Pediatric Prolonged-Release Melatonin for Sleep in Children with Autism Spectrum Disorder: Impact on Child Behavior and Caregiver's Quality of Life.

A randomized, 13-weeks, placebo-controlled double-blind study in 125 subjects aged 2-17.5 years with Autism Spectrum Disorder or Smith-Magenis syndrome and insomnia demonstrated efficacy and safety of easily-swallowed prolonged-release melatonin mini-tablets (PedPRM; 2-5 mg) in improving sleep duration and onset. Treatment effects on child behavior and caregiver's quality of life were evaluated. PedPRM treatment resulted in significant improvement in externalizing but not internalizing behavior (Strengths and Difficulties questionnaire; SDQ) compared to placebo (p = 0.021) with clinically-relevant improvements in 53.7% of PedPRM-treated versus 27.6% of placebo-treated subjects (p = 0.008). Caregivers' quality of life also improved with PedPRM versus placebo (p = 0.010) and correlated with the change in total SDQ (p = 0.0005). PedPRM alleviates insomnia-related difficulties, particularly externalizing behavior in the children, subsequently improving caregivers' quality of life.

Klotho suppresses colorectal cancer through modulation of the unfolded protein response.

Klotho is an anti-aging transmembrane protein, which can be shed and function as a hormone. Accumulating data indicate klotho as a tumor suppressor in a wide array of malignancies and indicate the subdomain KL1 as the active region of the protein. We aimed to study the role of klotho as a tumor suppressor in colorectal cancer. Bioinformatics analyses of TCGA datasets indicated reduced klotho mRNA levels in human colorectal cancer, along with negative regulation of klotho expression by hypermethylation of the promoter and 1st exon, and hypomethylation of an area within the gene. Overexpression or treatment with klotho or KL1 inhibited proliferation of colorectal cancer cells in vitro. The in vivo activity of klotho and KL1 was examined using two models recapitulating development of tumors in the normal colonic environment of immune-competent mice. Treatment with klotho inhibited formation of colon polyps induced by the carcinogen azoxymethane, and KL1 treatment slowed growth of orthotopically-implanted colorectal tumors. Gene expression array revealed that klotho and KL1 expression enhanced the unfolded protein response (UPR) and this was further established by increased levels of spliced XBP1, GRP78 and phosphorylated-eIF2α. Furthermore, attenuation of the UPR partially abrogated klotho tumor suppressor activity. In conclusion, this study indicates klotho as a tumor suppressor in colorectal cancer and identifies, for the first time, the UPR as a pathway mediating klotho activities in cancer. These data suggest that administration of exogenous klotho or KL1 may serve as a novel strategy for prevention and treatment of colorectal cancer.

Long-Term Efficacy and Safety of Pediatric Prolonged-Release Melatonin for Insomnia in Children with Autism Spectrum Disorder.

Objective: A recent double-blind randomized placebo-controlled study demonstrated 3-month efficacy and safety of a novel pediatric-appropriate prolonged-release melatonin (PedPRM) for insomnia in children and adolescents with autism spectrum disorder (ASD) and neurogenetic disorders (NGD) with/without attention-deficit/hyperactivity disorder comorbidity. Long-term efficacy and safety of PedPRM treatment was studied. Methods: A prospective, open-label efficacy and safety follow-up of nightly 2, 5, or 10 mg PedPRM in subjects who completed the 13-week double-blind trial (51 PedPRM; 44 placebo). Measures included caregiver-reported Sleep and Nap Diary, Composite Sleep Disturbance Index (CSDI), caregiver's Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale, and quality of life (WHO-5 Well-Being Index). Results: Ninety-five subjects (74.7% males; mean [standard deviation] age, 9 [4.24]; range, 2-17.5 years) received PedPRM (2/5 mg) according to the double-blind phase dose, for 39 weeks with optional dose adjustment (2, 5, or 10 mg/day) after the first 13 weeks. After 52 weeks of continuous treatment (PedPRM-randomized group) subjects slept (mean [SE]) 62.08 (21.5) minutes longer (p = 0.007); fell asleep 48.6 (10.2) minutes faster (p < 0.001); had 89.1 (25.5) minutes longer uninterrupted sleep episodes (p = 0.001); 0.41 (0.12) less nightly awakenings (>50% decrease; p = 0.001); and better sleep quality (p < 0.001) compared with baseline. The placebo-randomized group also improved with PedPRM. Altogether, by the end of 39-week follow-up, regardless of randomization assignment, 55/72 (76%) of completers achieved overall improvement of ≥1 hour in total sleep time (TST), sleep latency or both, over baseline, with no evidence of decreased efficacy. In parallel, CSDI child sleep disturbance and caregivers' satisfaction of their child's sleep patterns (p < 0.001 for both), PSQI global (p < 0.001), and WHO-5 (p = 0.001) improved in statistically significant and clinically relevant manner (n = 72) compared with baseline. PedPRM was generally safe; most frequent treatment-related adverse events were fatigue (5.3%) and mood swings (3.2% of patients). Conclusion: PedPRM, an easily swallowed formulation shown to be efficacious versus placebo, is an efficacious and safe option for long-term treatment (up to 52 weeks reported here) of children with ASD and NGD who suffer from insomnia and subsequently improves caregivers' quality of life.

Klotho response to treatment with growth hormone and the role of IGF-I as a mediator.

CONTEXT: Klotho is an aging-modulating protein expressed mainly in the kidneys, which can be cleaved and shed to act as a circulating hormone. Several lines of evidence suggest a tight interaction between klotho and the GH-IGF-I axis. We showed previously that klotho levels are decreased in pediatric patients with growth hormone deficiency (GHD). Our aim now is to investigate the effect of GH therapy on klotho levels in these patients and to elucidate the role of IGF-1 in mediating secretion of klotho. BASIC PROCEDURES: Klotho levels were measured in 29 GHD pediatric patients (males=15, aged 12.2±3.3years), treated with GH for 2.5±2.8years; nineteen patients had samples obtained both before and during treatment. The effect of IGF-I and its downstream effectors on secretion of klotho to media was studied in COS-7 cells overexpressing klotho. MAIN FINDINGS: Klotho levels increased under GH treatment (from 1321±691pg/ml to 3380±2120pg/ml, p<0.001), and were higher compared to controls (1645±778pg/ml, p<0.001), resulting in supraphysiological levels. Fold-increase in klotho correlated with fold-increase in IGF-I (r=0.63, p=0.004). Studies in COS-7 cells overexpressing klotho revealed mTOR-dependent induction of klotho shedding by IGF-I. PRINCIPAL CONCLUSIONS: Klotho levels increased during GH treatment of pediatric GHD patients. This increase was associated with an increase in IGF-I levels. Furthermore, we showed, for the first time, a direct role of IGF-I in the regulation of klotho's shedding which depends on activation of the AKT-mTOR pathway. Our findings add further support for the close association between klotho and the GH/IGF-I axis.

Alteration in serum klotho levels in anorexia nervosa patients.

BACKGROUND & AIMS: Klotho is a trans-membrane protein which can be shed to act as a hormone; its blood levels may be regulated by the GH/IGF-1 axis. Klotho deficient mice exhibit short lifespan and characteristics of aging and malnutrition, including decreased fat and muscle mass, osteopenia, and impaired fertility. As anorexia nervosa (AN) is characterized by malnutrition and GH resistance, we hypothesized klotho levels would be altered in AN, and aimed to assess klotho levels in undernourished AN patients and changes in klotho following weight rehabilitation. PARTICIPANTS AND METHODS: 19 adolescent female AN inpatients (aged 16.1 ± 1.8 years) admitted to an inpatient service for eating disorders in a tertiary center were recruited. Blood samples were obtained on admission and after weight restoration (interval 4.0 ± 2.3 months) and analyzed for klotho, IGF-1, calcium, phosphorus, and alkaline phosphatase. RESULTS: Klotho levels on admission were lower than expected for age, and correlated with lumbar spine BMD Z-score (r = -0.81, p < 0.001) and alkaline phosphatase levels (r = 0.66, p = 0.003) but not with age, height-SDS, weight-SDS, BMI-SDS, or serum calcium, phosphorus and IGF-1 levels. Both IGF-1 and klotho levels increased significantly during hospitalization (IGF-1: 44 ± 17 nmol/l to 53 ± 11 nmol/l, p = 0.008; klotho: 1061 ± 421 pg/ml to 1519 ± 781 pg/ml, p = 0.008). CONCLUSIONS: Klotho levels are low in the acute stage of AN and increase with nutritional rehabilitation. Low klotho on admission may be secondary to low IGF-1 levels and may contribute to the clinical manifestations of AN. The role of klotho in the pathophysiology of AN and as a novel marker of disease severity should be further explored.

Tumor Suppressor Activity of Klotho in Breast Cancer Is Revealed by Structure-Function Analysis.

UNLABELLED: Klotho is a transmembrane protein containing two internal repeats, KL1 and KL2, both displaying significant homology to members of the ß-glycosidase family. Klotho is expressed in the kidney, brain, and various endocrine tissues, but can also be cleaved and act as a circulating hormone. Klotho is an essential cofactor for binding of fibroblast growth factor 23 (FGF23) to the FGF receptor and can also inhibit the insulin-like growth factor-1 (IGF-1) pathway. Data from a wide array of malignancies indicate klotho as a tumor suppressor; however, the structure-function relationships governing its tumor suppressor activities have not been deciphered. Here, the tumor suppressor activities of the KL1 and KL2 domains were examined. Overexpression of either klotho or KL1, but not of KL2, inhibited colony formation by MCF-7 and MDA-MB-231 cells. Moreover, in vivo administration of KL1 was not only well tolerated but significantly slowed tumor formation in nude mice. Further studies indicated that KL1, but not KL2, interacted with the IGF-1R and inhibited the IGF-1 pathway. Based on computerized structural modeling, klotho constructs were generated in which critical amino acids have been mutated. Interestingly, the mutated proteins retained their tumor suppressor activity but showed reduced ability to modulate FGF23 signaling. These data indicate differential activity of the klotho domains, KL1 and KL2, in breast cancer and reveal that the tumor suppressor activities of klotho can be dissected from its physiologic activities. IMPLICATIONS: These findings pave the way for a rational design of safe klotho-based molecules for the treatment of breast cancer.

Association between decreased klotho blood levels and organic growth hormone deficiency in children with growth impairment.

OBJECTIVE: Klotho is an aging-modulating protein expressed mainly in the kidneys and choroid plexus, which can also be shed, released into the circulation and act as a hormone. Klotho deficient mice are smaller compared to their wild-type counterparts and their somatotropes show marked atrophy and reduced number of secretory granules. Recent data also indicated an association between klotho levels and growth hormone (GH) levels in acromegaly. We aimed to study the association between klotho levels and GH deficiency (GHD) in children with growth impairment. DESIGN: Prospective study comprising 99 children and adolescents (aged 9.0 ± 3.7 years, 49 male) undergoing GH stimulation tests for short stature (height-SDS = -2.1 ± 0.6). Klotho serum levels were measured using an α-klotho ELISA kit. RESULTS: Klotho levels were significantly lower (p<0.001) among children with organic GHD (n = 11, 727 ± 273 pg/ml) compared to both GH sufficient participants (n = 59, 1497 ± 754 pg/ml) and those with idiopathic GHD (n = 29, 1645 ± 778 pg/ml). The difference between GHS children and children with idiopathic GHD was not significant. Klotho levels positively correlated with IGF-1- standard deviation scores (SDS) (R = 0.45, p<0.001), but were not associated with gender, pubertal status, age or anthropometric measurements. CONCLUSIONS: We have shown, for the first time, an association between low serum klotho levels and organic GHD. If validated by additional studies, serum klotho may serve as novel biomarker of organic GHD.

The aging suppressor klotho: a potential regulator of growth hormone secretion.

Klotho is a transmembranal protein highly expressed in the kidneys, choroid plexus, and anterior pituitary. Klotho can also be cleaved and shed and acts as a circulating hormone. Klotho-deficient mice (kl/kl mice) develop a phenotype resembling early aging. Several lines of evidence suggest a role for klotho in the regulation of growth hormone (GH) secretion. The kl/kl mice are smaller compared with their wild-type counterparts, and their somatotropes show reduced numbers of secretory granules. Moreover, klotho is a potent inhibitor of the IGF-I pathway, a negative regulator of GH secretion. Therefore, we hypothesized that klotho may enhance GH secretion. The effect of klotho on GH secretion was examined in GH3 rat somatotrophs, cultured rat pituitaries, and cultured human GH-secreting adenomas. In all three models, klotho treatment increased GH secretion. Prolonged treatment of mice with intraperitoneal klotho injections increased mRNA levels of IGF-I and IGF-I-binding protein-3 mRNA in the liver, reflecting increased serum GH levels. In accord with its ability to inhibit the IGF-I pathway, klotho partially restored the inhibitory effect of IGF-I on GH secretion. Klotho is known to be a positive regulator of basic bFGF signaling. We studied rat pituitaries and human adenoma cultures and noted that bFGF increased GH secretion and stimulated ERK1/2 phosphorylation. Both effects were augmented following treatment with klotho. Taken together, our data indicate for the first time that klotho is a positive regulator of GH secretion and suggest the IGF-I and bFGF pathways as potential mediators of this effect.