Cardiovascular risk and glucocorticoids: a Dutch National Registry of growth hormone treatment in adults with growth hormone deficiency analysis.

PURPOSE: Patients with hypopituitarism are at increased cardiovascular risk, in part because of growth hormone deficiency (GHD), but probably also because of the overuse of glucocorticosteroids in concomitant adrenal insufficiency (AI). We hypothesized that patients with hypopituitarism that were on glucocorticosteroid replacement therapy for concomitant AI would have worse cardiovascular outcomes than those without. METHODS: Retrospective nationwide cohort study. GHD patients from the Dutch National Registry of Growth Hormone Treatment in adults were grouped by the presence (AI; N = 1836) or absence (non-AI; N = 750) of concomitant AI, and differences between groups were analyzed for baseline characteristics and cardiovascular risk, at baseline and during GHRT. RESULTS: At baseline, AI patients had higher levels of total and LDL cholesterol (both p < 0.01). During GHRT, AI patients were more likely to use cardiovascular drugs (p ≤ 0.01), but we did not find worse outcomes for blood pressure, body composition, lipid and glucose metabolism. The risk of developing peripheral arterial disease (HR 2.22 [1.06-4.65]) and non-fatal cerebrovascular events (HR 3.47 [1.60-7.52]) was higher in AI patients, but these differences disappeared in the models adjusted for baseline differences. CONCLUSION: We found no clear evidence to support our hypothesis that patients with hypopituitarism and concomitant AI have worse cardiovascular outcomes than non-AI patients. This suggests that glucocorticoid replacement therapy in AI may be safer than previously thought. However, cardiovascular burden, events and medication use at baseline and during GHRT (in unadjusted models) were higher in AI; so the lack of power, the important role of (adjusting for) other risk factors, and the inability to distinguish between glucocorticoid treatment regimens may have influenced the outcomes.

Exploring the sex difference in cardiovascular risk during growth hormone therapy in adults.

OBJECTIVE: Given the previously identified sex differences in cardiovascular (CV) morbidity and mortality in patients with growth hormone deficiency (GHD) receiving GH replacement therapy (GHRT), our aim is to investigate sex-specific differences in the efficacy of (long-term) GHRT on CV risk profile and disease in subjects with GHD. Our hypothesis is that women will experience less beneficial effects than men. DESIGN: Retrospective nationwide cohort study. METHODS: We compared all men (n = 1335) and women (n = 1251) with severe GHD registered in the Dutch National Registry of GH Treatment in Adults database with respect to CV risk profile and morbidity at baseline and during follow-up. RESULTS: Men had a more unfavourable CV risk profile at baseline. During the first years of GHRT, the reduction in waist circumference, waist-to-hip ratio, total cholesterol, and triglyceride levels was greater in men than in women (all P < .05). Between-sex differences in effects during later follow-up were less clear. No sex differences were found in the risk of developing non-fatal cardiovascular or cerebrovascular diseases during GHRT. CONCLUSIONS: Our results suggest that men with GHD did indeed experience more beneficial effects of GHRT on body composition and lipoprotein metabolism than women, at least in the early years of treatment. Also, the more unfavourable CV risk profile at baseline in men did not translate into a sex difference in the risk of developing CV and cerebrovascular morbidity during GHRT.

Clinical and immunological outcomes of SARS-CoV-2-infected vaccine responders, vaccine non-responders, and unvaccinated patients evaluated for neutralizing monoclonal antibody treatment at a single German tertiary care center: a retrospective cohort study with prospective follow-up.

PURPOSE: This study assessed the clinical and immunological outcomes of SARS-CoV-2-infected patients with risk factors for severe disease depending on their immunological status. METHODS: In this retrospective study with single follow-up visit, clinical outcome and humoral immunity was monitored in SARS-CoV-2 infected patients at risk. The results were compared based on the patients' initial immunological status: unvaccinated (UV), patients who did not develop neutralizing antibodies after vaccination (vaccine non-responders, VNR), and patients who expressed neutralizing antibodies after vaccination (vaccine responders, VR). Patients who lacked neutralizing antibodies (VNR and UV) were treated with nMABs. RESULTS: In total, 113 patients at risk of severe COVID-19 consented to participate in the study. VR and UV were not admitted to the hospital. During the observation period, UVs had the highest rate of SARS-CoV-2 re-infections. Three of 41 VNRs (7.3%) were hospitalized due to severe COVID-19, with two of them having undergone iatrogenic B-cell depletion. The humoral immune response after infection was significantly lower in the VNR group than in the VR group in terms of anti-N, anti-receptor-binding domain (RBD), anti-S antibody titers, and anti-S antibody avidity. In a sub-analysis of VNR, B cell-deficient non-responders had significantly lower levels of anti-N antibodies and anti-S avidity after infection than other VNRs. CONCLUSION: VNR, particularly B-cell-depleted VNR, remained at risk of hospitalization due to COVID-19. In the VR group, however, no clinical complications or severe disease were observed, despite not receiving nMAbs. Tailoring the administration of nMABs according to patient vaccination and immunological status may be advisable.

Impaired 26S proteasome causes learning and memory deficiency and induces neuroinflammation mediated by NF-κB in mice.

A reduction in proteasome activity, loss of synapses and increased neuroinflammation in the brain are hallmarks of aging and many neurodegenerative disorders, including Alzheimer's disease (AD); however, whether proteasome dysfunction is causative to neuroinflammation remains less understood. In this study, we investigated the impact of 26S proteasome deficiency on neuroinflammation in the Psmc1 knockout (KO) mice deficient in a 19S proteasome subunit limited to the forebrain region. Our results revealed that impaired 26S proteasome led to reduced learning and memory capability and overt neuroinflammation in the synapses of the Psmc1 KO brain at eight weeks of age. Moreover, pronounced neuroinflammation was also found in the whole brain cortex, which was confirmed by increased levels of several key immune response-related proteins, including Stat1, Trem2 and NF-κB, and by activation of astrocytes and microglia in the KO brain. To validate NF-κB mediating neuroinflammation, we administered a selective NF-κB inhibitor to the KO animals at 5 weeks of age for three weeks, and then, animal behaviors and neuroinflammation were assessed when they reached eight weeks of age. Following the treatment, the KO mice exhibited improved behaviors and reduced neuroinflammation compared to the control animals. These data indicate that impaired 26S proteasome causes AD-like cognitive deficiency and induces neuroinflammation mediated largely by NF-κB. These results may aid development of effective therapeutics and better understanding of the pathogenesis of AD and many other neurodegenerative disorders where impaired proteasome is consistently coupled with neuroinflammation.

Pathogenic and therapeutic role of exosomes in neurodegenerative disorders.

Neurodegenerative disorders affect millions of people worldwide, and the prevalence of these disorders is only projected to rise as the number of people over 65 will drastically increase in the coming years. While therapies exist to aid in symptomatic relief, effective treatments that can stop or reverse the progress of each neurodegenerative disease are lacking. Recently, research on the role of extracellular vesicles as disease markers and therapeutics has been intensively studied. Exosomes, 30-150 nm in diameter, are one type of extracellular vesicles facilitating cell-to-cell communication. Exosomes are thought to play a role in disease propagation in a variety of neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis. Accordingly, the exosomes derived from the patients are an invaluable source of disease biomarkers. On the other hand, exosomes, especially those derived from stem cells, could serve as a therapeutic for these disorders, as seen by a rapid increase in clinical trials investigating the therapeutic efficacy of exosomes in different neurological diseases. This review summarizes the pathological burden and therapeutic approach of exosomes in neurodegenerative disorders. We also highlight how heat shock increases the yield of exosomes while still maintaining their therapeutic efficacy. Finally, this review concludes with outstanding questions that remain to be addressed in exosomal research.

Meta-analysis of mortality in adults with growth hormone deficiency: Does growth hormone replacement therapy really improve mortality rates?

Growth hormone (GH) deficiency (GHD) is one of the most prevalent deficiencies in patients with hypopituitarism and several cohort studies have demonstrated an increased mortality risk in hypopituitary patients with a presumed GHD. The cause of the excess mortality is most likely multifactorial, including the etiology of the hypopituitarism, non-physiological replacement therapies (mostly glucocorticoid), tumor treatment and its side effects as well as untreated GHD. Several years later, other cohort studies that investigated life expectancy in patients with hypopituitarism on GH replacement therapy (GHRT) that showed a normalized mortality. By comparison of the distribution of characteristics of interest between cohorts, we discuss the existing literature to answer the following question: does growth hormone replacement really improve mortality rates in adult patients with hypopituitarism and GHD? We also conducted a meta-analysis of these studies. Since the literature suffers from selection and time bias (improvement of tumor management and other pituitary hormone replacement therapies), there is no high-quality evidence that replacement therapy for GHD really improves mortality. However, the available data does suggest that GHRT plays a significant part in the normalization of the mortality in patients with hypopituitarism.

Prevalence of clinical signs, symptoms and comorbidities at diagnosis of acromegaly: a systematic review in accordance with PRISMA guidelines.

OBJECTIVE: Diagnostic delay is high in acromegaly and leads to increased morbidity and mortality. The aim of this study is to systematically assess the most prevalent clinical signs, symptoms and comorbidities of acromegaly at time of diagnosis. DESIGN: A literature search (in PubMed, Embase and Web of Science) was performed on November 18, 2021, in collaboration with a medical information specialist. METHODS: Prevalence data on (presenting) clinical signs, symptoms and comorbidities at time of diagnosis were extracted and synthesized as weighted mean prevalence. The risk of bias was assessed for each included study using the Joanna Briggs Institute Critical Appraisal Checklist for Studies Reporting Prevalence Data. RESULTS: Risk of bias and heterogeneity was high in the 124 included articles. Clinical signs and symptoms with the highest weighted mean prevalence were: acral enlargement (90%), facial features (65%), oral changes (62%), headache (59%), fatigue/tiredness (53%; including daytime sleepiness: 48%), hyperhidrosis (47%), snoring (46%), skin changes (including oily skin: 37% and thicker skin: 35%), weight gain (36%) and arthralgia (34%). Concerning comorbidities, acromegaly patients more frequently had hypertension, left ventricle hypertrophy, dia/systolic dysfunction, cardiac arrhythmias, (pre)diabetes, dyslipidemia and intestinal polyps- and malignancy than age- and sex matched controls. Noteworthy, cardiovascular comorbidity was lower in more recent studies. Features that most often led to diagnosis of acromegaly were typical physical changes (acral enlargement, facial changes and prognatism), local tumor effects (headache and visual defect), diabetes, thyroid cancer and menstrual disorders. CONCLUSION: Acromegaly manifests itself with typical physical changes but also leads to a wide variety of common comorbidities, emphasizing that recognition of a combination of these features is key to establishing the diagnosis.

Mesenchymal and Neural Stem Cell-Derived Exosomes in Treating Alzheimer's Disease.

As the most common form of dementia and a progressive neurodegenerative disorder, Alzheimer's disease (AD) affects over 10% world population with age 65 and older. The disease is neuropathologically associated with progressive loss of neurons and synapses in specific brain regions, deposition of amyloid plaques and neurofibrillary tangles, neuroinflammation, blood-brain barrier (BBB) breakdown, mitochondrial dysfunction, and oxidative stress. Despite the intensive effort, there is still no cure for the disorder. Stem cell-derived exosomes hold great promise in treating various diseases, including AD, as they contain a variety of anti-apoptotic, anti-inflammatory, and antioxidant components. Moreover, stem cell-derived exosomes also promote neurogenesis and angiogenesis and can repair damaged BBB. In this review, we will first outline the major neuropathological features associated with AD; subsequently, a discussion of stem cells, stem cell-secreted exosomes, and the major exosome isolation methods will follow. We will then summarize the recent data involving the use of mesenchymal stem cell- or neural stem cell-derived exosomes in treating AD. Finally, we will briefly discuss the challenges, perspectives, and clinical trials using stem cell-derived exosomes for AD therapy.

Discovery of a Series of Substituted 1H-((1,2,3-Triazol-4-yl)methoxy)pyrimidines as Brain Penetrants and Potent GluN2B-Selective Negative Allosteric Modulators.

Herein, we describe a series of substituted 1H-((1,2,3-triazol-4-yl)methoxy)pyrimidines as potent GluN2B negative allosteric modulators. Exploration of several five- and six-membered heterocycles led to the identification of O-linked pyrimidine analogues that possessed a balance of potency and desirable ADME profiles. Due to initial observations of metabolic saturation, early metabolite identification studies were conducted on compound 18, and the results drove further iterative optimization efforts to avoid the formation of undesired saturating metabolites. The comprehensive investigation of substitution on the pyrimidine moiety of the 1H-1,2,3-triazol-4-yl)methoxy)pyrimidines allowed for the identification of compound 31, which demonstrated high GluN2B receptor affinity, improved solubility, and a clean cardiovascular profile. Compound 31 was profiled in an ex vivo target engagement study in rats at a 10 mg/kg oral dose and achieved an ED50 of 1.7 mg/kg.

Sex Differences in Long-Term Safety and Tolerability of GH Replacement Therapy in GH Deficient Adults.

CONTEXT: Previous studies report that outcomes of growth hormone (GH) replacement therapy (GHRT) might be less beneficial in growth hormone deficient (GHD) women compared with men. OBJECTIVE: This study investigated possible contributing factors regarding this previously found sex difference. METHODS: This retrospective cohort study, conducted at a nationwide outpatient clinic (the Dutch National Registry of GH Treatment in Adults), included Dutch adult GHD men (n = 1335) and women (n = 1251) treated with GHRT. The patients' baseline characteristics, details of GHRT, and the tolerability and long-term safety of GHRT were measured. RESULTS: During treatment, sensitivity analysis showed that insulin-like growth factor-1 (IGF-1) SD scores remained subnormal more often in women (P < 0.001), while scores above normal were more frequent in men (P < 0.001). Women reported more adverse events (P < 0.001), especially symptoms related to fluid retention, and more often needed a dose reduction or temporary stop of GHRT (P = 0.001). In percentages, both sexes equally discontinued GHRT, as was also true for the risk in developing type 2 diabetes mellitus, benign neoplasms, and tumor recurrence. The risk of developing malignant neoplasms was higher in men (P = 0.012). CONCLUSION: Data obtained from the Dutch National Registry of GH Treatment in Adults indicate that GHD women might be treated suboptimally, reflected as lower IGF-1 status and lower GHRT tolerability, leading to more frequent changes in treatment regimen but not discontinuation of GHRT. Regarding long-term safety, we found a higher risk for development of malignancies in GHD men.

Heat Shock-Induced Extracellular Vesicles Derived from Neural Stem Cells Confer Marked Neuroprotection Against Oxidative Stress and Amyloid-ß-Caused Neurotoxicity.

Alzheimer's disease (AD) is the most prevalent neurodegenerative disease and a leading cause of dementia. Although the amyloid-ß (Aß) peptide is deemed a crucial driver of AD, there are no effective therapeutics available to treat Aß-caused neurotoxicity. Extracellular vesicles (EVs) are membrane-bound small particles mediating intercellular traffic of nucleic acids, lipids, proteins, and metabolites. Exosomes are a subtype of EVs with a size range of 30-150 nm in diameter. Stem cell-derived EVs are a potential therapeutic for AD, while EVs isolated from normal stem cell cultures generally have a low yield. Here, we studied the EVs secreted by the rat neural stem cells in the presence of heat shock (HS) stimulus. Nanoparticle tracking analysis confirmed that HS-derived EVs exhibit significantly higher concentration and larger diameter in comparison to the non-heat shock (NHS)-derived EVs. Mass spectrometric studies of EV proteins revealed that HS-derived EVs contained fewer diverse proteins than NHS-derived exosomes. GO enrichment analysis of the proteins suggested that the top two biological functions of the proteins in HS-derived EVs are involved in the negative regulation of apoptotic process and positive modulation of DNA repair. Importantly, the therapeutic efficacy of the NHS- and HS-derived EVs were tested in a cell culture model of AD: HS-derived EVs exhibited greater neuroprotection against not only oxidative stress but also amyloid-ß (Aß) induced neurotoxicity compared to NHS-derived EVs. Moreover, HS-derived EVs were also able to dramatically attenuate Aß-induced apoptosis and oxidative stress. These data indicate that in response to HS, neural stem cells increase EV production and alter EV morphology and cargo to confer better neuroprotection against oxidative stress and Aß-caused neurotoxicity, suggesting that HS-induced EVs from neural stem cells can be a therapeutic agent for AD and possibly other neurological disorders.

Impact of Cardiovascular Diseases on Ischemic Stroke Outcomes.

Stroke induces complex pathological cascades in the affected brain area, leading to brain injury and functional disability. To fight against cerebral ischemia/reperfusion-induced neuronal death, numerous neuroprotective strategies and reagents have been studied. However, translation of these neuroprotective drugs to clinical trials has been unsuccessful. To date, the tissue plasminogen activator is still the only FDA-approved drug for treating ischemic stroke. Thus, it is obligatory to identify and validate additional therapeutic strategies for stroke. A stroke rarely occurs without any other pathophysiological condition; but instead, it often has multi-morbidity conditions, one of which is cardiac disease. Indeed, up to half of the stroke cases are associated with cardiac and large artery diseases. As an adequate blood supply is essential for the brain to maintain its normal function, any pathophysiological alterations in the heart are frequently implicated in stroke outcomes. In this review, we summarize some of the cardiovascular factors that influence stroke outcomes and propose that considering these factors in designing stroke therapies should enhance success in clinical trials. We also highlight the recent advances regarding the potential effect of protein aggregates in a peripheral organ, such as in the heart, on ischemic stroke-caused brain injury and functional recovery. Including these and other comorbidity factors in the future therapeutic strategy designs should facilitate translational success toward developing effective combinational therapies for the disorder.

Factors contributing to adolescents' COVID-19-related loneliness, distress, and worries.

As the world continues to face uncertainty due to COVID-19, there is concern for adolescent wellbeing as they attempt to cope with changes to their education and social interactions. Considering the trade-offs between physical distancing and virtual education versus in-person instruction may be particularly pertinent to understanding adolescent loneliness and worries surrounding COVID-19 and their academics. Adolescents (N = 1,708; age M = 12.42, SD = 2.40; 53.3% girls and 46.7% boys) from the United States self-reported their perceptions of social support, COVID-19 attitudes, and indicators of wellbeing (i.e., loneliness, COVID-19 stress, academic worry) in an online cross-sectional survey between November 30, 2020 to December 21, 2020. Higher levels of social support and attitudes of lower COVID-19 concern were associated with lower levels of loneliness, COVID-19 stress, and academic worries. Adolescents receiving greater virtual instruction were more worried about their academics compared to those receiving greater in-person instruction. A moderation effect between loneliness and instruction type revealed that the effect of social support was stronger for those receiving greater virtual instruction. Despite the quick and dramatic change to one's education, adolescents were relatively unaffected by the type of instruction they had recently received. Instead, perceived social support and their attitudes toward COVID-19 were more strongly related to their wellbeing.

Cardiovascular risk profile in growth hormone-treated adults with craniopharyngioma compared to non-functioning pituitary adenoma: a national cohort study.

CONTEXT: Cardiovascular (CV) risk profile might differ between growth hormone-treated patients with craniopharyngioma and non-functioning pituitary adenoma (NFPA), since patients with craniopharyngioma more frequently suffer from hypothalamic metabolic disruption. OBJECTIVE: The aim of this study is to investigate the CV risk profile in adult patients with craniopharyngioma compared to NFPA before and after treatment with growth hormone (GH) replacement therapy due to severe GH deficiency. DESIGN: A sub-analysis of the Dutch National Registry of Growth Hormone Treatment in Adults was performed, in which we compared 291 patients with craniopharyngioma to 778 patients with NFPA. CV risk profile and morbidity were evaluated at baseline and during long-term follow-up within and between both groups. RESULTS: At baseline, patients with craniopharyngioma demonstrated higher BMI than patients with NFPA, and men with craniopharyngioma showed greater waist circumference and lower HDL compared to men with NFPA. During follow-up, BMI, as well as diastolic blood pressure among patients using antihypertensive drugs, deteriorated in the craniopharyngioma group compared to the NFPA group. Lipid profile improved similarly in both groups over time. No differences were found between groups in the occurrence of diabetes mellitus, cerebrovascular accidents, CV disease, or overall mortality. CONCLUSION: This study suggests that overall CV risk profile is worse in craniopharyngioma patients with GH deficiency compared to patients with NFPA. During GH replacement therapy, patients with craniopharyngioma demonstrated an increase in BMI over time, where BMI remained stable in patients with NFPA. Also, diastolic blood pressure did not improve with antihypertensive drugs in craniopharyngioma patients as seen in patients with NFPA.

Impaired neuropsychological functioning in patients with hypopituitarism.

Background: Treatment of pituitary pathology mostly does not result in complete recovery of impairment in cognitive functioning. The primary aim of the current study was to assess cognitive impairment in patients with stable replacement therapy for hypopituitarism during the last 6 months prior to inclusion. It was expected that patients showed subjective and objective subnormal scores on neuropsychological functioning. Methods: Forty-two patients (40% men, 49 ± 15 years) treated for hypopituitarism conducted a neuropsychological test battery, including the Cognitive Failures Questionnaire (CFQ), 15-Word test (15-WT), Cambridge Neuropsychological Test Automated Battery (CANTAB) Motor Screening Task (MOT), Spatial Working Memory (SWM) and Affective Go/No-go (AGN). Results were compared to reference values of healthy norm groups. Results: Male and female participants scored significantly worse on the CFQ (P < .01, d = 0.91-4.09) and AGN mean correct latency (P < .01, d = 1.66 and 1.29, respectively). Female participants scored significantly worse on 15-WT direct recall (P = .01, d = 0.66), 15-WT delayed recall (P = .01, d = 0.79), SWM total errors (P = .05, d = 0.41), SWM strategy (P = .04, d = 0.43), AGN errors of commission (P = .02, d = 0.56) and omission (P = .04, d = 0.41). Conclusion: This study shows that subjective cognitive functioning is worse in patients treated for hypopituitarism compared to reference data. Also, female participants treated for hypopituitarism score worse on objective aspects of memory and executive functioning compared to reference data. Besides worse focus attention, this objective cognitive impairment was not found in male participants. It is recommended to conduct additional research, which focuses on the design and evaluation of a cognitive remediation therapy, aimed at compensation of impairments in different aspects of memory and executive functioning.

Psychological well-being and illness perceptions in patients with hypopituitarism.

OBJECTIVE: The primary aim of the current study was to objectify a spectrum of persisting subjective psychological complaints in patients with hypopituitarism, at least six months after normalizing of the hormonal disturbances. Also, gender differences on these outcomes were investigated. The secondary aim was to identify illness perceptions and causal attributions within this patient group. METHODS: A total of 42 adult participants (60% females) with treated hypopituitarism once filled out a number of psychological questionnaires. The Profile of Mood States (POMS) and the Hospital Anxiety and Depression Scale (HADS) assessed mood and the Symptom Checklist-90 (SCL-90) and the Work and Social Adjustment Scale (WSAS) assessed well-being. Illness perceptions were identified using the Illness Perceptions Questionnaire-Brief Dutch Language Version (IPQ-B DLV) and causal attributions by using the Causal Attribution List (CAL). Patient outcomes were compared to reference values of healthy norm groups. RESULTS: Participants scored significantly worse on the POMS depression, anger, fatigue and tension subscales, the SCL-90 psychoneuroticism, depression, inadequacy of thinking and acting and sleeping problems subscales and all subscales of the WSAS when compared to reference data. Women also scored worse on depression (HADS) and somatic symptoms (SCL-90). Compared to other illnesses, patients with hypopituitarism have more negative and realistic illness perceptions on consequences, timeline, identity and emotions. Participants attributed their complaints more to physical causes than psychological causes. CONCLUSION: Despite normalization of hormonal disturbances, patients with hypopituitarism in general can still experience problems during daily living, such as negative mood states and a decreased psychological well-being.

Peripherally misfolded proteins exacerbate ischemic stroke-induced neuroinflammation and brain injury.

BACKGROUND: Protein aggregates can be found in peripheral organs, such as the heart, kidney, and pancreas, but little is known about the impact of peripherally misfolded proteins on neuroinflammation and brain functional recovery following ischemic stroke. METHODS: Here, we studied the ischemia/reperfusion (I/R) induced brain injury in mice with cardiomyocyte-restricted overexpression of a missense (R120G) mutant small heat shock protein, αB-crystallin (CryABR120G), by examining neuroinflammation and brain functional recovery following I/R in comparison to their non-transgenic (Ntg) littermates. To understand how peripherally misfolded proteins influence brain functionality, exosomes were isolated from CryABR120G and Ntg mouse blood and were used to treat wild-type (WT) mice and primary cortical neuron-glia mix cultures. Additionally, isolated protein aggregates from the brain following I/R were isolated and subjected to mass-spectrometric analysis to assess whether the aggregates contained the mutant protein, CryABR120G. To determine whether the CryABR120G misfolding can self-propagate, a misfolded protein seeding assay was performed in cell cultures. RESULTS: Our results showed that CryABR120G mice exhibited dramatically increased infarct volume, delayed brain functional recovery, and enhanced neuroinflammation and protein aggregation in the brain following I/R when compared to the Ntg mice. Intriguingly, mass-spectrometric analysis of the protein aggregates isolated from CryABR120G mouse brains confirmed presence of the mutant CryABR120G protein in the brain. Importantly, intravenous administration of WT mice with the exosomes isolated from CryABR120G mouse blood exacerbated I/R-induced cerebral injury in WT mice. Moreover, incubation of the CryABR120G mouse exosomes with primary neuronal cultures induced pronounced protein aggregation. Transduction of CryABR120G aggregate seeds into cell cultures caused normal CryAB proteins to undergo dramatic aggregation and form large aggregates, suggesting self-propagation of CryABR120G misfolding in cells. CONCLUSIONS: These results suggest that peripherally misfolded proteins in the heart remotely enhance neuroinflammation and exacerbate brain injury following I/R likely through exosomes, which may represent an underappreciated mechanism underlying heart-brain crosstalk.

Growth hormone deficiency and replacement therapy in adults: Impact on survival.

In a seminal paper from 1990, Rosen and Bengtsson suggested that hypopituitary patients with a presumed growth hormone (GH) deficiency (GHD) have an excess mortality. Later studies have confirmed this finding but have also shown that the cause of the increased risk of death in these patients is multifactorial, including unreplaced GHD as well as non-physiological replacement therapy of other deficiencies, the etiology of hypopituitarism, and the side effects of tumor treatment. Only a few studies have investigated mortality in hypopituitary patients with GHD receiving GH replacement therapy (GHRT): these studies are retrospective observational studies with a wide range of underlying diseases but most of them show a mortality that is not different from the general population. Even though the research field of survival in GHD patients with and without GHRT is lacking prospective randomized trials, the evidence suggests that GHD in hypopituitary patients contributes to an excess mortality and modern replacement therapy including GHRT will result in a mortality that is approaching normal. Herein, we review the literature in the field of survival in GHD patients with and without GHRT. In addition, we outline the most important issues when evaluating studies in this area.

Design, Synthesis, and Preclinical Evaluation of 3-Methyl-6-(5-thiophenyl)-1,3-dihydro-imidazo[4,5-b]pyridin-2-ones as Selective GluN2B Negative Allosteric Modulators for the Treatment of Mood Disorders.

Selective inhibitors of the GluN2B subunit of N-methyl-d-aspartate receptors in the ionotropic glutamate receptor superfamily have been targeted for the treatment of mood disorders. We sought to identify structurally novel, brain penetrant, GluN2B-selective inhibitors suitable for evaluation in a clinical setting in patients with major depressive disorder. We identified a new class of negative allosteric modulators of GluN2B that contain a 1,3-dihydro-imidazo[4,5-b]pyridin-2-one core. This series of compounds had poor solubility properties and poor permeability, which was addressed utilizing two approaches. First, a series of structural modifications was conducted which included replacing hydrogen bond donor groups. Second, enabling formulation development was undertaken in which a stable nanosuspension was identified for lead compound 12. Compound 12 was found to have robust target engagement in rat with an ED70 of 1.4 mg/kg. The nanosuspension enabled sufficient margins in preclinical toleration studies to nominate 12 for progression into advanced good laboratory practice studies.

Disrupted blood-brain barrier in 5×FAD mouse model of Alzheimer's disease can be mimicked and repaired in vitro with neural stem cell-derived exosomes.

Alzheimer's disease (AD) is a devastating neurodegenerative disease and is associated with blood-brain barrier (BBB) disruption. AD mice and cell culture models play an essential role in understanding AD pathogenesis and validation of therapeutic reagents. One of the commonly used AD mice is the 5 × FAD mouse and previous studies have shown that BBB leakage occurs at 9 months of age in the mice. However, it remains unknown whether disrupted BBB also occurs in young animals and whether AD-caused BBB impairment can be replicated and further corrected in a cell culture model. Here, we examine BBB breakdown in the 5 × FAD mouse model at different ages including both pre-symptomatic and post-symptomatic ages and test an in vitro BBB model established with the 5 × FAD primary cerebral endothelial cells. Moreover, with the BBB in vitro model, we also examined the therapeutic effect of human neural stem cells (NSCs)-derived exosomes on AD-caused BBB leakage. Our result indicated that BBB breakdown in the 5 × FAD mice occurred at 4 months of age, which could be mimicked with an in vitro BBB model. Importantly, we further demonstrated that treatment of the in vitro BBB model with NSCs-derived exosomes reversed AD-caused BBB deficiency. The information should be useful for researchers to determine which ages of the AD mice should be employed in specific in vivo and in vitro studies and the data also suggest that AD-caused BBB disruption can be corrected at least by NSC-derived exosomes.