baseline clinical data, BP parameters, and markers of AS (pulse wave velocity [PWV], augmentation index [AIx]) were assessed 1, 6, and >90 days after AIS. The outcomes were defined using modified Rankin scale (mRS) score: early favourable (EFO) and early poor (EPO), as mRS ≤1 and >2 points at discharge, respectively; late favourable (LFO) and late poor (LPO), as mRS ≤1 and >2 points on day >90, respectively.Results: In the recruited 50 patients (62.2 ± 12.1 years, 68% males), BP and PWV decreased while AIx did not change within 90 days after AIS. Twenty-eight patients (56%) had EFO, 10 (20%) - EPO, 29 (58%) - LFO, and 9 (18%) - LPO. In univariate analysis, rise in AIx in days 1-6 was associated with EFO (odds ratio [OR] = 1.09, 95% confidence interval [CI] = 1.02-1.17, p = 0.01) and LFO (OR = 1.08; 95%CI = 1.01-1.14, p = 0.02), whereas decrease in AIx in days 1-6 was associated with EPO (OR = 1.07, 95%CI = 1.00-1.15, p = 0.05). For EFO and LFO, the relationships remained significant after including confounders (p = 0.03 and p = 0.03, respectively).Conclusions: Rise in AIx within one week after ischaemic stroke may be of additional importance in determining better early and late favourable functional outcome.

The salvageable brain in acute ischemic stroke. The concept of a reverse mismatch: a mini-review.

Recent studies have opened a new era in treatment of acute ischemic stroke, enabling thrombolysis or thrombectomy far beyond the standard therapeutic "time windows". These therapeutic protocols are built on various combinations of perfusion parameters, lesion volume, and neurological assessment. However, on top of the brain perfusion, there are other multiple factors that might modify the probability of neuronal apoptosis and necrosis following focal cerebral ischemia. We hypothesize that a diagnostic approach with measurements of selected biochemical parameters in the brain, in addition to those based solely on perfusion or MR diffusion, might allow for more personalized management protocols. Moreover, some local processes in the brain, triggered by acute ischemia or its consequences other than hypoperfusion directly, like, for example, excitotoxicity, might lead to apoptosis of the cells in the brain localized also beyond the area of hypoperfusion. This phenomenon might be responsible for the expansion of the brain damage much beyond the initial perfusion deficit or beyond the initial diffusion (DWI) restriction area, reported for example in T2W or FLAIR MRI in some stroke patients who have no other reasons to deteriorate (a reverse DWI - T2W / FLAIR, a reverse perfusion - DWI, or a reverse DWI - DWI mismatch).

Specificity of expression of TaCKX family genes in developing plants of wheat and their co-operation within and among organs.

Multigene families of CKX genes encode cytokinin oxidase/dehydrogenase proteins (CKX), which regulate cytokinin content in organs of developing plants. It has already been documented that some of them play important roles in plant productivity. The presented research is the first step of comprehensive characterization of the bread wheat TaCKX gene family with the goal to select genes determining yield-related traits. The specificity of expression patterns of fifteen formerly annotated members of the TaCKX family was tested in different organs during wheat development. Based on this, the genes were assigned to four groups: TaCKX10, TaCKX5 and TaCKX4, highly specific to leaves; TaCKX3, TaCKX6 and TaCKX11, expressed in various levels through all the organs tested; TaCKX1, TaCKX2.3, TaCKX2.2, TaCKX2.1, TaCKX2.4 and TaCKX2.5 specific to developing spikes and inflorescences; TaCKX9, TaCKX8 and TaCKX7, highly specific to roots. Amplification products of tested genes were mapped to the chromosomes of the A, B or D genome using T. aestivum Ensembl Plants. Based on analysis of TaCKX transcripts as well as encoded amino acids in T. aestivum and Hordeum vulgare the number of CKX genes in wheat was limited to 11 and new numbering of selected TaCKX genes was proposed. Moreover, we found that there were developmental differences in expression of TaCKX in the first and the second spike and expression of some of the genes was daily time dependent. A very high and significant correlation was found between expression levels of TaCKX7 and TaCKX9, genes specific to seedling roots, TaCKX1, TaCKX2.1 and TaCKX2.2, specific to developing spikes, and the group of TaCKX3, 4, 5, 6, 10 and 11, highly expressed in leaves and other organs. The genes also co-operated among organs and were included in two groups representing younger or maturating stages of developing plants. The first group was represented by seedling roots, leaves from 4-week old plants, inflorescences and 0 DAP spikes; the second by developing spikes, 0 DAP, 7 DAP and 14 DAP. The key genes which might determine yield-related traits are indicated and their possible roles in breeding strategies are discussed.