N-acetyl-L-leucine for Niemann-Pick type C: a multinational double-blind randomized placebo-controlled crossover study

BACKGROUND

Niemann-Pick disease type C (NPC) is a rare autosomal recessive neurodegenerative lysosomal disease characterized by multiple symptoms such as progressive cerebellar ataxia and cognitive decline. The modified amino acid N-acetyl-leucine has been associated with positive symptomatic and neuroprotective, disease-modifying effects in various studies, including animal models of NPC, observational clinical case studies, and a multinational, rater-blinded phase IIb clinical trial. Here, we describe the development of a study protocol (Sponsor Code "IB1001-301") for the chronic treatment of symptoms in adult and pediatric patients with NPC.

METHODS

This multinational double-blind randomized placebo-controlled crossover phase III study will enroll patients with a genetically confirmed diagnosis of NPC patients aged 4 years and older across 16 trial sites. Patients are assessed during a baseline period and then randomized (1:1) to one of two treatment sequences: IB1001 followed by placebo or vice versa. Each sequence consists of a 12-week treatment period. The primary efficacy endpoint is based on the Scale for the Assessment and Rating of Ataxia, and secondary outcomes include cerebellar functional rating scales, clinical global impression, and quality of life assessments.

DISCUSSION

Pre-clinical as well as observational and phase IIb clinical trials have previously demonstrated that IB1001 rapidly improved symptoms, functioning, and quality of life for pediatric and adult NPC patients and is safe and well tolerated. In this placebo-controlled cross-over trial, the risk/benefit profile of IB1001 for NPC will be evaluated. It will also give information about the applicability of IB1001 as a therapeutic paradigm for other rare and common neurological disorders.

TRIAL REGISTRATIONS

The trial (IB1001-301) has been registered at www.

CLINICALTRIALS

gov (NCT05163288) and www.clinicaltrialsregister.eu (EudraCT: 2021-005356-10). Registered on 20 December 2021.

Daily Functionality in Adults with POTS: Predictive Factors

Symptoms associated with postural orthostatic tachycardia syndrome (POTS) hinder overall functionality. This study examined factors that impacted daily life and contributed to overall daily functionality in adults with POTS (n = 958, ages 18-60). Descriptive and multiple linear regression analyses indicated that participants with fewer challenges in ADLs, IADLs, work, school, leisure, and socializing had overall better functionality. Furthermore, 'younger age with exercise tolerance', 'having a job', and 'no falls in the last year' were predictors of better functionality. A comprehensive approach to addressing physical, environmental, and psychological factors could help improve overall functionality and enhance quality of life in individuals with POTS.

Establishing the shadowline: the border between legally acceptable and unacceptable standards of surgical practice

INTRODUCTION

Our study investigated how the standard of surgical care is assessed within the English and Welsh litigation process. The 'shadowline' represents the dividing line between acceptable and unacceptable standards of care. Our hypothesis was that different assessors risk adopting materially different interpretations regarding the acceptable standard of care. Any variation in the interpretation of where the shadowline falls will create uncertainty and unfairness to surgeons and patients alike.

METHODS

We summarised the legal literature and suggested the factors affecting the assessment of surgical standards. We illustrated our findings on distribution curves.

RESULTS

There was a risk that the shape of the curve and the location of the shadowline may vary according to the assessor. Importantly, a gap may have developed between the legal and clinical shadowlines in respect of the consenting process.

DISCUSSION AND CONCLUSION

We suggested how a gap between the surgical and legal shadow lines could be narrowed. Clinical governance, balanced literature and realistic expert assessments were all part of the solution.

The implementation of rifapentine and isoniazid (3HP) in two remote Arctic communities with a predominantly Inuit population, the Taima TB 3HP study

Background: The incidence of TB among Inuit is the highest in Canada. A significantly shorter latent TB infection (LTBI) treatment with rifapentine and isoniazid once weekly for 12 weeks (3HP) is now available in limited settings in Canada.Methods: A prospective open-label 2-year observational postmarketing study was conducted introducing 3HP for the first time in Canada in Iqaluit followed by a program rollout in Qikiqtarjuaq, Nunavut.Results: A total of 247 people were offered 3HP, 102 in the Iqaluit postmarketing study and 145 in the Qikiqtarjuaq program roll out. Although statistical significance was not reached, more people who started treatment completed treatment in the 3HP group (Iqaluit, 60/73 (82.2%) and Qikiqtarjuaq, 89/115 (77.4%)) than in the historical control 9INHgroup (306/420 = 72.9%) (p = 0.2). Most of the adverse events in 3HP treated patients were associated with mild discomfort but no disruption of normal daily activity. Not drinking alcohol was associated with increased 3HP completion (OR 13.33, 95% CI, 2.27-78.20) as was not taking concomitant medications (OR 7.19, 95% CI, 1.47-35.30).Conclusions: The present study supports the feasibility and safety profile of 3HP for the treatment of LTBI in Nunavut.

How do you develop systems leadership in public health? Insights from a scoping study

OBJECTIVES

Systems leadership is widely acknowledged to be needed to address the many 'wicked issues' challenging public health systems. However, there is a lack of evidence on how to develop public health professionals into effective systems leaders. This study scoped the possibilities for developing the systems leadership capacity of public health specialists in England.

STUDY DESIGN

This was a mixed-methods qualitative scoping study design.

METHODS

The study involved three stages. In the first, a rapid literature review mapped key documents in three relevant areas: systems leadership theory and practice, the changing context of public health in the UK, and training and development for UK public health professionals. In the second, 29 stakeholders were consulted to understand the context and needs for systems leadership development in public health. A third phase involved stakeholders codesigning a potential development framework for the project commissioners.

RESULTS

Four main themes were identified: the nature and purpose of systems leadership; development needs and opportunities for public health specialists; the enabling environment; and wider contextual factors impacting public health.

CONCLUSIONS

Key principles of, and a framework for, a systems leadership development approach are identified, which could be applied to any public health system.

A183 TELEHEALTH USE IN RURAL SASKATCHEWAN AND INFLAMMATORY BOWEL DISEASE OUTCOMES

Background

Appropriate management of inflammatory bowel disease (IBD) often requires multiple specialist appointments per year. Living in rural locations may pose a barrier to regular specialist care. Saskatchewan (SK) has a large rural population. Prior to COVID-19, telehealth (TH) in SK was not routinely used for either patient assessment or follow up. Furthermore, TH was exclusively between hospitals and specific TH sites without direct contact using patient’s personal phones.

Aims

The objective of this study was to assess the differences in demographics, disease characteristics, outcomes, and health care utilization between patients from rural SK with IBD who used TH and those who did not.

Methods

A retrospective chart review was completed on all rural patients (postal code S0*) with IBD in SK who were followed at the Multidisciplinary IBD Clinic in Saskatoon between January 2018 and February 2020. Patients were classified as using TH if they had ever used it. Information on demographics, disease characteristics, and access to IBD-related health care in the year prior to their last IBD clinic visit or endoscopy was collected. Data was not collected for clinic visits after March 1, 2020 as all outpatient care became remote secondary to the COVID-19 pandemic. Mean, standard deviations, median and interquartile ranges (IQR) were reported. Mann-Witney U and Chi-Square tests were used to determine differences between the groups.

Results

In total, 288 rural SK IBD patients were included, 30 (10.4%) used TH and 258 (89.6%) did not. Patient demographics were not significantly different between the two groups; although, there was a statistically significant difference in the proportion of ulcerative colitis patients (17% TH vs. 38% non-TH, p=0.02). The percentage of patients with clinical remission was 87% for TH patients and 74% for non-TH patients (p=0.13). There were no significant differences in health care utilization patterns and biochemical markers of disease, including c-reactive protein (CRP) and fecal calprotectin (FCP) (p>0.05).

Conclusions

Prior to the pandemic, a small percentage of patients with IBD in rural SK ever used TH. A small proportion of UC patients used TH. No significant differences in disease characteristics, outcomes, or health care utilization were identified. Further study is warranted to identify barriers to use of this technology to tailor care to this patient group and improve access to care, especially now as the COVID-19 pandemic has drastically changed the use of virtual care.

Funding Agencies

None

A master protocol to investigate a novel therapy acetyl-L-leucine for three ultra-rare neurodegenerative diseases: Niemann-Pick type C, the GM2 gangliosidoses, and ataxia telangiectasia

BACKGROUND

The lack of approved treatments for the majority of rare diseases is reflective of the unique challenges of orphan drug development. Novel methodologies, including new functionally relevant endpoints, are needed to render the development process more feasible and appropriate for these rare populations and thereby expedite the approval of promising treatments to address patients' high unmet medical need. Here, we describe the development of an innovative master protocol and primary outcome assessment to investigate the modified amino acid N-acetyl-L-leucine (Sponsor Code: IB1001) in three separate, multinational, phase II trials for three ultra-rare, autosomal-recessive, neurodegenerative disorders: Niemann-Pick disease type C (NPC), GM2 gangliosidoses (Tay-Sachs and Sandhoff disease; "GM2"), and ataxia telangiectasia (A-T).

METHODS/DESIGN

The innovative IB1001 master protocol and novel CI-CS primary endpoints were developed through a close collaboration between the Industry Sponsor, Key Opinion Leaders, representatives of the Patient Communities, and National Regulatory Authorities. As a result, the open-label, rater-blinded study design is considerate of the practical limitations of recruitment and retention of subjects in these ultra-orphan populations. The novel primary endpoint, the Clinical Impression of Change in Severity© (CI-CS), accommodates the heterogenous clinical presentation of NPC, GM2, and A-T: at screening, the principal investigator appoints for each patient a primary anchor test (either the 8-m walk test (8MWT) or 9-hole peg test of the dominant hand (9HPT-D)) based on his/her unique clinical symptoms. The anchor tests are videoed in a standardized manner at each visit to capture all aspects related to the patient's functional performance. The CI-CS assessment is ultimately performed by independent, blinded raters who compare videos of the primary anchor test from three periods: baseline, the end of treatment, and the end of a post-treatment washout. Blinded to the time point of each video, the raters make an objective comparison scored on a 7-point Likert scale of the change in the severity of the patient's neurological signs and symptoms from video A to video B. To investigate both the symptomatic and disease-modifying effects of treatment, N-acetyl-L-leucine is assessed during two treatment sequences: a 6-week parent study and 1-year extension phase.

DISCUSSION

The novel CI-CS assessment, developed through a collaboration of all stakeholders, is advantageous in that it better ensures the primary endpoint is functionally relevant for each patient, is able to capture small but meaningful clinical changes critical to the patients' quality of life (fine-motor skills; gait), and blinds the primary outcome assessment. The results of these three trials will inform whether N-acetyl-L-leucine is an effective treatment for NPC, GM2, and A-T and can also serve as a new therapeutic paradigm for the development of future treatments for other orphan diseases.

TRIAL REGISTRATION

The three trials (IB1001-201 for Niemann-Pick disease type C (NPC), IB1001-202 for GM2 gangliosidoses (Tay-Sachs and Sandhoff), IB1001-203 for ataxia telangiectasia (A-T)) have been registered at www.clinicaltrials.gov (NCT03759639; NCT03759665; NCT03759678), www.clinicaltrialsregister.eu (EudraCT: 2018-004331-71; 2018-004406-25; 2018-004407-39), and https://www.germanctr.de (DR KS-ID: DRKS00016567; DRKS00017539; DRKS00020511).

Predictors of Bacteraemia in Emergency Department Patients with Pneumonia

Objective

To determine the proportion of patients investigated in an Australian emergency department (ED) for non-hospital-acquired pneumonia with bacteraemia and to identify risk factors for bacteraemia.

Method

Retrospective cohort study of patients with an ED diagnosis of non-hospital-acquired pneumonia in whom blood cultures were taken. Data collected included demographics, history of chronic obstructive pulmonary disease (COPD), immunosuppression, intravenous (IV) drug use or diabetes, prior antibiotic use, clinical features, biochemistry, haematology and blood culture results, ED disposition and pneumonia severity index (PSI) class. Outcomes of interest were the proportion of blood cultures that identified bacteraemia and identification of independent predictors of bacteraemia. Data analysis was by descriptive statistics, odds ratios (OR) and multivariate analysis.

Results

Two hundred patients were studied. The bacteraemia rate was 7% (95% CI=4-11%). IV drug use (OR 16.7, 95% CI=2.65-105) and pulse rate (OR 1.29, 95% CI=1.01-1.65, per 10 beat rise) were independently associated with bacteraemia. Overall, 1/199 patients had a significant broadening of therapy based on a blood culture result (0.5%, 95% CI=0.09-2.8%). On post hoc analysis, using PSI class IV/V or known IV drug use as criteria for blood culture ordering had sensitivity 92.9% (95% CI=64.1-99.6%) and negative predictive value 98.9% (95% CI=93.5-99.9%) for bacteraemia.

Conclusion

7% of blood cultures from patients with non-hospital acquired pneumonia showed bacteraemia. Using the combination of PSI class IV/V or IV drug use as criteria for blood culture ordering shows promise.

Can community midwives prevent antenatal depression? An external pilot study to test the feasibility of a cluster randomized controlled universal prevention trial

BACKGROUND

Repeated epidemiological surveys show no decline in depression although uptake of treatments has grown. Universal depression prevention interventions are effective in schools but untested rigorously in adulthood. Selective prevention programmes have poor uptake. Universal interventions may be more acceptable during routine healthcare contacts for example antenatally. One study within routine postnatal healthcare suggested risk of postnatal depression could be reduced in non-depressed women from 11% to 8% by giving health visitors psychological intervention training. Feasibility and effectiveness in other settings, most notably antenatally, is unknown.

METHOD

We conducted an external pilot study using a cluster trial design consisting of recruitment and enhanced psychological training of randomly selected clusters of community midwives (CMWs), recruitment of pregnant women of all levels of risk of depression, collection of baseline and outcome data prior to childbirth, allowing time for women 'at increased risk' to complete CMW-provided psychological support sessions.

RESULTS

Seventy-nine percent of eligible women approached agreed to take part. Two hundred and ninety-eight women in eight clusters participated and 186 termed 'at low risk' for depression, based on an Edinburgh Perinatal Depression Scale (EPDS) score of <12 at 12 weeks gestation, provided baseline and outcome data at 34 weeks gestation. All trial protocol procedures were shown to be feasible. Antenatal effect sizes in women 'at low risk' were similar to those previously demonstrated postnatally. Qualitative work confirmed the acceptability of the approach to CMWs and intervention group women.

CONCLUSION

A fully powered trial testing universal prevention of depression in pregnancy is feasible, acceptable and worth undertaking.

let-7 miRNAs can act through notch to regulate human gliogenesis

It is clear that neural differentiation from human pluripotent stem cells generates cells that are developmentally immature. Here, we show that the let-7 plays a functional role in the developmental decision making of human neural progenitors, controlling whether these cells make neurons or glia. Through gain- and loss-of-function studies on both tissue and pluripotent derived cells, our data show that let-7 specifically regulates decision making in this context by regulation of a key chromatin-associated protein, HMGA2. Furthermore, we provide evidence that the let-7/HMGA2 circuit acts on HES5, a NOTCH effector and well-established node that regulates fate decisions in the nervous system. These data link the let-7 circuit to NOTCH signaling and suggest that this interaction serves to regulate human developmental progression.

•

let-7 miRNAs influence developmental maturity of neural progenitors

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let-7 miRNAs act through HMGA2 and NOTCH to regulate gliogenesis

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HMGA2 expression regulates access of NICD to HES5 promoter

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Induction of let-7 miRNAs can accelerate oligodendrogenesis

Longitudinal evaluation of cognitive functioning in pediatric multiple sclerosis: report from the US Pediatric Multiple Sclerosis Network

BACKGROUND

Approximately one-third of those with pediatric-onset multiple sclerosis (MS) experience cognitive impairment. Less is known concerning their change in cognitive functioning over time.

OBJECTIVE

Changes in cognitive function over time were measured in the largest pediatric cohort to date through the US Network of Pediatric MS Centers.

METHODS

A total of 67 individuals with pediatric MS (n=62) or clinically isolated syndrome (CIS, n=5), ranging from 8-17 years of age (mean age ± standard deviation (SD)=14.37 ± 2.02) completed initial and follow-up neuropsychological testing after an average of 1.64 ± 0.63 years apart. The nine tests administered measure general intellect, attention and working memory, verbal memory, visuomotor integration, language, and executive functioning.

RESULTS

Rate of impairment (having one-third or more scores in the impaired range) was 37% at baseline and 33% at follow-up. Tests commonly impaired were measures of visuomotor integration, speeded processing, and attention. Most tested did not decline over two years. There was no clear pattern of change on any specific measure.

CONCLUSION

Findings suggest that, over short timeframes, stable or even improved performances on measures of cognitive ability can occur. Pediatric MS may instead prevent expected age-related cognitive gains.

Tumour cell retention of rucaparib, sustained PARP inhibition and efficacy of weekly as well as daily schedules

Background:

Poly(ADP-ribose) polymerase-1 (PARP) inhibitors (PARPi) exploit tumour-specific defects in homologous recombination DNA repair and continuous dosing is most efficacious. Early clinical trial data with rucaparib suggested that it caused sustained PARP inhibition. Here we investigate the mechanism of this durable inhibition and potential exploitation.

Methods:

Uptake and retention of rucaparib and persistence of PARP inhibition were determined by radiochemical and immunological assays in human cancer cell lines. The pharmacokinetics and pharmacodynamics of rucaparib were determined in tumour-bearing mice and the efficacy of different schedules of rucaparib was determined in mice bearing homologous recombination DNA repair-defective tumours.

Results:

Rucaparib accumulation is carrier mediated (Km=8.4±1.2 μM, Vmax=469±22 pmol per 10⁶ cells per 10 min), reaching steady-state levels >10 times higher than the extracellular concentration within 30 min. Rucaparib is retained in cells and inhibits PARP ⩾50% for ⩾72 h days after a 30-min pulse of 400 nM. In Capan-1 tumour-bearing mice rucaparib accumulated and was retained in the tumours, and PARP was inhibited for 7 days following a single dose of 10 mg kg⁻¹ i.p or 150 mg kg⁻¹ p.o. by 70% and 90%, respectively. Weekly dosing of 150 mg kg⁻¹ p.o once a week was as effective as 10 mg kg⁻¹ i.p daily for five days every week for 6 weeks in delaying Capan-1 tumour growth.

Conclusions:

Rucaparib accumulates and is retained in tumour cells and inhibits PARP for long periods such that weekly schedules have equivalent anticancer activity to daily dosing in a pre-clinical model, suggesting that clinical evaluation of alternative schedules of rucaparib should be considered.

Differential expression and cellular localization of novel isoforms of the tendon biomarker tenomodulin

Tenomodulin (Tnmd, also called Tendin) is classified as a type II transmembrane glycoprotein and is highly expressed in developing as well as in mature tendons. Along with scleraxis (scx), Tnmd is a candidate marker gene for tenocytes. Its function is unknown, but it has been reported to have anti-angiogenic properties. Results in a knockout mouse model did not substantiate that claim. It has homology to chondromodulin-I. Single nucleotide polymorphisms of TNMD have been associated with obesity, macular degeneration, and Alzheimer's disease in patients. In the present study, three Tnmd isoforms with deduced molecular weights of 20.3 (isoform II), 25.4 (isoform III), and 37.1 (isoform I) kDa were proposed and verified by Western blot from cells with green fluorescent protein-linked, overexpressed constructs, tissue, and by qPCR of isoforms from human tissues and cultured cells. Overexpression of each Tnmd isoform followed by immunofluorescence imaging showed that isoforms I and II had perinuclear localization while isoform III was cytoplasmic. Results of qPCR demonstrated differential expression of each Tnmd isoform in patient's specimens taken from flexor carpi radialis, biceps brachii, and flexor digitorum profundus tendons. Knockdown of Tnmd increased the expression of both scleraxis (scx) and myostatin, indicating a potential negative feedback loop between Tnmd and its regulators. Knockdown of all Tnmd isoforms simultaneously also reduced tenocyte proliferation. I-TASSER protein three-dimensional conformation modeling predictions indicated each Tnmd isoform had different structures and potential functions: isoform 1, modeled as a cytosine methyltransferase; isoform 2, a SUMO-1-like SENP-1 protease; and isoform 3, an α-syntrophin, plextrin homology domain scaffolding protein. Further functional studies with each Tnmd isoform may help us to better understand regulation of tenocyte proliferation, tendon development, response to injury and strain, as well as mechanisms in tendinoses. These results may indicate novel therapeutic targets in specific tenomodulin isoforms as well as treatments for tendon diseases.

The Effects of Children on the Process of Recovery in Oxford Houses

The effects of children on the process of substance use recovery for adults living in Oxford Houses is explored in two qualitative studies. Oxford Houses are self-run, community-based residential homes for small groups of adults who live together and support each other's efforts to recover from drug and/or alcohol addiction. In the first study, telephone interviews were conducted with 29 adults who were living in Oxford Houses that allowed children to live in the house with their parent. Results suggest that having children in the house supported a positive living environment for the recovery of house members. In the second study, telephone interviews were conducted with an additional 15 mothers who lived in Oxford Houses. These interviews focused on the effects of the mothers' addiction and recovery on their relationships with their children. This study found that most parents acknowledged the negative effects of their addiction on their relationship with their child and the effects of their recovery on improving those relationships.

Investigation of the presence of ghrelin in the central nervous system of the rat and mouse

Ghrelin and ghrelin receptor agonist have effects on central neurons in many locations, including the hypothalamus, caudal brain stem, and spinal cord. However, descriptions of the distributions of ghrelin-like immunoreactivity in the CNS in published work are inconsistent. We have used three well-characterized anti-ghrelin antibodies, an antibody to the unacylated form of ghrelin, and a ghrelin peptide assay in rats, mice, ghrelin knockout mice, and ghrelin receptor reporter mice to re-evaluate ghrelin presence in the rodent CNS. The stomach served as a positive control. All antibodies were effective in revealing gastric endocrine cells. However, no specific staining could be found in the brain or spinal cord. Concentrations of antibody 10 to 30 times those effective in the stomach bound to nerve cells in rat and mouse brain, but this binding was not reduced by absorbing concentrations of ghrelin peptide, or by use of ghrelin gene knockout mice. Concentrations of ghrelin-like peptide, detected by enzyme-linked immunosorbent assay in extracts of hypothalamus, were 1% of gastric concentrations. Ghrelin receptor-expressing neurons had no adjacent ghrelin immunoreactive terminals. It is concluded that there are insignificant amounts of authentic ghrelin in neurons in the mouse or rat CNS and that ghrelin receptor-expressing neurons do not receive synaptic inputs from ghrelin-immunoreactive nerve terminals in these species.

Quantifying show jumping horse rider expertise using IMUs

Horse rider ability has long been measured using horse performance, competition results and visual observation. Scientific methods of measuring rider ability on the flat are emerging such as measuring position angles and harmony of the horse-rider system. To date no research has quantified rider ability in show jumping. Kinematic analysis and motion sensors have been used in sports other than show jumping to measure the quality of motor control patterns in humans. The aim of this study was to quantify rider ability in show jumping using body-mounted IMUs. Preliminary results indicate that there are clear differences in experienced and novice riders during show jumping.

Alarin stimulates food intake and gonadotrophin release in male rats

BACKGROUND AND PURPOSE

Alarin is a recently discovered member of the galanin peptide family encoded by a splice variant of galanin-like peptide (GALP) mRNA. Galanin and GALP regulate energy homeostasis and reproduction. We therefore investigated the effects of alarin on food intake and gonadotrophin release.

EXPERIMENTAL APPROACH

Alarin was administered into the third cerebral ventricle (i.c.v.) of rats, and food intake or circulating hormone levels were measured. The effect of alarin on the hypothalamo-pituitary-gonadal axis was investigated in vitro using hypothalamic and anterior pituitary explants, and immortalized cell lines. Receptor binding assays were used to determine whether alarin binds to galanin receptors.

KEY RESULTS

The i.c.v. administration of alarin (30 nmol) to ad libitum fed male rats significantly increased acute food intake to 500%, and plasma luteinizing hormone (LH) levels to 170% of responses to saline. In vitro, 100 nM alarin stimulated neuropeptide Y (NPY) and gonadotrophin-releasing hormone (GnRH) release from hypothalamic explants from male rats, and 1000 nM alarin increased GnRH release from GT1-7 cells. In vivo, pretreatment with the GnRH receptor antagonist cetrorelix prevented the increase in plasma LH levels observed following i.c.v. alarin administration. Receptor binding studies confirmed alarin did not bind to any known galanin receptor, or compete with radiolabelled galanin for hypothalamic binding sites.

CONCLUSIONS AND IMPLICATIONS

These results suggest alarin is a novel orexigenic peptide, and that it increases circulating LH levels via hypothalamic GnRH. Further work is required to identify the receptor(s) mediating the biological effects of alarin.

Cerebellin1 is a novel orexigenic peptide

AIM

Cerebellin1 (Cbln1) is highly expressed in the hypothalamus, a region of the brain involved in appetite regulation. However, the effects of Cbn1 on food intake are not known. The present study aimed to investigate the effect of Cbln1 on appetite regulation in rats.

METHODS

We determined the effect of (i) intracerebroventricular (ICV) injection of Cbln1 on food intake, behaviour and plasma pituitary hormone levels in male Wistar rats; (ii) Cbln1 on the release of hypothalamic neuropeptides known to modulate food intake from hypothalamic explants and (iii) fasting on hypothalamic Cbln1 mRNA expression.

RESULTS

(i) ICV administration of Cbln1 significantly increased food intake in rats and caused no adverse behaviours. ICV administration of Cbln1 significantly reduced plasma thyroid stimulating hormone (TSH) levels 10 min postinjection in rats. (ii) Cbln1 significantly increased the release of neuropeptide Y (NPY) from hypothalamic explants. (iii) Cbln1 mRNA expression levels were increased in the ventromedial nucleus of the hypothalamus in fasted rats.

CONCLUSIONS

These data suggest that Cbln1 is a novel orexigenic peptide, which may mediate its effects via hypothalamic NPY.

Augurin stimulates the hypothalamo-pituitary-adrenal axis via the release of corticotrophin-releasing factor in rats

BACKGROUND AND PURPOSE

The functional characterization of secreted peptides can provide the basis for the development of novel therapeutic agents. Augurin is a recently identified secreted peptide of unknown function expressed in multiple endocrine tissues, and in regions of the brain including the hypothalamus. We therefore investigated the effect of hypothalamic injection of augurin on the hypothalamo-pituitary-adrenal (HPA) axis in male Wistar rats.

EXPERIMENTAL APPROACH

Augurin was given as a single injection into the third cerebral ventricle (i.c.v.) or into the paraventricular nucleus (iPVN) of the hypothalamus. Circulating hormone levels were then measured by radioimmunoassay. The effect of augurin on the release of hypothalamic neuropeptides was investigated ex vivo using hypothalamic explants. The acute effects of iPVN augurin on behaviour were also assessed.

KEY RESULTS

i.c.v. injection of augurin significantly increased plasma ACTH and corticosterone, compared with vehicle-injected controls, but had no effect on other hypothalamo-pituitary axes hormones. Microinjection of lower doses of augurin into the PVN caused a similar increase in plasma ACTH and corticosterone, without significant alteration in behavioural patterns. Incubation of hypothalamic explants with increasing doses of augurin significantly elevated corticotrophin-releasing factor (CRF) and arginine vasopressin release. In vivo, peripheral injection of a CRF(1/2) receptor antagonist prevented the rise in ACTH and corticosterone caused by i.c.v. augurin injection.

CONCLUSIONS AND IMPLICATIONS

These data suggest that augurin stimulates the release of ACTH via the release of hypothalamic CRF. Pharmacological manipulation of the augurin system may therefore be a novel target for regulation of the HPA axis.