Neuroprotective strategies following intraparenchymal hemorrhage

Salvianolic acid A inhibits ferroptosis and protects against intracerebral hemorrhage

Intracerebral hemorrhage (ICH) is a common cerebral vascular disease with high incidence, disability, and mortality. Ferroptosis is a regulated type of iron-dependent, non-apoptotic programmed cell death. There is increasing evidence that ferroptosis may lead to neuronal damage mediated by hemorrhagic stroke mediated neuronal damage. Salvianolic acid A (SAA) is a natural bioactive polyphenol compound extracted from salvia miltiorrhiza, which has anti-inflammatory, antioxidant, and antifibrosis activities. SAA is reported to be an iron chelator that inhibits lipid peroxidation and provides neuroprotective effects. However, whether SAA improves neuronal ferroptosis mediated by hemorrhagic stroke remains unclear. The study aims to evaluate the therapeutic effect of SAA on Ferroptosis mediated by Intracerebral hemorrhage and explore its potential mechanisms. We constructed in vivo and in vitro models of intracerebral hemorrhage in rats. Multiple methods were used to analyze the inhibitory effect of SAA on ferroptosis in both in vivo and in vitro models of intracerebral hemorrhage in rats. Then, network pharmacology is used to identify potential targets and mechanisms for SAA treatment of ICH. The SAA target ICH network combines SAA and ICH targets with protein-protein interactions (PPIs). Find the specific mechanism of SAA acting on ferroptosis through molecular docking and functional enrichment analysis. In rats, SAA (10 mg/kg in vivo and 50 μM in vitro, p < 0.05) alleviated dyskinesia and brain injury in the ICH model by inhibiting ferroptosis (p < 0.05). The molecular docking results and functional enrichment analyses suggested that AKT (V-akt murine thymoma viral oncogene homolog) could mediate the effect of SAA. NRF2 (Nuclear factor erythroid 2-related factor 2) was a potential target of SAA. Our further experiments showed that salvianolic acid A enhanced the Akt /GSK-3β/Nrf2 signaling pathway activation in vivo and in vitro. At the same time, SAA significantly expanded the expression of GPX4, XCT proteins, and the nuclear expression of Nrf2, while the AKT inhibitor SH-6 and the Nrf2 inhibitor ML385 could reduce them to some extent. Therefore, SAA effectively ameliorated ICH-mediated neuronal ferroptosis. Meanwhile, one of the critical mechanisms of SAA inhibiting ferroptosis was activating the Akt/GSK-3β/Nrf2 signaling pathway.

Minimally Invasive Surgery for Spontaneous Intracerebral Hematoma. Real-Life Implementation Model and Economic Estimation

Objective

Spontaneous intracerebral hemorrhage is characterized by high fatality outcomes, even under best medical treatment. Recently, minimally invasive surgical (MIS) evacuation of the hematoma has shown promising results and may soon be implemented in the clinical practice. Hereby, we intended to foresee the logistic requirements for an early hematoma evacuation protocol, as well as to evaluate in a real-life implementation model the cost-utility of the two main MIS techniques for hemorrhagic stroke (catheter evacuation plus thrombolysis and neuroendoscopic aspiration).

Methods

Data were obtained from the pool of hemorrhagic-stroke patients admitted to our institution during an annual period (2020-2021) and contrasted to the reported results in published trials of MIS techniques. Potential candidates for surgical treatment were identified according to the inclusion/exclusion criteria established in these trials. Then, a cost-utility analysis was performed, which explored the incremental cost per unit of health gained with a given treatment. The treatment effect was measured by differences in modified Rankin Score, and subsequently converted to quality-adjusted life years (QALY).

Results

Of the 137 patients admitted to our center with supratentorial spontaneous intracerebral hemorrhage in a 1-year period, 17 (12.4%) were potential candidates for the catheter evacuation plus thrombolysis technique (Minimally Invasive Surgery with Thrombolysis in Intracerebral Hemorrhage Evacuation trial, MISTIE III criteria) and 59 (43.0%) for the neuroendoscopic aspiration technique (Dutch Intracerebral Hemorrhage Surgery Trial Pilot Study, DIST criteria). The incremental cost-utility ratio was € 76,533.13 per QALY for the catheter-based evacuation and € 60,703.89 per QALY for the endoscopic-based technique.

Conclusion

Around 12-43% of patients admitted to hospital with spontaneous hemorrhagic stroke could be potential candidates to MIS early evacuation of the cerebral hematoma. In our real-life implementation model, the cost-utility analysis favored the neuroendoscopic evacuation over the catheter aspiration technique. Further studies are advisable as new data from the ongoing randomized trials becomes available.

Potential application of intranasal insulin delivery for treatment of intracerebral hemorrhage: A review of the literature

Intracerebral hemorrhage (ICH) is a devastating subtype of stroke associated with high morbidity and mortality that is considered a medical emergency, mainly managed with adequate blood pressure control and creating a favorable hemostatic condition. However, to date, none of the randomized clinical trials have led to an effective treatment for ICH. It is vital to better understand the mechanisms underlying brain injury to effectively decrease ICH-associated morbidity and mortality. It is well known that initial hematoma formation and its expansion have detrimental consequences. The literature has recently focused on other pathological processes, including oxidative stress, neuroinflammation, blood-brain barrier disruption, edema formation, and neurotoxicity, that constitute secondary brain injury. Since conventional management has failed to improve clinical outcomes significantly, various neuroprotective therapies are tested in preclinical and clinical settings. Unlike intravenous administration, intranasal insulin can reach a higher concentration in the cerebrospinal fluid without causing systemic side effects. Intranasal insulin delivery has been introduced as a novel neuroprotective agent for certain neurological diseases, including ischemic stroke, subarachnoid hemorrhage, and traumatic brain injury. Since there is an overlap of mechanisms causing neuroinflammation in these neurological diseases and ICH, we believe that preclinical studies testing the role of intranasal insulin therapy in ICH are warranted.

Predicting mortality from intracranial hemorrhage in patients who undergo allogeneic hematopoietic stem cell transplantation

Intracranial hemorrhage (ICH) is a rare but fatal central nervous system complication of allogeneic hematopoietic stem cell transplantation (allo-HSCT). However, factors that are predictive of early mortality in patients who develop ICH after undergoing allo-HSCT have not been systemically investigated. From January 2008 to June 2020, a total of 70 allo-HSCT patients with an ICH diagnosis formed the derivation cohort. Forty-one allo-HSCT patients with an ICH diagnosis were collected from 12 other medical centers during the same period, and they comprised the external validation cohort. These 2 cohorts were used to develop and validate a grading scale that enables the prediction of 30-day mortality from ICH in all-HSCT patients. Four predictors (lactate dehydrogenase level, albumin level, white blood cell count, and disease status) were retained in the multivariable logistic regression model, and a simplified grading scale (termed the LAWS score) was developed. The LAWS score was adequately calibrated (Hosmer-Lemeshow test, P > .05) in both cohorts. It had good discrimination power in both the derivation cohort (C-statistic, 0.859; 95% confidence interval, 0.776-0.945) and the external validation cohort (C-statistic, 0.795; 95% confidence interval, 0.645-0.945). The LAWS score is the first scoring system capable of predicting 30-day mortality from ICH in allo-HSCT patients. It showed good performance in identifying allo-HSCT patients at increased risk of early mortality after ICH diagnosis. We anticipate that it would help risk stratify allo-HSCT patients with ICH and facilitate future studies on developing individualized and novel interventions for patients within different LAWS risk groups.

Iron toxicity in intracerebral hemorrhage: Physiopathological and therapeutic implications

Intracerebral hemorrhage (ICH)-induced brain injury is a continuous pathological process that involves the deterioration of neurological functions, such as sensory, cognitive or motor functions. Cytotoxic byproducts of red blood cell lysis, especially free iron, appear to be a significant pathophysiologic mechanism leading to ICH-induced injury. Free iron has a crucial role in secondary brain injury after ICH. Chelating iron may attenuate iron-induced neurotoxicity and may be developed as a therapeutic candidate for ICH treatment. In this review, we focused on the potential role of iron toxicity in ICH-induced injury and iron chelation therapy in the management of ICH. It will hopefully advance our understanding of the pathogenesis of ICH and lead to new approaches for treatment.

Neuroprotective Therapies for Spontaneous Intracerebral Hemorrhage

Patients who survive the initial ictus of spontaneous intracerebral hemorrhage (ICH) remain vulnerable to subsequent injury of the perilesional parenchyma by molecular and cellular responses to the hematoma. Secondary brain injury after ICH, which contributes to long-term functional impairment and mortality, has emerged as an attractive therapeutic target. This review summarizes preclinical and clinical evidence for neuroprotective therapies targeting secondary injury pathways following ICH. A focus on therapies with pleiotropic antiinflammatory effects that target thrombin-mediated chemotaxis and inflammatory cell migration has led to studies investigating statins, anticholinergics, sphingosine-1-phosphate receptor modulators, peroxisome proliferator activated receptor gamma agonists, and magnesium. Attempts to modulate ICH-induced blood-brain barrier breakdown and perihematomal edema formation has prompted studies of nonsteroidal antiinflammatory agents, matrix metalloproteinase inhibitors, and complement inhibitors. Iron chelators, such as deferoxamine and albumin, have been used to reduce the free radical injury that ensues from erythrocyte lysis. Stem cell transplantation has been assessed for its potential to enhance subacute neurogenesis and functional recovery. Despite promising preclinical results of numerous agents, their outcomes have not yet translated into positive clinical trials in patients with ICH. Further studies are necessary to improve our understanding of the molecular events that promote damage and inflammation of the perihematomal parenchyma after ICH. Elucidating the temporal and pathophysiologic features of this secondary brain injury could enhance the clinical efficacy of neuroprotective therapies for ICH.

The α2δ-1/NMDA receptor complex is involved in brain injury after intracerebral hemorrhage in mice

Background

Intracerebral hemorrhage (ICH), a common cerebrovascular disease, seriously threatens human health and has severe secondary injuries, while existing treatment methods have many limitations. α2δ‐1 is a subunit of voltage‐gated Ca²⁺ channels (VGCCs) and can act on glutamate receptor N‐methyl‐D‐aspartate receptors (NMDARs) to relieve neuropathic pain.

Methods

We first performed ICH modeling on WT mice and Cacna2d1 knockout (KO) mice. The expression levels of GluN1 and α2δ‐1 were measured by Western blot and q‐PCR, and the interaction between the two proteins was evaluated by co‐precipitation. The neuronal apoptosis was detected by the TUNEL assay, and the expression levels of inflammatory factors were assessed by ELISA. The nerve functions of mice were evaluated using behavioral experiments including corner turn test and forelimb use asymmetry. Cerebral hematoma was indicated by brain water content and lesion volume.

Results

ICH up‐regulated the expression levels of α2δ‐1 and GluN1. KO of Cacna2d1 significantly reduced the ICH‐induced apoptosis. The treatment of gabapentin on α2δ‐1 also significantly reduced the occurrence of apoptosis. KO of Cacna2d1 also reduced the ICH‐induced levels of inflammatory factors. Furthermore, neural functions were also significantly improved.

Conclusion

Cacna2d1 KO alleviates cerebral hematoma in ICH mice, exhibits a significant regulating effect on its secondary injuries such as neuronal apoptosis and inflammation, and restores the nerve functions of ICH mice. Loss of Cacna2d1 can provide useful therapeutic clues for ICH treatment.

Deletion of MicroRNA-144/451 Cluster Aggravated Brain Injury in Intracerebral Hemorrhage Mice by Targeting 14-3-3ζ

This study aims at evaluating the importance and its underlying mechanism of the cluster of microRNA-144/451 (miR-144/451) in the models with intracerebral hemorrhage (ICH). A model of collagenase-induced mice with ICH and a model of mice with simple miR-144/451 gene knockout (KO) were used in this study. Neurodeficits and the water content of the brain of the mice in each group were detected 3 days after collagenase injection. The secretion of proinflammatory cytokines, such as tumor necrosis factor α (TNF-α) and interleukin 1β (IL-1β), as well as certain biomarkers of oxidative stress, was determined in this study. The results revealed that the expression of miR-451 significantly decreased in the mice with ICH, whereas miR-144 showed no significant changes. KO of the cluster of miR-144/451 exacerbated the neurological deficits and brain edema in the mice with ICH. Further analyses demonstrated that the KO of the cluster of miR-144/451 significantly promoted the secretion of TNF-α and IL-1β and the oxidative stress in the perihematomal region of the mice with ICH. In addition, the miR-144/451's depletion inhibited the regulatory axis' activities of miR-451-14-3-3ζ-FoxO3 in the mice with ICH. In conclusion, these data demonstrated that miR-144/451 might protect the mice with ICH against neuroinflammation and oxidative stress by targeting the pathway of miR-451-14-3-3ζ-FoxO3.

Treatment of intracerebral hemorrhage: Current approaches and future directions

Intracerebral hemorrhage (ICH) stands out among strokes, both for the severely morbid outcomes it routinely produces, and for the striking deficiency of defenses possessed against the same. The brain damage caused by ICH proceeds through multiple pathophysiological mechanisms, broadly differentiated into those considered primary, arising from the hematoma itself, and the secondary consequences of hematoma presence and expansion thereof. A number of interventions against ICH and its sequelae have been investigated (e.g., hemostatic therapies, blood pressure control, hematoma evacuation, and a variety of neuroprotective strategies), but conclusive demonstrations of clinical benefit have remained largely elusive. In this review, we begin with a description of these interventions and the trials in which they have been implemented, coupled with an attempt to account for their failure. Possible causes discussed include iatrogenic injury during hematoma evacuation, secondary injury initiated by hematoma persistence after evacuation, and inadequate therapeutic power arising from an excessively narrow focus on a single component of the complex pathophysiology of ICH injury. To conclude, we propose several strategies, such as enhancing endogenous hematoma resolution, hematoma evacuation-based neuroprotection, and multi-targeted therapy, that hold promise as prospects for the extension of anti-ICH therapy into the domain of clinical significance.

MicroRNA-152 attenuates neuroinflammation in intracerebral hemorrhage by inhibiting thioredoxin interacting protein (TXNIP)-mediated NLRP3 inflammasome activation

Neuroinflammation significantly contributes to brain injury and neurological deterioration following intracerebral hemorrhage (ICH). MicroRNA-152(miR-152) was reported to be downregulated in ICH patients and to possess anti-inflammatory properties in other diseases. In this study, we aimed to explore the role of miR-152 in ICH, and the underlying mechanisms, using a collagenase-induced rat ICH model and hemin-exposure as a cell model. We first confirmed that miR-152 was consistently downregulated in both models. Overexpression of miR-152 in microglial BV2 cells reduced hemin-induced inflammatory response and reactive oxygen species (ROS) generation, thus protecting co-cultured neuronal HT22 cells. Moreover, overexpression of miR-152 by intracerebroventricular lentivirus injection in ICH rats significantly alleviated neurodecifits, brain edema, and hematoma. These changes were associated with a marked reduction in ICH-induced neuronal death, as detected by co-staining of NeuN and TUNEL, and ICH-induced neuroinflammation, as revealed by inflammatory cytokine levels as well as by the number of Iba1 positive-stained cells in the perihematomal region. Mechanistically, miR-152 significantly inhibited ICH-induced TXNIP expression, and its overexpression blocked the interaction between TXNIP and NOD-like receptor pyrin domain containing 3(NLRP3), thus inhibiting NLRP3-driven inflammasome activation to attenuate neuroinflammation in vivo and in vitro. Moreover, the results of si-TXNIP transfection further confirmed that TXNIP inhibition was involved in the reduction of NLRP3 inflammasome activation by the overexpression of miR-152. Collectively, the present study demonstrates that miR-152 confers protection against ICH-induced neuroinflammation and brain injury by inhibiting TXNIP-mediated NLRP3 inflammasome activation, indicating a potential strategy for ICH treatment.

Blood-Related Toxicity after Traumatic Brain Injury: Potential Targets for Neuroprotection

Emergency visits, hospitalizations, and deaths due to traumatic brain injury (TBI) have increased significantly over the past few decades. While the primary early brain trauma is highly deleterious to the brain, the secondary injury post-TBI is postulated to significantly impact mortality. The presence of blood, particularly hemoglobin, and its breakdown products and key binding proteins and receptors modulating their clearance may contribute significantly to toxicity. Heme, hemin, and iron, for example, cause membrane lipid peroxidation, generate reactive oxygen species, and sensitize cells to noxious stimuli resulting in edema, cell death, and increased morbidity and mortality. A wide range of other mechanisms such as the immune system play pivotal roles in mediating secondary injury. Effective scavenging of all of these pro-oxidant and pro-inflammatory metabolites as well as controlling maladaptive immune responses is essential for limiting toxicity and secondary injury. Hemoglobin metabolism is mediated by key molecules such as haptoglobin, heme oxygenase, hemopexin, and ferritin. Genetic variability and dysfunction affecting these pathways (e.g., haptoglobin and heme oxygenase expression) have been implicated in the difference in susceptibility of individual patients to toxicity and may be target pathways for potential therapeutic interventions in TBI. Ongoing collaborative efforts are required to decipher the complexities of blood-related toxicity in TBI with an overarching goal of providing effective treatment options to all patients with TBI.

Activation of TrkB/Akt signaling by a TrkB receptor agonist improves long-term histological and functional outcomes in experimental intracerebral hemorrhage

BACKGROUND

Intracerebral hemorrhage (ICH) induces a complex sequence of apoptotic cascades that contribute to secondary neuronal damage. Tropomyosin-related kinase receptor B (TrkB) signaling plays a crucial role in promoting neuronal survival following brain damage.

METHODS

The present study investigated the protective effects and underlying mechanisms of TrkB activation by the specific TrkB agonist, 7,8-dihydroxyflavone (7,8-DHF), in a model of collagenase-induced ICH and in neuronal cultures. Mice subjected to collagenase-induced ICH were intraperitoneally injected with either 7,8-DHF or vehicle 10 min after ICH and, subsequently, daily for 3 days. Behavioral studies, brain edema measurement, and histological analysis were conducted. Levels of TrkB signaling-related molecules and apoptosis-related proteins were analyzed by western blots.

RESULTS

Treatment with 20 mg/kg 7,8-DHF significantly improved functional recovery and reduced brain damage up to 28 days post-ICH. Reduction in neuronal death, apoptosis, and brain edema were also observed in response to 7,8-DHF treatment at 3 days post-ICH. These changes were accompanied by a significant increase in the phosphorylation of TrkB and Akt (Ser473/Thr308) at 1 and 3 days, but had no effect on Erk 44/42 phosphorylation. 7,8-DHF also enhanced the phosphorylation of Ask-1 Ser967 and FOXO-1, downstream targets of Akt at 1 and 3 days. Moreover, 7,8-DHF increased brain-derived neurotrophic factor levels at 1 day. In primary cultured neurons stimulated with hemin, 7,8-DHF promoted survival and reduced apoptosis. Furthermore, delaying the administration of 7,8-DHF to 3 h post-ICH reduced brain tissue damage and neuronal death.

CONCLUSIONS

Our findings demonstrate that the activation of TrkB signaling by 7,8-DHF protects against ICH via the Akt, but not the Erk, pathway. These data provide new insights into the role of TrkB signaling deficit in the pathophysiology of ICH and highlight TrkB/Akt as possible therapeutic targets in this disease.

Predictive Accuracy of Neutrophil-to-Lymphocyte Ratio on Long-Term Outcome in Patients with Spontaneous Intracerebral Hemorrhage

BACKGROUND

It is well established that inflammation plays a critical role in the progression of intracerebral hemorrhage (ICH). Recently the neutrophil-to-lymphocyte ratio (NLR) was identified as a predictor for the short-term outcome in ICH patients. However, the association of NLR with the long-term outcome in patients with ICH remains unknown. Here, we aimed to assess the relationship between NLR and the long-term prognosis in ICH patients.

METHODS

All patients with spontaneous ICH who were hospitalized at West China Hospital of Sichuan University from October 2013 to May 2017 were retrospectively enrolled. White blood count, absolute count of neutrophils, and lymphocytes were extracted from electronic medical records, and NLR was calculated according to admission neutrophil count (ANC) and lymphocyte count (ALC). The associations between long-term outcomes and laboratory biomarkers were estimated by multivariable logistic regression analysis. Receiver operating characteristic (ROC) curves were also determined to compare the predictive powers between each inflammatory factor.

RESULTS

A total of 481 ICH patients were included in the study. Of those, 204 presented with unfavorable outcomes, and 142 were dead within 6 months. Age, Glasgow Coma Scale (GCS) scores, WBC, ANC, NLR, hematoma size, and hydrocephalus were independently associated with poor prognosis of ICH. Multiple linear analysis showed GCS, hematoma volume, WBC, ANC, and ALC to be correlated with NLR. Moreover, in comparison with other single laboratory determinations, NLR also showed better predictive capacity for long-term mortality and morbidity, for which the best predictive cutoff values were 9.07 and 8.69, respectively.

CONCLUSIONS

NLR independently predicts 180-day morbidity and 180-day mortality in patients with spontaneous ICH.

Neutrophil and Platelet to Lymphocyte Ratios in Associating with Blood Glucose Admission Predict the Functional Outcomes of Patients with Primary Brainstem Hemorrhage

BACKGROUND

Because of a lack of markers for predicting prognosis and an underlying mechanism, patients with primary brainstem hemorrhage (PBH) are currently treated with multiple strategies, but most of them have poor outcomes in a comparison with patients with supratentorial intracranial hemorrhage. Recently, it has been reported that the neutrophil-to-lymphocyte ratio (NLR) represents a novel composite inflammatory marker to predict the prognosis of patients with intracranial hemorrhage, a majority of whom have supratentorial hemorrhage. In this report, we aim to assess the potential predictive value of NLR in patients with PBH. In addition, other available laboratory parameters, including platelet-to-lymphocyte ratio (PLR), and admission blood glucose level (ABG), will be also investigated as markers for prognosis in patients with PBH.

METHODS

This study retrospectively enrolled 225 patients with acute PBH who were admitted West China Hospital from January 2012 to December 2016. ABG and absolute numbers of neutrophils, lymphocytes, white blood cells, and platelets were extracted from electronic medical records. ABG, NLR, and PLR were calculated and further assessed using multivariable logistic regression analysis for understanding the associations of treatment outcomes. The comparison of predictive power of independent predictors was evaluated using receiver operating characteristic.

RESULTS

Of 225 inpatients, NLR (odds ratio [OR], 1.82; 95% confidence interval [CI], 1.24-2.62, P < 0.01), PLR (OR, 1.43; 95% CI, 1.11-2.36; P = 0.013), and ABG (OR, 6.57; 95% CI, 2.78-15.52; P < 0.01) were independently associated with 90-day status in 112 patients with unfavorable outcomes. All 3 parameters also correlated with admission Glasgow Coma Scale score (r = -0.244, P < 0.001; r = -0.292, P < 0.001; r = -0.661, P < 0.01) and absolute neutrophil counts (r = 0.645, P < 0.001; r = 0.347, P < 0.001; r = 0.695, P < 0.01). Meanwhile, NLR exhibits a comparable predictive power by comparing with PLR (area under the curve [AUC], 0.694; 95% CI, 0.626-0.764; P < 0.001; versus AUC, 0.662; 95% CI, 0.596-0.724; P < 0.001). In addition, ABG shows a positive predictive value (AUC, 0.784; 95% CI, 0.725-0.832; P < 0.001). The best independent predictive cutoff points were 6.65, 59.3, and 7.81 mmol/L for NLR, PLR, and ABG, respectively. Nevertheless, a combination of 3 parameters shows the best predictive ability (AUC, 0.835; 95% CI, 0.781-0.883; P < 0.001).

CONCLUSIONS

NLR, PLR, and ABG can be used to independently predict 90-day functional outcome in patients after PBH. When combined, they have better predictive power in identifying PBH patients with a poor prognosis. To our knowledge, this study is the first to reveal the associations between NLR, PLR, and hyperglycemia and the functional outcomes of patient with PBH. In associating with previously studies on hemorrhage site, our results provide a good opportunity to elucidate the underlying mechanisms of PBH.

Uncovering the Rosetta Stone: Report from the First Annual Conference on Key Elements in Translating Stroke Therapeutics from Pre-Clinical to Clinical

The first annual Stroke Translational Research Advancement Workshop (STRAW), entitled “Uncovering the Rosetta Stone: Key Elements in Translating Stroke Therapeutics from Pre-Clinical to Clinical” was held at the University of Kentucky on October 4–5, 2017. This workshop was organized by the Center for Advanced Translational Stroke Science. The workshop consisted of 2 days of activities. These included three presentations establishing the areas of research in stroke therapeutics, discussing the routes for translation from bench to bedside, and identifying successes and failures in the field. On day 2, grant funding opportunities and goals for the National Institute for Neurological Diseases and Stroke were presented. In addition, the meeting also included break-out sessions designed to connect researchers in areas of stroke, and to foster potential collaborations. Finally, the meeting concluded with an open discussion among attendees led by a panel of experts.