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Introduction: Adrenocorticotropic hormone (ACTH) is a peptide secreted by pituitary gland that plays an important role in regulating cortisol secretion. Its determination is difficult because of instability in whole blood. Several factors that influence ACTH stability in blood before analysis have been identified: temperature, hemolysis, time to centrifugation and presence of protease inhibitors. Published results on ACTH whole blood stability seem contradictory. Materials and methods: We performed a stability study in 10 healthy volunteers. Three different conditions were tested: ethylenediaminetetraacetic acid (EDTA) at 4 °C, EDTA + aprotinin at 4 °C, EDTA + aprotinin at room temperature. Stability was evaluated for 8 hours. Adrenocorticotropic hormone measurements and hemolysis index were performed respectively on Cobas e602 and c701 (Roche Diagnostics, Mannheim, Germany). We compared percentage deviations with total change limit using a threshold of 7.5%. Results: We showed that ACTH is stable 8 hours with EDTA at 4 °C, 4 hours with EDTA + aprotinin at 4 °C and 2 hours with EDTA + aprotinin at 22 °C. Conclusions: Aprotinin does not appear to give ACTH greater stability but can be used without exceeding 4 hours at 4 °C. Refrigerated pouch transport also seems to be more appropriate for ACTH in whole blood. [ABSTRACT FROM AUTHOR]

In cardiac surgery with cardiopulmonary bypass (CPB) is a common complication. The incidence of this complication in cardiac surgery patients is estimated at about 10%. For this reason, the introduction of a patient blood management (PBM) in cardiac surgery is extremely relevant. Antifibrinolytic therapy is a key pharmacological tool of a multimodal PBM in cardiac surgery with CPB. The use of antifibrinolytics (tranexamic acid (TXA) and epsilon aminocaproic acid (EACA)) is standard practice in complex cardiac surgery with CPB. However, there is currently ongoing discussion regarding the search for the optimal dose of EACA and TXA to achieve an effective concentration in blood plasma in order to inhibit fibrinolysis with the minimization of adverse events. The use of aprotinin has a number of potential advantages, but its use in routine clinical practice is significantly limited. This review presents modern approaches to antifibrinolytic therapy, examines the mechanisms of action of the main drugs, highlights the side effects associated with the use of antifibrinolytic agents.

Abstract Background Aprotinin, a serine protease inhibitor, has been used variably in cardiac surgery amidst ongoing debates about its safety following several previous studies. This study assesses the outcomes of aprotinin in high-risk isolated Coronary Artery Bypass Graft (iCABG) patients. Methods The study retrospectively analysed a cohort of 1026 iCABG patients, including 51 patients who underwent aprotinin treatment. Logistic regression powered score matching was employed to compare aprotinin patients with a control group, in a propensity-matched cohort of 96 patients. The primary outcome measured was in-hospital death, with secondary outcomes including renal dysfunction, stroke, myocardial infarction, re-exploration for bleeding or tamponade, and postoperative stay durations. Results The aprotinin cohort had high-risk preoperative patients with significantly higher EUROSCORE II values, 7.5 (± 4.2), compared to 3.9 (± 2.5) in control group. However, aprotinin group showed no statistically significant increase (p-value: 0.44) in hospital mortality with OR 2.5 [95% CI 0.51, 12.3]. Major secondary outcome rates of renal replacement therapy and postoperative stroke compared to the control group were also statistically insignificant between the two groups. Conclusion This study suggests that aprotinin may be safely used in a select group of high-risk iCABG patients. The reintroduction of aprotinin under specific conditions reflects its potential benefits in managing bleeding in high-risk surgeries, but also underscores the complexity of its risk-benefit profile in such critical care settings. Nonetheless, it highlights the importance of carefully selecting patients and conducting additional research, including larger and more controlled studies to fully comprehend the potential risks and benefits of aprotinin.

Abstract Background Recombinant peptide production in Escherichia coli provides a sustainable alternative to environmentally harmful and size-limited chemical synthesis. However, in-vivo production of disulfide-bonded peptides at high yields remains challenging, due to degradation by host proteases/peptidases and the necessity of translocation into the periplasmic space for disulfide bond formation. Results In this study, we established an expression system for efficient and soluble production of disulfide-bonded peptides in the periplasm of E. coli. We chose model peptides with varying complexity (size, structure, number of disulfide bonds), namely parathyroid hormone 1–84, somatostatin 1–28, plectasin, and bovine pancreatic trypsin inhibitor (aprotinin). All peptides were expressed without and with the N-terminal, low molecular weight CASPON™ tag (4.1 kDa), with the expression cassette being integrated into the host genome. During BioLector™ cultivations at microliter scale, we found that most of our model peptides can only be sufficiently expressed in combination with the CASPON™ tag, otherwise expression was only weak or undetectable on SDS-PAGE. Undesired degradation by host proteases/peptidases was evident even with the CASPON™ tag. Therefore, we investigated whether degradation happened before or after translocation by expressing the peptides in combination with either a co- or post-translational signal sequence. Our results suggest that degradation predominantly happened after the translocation, as degradation fragments appeared to be identical independent of the signal sequence, and expression was not enhanced with the co-translational signal sequence. Lastly, we expressed all CASPON™-tagged peptides in two industry-relevant host strains during C-limited fed-batch cultivations in bioreactors. We found that the process performance was highly dependent on the peptide-host-combination. The titers that were reached varied between 0.6–2.6 g L−1, and exceeded previously published data in E. coli. Moreover, all peptides were shown by mass spectrometry to be expressed to completion, including full formation of disulfide bonds. Conclusion In this work, we demonstrated the potential of the CASPON™ technology as a highly efficient platform for the production of soluble peptides in the periplasm of E. coli. The titers we show here are unprecedented whenever parathyroid hormone, somatostatin, plectasin or bovine pancreatic trypsin inhibitor were produced in E. coli, thus making our proposed upstream platform favorable over previously published approaches and chemical synthesis.

Glutinous rice (mochi rice), compared to non-glutinous rice (uruchi rice), exhibits a wide range of glycemic index (GI) values, from low to high. However, the underlying mechanisms behind the variation in GI values remain poorly understood. In this study, we aimed to identify rice cultivars with a low postprandial glycemic response and investigate the mechanisms, focusing on insulin and incretin hormones. We examined seven glutinous rice cultivars and three non-glutinous rice cultivars. We discovered that Anekomochi, a glutinous rice cultivar, has the lowest postprandial glycemic response. Anekomochi significantly enhanced glucagon-like peptide-1 (GLP-1) secretion while suppressing insulin secretion. These effects were completely blunted by inhibiting GLP-1 receptor signaling and denervating the common hepatic branch of vagal afferent nerves that are crucial for sensing intestinal GLP-1. Our findings demonstrate that Anekomochi markedly enhances insulin action via GLP-1 release and vagal afferent neural pathways, thereby leading to a lower postprandial glycemic response. Keywords: Glutinous rice, Postprandial glycemic response, GLP-1, Insulin, Vagal afferent nerves, Author(s): Kento Ohbayashi[sup.1], Yudai Sugiyama[sup.1], Taichi Nohmi[sup.1], Kazusa Nishimura[sup.2,3], Tetsuya Nakazaki[sup.3,4], Yo-Ichiro Sato[sup.5,6], Takehiro Masumura[sup.7] and Yusaku Iwasaki[sup.1] Background Postprandial hyperglycemia is associated with the development of type 2 diabetes [...]

Background: Aprotinin, a serine protease inhibitor, has been used variably in cardiac surgery amidst ongoing debates about its safety following several previous studies. This study assesses the outcomes of aprotinin in high-risk isolated Coronary Artery Bypass Graft (iCABG) patients. Methods: The study retrospectively analysed a cohort of 1026 iCABG patients, including 51 patients who underwent aprotinin treatment. Logistic regression powered score matching was employed to compare aprotinin patients with a control group, in a propensity-matched cohort of 96 patients. The primary outcome measured was in-hospital death, with secondary outcomes including renal dysfunction, stroke, myocardial infarction, re-exploration for bleeding or tamponade, and postoperative stay durations. Results: The aprotinin cohort had high-risk preoperative patients with significantly higher EUROSCORE II values, 7.5 (± 4.2), compared to 3.9 (± 2.5) in control group. However, aprotinin group showed no statistically significant increase (p-value: 0.44) in hospital mortality with OR 2.5 [95% CI 0.51, 12.3]. Major secondary outcome rates of renal replacement therapy and postoperative stroke compared to the control group were also statistically insignificant between the two groups. Conclusion: This study suggests that aprotinin may be safely used in a select group of high-risk iCABG patients. The reintroduction of aprotinin under specific conditions reflects its potential benefits in managing bleeding in high-risk surgeries, but also underscores the complexity of its risk-benefit profile in such critical care settings. Nonetheless, it highlights the importance of carefully selecting patients and conducting additional research, including larger and more controlled studies to fully comprehend the potential risks and benefits of aprotinin. [ABSTRACT FROM AUTHOR]

Proteases are produced and released in the mucosal cells of the respiratory tract and have important physiological functions, for example, maintaining airway humidification to allow proper gas exchange. The infectious mechanism of severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2), which causes coronavirus disease 2019 (COVID-19), takes advantage of host proteases in two ways: to change the spatial conformation of the spike (S) protein via endoproteolysis (e.g., transmembrane serine protease type 2 (TMPRSS2)) and as a target to anchor to epithelial cells (e.g., angiotensin-converting enzyme 2 (ACE2)). This infectious process leads to an imbalance in the mucosa between the release and action of proteases versus regulation by anti-proteases, which contributes to the exacerbation of the inflammatory and prothrombotic response in COVID-19. In this article, we describe the most important proteases that are affected in COVID-19, and how their overactivation affects the three main physiological systems in which they participate: the complement system and the kinin–kallikrein system (KKS), which both form part of the contact system of innate immunity, and the renin–angiotensin–aldosterone system (RAAS). We aim to elucidate the pathophysiological bases of COVID-19 in the context of the imbalance between the action of proteases and anti-proteases to understand the mechanism of aprotinin action (a panprotease inhibitor). In a second-part review, titled "Aprotinin (II): Inhalational Administration for the Treatment of COVID-19 and Other Viral Conditions", we explain in depth the pharmacodynamics, pharmacokinetics, toxicity, and use of aprotinin as an antiviral drug. [ABSTRACT FROM AUTHOR]

Aprotinin is a broad-spectrum inhibitor of human proteases that has been approved for the treatment of bleeding in single coronary artery bypass surgery because of its potent antifibrinolytic actions. Following the outbreak of the COVID-19 pandemic, there was an urgent need to find new antiviral drugs. Aprotinin is a good candidate for therapeutic repositioning as a broad-spectrum antiviral drug and for treating the symptomatic processes that characterise viral respiratory diseases, including COVID-19. This is due to its strong pharmacological ability to inhibit a plethora of host proteases used by respiratory viruses in their infective mechanisms. The proteases allow the cleavage and conformational change of proteins that make up their viral capsid, and thus enable them to anchor themselves by recognition of their target in the epithelial cell. In addition, the activation of these proteases initiates the inflammatory process that triggers the infection. The attraction of the drug is not only its pharmacodynamic characteristics but also the possibility of administration by the inhalation route, avoiding unwanted systemic effects. This, together with the low cost of treatment (≈2 Euro/dose), makes it a good candidate to reach countries with lower economic means. In this article, we will discuss the pharmacodynamic, pharmacokinetic, and toxicological characteristics of aprotinin administered by the inhalation route; analyse the main advances in our knowledge of this medication; and the future directions that should be taken in research in order to reposition this medication in therapeutics. [ABSTRACT FROM AUTHOR]

Background: Recombinant peptide production in Escherichia coli provides a sustainable alternative to environmentally harmful and size-limited chemical synthesis. However, in-vivo production of disulfide-bonded peptides at high yields remains challenging, due to degradation by host proteases/peptidases and the necessity of translocation into the periplasmic space for disulfide bond formation. Results: In this study, we established an expression system for efficient and soluble production of disulfide-bonded peptides in the periplasm of E. coli. We chose model peptides with varying complexity (size, structure, number of disulfide bonds), namely parathyroid hormone 1–84, somatostatin 1–28, plectasin, and bovine pancreatic trypsin inhibitor (aprotinin). All peptides were expressed without and with the N-terminal, low molecular weight CASPON™ tag (4.1 kDa), with the expression cassette being integrated into the host genome. During BioLector™ cultivations at microliter scale, we found that most of our model peptides can only be sufficiently expressed in combination with the CASPON™ tag, otherwise expression was only weak or undetectable on SDS-PAGE. Undesired degradation by host proteases/peptidases was evident even with the CASPON™ tag. Therefore, we investigated whether degradation happened before or after translocation by expressing the peptides in combination with either a co- or post-translational signal sequence. Our results suggest that degradation predominantly happened after the translocation, as degradation fragments appeared to be identical independent of the signal sequence, and expression was not enhanced with the co-translational signal sequence. Lastly, we expressed all CASPON™-tagged peptides in two industry-relevant host strains during C-limited fed-batch cultivations in bioreactors. We found that the process performance was highly dependent on the peptide-host-combination. The titers that were reached varied between 0.6–2.6 g L−1, and exceeded previously published data in E. coli. Moreover, all peptides were shown by mass spectrometry to be expressed to completion, including full formation of disulfide bonds. Conclusion: In this work, we demonstrated the potential of the CASPON™ technology as a highly efficient platform for the production of soluble peptides in the periplasm of E. coli. The titers we show here are unprecedented whenever parathyroid hormone, somatostatin, plectasin or bovine pancreatic trypsin inhibitor were produced in E. coli, thus making our proposed upstream platform favorable over previously published approaches and chemical synthesis. [ABSTRACT FROM AUTHOR]

Background: The role of aprotinin in modern cardiac surgery is not well defined. While licensed for use in isolated coronary artery bypass grafting it is more commonly used for cases deemed to be at an increased risk of bleeding. The relative efficacy, and safety profile, of aprotinin as compared to other antifibrinolytics in these high‐risk cases is uncertain. Study Design and Methods: A retrospective observational study with propensity matching to determine whether aprotinin versus tranexamic acid reduced bleeding or transfusion requirements in patients presenting for surgical repair of type A aortic dissection (TAD). Results: Between 2016 and 2022, 250 patients presented for repair of TAD. A total of 231 patients were included in the final analysis. Bleeding and transfusion were similar between both groups in both propensity matched and unmatched cohorts. Compared to tranexamic acid, aprotinin use did not reduce transfusion requirements for any product. Rates of bleeding in the first 12 h, return to theater and return to intensive care unit with an open packed chest were similar between groups. There was no difference in rates of renal failure, stroke, or death. Conclusion: Aprotinin did not reduce the risk of bleeding or transfusion requirements in patients undergoing repair of type A aortic dissections. Efficacy of aprotinin may vary depending on the type of surgery performed and the underlying pathology. [ABSTRACT FROM AUTHOR]

Antifibrinolytics have gained increasing attention in minimizing blood loss and mitigating the risks associated with massive transfusions, including infection and coagulopathy in pediatric patients undergoing spine surgery. Nevertheless, the selection of optimal agent is still a matter of debate. We aim to review the utility of these agents and compare the efficacy of antifibrinolytics in pediatric and adolescent spine surgeries. A comprehensive search was performed in Scopus, Web of Science, and MEDLINE databases for relevant works. Studies providing quantitative data on predefined outcomes were included. Primary outcome was perioperative bleeding between the groups. Secondary outcomes included transfusion volume, rate of complications, and operation time. Twenty-eight studies were included in the meta-analysis incorporating 2553 patients. The use of Tranexamic acid (RoM: 0.71, 95%CI: [0.62–0.81], p < 0.001, I2 = 88%), Aprotinin (RoM: 0.54, 95%CI: [0.46–0.64], p < 0.001, I2 = 0%), and Epsilon-aminocaproic acid (RoM: 0.71, 95%CI: [0.62–0.81], p < 0.001, I2 = 60%) led to a 29%, 46%, and 29% reduction in perioperative blood loss, respectively. Network meta-analysis revealed higher probability of efficacy with Tranexamic acid compared to Epsilon-aminocaproic acid (P score: 0.924 vs. 0.571). The rate of complications was not statistically different between each two antifibrinolytic agent or antifibrinolytics compared to placebo or standard of care. Our network meta-analysis suggests a superior efficacy of all antifibrinolytics compared to standard of care/placebo in reducing blood loss and transfusion rate. Further adequately-powered randomized clinical trials are recommended to reach definite conclusion on comparative performance of these agents and to also provide robust objective assessments and standardized outcome data and safety profile on antifibrinolytics in pediatric and adolescent pediatric surgeries. [ABSTRACT FROM AUTHOR]

Open in new tab Download slide OBJECTIVES Following the reintroduction of aprotinin into the European market, the French Society of Cardiovascular and Thoracic Anaesthesiologists recommended its prophylactic use at half-dose for high-risk cardiac surgery patients. We examined whether the use of aprotinin instead of tranexamic acid could significantly reduce severe perioperative bleeding. METHODS This multicentre, retrospective, historical study included cardiac surgery patients treated with aprotinin or tranexamic acid between December 2017 and September 2020. The primary efficacy end point was the severe or massive perioperative bleeding (class 3–4 of the universal definition of perioperative bleeding). The safety secondary end points included the occurrence of thromboembolic events and all-cause mortality within 30 days after surgery. RESULTS Among the 693 patients included in the study, 347 received aprotinin and 346 took tranexamic acid. The percentage of patients with severe or massive bleeding was similar in the 2 groups (42.1% vs 43.6%, Adjusted odds ratio [ORadj] = 0.87, 95% confidence interval: 0.62–1.23, P  =   0.44), as was the perioperative need for blood products (81.0% vs 83.2%, ORadj = 0.75, 95% confidence interval: 0.48–1.17, P  =   0.20). However, the median (Interquartile range) 12 h postoperative blood loss was significantly lower in the aprotinin group (383 ml [241–625] vs 450 ml [290–730], P  <   0.01). Compared to tranexamic acid, the intraoperative use of aprotinin was associated with increased risk for thromboembolic events (adjusted Hazard ratio 2.30 [95% Cl: 1.06–5.30]; P  = 0.04). CONCLUSIONS Given the modest reduction in blood loss at the expense of a significant increase in thromboembolic adverse events, aprotinin use in high-risk cardiac surgery patients should be based on a carefully considered benefit–risk assessment. [ABSTRACT FROM AUTHOR]

The use of strategies to reduce blood loss and transfusions is essential in the treatment of surgical patients, including in complex cardiac surgeries and those that use cardiopulmonary bypass. Antifibrinolytics, such as epsilon-aminocaproic acid (EACA) and tranexamic acid (TXA), are widely used in these procedures, as well as in other types of surgeries. These medicines are included in the World Health Organization (WHO) list of ‘essential medicines’. Scientific evidence demonstrates the effectiveness of EACA in reducing bleeding and the need for transfusions in heart surgery. EACA is highly recommended for use in heart surgery by the American Society of Anesthesiology Task Force on Perioperative Blood Management. Regarding the safety of EACA, there is no robust evidence of any significant thrombotic potential. TXA has also been shown to be effective in reducing the use of blood transfusions in cardiac and non-cardiac surgeries and is considered safer than other antifibrinolytic agents. There is no evidence of any increased risk of thromboembolic events with TXA, but doses greater than 2 g per day have been associated with an increased risk of seizures. It is also important to adjust the dose in patients with renal impairment. In conclusion, antifibrinolytics, such as EACA and TXA, are effective in reducing blood loss and transfusion use in cardiac and non-cardiac surgeries, without causing serious adverse effects.

Introduction. The review is devoted to the actual problem of treating patients with keratolysis. The role of matrix metalloproteinases in the pathogenesis of cornea and corneal graft melting is discussed as well as the practical experience of using synthetic metalloproteinase inhibitors in various branches of medicine and in ophthalmology, in particular. In the field of eye diseases, the search for effective methods for the treatment of corneal injuries of various origins, as well as its post-transplant complications, has been underway for a long time. Recent studies have shown that local imbalance of matrix metalloproteinases and their inhibitors system, as well as the immune system status, may play the main role in the outcome of urgent keratoplasty, and the use of synthetic metalloproteinase inhibitors can significantly improve the biological result of the donor cornea transplant. The role of platelets in the regulation of the proteolytic system has not been fully studied. However, some literature data on the platelet-associated inhibitor of metalloproteinases and the use of platelet-rich plasma to correct the collagenolytic activity of enzymes are of great interest to ophthalmologists, due to therapeutic efficacy and simple method of producing its production the autologous platelet-rich plasma.The present brief literature review covers the pathogenesis and clinical features of keratolysis, factors which can affect the outcome of urgent keratoplasty, describes the features of matrix metalloproteinases, their inhibitors, and the plateletrich plasma as a potential endogenous source of a tissue inhibitor of matrix metalloproteinases.Aim. To evaluate the possibility of using inhibitors of matrix metalloproteinases for keratoplasty based on a literature review.Material and methods. To write the review article, we have made the search in the homeland eLibrary.RU database and in the PubMed resource database to select the articles on the topic published in the period from 1985 to 2022.

Proteases are produced and released in the mucosal cells of the respiratory tract and have important physiological functions, for example, maintaining airway humidification to allow proper gas exchange. The infectious mechanism of severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2), which causes coronavirus disease 2019 (COVID-19), takes advantage of host proteases in two ways: to change the spatial conformation of the spike (S) protein via endoproteolysis (e.g., transmembrane serine protease type 2 (TMPRSS2)) and as a target to anchor to epithelial cells (e.g., angiotensin-converting enzyme 2 (ACE2)). This infectious process leads to an imbalance in the mucosa between the release and action of proteases versus regulation by anti-proteases, which contributes to the exacerbation of the inflammatory and prothrombotic response in COVID-19. In this article, we describe the most important proteases that are affected in COVID-19, and how their overactivation affects the three main physiological systems in which they participate: the complement system and the kinin–kallikrein system (KKS), which both form part of the contact system of innate immunity, and the renin–angiotensin–aldosterone system (RAAS). We aim to elucidate the pathophysiological bases of COVID-19 in the context of the imbalance between the action of proteases and anti-proteases to understand the mechanism of aprotinin action (a panprotease inhibitor). In a second-part review, titled “Aprotinin (II): Inhalational Administration for the Treatment of COVID-19 and Other Viral Conditions”, we explain in depth the pharmacodynamics, pharmacokinetics, toxicity, and use of aprotinin as an antiviral drug.

Aprotinin is a broad-spectrum inhibitor of human proteases that has been approved for the treatment of bleeding in single coronary artery bypass surgery because of its potent antifibrinolytic actions. Following the outbreak of the COVID-19 pandemic, there was an urgent need to find new antiviral drugs. Aprotinin is a good candidate for therapeutic repositioning as a broad-spectrum antiviral drug and for treating the symptomatic processes that characterise viral respiratory diseases, including COVID-19. This is due to its strong pharmacological ability to inhibit a plethora of host proteases used by respiratory viruses in their infective mechanisms. The proteases allow the cleavage and conformational change of proteins that make up their viral capsid, and thus enable them to anchor themselves by recognition of their target in the epithelial cell. In addition, the activation of these proteases initiates the inflammatory process that triggers the infection. The attraction of the drug is not only its pharmacodynamic characteristics but also the possibility of administration by the inhalation route, avoiding unwanted systemic effects. This, together with the low cost of treatment (≈2 Euro/dose), makes it a good candidate to reach countries with lower economic means. In this article, we will discuss the pharmacodynamic, pharmacokinetic, and toxicological characteristics of aprotinin administered by the inhalation route; analyse the main advances in our knowledge of this medication; and the future directions that should be taken in research in order to reposition this medication in therapeutics.

Pancreatic [beta] cells are specialized for coupling glucose metabolism to insulin peptide production and secretion. Acute glucose exposure robustly and coordinately increases translation of proinsulin and proteins required for secretion of mature insulin peptide. By contrast, chronically elevated glucose levels that occur during diabetes impair [beta] cell insulin secretion and have been shown experimentally to suppress insulin translation. Whether translation of other genes critical for insulin secretion is similarly downregulated by chronic high glucose is unknown. Here, we used high-throughput ribosome profiling and nascent proteomics in MIN6 insulinoma cells to elucidate the genome- wide impact of sustained high glucose on [beta] cell mRNA translation. Before induction of ER stress or suppression of global translation, sustained high glucose suppressed glucose-stimulated insulin secretion and downregulated translation of not only insulin, but also mRNAs related to insulin secretory granule formation, exocytosis, and metabolism-coupled insulin secretion. Translation of these mRNAs was also downregulated in primary rat and human islets following ex vivo incubation with sustained high glucose and in an in vivo model of chronic mild hyperglycemia. Furthermore, translational downregulation decreased cellular abundance of these proteins. Our study uncovered a translational regulatory circuit during [beta] cell glucose toxicity that impairs expression of proteins with critical roles in [beta] cell function., Introduction Diabetes results from failure of pancreatic [beta] cells to secrete sufficient insulin to regulate glucose homeostasis. Progressive decline in [beta] cell function occurs in the setting of hyperglycemia during [...]

Aprotinin (APR) was discovered in 1930. APR is an effective pan-protease inhibitor, a typical "magic shotgun". Until 2007, APR was widely used as an antithrombotic and anti-inflammatory drug in cardiac and noncardiac surgeries for reduction of bleeding and thus limiting the need for blood transfusion. The ability of APR to inhibit proteolytic activation of some viruses leads to its use as an antiviral drug for the prevention and treatment of acute respiratory virus infections. However, due to incompetent interpretation of several clinical trials followed by incredible controversy in the literature, the usage of APR was nearly stopped for a decade worldwide. In 2015–2020, after re-analysis of these clinical trials' data the restrictions in APR usage were lifted worldwide. This review discusses antiviral mechanisms of APR action and summarizes current knowledge and prospective regarding the use of APR treatment for diseases caused by RNA-containing viruses, including influenza and SARS-CoV-2 viruses, or as a part of combination antiviral treatment. [ABSTRACT FROM AUTHOR]

Simple Summary: Cats with chronic kidney disease (CKD) frequently suffer from weight loss and inadequate caloric intake due to poor appetite. Ghrelin is a key hormone involved in the regulation of appetite, and it circulates in two forms: acylated and desacyl ghrelin. Acylated ghrelin is associated with initiating and stimulating appetite, whereas desacyl ghrelin is considered anorexigenic. To investigate appetite regulation in cats, this study compared plasma acylated, total, and calculated desacyl ghrelin concentrations in cats with and without CKD. The results demonstrate that cats with CKD have increased desacyl and total ghrelin concentrations in comparison to normal cats, consistent with dysregulation of appetite. This increase was correlated with disease severity. Appetite abnormalities and weight loss are important comorbidities in the treatment of chronic kidney disease (CKD) in cats. Ghrelin, a key hormone involved in the regulation of appetite and metabolism, is a potential marker of appetite dysregulation in cats with CKD. The aim of this study was to compare the plasma concentrations of acylated, desacyl, and total ghrelin in normal cats and cats with CKD. Storage methodology was investigated prior to evaluating ghrelin concentrations in normal and CKD cats to facilitate clinical sample collection. Twelve normal cats and twelve cats with CKD were enrolled. Plasma acylated and total ghrelin concentrations were measured using radioimmunoassay. Desacyl ghrelin was calculated (total ghrelin minus acylated ghrelin). Cats with CKD had significantly increased total ghrelin and calculated desacyl ghrelin concentrations in comparison to normal cats (p < 0.0001 and p = 0.0001). There was no significant difference in active ghrelin concentrations between groups. Both total ghrelin and calculated desacyl ghrelin were significantly correlated with serum creatinine concentrations (p < 0.0001, r = 0.70 and p < 0.0001, r = 0.73). Elevated plasma desacyl ghrelin concentrations in cats with CKD provides evidence for dysregulation of appetite in feline CKD. [ABSTRACT FROM AUTHOR]

Current antifibrinolytic agents reduce blood loss by inhibiting plasmin active sites (e.g., aprotinin) or by preventing plasminogen/tissue plasminogen activator (tPA) binding to fibrin clots (e.g., ε-aminocaproic acid and tranexamic acid); however, they have adverse side effects. Here, we expressed 60-residue (NH2NAE…IEKCOOH) Kunitz domain1 (KD1) mutants of human tissue factor pathway inhibitor type-2 that inhibit plasmin as well as plasminogen activation. A single (KD1-L17R-KCOOH) and a double mutant (KD1-Y11T/L17R- KCOOH) were expressed in Escherichia coli as His-tagged constructs, each with enterokinase cleavage sites. KD1-Y11T/L17R-KCOOH was also expressed in Pichia pastoris. KD1-Y11T/L17R-KCOOH inhibited plasmin comparably to aprotinin and bound to the kringle domains of plasminogen/plasmin and tPA with Kd of ~50 nM and ~35 nM, respectively. Importantly, compared to aprotinin, KD1-L17R-KCOOH and KD1-Y11T/L17R-KCOOH did not inhibit kallikrein. Moreover, the antifibrinolytic potential of KD1-Y11T/L17R-KCOOH was better than that of KD1-L17R-KCOOH and similar to that of aprotinin in plasma clot-lysis assays. In thromboelastography experiments, KD1-Y11T/L17R-KCOOH was shown to inhibit fibrinolysis in a dose dependent manner and was comparable to aprotinin at a higher concentration. Further, KD1-Y11T/L17R-KCOOH did not induce cytotoxicity in primary human endothelial cells or fibroblasts. We conclude that KD1-Y11T/L17R-KCOOH is comparable to aprotinin, the most potent known inhibitor of plasmin and can be produced in large amounts using Pichia.

Byline: Qian. Jiang, Yifei. Chen, Fangyong. Zhu, Yujia. Xie, Zhidan. Zhu, Xiaojing. Sun OBJECTIVES: Patients with condylar fractures were treated with osteopeptide injections as an adjuvant therapy to assess pain [...]

Introduction: The European Medicines Agency restored aprotinin (APR) use for preventing blood loss in patients undergoing isolated coronary artery bypass graft (iCABG) in 2016 but requested the collection of patient and surgery data in a registry (NAPaR). The aim of this analysis was to evaluate the impact of APR reintroduction in France on the main hospital costs (operating room, transfusion and intensive unit stay) compared to the current use of tranexamic acid (TXA), which was the only antifibrinolytic available before APR reinstatement. Methods: A multicenter before-after post-hoc analysis to compare APR and TXA was carried out in four French university hospitals. APR use followed the ARCOTHOVA (French Association of Cardiothoracic and Vascular Anesthetists) protocol, which had framed three main indications in 2018. Data from 236 APR patients were retrieved from the NAPaR (N = 874); 223 TXA patients were retrospectively retrieved from each center database and matched to APR patients upon indication classes. Budget impact was evaluated using both direct costs associated with antifibrinolytics and transfusion products (within the first 48 h) and other costs such as surgery duration and ICU stay. Results: The 459 collected patients were distributed as: 17% on-label; 83% off-label. Mean cost per patient until ICU discharge tended to be lower in the APR group versus the TXA group, which resulted in an estimated gross saving of €3136 per patient. These savings concerned operating room and transfusion costs but were mainly driven by reduced ICU stays. When extrapolated to the whole French NAPaR population, the total savings of the therapeutic switch was estimated at around €3 million. Conclusion: The budget impact projected that using APR according to ARCOTHOVA protocol resulted in decreased requirement for transfusion and complications related to surgery. Both were associated with substantial cost savings from the hospital's perspective compared with exclusive use of TXA. [ABSTRACT FROM AUTHOR]

Serine protease inhibitors of the Kunitz-bovine pancreatic trypsin inhibitor (BPTI) family are ubiquitous biological regulators of proteolysis. These small proteins are resistant to proteolysis, but can be slowly cleaved within the protease-binding loop by target proteases, thereby compromising their activity. For the human protease mesotrypsin, this cleavage is especially rapid. Here, we aimed to stabilize the Kunitz domain structure against proteolysis through disulfide engineering. Substitution within the Kunitz inhibitor domain of the amyloid precursor protein (APPI) that incorporated a new disulfide bond between residues 17 and 34 reduced proteolysis by mesotrypsin 74-fold. Similar disulfide engineering of tissue factor pathway inhibitor-1 Kunitz domain 1 (KD1TFPI1) and bikunin Kunitz domain 2 (KD2bikunin) likewise stabilized these inhibitors against mesotrypsin proteolysis 17- and 6.6-fold, respectively. Crystal structures of disulfide-engineered APPI and KD1TFPI1 variants in a complex with mesotrypsin at 1.5 and 2.0 Å resolution, respectively, confirmed the formation of well-ordered disulfide bonds positioned to stabilize the binding loop. Long all-atom molecular dynamics simulations of disulfide-engineered Kunitz domains and their complexes with mesotrypsin revealed conformational stabilization of the primed side of the inhibitor-binding loop by the engineered disulfide, along with global suppression of conformational dynamics in the Kunitz domain. Our findings suggest that the Cys-17-Cys-34 disulfide slows proteolysis by dampening conformational fluctuations in the binding loop and minimizing motion at the enzyme-inhibitor interface. The generalizable approach developed here for the stabilization against proteolysis of Kunitz domains, which can serve as important scaffolds for therapeutics, may thus find applications in drug development.

Bleeding is a major complication in coronary artery bypass graft surgery. Antifibrinolytic agents like serine protease inhibitor aprotinin can decrease postoperative bleeding and complications of cardiac surgery. However, the effects of aprotinin on vascular function are not completely elucidated. We compared the ex vivo vascular function of left internal mammary arteries from patients undergoing coronary artery bypass graft surgery with and without intraoperative application of aprotinin using a Mulvany Myograph. Human internal mammary arteries were treated with aprotinin ex vivo and tested for changes in vascular function. We analyzed the impact of aprotinin on vascular function in rat aortic rings. Finally, impact of aprotinin on expression and activity of endothelial nitric oxide synthase was tested in human endothelial cells. Intraoperative application of aprotinin did not impair ex vivo vascular function of internal mammary arteries of patients undergoing coronary artery bypass graft surgery. Endothelium-dependent and -independent relaxations were not different in patients with or without aprotinin after nitric oxide synthase blockade. A maximum vasorelaxation of 94.5%±11.4vs. 96.1%±5.5% indicated a similar vascular smooth muscle function in both patient groups (n=13 each). Long-term application of aprotinin under physiological condition preserved vascular function of the rat aorta. In vitro application of increasing concentrations of aprotinin on human endothelial cells resulted in a similar expression and activity of endothelial nitric oxide synthase. In conclusion, intraoperative and ex vivo application of aprotinin does not impair the endothelial function in human internal mammary arteries and experimental models. [ABSTRACT FROM AUTHOR]

Injuries of the respiratory system caused by viral infections (e.g., by influenza virus, respiratory syncytial virus, metapneumovirus, or coronavirus) can lead to long-term complications or even life-threatening conditions. The challenges of treatment of such diseases have become particularly pronounced during the recent pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). One promising drug is the anti-fibrinolytic and anti-inflammatory protease inhibitor aprotinin, which has demonstrated considerable inhibition of the replication of some viruses. Encapsulation of aprotinin in liposomes can significantly improve the effectiveness of the drug, however, the use of nanoparticles as carriers of aprotinin can radically change its biodistribution in the body. Here we show that the liposomal form of aprotinin accumulates more efficiently in the lungs, heart, and kidneys than the molecular form by side-by-side comparison of the ex vivo biodistribution of these two fluorescently labeled formulations in mice using bioimaging. In particular, we synthesized liposomes of different compositions and studied their accumulation in various organs and tissues. Direct comparison of the biodistributions of liposomal and free aprotinin showed that liposomes accumulated in the lungs 1.82 times more effectively, and in the heart and kidneys – 3.56 and 2.00 times, respectively. This suggests that the liposomal formulation exhibits a longer residence time in the target organ and, thus, has the potential for a longer therapeutic effect. The results reveal the great potential of the aprotinin-loaded liposomes for the treatment of respiratory system injuries and heart- and kidney-related complications of viral infections. • The biodistribution study of molecular and liposomal form of aprotinin was performed. • The liposomal form accumulates more efficiently in the lungs, heart, and kidneys. • The composition of liposomes affects the biodistribution of aprotinin. [ABSTRACT FROM AUTHOR]

Radiolabeled FSH1 peptides are potential specific probes for FSHR imaging. However, moderate uptakes and fast washout from the tumors may limit its widespread use. In this study, 68Ga labeled modified FSH1 analogs was prepared and the imaging properties were determined in the prostate cancer model with or without aprotinin. NOTA-MAL-FSH4 was synthesized and labeled with 68Ga. The pharmacokinetic profile of the peptide after co-administration with aprotinin was determined through metabolism analyses and microPET imaging. 68Ga-NOTA-MAL-FSH4 was successfully prepared. The IC50 value of displacement 68Ga-NOTA-MAL-FSH4 with FSH1 was 139.4 ± 1.16 nM. The PC-3 prostate tumor was visible after administration of the 68Ga labeled tracer. In vitro RP-HPLC analysis revealed that the average percentage of intact peptide in the plasma, liver and tumor was 8.30, 9.57 and 7.06% respectively. In presence of aprotinin, the amounts of intact peptide increased to 34.32%, 20.63% and 15.39% in the counterparts respectively. MicroPET imaging showed that the uptakes of PC-3 tumors at 60mins after co-administration of 100 μg, 200 μg or 400 μg enzyme inhibitors were 2.91 ± 0.21%ID/g, 3.89 ± 0.16%ID/g and 9.21 ± 0.22%ID/g respectively. With the aid of a serine protease inhibitor, the performance of the 68Ga labeled peptide was optimized, which may benefit further clinical application. [ABSTRACT FROM AUTHOR]

Objectives: An increased risk of mortality and postoperative side effects led to aprotinin (Trasylol®) withdrawal from the market in 2008, but since 2018 aprotinin has again been used in France. The French retrospective multicentre APACHE study (AProtinin versus tranexamic Acid in Cardiac surgery patients with High-risk for Excessive bleeding) compared the efficacy of tranexamic acid versus half-dose aprotinin. The aim of this study, ancillary to the APACHE study, is to carry out a medico-economic analysis of the use of these two antifibrinolytics on an APACHE subpopulation., Methods: Economic data on reimbursement by the French health insurance system were extracted from the program for the data processing of medical information, and quantitative data on the cost of healthcare products were obtained from the hospital pharmacy software., Results: The main analysis of costs for the population shows that the global valuation was not significantly different between the two treatment groups (P=0.60), but the costs of blood products included in the related hospital stay group (Groupe Homogène de séjour [GHS]) (whole blood, platelets and plasma) were higher for the tranexamic acid group (P=0.007). In a sub-analysis of patients alive at discharge, the costs of blood products in addition to GHS (blood-derived medicines) and the costs of blood products in the GHS were higher for the tranexamic acid group (P=0.04 and 0.001, respectively)., Conclusions: The additional cost of aprotinin at the time of purchase is offset by the additional costs of blood products in the tranexamic acid group., (Copyright © 2024 Académie Nationale de Pharmacie. Published by Elsevier Masson SAS. All rights reserved.)

Abstract Background There are few cases of anaphylaxis after local application of fibrin sealant diagnosed by skin tests. Case presentation A 49-year-old woman underwent partial lung resection under general anesthesia. Anesthesia was induced uneventfully. Shortly after applying absorbable suture reinforcement felt that contained fibrin sealant, her systolic blood pressure fell to approximately 70 mmHg, along with facial flushing. Anaphylaxis was diagnosed based on the clinical symptoms and high serum tryptase levels. Three months after the event, skin tests were performed with all agents and were positive only for fibrin sealant vial no. 2, whose main component is aprotinin. Subsequently, basophil activation tests using fibrin sealant vial no. 2 and pure aprotinin demonstrated that the causative agent was likely aprotinin. Conclusions We diagnosed aprotinin-induced anaphylaxis using skin tests and basophil activation tests. The occurrence of anaphylaxis should be considered when changes in vital signs are observed after the use of fibrin sealant.