Effects of induced precocious puberty on cranial growth in female Wistar rats

Apparent diffusion coefficient (ADC) measurements and morphometric evaluation of the cranium in age-matched children with central precocious puberty

OBJECTIVES

Central precocious puberty (CPP) is one of the common reasons for referral to pediatric endocrinology. Magnetic resonance imaging (MRI) is used to rule out intracranial pathologies. However, there is insufficient information in the literature about bone marrow abnormalities on MRI in CPP cases. The aim of this study was to evaluate the apparent diffusion coefficient (ADC) values obtained from bone marrow diffusion weight images (DWI) of cranial bone structures and the status of sphenooccipital synchondrosis (SOS) in CPP.

METHODS

MRI data from 6-to 9-year-old girls with CPP and a healthy control group were evaluated. Anthropometric data, FSH, LH, and oestradiol tests were recorded, and the relationship between SOS status, DWI-ADC values of the clivus, parietal bone, and occipital protuberance were compared.

RESULTS

The study included 146 girls, 79 CPP, and 67 healthy aged 6-9 years (median: 8 (2)). The diagnosis age was 8.30 ± 0.8 years. The ADC values were significantly lower on CPP than normal controls (p=<0.05). In the CPP group, pattern 1 was found at 2 % (n=2), pattern 2 at 3.5 % (n=3), and pattern 3 at 3.5 % (n=3) in clivus sphenooccipital synchondrosis. There was no correlation between the mean parietal, occipital, and clivus ADC values and any variable (p>0.05).

CONCLUSIONS

DWI-MRI ADC analysis can be used as a quantitative radiological marker for early detection of CPP, even before changes in sphenooccipital synchondrosis.

Human mesenchymal stem-derived extracellular vesicles improve body growth and motor function following severe spinal cord injury in rat

BACKGROUND

Spinal cord injury (SCI) in young adults leads to severe sensorimotor disabilities as well as slowing of growth. Systemic pro-inflammatory cytokines are associated with growth failure and muscle wasting. Here we investigated whether intravenous (IV) delivery of small extracellular vesicles (sEVs) derived from human mesenchymal stem/stromal cells (MSC) has therapeutic effects on body growth and motor recovery and can modulate inflammatory cytokines following severe SCI in young adult rats.

METHODS

Contusional SCI rats were randomized into three different treatment groups (human and rat MSC-sEVs and a PBS group) on day 7 post-SCI. Functional motor recovery and body growth were assessed weekly until day 70 post-SCI. Trafficking of sEVs after IV infusions in vivo, the uptake of sEVs in vitro, macrophage phenotype at the lesion and cytokine levels at the lesion, liver and systemic circulation were also evaluated.

RESULTS

An IV delivery of both human and rat MSC-sEVs improved functional motor recovery after SCI and restored normal body growth in young adult SCI rats, indicating a broad therapeutic benefit of MSC-sEVs and a lack of species specificity for these effects. Human MSC-sEVs were selectively taken up by M2 macrophages in vivo and in vitro, consistent with our previous observations of rat MSC-sEV uptake. Furthermore, the infusion of human or rat MSC-sEVs resulted in an increase in the proportion of M2 macrophages and a decrease in the production of the pro-inflammatory cytokines tumour necrosis factor-alpha (TNF-α) and interleukin (IL)-6 at the injury site, as well as a reduction in systemic serum levels of TNF-α and IL-6 and an increase in growth hormone receptors and IGF-1 levels in the liver.

CONCLUSIONS

Both human and rat MSC-sEVs promote the recovery of body growth and motor function after SCI in young adult rats possibly via the cytokine modulation of growth-related hormonal pathways. Thus, MSC-sEVs affect both metabolic and neurological deficits in SCI.

Variation of the apparent diffusion coefficient of skull bone marrow by age group, pubertal status, and gender in a pediatric population

BACKGROUND

Bone marrow composition varies with stage of development.

PURPOSE

To assess differences in apparent diffusion coefficient (ADC) derived from clivus bone marrow in healthy children by age, pubertal status, and gender as a benchmark when monitoring local and systemic treatment-induced effects.

MATERIAL AND METHODS

Non-oncological pediatric patients (30 pre-pubertal [15 girls, 15 boys] and 30 post-pubertal [15 girls, 15 boys]) with previous normal magnetic resonance imaging (MRI) of the brain including diffusion-weighted magnetic resonance imaging (DW-MRI; 1.5-T Philips Achieva-Ingenia, b-values 0 and 1000s/mm2) were studied. A 4-6 mm diameter region of interest (ROI), drawn within the clivus on two or three DW-MRI slices, yielded mean and centile ADC values. Pubertal status was recognized from imaging appearances of the pituitary gland and from fusion of the spheno-occipital synchondrosis. Correlations between ADC and age were assessed (Pearson's coefficient). Mann-Whitney U tests compared ADC by age, pubertal status, and gender.

RESULTS

Age and ADC were significantly negatively correlated (median ADC r=-0.48, mean ADC r=-0.42, P=0.0001 and 0.0008, respectively) which held true when divided by gender. Mean and median ADC differed significantly before and after puberty for the whole population (P=0.0001 and 0.0001, respectively). There was a left shift of the ADC histogram after puberty with significant differences in centile values. ADC differences before and after puberty remained when divided by gender (girls: P=0.04 and 0.009, respectively; boys: P=0.005 and 0.0002, respectively).

CONCLUSION

ADC of clivus bone marrow correlates with age in children. ADC decreases significantly after puberty, likely due to replacement of hypercellular marrow with fat. There are no gender-related differences in clivus bone-marrow ADC before or after puberty.

Dynamic Changes of RFRP3/GPR147 in the Precocious Puberty Model Female Rats

BACKGROUND

Pubertal development is a complex physiological process regulated by the neuroendocrine system and hypothalamic-pituitary-gonadal axis. Sexual precocity is a common childhood endocrine disease.The pathogenesis of sexual precocity has not been fully elucidated. RFRP3/GPRl47 signal pathway is able to inhibit the reproductive capability in avians and mammals, probably by acting on the GnRH neuron and pituitary to regulate gonadotrophin synthesis and release. However, little is known about the role of RFRP3 in puberty development and sexual precocity.

OBJECTIVE

To observe the dynamic changes of RFamide related peptide 3/G proteincoupled receptor 147 (RFRP3/GPR147) in hypothalamic during puberty development and explore their role in precocious puberty based on a female rat model.

METHODS

The Sprague-Dawley female rats were randomly divided into three groups, normal, vehicle, and precocious puberty model. At 5 days old, the rat model with precocious puberty was prepared by subcutaneously injecting a mixture of danazoldissolved ethanol and glycol. At different day-age (15, 25, 30, 35, and 40 days), the levels of estradiol(E2), follicle-stimulating hormone(FSH), and luteinizing hormone (LH) in the peripheral blood were detected by the enzyme-linked immunosorbent assay, the messenger ribonucleic acid (mRNA) expressions of RFRP3, gonadotropin releasing hormone and GPR147 were examined by real-time polymerase chain reaction(R-T PCR). RFRP3 positive cells were observed using Immunofluorescence confocal microscopy.

RESULTS

At 25 and 30 days, the levels of sex hormones and the uterus coefficients were significantly higher in the precocious puberty model group than those in the normal and vehicle groups. The ovarian morphological development in the precocious puberty model rats was significantly earlier than those in the normal and vehicle groups. The mRNA expressions of RFRP3/GPR147 and GnRH in the precocious puberty model group gradually increased and peaked at 25 days. The different day-age and the interaction have significant statistical significance on the expression of RFRP3 mRNA, while the levels of RFRP3 mRNA in the model group and vehicle groups have no significant statistical significance. There was statistical significance between the model group and vehicle groups in different day-age on the expression of GPR147 mRNA.The expression of hypothalamic RFRP3/GPR147 mRNA and RFRP3 positive cells gradually decreased with puberty onset. At 35 days, the levels of RFRP3 mRNA and GPR147 mRNA were significantly lower in the precocious puberty model group than those in the vehicle groups. Meanwhile, the levels of LH in the precocious puberty model rats reached its peak at this age. In the vehicle group, the levels of RFRP3 mRNA and serum LH were gradually increased and LH nearly peaked at 35 day-age. Subsequently, it gradually decreased and reached the lowest level at 35 day-age. The expression of RFRP3 mRNA and LH were positively correlated.

CONCLUSION

The findings suggested that RFRP3/GPR147 signaling pathway may be involved in the pathogenesis of sexual precocity by regulating puberty development and sexual maturity in rats.

Malocclusion and maxillofacial characteristics of young girls having precocious puberty

AIM

This study aimed to evaluate the dentofacial characteristics and need for orthodontic treatment in young girls having precocious puberty (PP).

DESIGN

It was a cross-sectional study that included 39 girls, age ranging from 6 to 11 years old, with confirmed diagnosis of PP. The Dental Aesthetic Index (DAI) and the Index of Orthodontic Treatment Need (IOTN) were used to assess malocclusion and the need for orthodontic treatment, and cephalometric analysis was used for the diagnosis of facial growth abnormalities. Data analysis included descriptive statistics and one-sample t-test.

RESULTS

Findings revealed high prevalence (64.1%) of severe and very severe malocclusion (DAI grades 3-4), and 82.1% of cases were classified as having moderate to high treatment need (IOTN grades 3-4). All linear cephalometric measures and most of the angular parameters differed significantly from the reference values, indicating a tendency for Class II molar relationship. There was a high proportion of the sample outside the reference value limits, ranging from 79.5% of cases below the reference limits for facial height to 59.0% of cases above the limits for incisor-mandibular plane angle.

CONCLUSIONS

Results suggest that dental and craniofacial development may be associated with PP in young girls, which may be considered in the diagnosis and treatment decisions for orthopaedic/orthodontic intervention.

Evaluation of characteristics of the craniofacial complex and dental maturity in girls with central precocious puberty

OBJECTIVES

To identify unique characteristics of the craniofacial complex and dental maturity in girls with central precocious puberty (CPP).

MATERIALS AND METHODS

This study included 34 Korean girls with idiopathic CPP (mean age, 8.6 ± .5 years) and 28 normal healthy girls of the same chronological age. An initial evaluation of the growth pattern of the craniofacial complex and dental maturity was conducted by analyzing lateral cephalometric and panoramic radiographs.

RESULTS

The mandibular ramus height (44.4 ± 4.1 mm) and total mandibular length (10.8 ± 4.3 mm) ( P = .004 and .021, respectively) were greater and the lower anterior facial height was lesser (63.2 ± 2.4 mm) ( P = .040) in the CPP group than in the reference group. In addition, the gonial angle (12.9 ± 6.1°; P = .045) and the mandibular plane angle (34.9 ± 4.8°; P = .012) were smaller in girls with CPP than in normal healthy girls. All the mandibular teeth were more mature in girls with CPP ( P < .001). A strong positive correlation was observed between the mandibular tooth formation stages and the presence of CPP in girls ( r = .756 to .957; P < .001).

CONCLUSIONS

CPP had an effect on the anteroposterior growth of the mandible in the craniofacial complex and the rotation of the mandibular plane angle. Early maturation of the mandibular teeth was observed in girls with CPP.