HNF1A gene mutations and premature ovarian failure (POF): evidence from a clinical paradigm combining MODY 3 and POF

Premature ovarian failure (POF) defines the occurrence of ovarian failure prior to the age of 40. It occurs in one out of 100 women but is very rare before age 20 (1:10,000). Maturity-onset diabetes of the young (MODY), caused by mutations in the HNF1A gene, is also a rare disorder; all types of MODY account for 1-2% of adult diabetic cases. These two rare nosologic entities coexisted in an adolescent girl evaluated for delayed puberty. Although this combination could represent a chance association, an interrelation might exist. We examined HNF1A expression in human fetal and adult ovaries by immunohistochemistry using a polyclonal HNF1A antibody. HNF1A protein was expressed in both the fetal and adult human ovaries. Based on these findings, we hypothesize that HNF1A participates in ovarian organogenesis and/or function and that mutations in the HNF1A gene might represent another molecular defect causing POF, possibly in combination with other genetic factors. The study underlines the importance of rare clinical paradigms in leading the way to elucidation of the pathogenetic mechanisms of rare diseases.

Evaluation of a rapamycin-regulated serotype 2 adeno-associated viral vector in macaque parotid glands

OBJECTIVES

Salivary glands are useful target organs for local and systemic gene therapeutics. For such applications, the regulation of transgene expression is important. Previous studies by us in murine submandibular glands showed that a rapamycin transcriptional regulation system in a single serotype 2, adeno-associated viral (AAV2) vector was effective for this purpose. This study evaluated if such a vector was similarly useful in rhesus macaque parotid glands.

METHODS

A recombinant AAV2 vector (AAV-TF-RhEpo-2.3w), encoding rhesus erythropoietin (RhEpo) and a rapamycin-inducible promoter, was constructed. The vector was administered to macaques at either of two doses [1.5 x 10(11) (low dose) or 1.5 x 10(12) (high dose) vector genomes] via cannulation of Stensen's duct. Animals were followed up for 12-14 weeks and treated at intervals with rapamycin (0.1 or 0.5 mg kg(-1)) to induce gene expression. Serum chemistry, hematology, and RhEpo levels were measured at interval.

RESULTS

AAV-TF-RhEpo-2.3w administration led to low levels of rapamycin-inducible RhEpo expression in the serum of most macaques. In five animals, no significant changes were seen in serum chemistry and hematology values over the study. One macaque, however, developed pneumonia, became anemic and subsequently required euthanasia. After the onset of anemia, a single administration of rapamycin led to significant RhEpo production in this animal.

CONCLUSION

Administration of AAV-TF-RhEpo-2.3w to macaque parotid glands was generally safe, but led only to low levels of serum RhEpo in healthy animals following rapamycin treatment.

AAV5-mediated gene transfer to the parotid glands of non-human primates

Salivary glands are potentially useful target sites for multiple clinical applications of gene transfer. Previously, we have shown that serotype 2 adeno-associated viral (AAV2) vectors lead to stable gene transfer in the parotid glands of rhesus macaques. As AAV5 vectors result in considerably greater transgene expression in murine salivary glands than do AAV2 vectors, herein we have examined the use of AAV5 vectors in macaques at two different doses (n = 3 per group; 10(10) or 3 x 10(11) particles per gland). AAV5 vector delivery, as with AAV2 vectors, led to no untoward clinical, hematological or serum chemistry responses in macaques. The extent of AAV5-mediated expression of rhesus erythropoietin (RhEpo) was dose-dependent and similar to that seen with an AAV2 vector. However, unlike results with the AAV2 vector, AAV5 vector-mediated RhEpo expression was transient. Maximal expression peaked at day 56, was reduced by approximately 80% on day 84 and thereafter remained near background levels until day 182 (end of experiment). Quantitative PCR studies of high-dose vector biodistribution at this last time point showed much lower AAV5 copy numbers in the targeted parotid gland (approximately 1.7%) than found with the same AAV2 vector dose. Molecular analysis of the conformation of vector DNA indicated a markedly lower level of concatamerization for the AAV5 vector compared with that of a similar AAV2 vector. In addition, cellular immunological studies suggest that host response differences may occur with AAV2 and AAV5 vector delivery at this mucosal site. The aggregate data indicate that results with AAV5 vectors in murine salivary glands apparently do not extend to macaque glands.

Gender differences in serotype 2 adeno-associated virus biodistribution after administration to rodent salivary glands

Salivary glands (SGs) have proven useful targets for clinical applications of gene therapeutics. In this toxicology and biodistribution study, which conforms to U.S. Food and Drug Administration Good Laboratory Practice regulations, four doses (10(7)-10(10) particles) of a serotype 2 adeno-associated viral (AAV2) vector encoding human erythropoietin were directly administered to the right submandibular gland of male and female BALB/c mice (n = 21 per gender dose group). Control-treated (saline administered; n = 66) and vector-treated (n = 168) animals did not differ in clinical appearance, morbidity and mortality rates, food and water consumption, weight gain ratios, and final weight. Clinical hematology values also were unaffected by AAV2 administration except for parameters influenced by the expression of the recombinant protein (e.g., hematocrit). Mice were killed on days 3, 30, 55, and 92. No major vector-related toxicity was uncovered after complete pathology and histopathology review. However, a significant gender-related difference in vector biodistribution was revealed by quantitative polymerase chain reaction. In male mice vector (group receiving 10(10) particles/animal) effectively transduced, and was primarily confined within, the SGs (i.e., approximately 800 times more copies in SGs than in liver; day 3) and long lived. In contrast, in female mice, SG transduction was less efficient (260-fold less than in males; day 3) and short lived, and vector was disseminated widely via both the bloodstream (SG:liver copy ratio, approximately 1) and saliva (30-fold greater than in males). The observed vector biodistribution is likely due to differences in AAV2 receptor targets and structural differences affecting SG integrity. Sexual dimorphism is a factor of major significance that could potentially affect gene therapy clinical applications in SGs.

Rapamycin control of transgene expression from a single AAV vector in mouse salivary glands

Salivary glands (SGs) appear to be a useful target site for gene therapeutics. The ability to control transgene expression is essential for clinical application. Previously, in a proof-of-concept study, we have shown that the rapamycin-inducible transcriptional regulation system can regulate protein expression after adenoviral-mediated gene transfer to SGs. To evaluate the potential ability to utilize this regulatory system for long-term control of transgene expression in this tissue, we employed a 'third generation', single adenoassociated serotype 2 viral (AAV2) vector encoding human erythropoietin (hEPO) under the control of a rapamycin-inducible promoter. The vector, rAAV-TF2.3-hEPO (10(10) particles/animal), was delivered to mouse SGs. No detectable increase in serum hEPO or hematocrit levels was observed in the absence of rapamycin administration. However, rapamycin induced elevation of serum hEPO levels, as well as concomitant hematocrit changes, that were dose-dependent, completely reversible, and relatively stable over the course of this study (6 months), with no appreciable change in rapamycin responsiveness. Our results suggest that the rapamycin transcriptional regulation system delivered in a single AAV2 vector to SGs may be valuable for systemic protein replacement applications.

Pituitary size fluctuation in long-term MR studies of PROP1 deficient patients: A persistent pathophysiological mechanism?

Inactivating PROP1 gene alterations are responsible for over 50% of familial combined pituitary hormone deficiency cases. Pituitary enlargement followed by regression and subnormal pituitary size has been documented in a number of PROP1 deficient patients. Data derived from PROP1 deficient mice (Ames dwarfs) have revealed some of the underlying cellular mechanisms. Nevertheless, long-term magnetic resonance imaging (MRI) findings in two PROP1 deficient patients suggest the evolution of pituitary pathology as more complex and persistent than previously described. Patient A had enlarged pituitary gland (pituitary height: 9-10 mm), demonstrated by serial MRI carried out from age 5 to 8.5 yr, small pituitary gland (4 mm) at age 10 yr and pituitary enlargement (11 mm) at age 19 yr. Patient B had a pituitary gland of normal size at age 7 yr (5 mm), whereas at age 14.3 and 16.3 yr, an enlarged pituitary gland was disclosed (10 and 11 mm, respectively). Both series of events are suggestive of a persistent pathophysiological mechanism in the pituitary gland of patients with PROP1 gene defects. Therefore, long-term pituitary follow-up by MRI in such patients may be necessary even in the case of a small or normal pituitary gland. It must be noted that current data from the Ames dwarf mouse cannot fully explain the observed pituitary size fluctuation.

Toxicity and biodistribution of a first-generation recombinant adenoviral vector, in the presence of hydroxychloroquine, following retroductal delivery to a single rat submandibular gland

OBJECTIVE

We examined the toxicity and biodistribution associated with a single administration of a first-generation, serotype 5, adenoviral vector encoding human growth hormone (hGH; AdCMVhGH) to a single rat submandibular gland in the presence of hydroxychloroquine (HCQ). Previously, we showed that hGH is primarily secreted into saliva (approximately ninefold serum level) when expressed as a transgene in salivary glands (e.g. Baum et al, 1999), but administration of HCQ substantially increases the hGH levels secreted into the bloodstream (Hoque et al, 2001). A potential application of this observation is for patients with adult hGH deficiency.

METHODS

Six groups of male and female adult rats (n = 12 each) were studied, with zero to 1.5 x 10(11) particles of AdCMVhGH, +/-HCQ, administered retroductally. Multiple clinical and pathological parameters, as well as vector tissue distribution, were assessed.

RESULTS

All animals survived until the scheduled day of sacrifice, and essentially no untoward events were observed clinically or at gross necropsy. We observed no vector-related effects on clinical hematology evaluations and a single, transient significant change on clinical chemistry evaluations (increased serum globulin levels). Three days after AdCMVhGH administration, the vector distributed to all tissues analyzed with the exception of gonads and heart. By day 29, most organs, other than the targeted and contralateral submandibular glands, were negative for the presence of vector. On day 3, none of the animals tested positive for the presence of replication competent adenovirus in either their blood or saliva.

CONCLUSION

Salivary gland delivery of AdCMVhGH +/-HCQ appears associated with limited toxicity in rats.

Low serum insulin values in children with multiple lesions of granuloma annulare: a prospective study

BACKGROUND

The relationship between granuloma annularae (GA) and diabetes mellitus (DM) is controversial.

OBJECTIVE

To investigate the relationship between multiple lesions of GA and carbohydrate metabolism in children.

SUBJECTS AND METHODS

Fifteen children (seven boys, eight girls, mean age 4.8 years) with five or more lesions of GA were evaluated. A personal and family history of DM or other autoimmune diseases was obtained and the glycaemic and insulin response during an oral glucose tolerance test (OGTT) was determined. Thirteen children with a negative personal and family history of DM served as controls for the OGTT and 100 other children as 'clinical controls'.

RESULTS

At the 30-min sampling of the OGTT the mean insulin values were comparable in GA children and controls (P=0.1), while the mean glucose values were significantly higher in GA children than in controls (P=0.005). All other insulin values during the OGTT were significantly lower in GA children than in controls, while all other glucose values were comparable in GA children and controls with all indices applied. Eleven out of 15 GA children had a positive family history of DM (73.3% vs. 16% of the clinical controls; P<0.0001).

CONCLUSION

Multiple lesions of GA in children are associated with significantly lower serum insulin values than in controls and mildly impaired glucose tolerance.

A pleiomorphic GH pituitary adenoma from a Carney complex patient displays universal allelic loss at the protein kinase A regulatory subunit 1A (PRKARIA) locus

Carney complex (CNC) is a familial multiple endocrine neoplasia syndrome associated with GH-producing pituitary tumours and transmitted as an autosomal dominant trait. Mutations of the PRKAR1A gene are responsible for approximately half the known CNC cases but have never found in sporadic pituitary tumours. Pituitary tissue was obtained from an acromegalic CNC patient heterozygote for a common (PRKARIA)i-inactivating mutation. Both immunohistochemistry and electron microscopy showed a highly pleiomorphic pituitary adenoma. The cell culture population appeared morphologically heterogeneous and remained so after more than 30 passages. The mixture was comprised of cells strongly immunostained for GH, spindle-shaped myofibroblast-like cells, and cuboid cells with large axonal projections (negative for GH). The population appeared to have both epithelial and mesenchymal cells. Both at baseline and at passage 30, cytogenetic analysis indicated the presence of normal 46, XY diploid karyotype, whereas losses of the PRKARIA(i) locus were demonstrated in more than 98% of the cells by fluorescent in situ hybridisation, supporting this gene's involvement in pituitary tumorigenesis. Allelic loss may have occurred in a single precursor cell type that differentiated and clonally expanded into several phenotypes. Epithelial-to-mesenchymal transition may also occur in CNC-associated pleiomorphic pituitary adenomas.

Protein kinase A and its role in human neoplasia: the Carney complex paradigm

The type 1 alpha regulatory subunit (R1alpha) of cAMP-dependent protein kinase A (PKA) (PRKAR1A) is an important regulator of the serine-threonine kinase activity catalyzed by the PKA holoenzyme. Carney complex (CNC) describes the association 'of spotty skin pigmentation, myxomas, and endocrine overactivity'; CNC is in essence the latest form of multiple endocrine neoplasia to be described and affects the pituitary, thyroid, adrenal and gonadal glands. Primary pigmented nodular adrenocortical disease (PPNAD), a micronodular form of bilateral adrenal hyperplasia that causes a unique, inherited form of Cushing syndrome, is also the most common endocrine manifestation of CNC. CNC and PPNAD are genetically heterogeneous but one of the responsible genes is PRKAR1A, at least for those families that map to 17q22-24 (the chromosomal region that harbors PRKAR1A). CNC and/or PPNAD are the first human diseases to be caused by mutations in one of the subunits of the PKA holoenzyme. Despite the extensive literature on R1alpha and PKA, little is known about their potential involvement in cell cycle regulation, growth and/or proliferation. The presence of inactivating germline mutations and the loss of its wild-type allele in CNC lesions indicated that PRKAR1A could function as a tumor-suppressor gene in these tissues. However, there are conflicting data in the literature about PRKAR1A's role in human neoplasms, cancer cell lines and animal models. In this report, we review briefly the genetics of CNC and focus on the involvement of PRKAR1A in human tumorigenesis in an effort to reconcile the often diametrically opposite reports on R1alpha.

Rapamycin control of exocrine protein levels in saliva after adenoviral vector-mediated gene transfer

Transgene-encoded therapeutic secretory proteins can be efficiently secreted from salivary glands into saliva or the bloodstream after adenoviral (Ad)-mediated gene transfer. Since transgene expression from conventional vectors is typically unregulated, we evaluated the rapamycin-based dimerizer regulation system for control of transgene expression in, and consequent exocrine protein secreted from, rat salivary glands. We used human growth hormone (hGH) as a surrogate exocrine secretory protein. Two Ad vectors, Ad C4ZF3, encoding activation and DNA binding domain fusion polypeptides, and Ad Z12-I-GH-2, encoding hGH, were constructed and shown useful in vitro. Thereafter, both vectors were delivered into submandibular glands by retroductal infusion. After 24 h, rapamycin (0, 1, 3 or 10 mg/kg) was administered, and 20 h later hGH levels in saliva were determined. Salivary hGH levels were rapamycin concentration dependent. At a rapamycin dose of 10 mg/kg, total salivary hGH was 693+/-197 ng and the hGH concentration in saliva was 4.6+/-1.3 microg/ml. Over a 16-day experimental period, three separate administrations of rapamycin (3 mg/kg) induced distinct elevations of salivary hGH (approximately 100-200 ng total hGH) that were entirely rapamycin dependent. This study demonstrates for the first time pharmacological control of transgenic exocrine protein production and presence in saliva after salivary gland gene transfer, and the potential for its application to the management of oral, oropharyngeal and upper gastrointestinal tract disorders.

Human growth hormone and gonadotropin releasing hormone analog combination therapy increases predicted height in short normal girls

The "short normal" child constitutes a real challenge for the pediatric endocrinologist. In a subgroup of short normal children, puberty starts at a normal age but with low height, and hence, the final height is expected to be quite compromised. Efforts to improve the outcome in this group have been made in the past with equivocal results. We present the growth data of 8 short girls with normal growth hormone values on provocative testing and low height at puberty initiation. At intervention the height and the stage of puberty were 129.3 +/- 5 cm and II to III, respectively, and the predicted height was 148.8 +/- 2.6 cm. Gonadotropin releasing hormone analog, triptorelin (3.6 +/- 0.5 microg/kg/day) and growth hormone (0.5 IU/kg/week) were used in different sequential order and simultaneously in each child. The mean total treatment period was 47.6 +/- 11.2 months. The mean predicted and the mean final height in the total group were 148.8 +/- 2.6 and 154.5 +/- 3.6 cm, respectively (p:0.028). The final height did not differ from the target height (154.8 +/- 8 cm versus 154.5 +/- 3.6 cm), while in 4 children, the final height was greater than the target height. The height gain (delta Final height - Predicted height) was 5.7 +/- 1.3 cm. If we analyze separately the girls in whom growth hormone was started first and gonadotropin releasing hormone analog followed versus those who started the analog first, the delta Final height - Predicted height was 8 +/- 3 cm in the former and 4.8 +/- 3.1 cm in the latter (p:0.03). It seemed that the difference was accounted for by duration of growth hormone therapy (51.3 +/- 10.6 months versus 28.6 +/- 10.6 months) (p:0.026), rather than by other factors. In conclusion, under the conditions of the present study, the combination of puberty arrest and growth hormone therapy significantly improved predicted height. The most significant determinant of the height gain was the duration of growth hormone therapy.

Early growth, pubertal development, body mass index and final height of patients with congenital adrenal hyperplasia: factors influencing the outcome

OBJECTIVE

The management of children with congenital adrenal hyperplasia (CAH) remains a challenge, especially with regard to growth potentials. The objective of our analysis was to uncover the factors that influence the growth and final height of patients with CAH.

DESIGN

The linear growth pattern and body mass index (BMI) at different developmental stages (birth to 2 years, 2 years to puberty initiation and puberty initiation to final height) and the final height achieved were analysed retrospectively in 48 patients with 21-hydroxylase deficiency; 17 with the salt-wasting (SW) form, 25 with the simple virilizing (SV) and six with the nonclassical (NC) form.

RESULTS

Mean final height (FH) and FH-SDS were, respectively, 170.8 +/- 5.6 m and -0.57 +/- 0.8 in males and 156.7 +/- 6 cm and -0.61 +/- 1 in females with the SW form, 166.1 +/- 6.1 cm and -1.05 +/- 1 in males and 151.6 +/- 5.4 cm and -1.4 +/- 1 in females with the SV form and 159.7 +/- 6.9 cm and 0.3 +/- 1.4 in females with the NC form. In subjects with the SW form, height SDS at 2 years, at puberty initiation and at FH were -0.18 +/- 0.9, 0.11 +/- 1.28 and -0.6 +/- 1.0, respectively. FH achieved was not different from target height (TH) in the SW group, but it was significantly lower than TH in the SV group (P = 0.003). FH in the SW group showed a positive correlation to the height achieved at 2 years of age (r = 0.68, P = 0.019), and height at 2 years was negatively related to the hydrocortisone dose in the birth to 2-year period (r = -0.79, P = 0.011). FH showed no correlation to hydrocortisone dose at any of the three developmental periods studied. BMI-SDS were not different in the various forms of CAH and showed no correlation to FH or hydrocortisone dose. Age at menarche was comparable to that in our general population.

CONCLUSIONS

Under our conditions of management, the final height of patients with the salt-wasting form was comparable to the target height and to the most favourable literature data. The patients with the simple virilizing form fare less well, mainly due to delayed diagnosis and consequent advancement of bone age and early puberty. In salt-wasting patients, height at 2 years is comparable to normals, it is influenced by the hydrocortisone dose and is related to the final height. Some height is lost during puberty. Hence, monitoring treatment over the first 2 years and during puberty is critical for the outcome in these patients.

Insufficient adrenarche in patients with combined pituitary hormone deficiency caused by a PROP-1 gene defect

Adrenarche was evaluated in five patients, aged 17.4 +/- 3 years, with combined pituitary hormone deficiency (CPHD), caused by a PROP-1 gene defect. Adrenocorticotrophic hormone (ACTH), cortisol and dehydroepiandrosterone sulfate (DHEAS) were determined prior to and following the administration of corticotropin-releasing hormone (CRH) in four of the five patients, while only basal values of ACTH, cortisol and DHEAS were determined in the fifth. In the four patients in whom a CRH test was carried out, the mean basal values of cortisol, ACTH and DHEAS were 289 +/- 140 nmol/l, 4.5 +/- 1.7 pmol/l and 0.26 +/- 0.36 micromol/l, respectively. The corresponding post-CRH peak values were 584 +/- 204 nmol/l, 12.7 +/- 3.9 pmol/l and 0.43 +/- 0.41 micromol/l. In the fifth patient, basal ACTH, cortisol and DHEAS values were 4 pmol/l, 411 nmol/l, and 2.33 micromol/l, respectively. Thus the basal and post CRH values of DHEAS (a marker of adrenarche) were low for age, while basal and post-CRH cortisol and ACTH values were within normal limits. For the interpretation of these findings two hypotheses can be proposed: 1) The PROP-1 gene is only expressed in the pituitary, and the role of PROP-1 is related to the maturation of the cells which synthesize the presumed adrenal androgen stimulating hormone (AASH). 2) The PROP-1 gene is also expressed in the adrenal cortex and, when defective, the zona reticularis does not function appropriately. Regardless of the interpretation

"White coat hypertension" in adolescents: increased values of urinary cortisol and endothelin

OBJECTIVE

To investigate whether "white coat hypertension" (WCH) in adolescents is an innocent phenomenon or is associated with early changes of the vascular system and/or increased stress response, reflected in the urinary endothelin and cortisol values, respectively.

STUDY DESIGN

The study group included 36 subjects, 14 with WCH (8 males and 6 females) aged 12.9 +/- 3 years and 22 normotensive control subjects (12 males and 10 females) aged 13 +/- 3.5 years. WCH was defined as systolic and/or diastolic blood pressure (BP) > or =95th percentile for age, sex, and height and with reported normal BP measurements at home. Urinary endothelin (UET1), urinary free cortisol (UFC), and plasma renin levels were determined by radioimmunoassay; and urinary albumin levels were determined by nephelometry. For statistical analysis, the Mann Whitney U test, Spearman correlation coefficient, and multivariate analysis of variance/multivariate analysis of covariance were used, as applicable.

RESULTS

The 24-hour values of UET1 and UFC were greater in male subjects with WCH than in male control subjects (P =.02), whereas no such difference was found in female subjects. The difference in UFC values in male subjects was accounted for by the day values. In subjects with WCH, and not in control subjects, a positive correlation of UET1 to UFC (r = 0.59, P =.027), diastolic BP (r = 0.55, P =.04), and mean BP (r = 0.65, P =.012) was detected.

CONCLUSIONS

Our data indicate that WCH in adolescence may not be an innocent phenomenon and may represent a prelude to permanent idiopathic hypertension of adulthood.