Myocardial ischemia and delayed recovery after anesthesia in a patient with Cockayne syndrome: a case report

Inhibition of activin A receptor signalling attenuates age-related pathological cardiac remodelling

In the heart, ageing is associated with DNA damage, oxidative stress, fibrosis and activation of the activin signalling pathway, leading to cardiac dysfunction. The cardiac effects of activin signalling blockade in progeria are unknown. This study investigated the cardiac effects of progeria induced by attenuated levels of Ercc1, which is required for DNA excision and repair, and the impact of activin signalling blockade using a soluble activin receptor type IIB (sActRIIB). DNA damage and oxidative stress were significantly increased in Ercc1^Δ/− hearts, but were reduced by sActRIIB treatment. sActRIIB treatment improved cardiac systolic function and induced cardiomyocyte hypertrophy in Ercc1^Δ/− hearts. RNA-sequencing analysis showed that in Ercc1^Δ/− hearts, there was an increase in pro-oxidant and a decrease in antioxidant gene expression, whereas sActRIIB treatment reversed this effect. Ercc1^Δ/− hearts also expressed higher levels of anti-hypertrophic genes and decreased levels of pro-hypertrophic ones, which were also reversed by sActRIIB treatment. These results show for the first time that inhibition of activin A receptor signalling attenuates cardiac dysfunction, pathological tissue remodelling and gene expression in Ercc1-deficient mice and presents a potentially novel therapeutic target for heart diseases.

Summary: Attenuated DNA repair is associated with pathological cardiac remodelling and gene expression. Much of this phenotype is attenuated by inhibition of the activin signalling pathway using soluble activin receptor treatment.

Cockayne syndrome: Clinical features, model systems and pathways

Cockayne syndrome (CS) is a disorder characterized by a variety of clinical features including cachectic dwarfism, severe neurological manifestations including microcephaly and cognitive deficits, pigmentary retinopathy, cataracts, sensorineural deafness, and ambulatory and feeding difficulties, leading to death by 12 years of age on average. It is an autosomal recessive disorder, with a prevalence of approximately 2.5 per million. There are several phenotypes (1-3) and two complementation groups (CSA and CSB), and CS overlaps with xeroderma pigmentosum (XP). It has been considered a progeria, and many of the clinical features resemble accelerated aging. As such, the study of CS affords an opportunity to better understand the underlying mechanisms of aging. The molecular basis of CS has traditionally been ascribed to defects in transcription and transcription-coupled nucleotide excision repair (TC-NER). However, recent work suggests that defects in base excision DNA repair and mitochondrial functions may also play key roles. This opens up the possibility for molecular interventions in CS, and by extrapolation, possibly in aging.

Discrepancy between electroencephalography and hemodynamics in a patient with Cockayne syndrome during general anesthesia

Cockayne syndrome is a kind of progeria with autosomal chromosome recessiveness described first by Cockayne in 1936. Patients with this syndrome were characterized by retarded growth, cerebral atrophy, and mental retardation. We experienced an anesthetic management of a patient with Cockayne syndrome, who underwent dental treatment twice. The primary concern was discrepancy between electroencephalography and hemodynamics. The values of bispectral index showed a sharp fall to 1 digit and suppression ratio more than 40, while hemodynamics was stable during induction of anesthesia with sevoflurane 8%. We should pay attention to anesthetic depth in the central nervous system in patients with Cockayne syndrome. Titration of anesthetics should be performed by the information from electroencephalography.

Cockayne syndrome: the expanding clinical and mutational spectrum

Cockayne syndrome is a progressive multisystem disorder characterized by a specific cellular defect in transcription-coupled repair. Typical features include developmental delay, failure to thrive, microcephaly, cutaneous photosensitivity, dental anomalies, progressive hearing loss, pigmentary retinopathy, cataracts and enophthalmia. Various levels of severity have been described including the "classical" or moderate type I CS, the early-onset or severe type II and the mild or late-onset type III. Adult-onset cases with prolonged survival and normal initial development have also been identified. At the opposite end of the scale, the most severely affected patients, showing a prenatal onset of the symptoms, are overlapping with the cerebro-oculo-facio-skeletal (COFS) syndrome. These overlapping subtypes build a continuous spectrum without clear thresholds. Revised diagnostic criteria are proposed to improve the recognition of the disease. Two thirds of the patients are linked to mutations in the CSB (ERCC6) gene, one third to mutations in the CSA (ERCC8) gene. At least 78 different mutations are known in the CSB gene and 30 in the CSA gene to date, in more than 120 genetically confirmed patients. Large clinical and molecular databases are needed to unravel genotype-phenotype correlations and to gain more insight into the underlying molecular mechanisms.

A possible cranio-oro-facial phenotype in Cockayne syndrome

Background

Cockayne Syndrome CS (Type A – CSA; or CS Type I OMIM #216400) (Type B – CSB; or CS Type II OMIM #133540) is a rare autosomal recessive neurological disease caused by defects in DNA repair characterized by progressive cachectic dwarfism, progressive intellectual disability with cerebral leukodystrophy, microcephaly, progressive pigmentary retinopathy, sensorineural deafness photosensitivity and possibly orofacial and dental anomalies.

Methods

We studied the cranio-oro-facial status of a group of 17 CS patients from 15 families participating in the National Hospital Program for Clinical Research (PHRC) 2005 « Clinical and molecular study of Cockayne syndrome ». All patients were examined by two investigators using the Diagnosing Dental Defects Database (D[4]/phenodent) record form.

Results

Various oro-facial and dental anomalies were found: retrognathia; micrognathia; high- arched narrow palate; tooth crowding; hypodontia (missing permanent lateral incisor, second premolars or molars), screwdriver shaped incisors, microdontia, radiculomegaly, and enamel hypoplasia. Eruption was usually normal. Dental caries was associated with enamel defects, a high sugar/carbohydrate soft food diet, poor oral hygiene and dry mouth. Cephalometric analysis revealed mid-face hypoplasia, a small retroposed mandible and hypo-development of the skull.

Conclusion

CS patients may have associated oro-dental features, some of which may be more frequent in CS children – some of them being described for the first time in this paper (agenesis of second permanent molars and radiculomegaly). The high susceptibility to rampant caries is related to a combination of factors as well as enamel developmental defects. Specific attention to these anomalies may contribute to diagnosis and help plan management.