Understanding of self-harm behaviour in adolescents

Introduction

The incidence and prevalence of self-harm behaviour, with or without suicidal intent, is on the rise, both in other countries as well as in Croatia. Understanding the nature of patients who show self-harm behaviour can help us to better understand the components that contribute to their morbidity and mortality.

Objectives

To expand the understanding of self-harm behaviour in adolescents as a contribution to the planning and implementation of preventive and curative programs.

Aims

To explore the psychopathological characteristics of adolescents with and without self-harm behaviour who seek psychiatric help for their mental health problems.

Methods

In this study participated 150 adolescents, aged 14–18 years, of which 52% showed some form of self-harm behaviour. During the initial examination of child and adolescent psychiatrist, participants completed self-reported questionnaires: functional assessment of self-mutilation (FASM, 1997) and the youth self report (YSR, 2001).

Results

Statistically significant difference between groups of female adolescents with and without self-harm behaviour was observed in all of eight problem scales, while in male adolescents it was observed in five of them. This indicates considerably higher level of psychopathological features in the group of patients with self-harm behaviour.

Conclusions

It is necessary to intensify monitoring of adolescents who show self-harm behaviour because of the overall level of psychopathological symptoms and the comorbidity which significantly complicates the therapeutic process. It is particularly important to continuously assess the suicide risk.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Glial cell line-derived neurotrophic factor is essential for neuronal survival in the locus coeruleus–hippocampal noradrenergic pathway

It has been shown that the noradrenergic (NE) locus coeruleus (LC)-hippocampal pathway plays an important role in learning and memory processing, and that the development of this transmitter pathway is influenced by neurotrophic factors. Although some of these factors have been discovered, the regulatory mechanisms for this developmental event have not been fully elucidated. Glial cell line-derived neurotrophic factor (GDNF) is a potent neurotrophic factor influencing LC-NE neurons. We have utilized a GDNF knockout animal model to explore its function on the LC-NE transmitter system during development, particularly with respect to target innervation. By transplanting various combinations of brainstem (including LC) and hippocampal tissues from wildtype or GDNF knockout fetuses into the brains of adult wildtype mice, we demonstrate that normal postnatal development of brainstem LC-NE neurons is disrupted as a result of the GDNF null mutation. Tyrosine hydroxylase immunohistochemistry revealed that brainstem grafts had markedly reduced number and size of LC neurons in transplants from knockout fetuses. NE fiber innervation into the hippocampal co-transplant from an adjacent brainstem graft was also influenced by the presence of GDNF, with a significantly more robust innervation observed in transplants from wildtype fetuses. The most successful LC/hippocampal co-grafts were generated from fetuses expressing the wildtype GDNF background, whereas the most severely affected transplants were derived from double transplants from null-mutated fetuses. Our data suggest that development of the NE LC-hippocampal pathway is dependent on the presence of GDNF, most likely through a target-derived neurotrophic function.

Distinct roles for GFRalpha1 and GFRalpha2 signalling in different cranial parasympathetic ganglia in vivo

Neurturin (NRTN), signalling via the GDNF family receptor alpha2 (GFRalpha2) and Ret tyrosine kinase, has recently been identified as an essential target-derived factor for many parasympathetic neurons. NRTN is expressed in salivary and lacrimal glands, while GFRalpha2 and Ret are expressed in the corresponding submandibular, otic and sphenopalatine ganglia. Here, we have characterized in more detail the role of GDNF and NRTN signalling in the development of cranial parasympathetic neurons and their target innervation. Gfra1 mRNA was expressed at E12 but not in newborn cranial parasympathetic ganglia, while Gfra2 mRNA and protein were strongly expressed in newborn and adult cranial parasympathetic neurons and their projections, respectively. In newborn GFRalpha1- or Ret-deficient mice, where many submandibular ganglion neurons were still present, the otic and sphenopalatine ganglia were completely missing. In contrast, in newborn GFRalpha2-deficient mice, most neurons in all these ganglia were present. In these mice, the loss and atrophy of the submandibular and otic neurons were amplified postnatally, accompanied by complete loss of innervation in some target regions and preservation in others. Surprisingly, GFRalpha2-deficient sphenopalatine neurons, whose targets were completely uninnervated, were not reduced in number and only slightly atrophied. Thus, GDNF signalling via GFRalpha1/Ret is essential in the early gangliogenesis of some, but not all, cranial parasympathetic neurons, whereas NRTN signalling through GFRalpha2/Ret is essential for the development and maintenance of parasympathetic target innervation. These results indicate that GDNF and NRTN have distinct functions in developing parasympathetic neurons, and suggest heterogeneity among and within different parasympathetic ganglia.

Role of retinoids in the CNS: differential expression of retinoid binding proteins and receptors and evidence for presence of retinoic acid

Retinoic acid (RA), a retinoid metabolite, acts as a gene regulator via ligand-activated transcription factors, known as retinoic acid receptors (RARs) and retinoid X receptors (RXRs), both existing in three different subtypes, alpha, beta and gamma. In the intracellular regulation of retinoids, four binding proteins have been implicated: cellular retinol binding protein (CRBP) types I and II and cellular retinoic acid binding protein (CRABP) types I and II. We have used in situ hybridization to localize mRNA species encoding CRBP- and CRABP I and II as well as all the different nuclear receptors in the developing and adult rat and mouse central nervous system (CNS), an assay to investigate the possible presence of RA, and immunohistochemistry to also analyse CRBP I- and CRABP immunoreactivity (IR). RXRbeta is found in most areas while RARalpha and -beta and RXRalpha and -gamma show much more restricted patterns of expression. RARalpha is found in cortex and hippocampus and RARbeta and RXRgamma are both highly expressed in the dopamine-innervated areas caudate/putamen, nucleus accumbens and olfactory tubercle. RARgamma could not be detected in any part of the CNS. Using an in vitro reporter assay, we found high levels of RA in the developing striatum. The caudate/putamen of the developing brain showed strong CRBP I-IR in a compartmentalized manner, while at the same time containing many evenly distributed CRABP I-IR neurons. The CRBP I- and CRABP I-IR patterns were closely paralleled by the presence of the corresponding transcripts. The specific expression pattern of retinoid-binding proteins and nuclear retinoid receptors as well as the presence of RA in striatum suggests that retinoids are important in many brain structures and emphasizes a role for retinoids in gene regulatory events in postnatal and adult striatum.

Molecular pathology of hemangiopericytomas accompanied by severe hypoglycemia: oncogenes, tumor-suppressor genes and the insulin-like growth factor family

Relatively little is known about molecular genetic events that participate in the genesis and progression of hemangiopericytoma. In this study, we describe two cases of hemangiopericytoma accompanied by severe hypoglycemia. Tumor cells from patient 1 exhibited insulin-growth factor I (IGF I) and insulin-like growth factor I receptor (IGF IR) mRNA transcripts. Tumor cells from patient 2 exhibited IGF II, IGF IR and IGF binding proteins 1-3 mRNA. Serum from patient 2 contained IGF II, mostly in a large molecular form ("big" IGF II); the IGF II level did not change after the tumor removal. The presence of IGF IR in tumor cells was confirmed by immunoprecipitation with antibodies that recognize human IGF IR subunit (visualized as a 460-kDa band). The hemangiopericytoma cells derived from patient 1 expressed 210000 IGF I receptors/cell. Specific binding of IGF I to the tumor cell membrane fraction was higher in tissue from patient 1, while the tissue of patient 2 showed relatively low IGF I binding. In contrast, IGF II binding was much higher in tissue from patient 2. Both tumor tissues showed positive immunostaining for c-Jun; one tumor showed strong immunostaining for c-Myc, H-Ras and p53, while the other exhibited strong reaction with H-Ras antibodies only. No loss of the heterozygosity at the genes APC, NFI and nm23-H1 loci in tumor tissue obtained from patient 1 was found. In effect, our results suggest multiple molecular genetic changes in hemangiopericytoma -- activation of some oncogenes and the IGF growth factor family. IGF ligands together with IGF IR could be responsible for hypoglycemia and perhaps the transformed phenotype.

GFRalpha-3, a protein related to GFRalpha-1, is expressed in developing peripheral neurons and ensheathing cells

We report here the identification of a gene, termed GFRalpha-3 (glial cell line-derived neurotrophic factor family receptor alpha-3), related to GFRalpha-1 and GFRalpha-2 (also known as GDNFR-alpha and GDNFR-beta), and describe distribution of GDNFalpha-3 in the nervous system and other parts of the mouse body during development and in the adult. GFRalpha-3 in situ hybridization signals were found mainly in the peripheral nervous system, with prominent signals in developing dorsal root and trigeminal ganglia. Sympathetic ganglia were also positive. Developing nerves manifested strong GFRalpha-3 mRNA signals, presumably generated by the Schwann cells. Olfactory ensheathing cells were also positive. Other non-neuronal cells appearing positive during development included chromaffin cells in the adrenal gland and small clusters of cells in the intestinal epithelium. In the central nervous system no robust signals could be detected at any stage investigated with the present probes. Compared with the previously described GFRalpha-1 and GFRalpha-2 mRNAs, which are widely distributed in the central nervous system and peripheral organs, the expression of GFRalpha-3 mRNA is much more restricted. The prominent expression in Schwann cells during development suggests a key role for GFRalpha-3 in the development of the peripheral nervous system. As Schwann cells are known to lack expression of the transducing RET receptor, we propose that a possible function of GFRalpha-3 during development could be to bind Schwann cell-derived GDNF-like ligands, thus presenting such molecules to growing axons.

Neurturin and glial cell line-derived neurotrophic factor receptor-beta (GDNFR-beta), novel proteins related to GDNF and GDNFR-alpha with specific cellular patterns of expression suggesting roles in the developing and adult nervous system and in peripheral organs

Cloning strategies were used to identify a gene termed glial cell line-derived neurotrophic factor receptor-beta (GDNFR-beta) related to GDNFR-alpha. In situ hybridization was then used to map cellular expression of the GDNF-related trophic factor neurturin (NTN) and GDNFR-beta mRNA in developing and adult mice, and comparisons with GDNFR-alpha and RET were made. Neurturin is expressed in postnatal cerebral cortex, striatum, several brainstem areas, and the pineal gland. GDNFR-beta mRNA was more widely expressed in the developing and adult CNS, including cerebral cortex, cerebellum, thalamus, zona incerta, hypothalamus, brainstem, and spinal cord, and in subpopulations of sensory neurons and developing peripheral nerves. NTN colocalized with RET and GDNFR-alpha in ureteric buds of the developing kidney. The circular muscle layer of the developing intestines, smooth muscle of the urether, and developing bronchiolae also expressed NTN. GDNFR-beta was found in myenteric but not submucosal intestinal plexuses. In developing salivary glands NTN had an epithelial expression, whereas GDNFR-beta was expressed in surrounding tissue. Neurturin and GDNFR-beta were present in developing sensory organs. In the gonads, NTN appeared to be expressed in Sertoli cells and in the epithelium of the oviduct, whereas GDNFR-beta was expressed by the germ cell line. Our findings suggest multiple roles for NTN and GDNFR-beta in the developing and adult organism. Although NTN and GDNFR-beta expression patterns are sometimes complementary, this is not always the case, suggesting multiple modi operandi of GDNF and NTN in relation to RET and the two binding proteins, GDNFR-alpha and GDNFR-beta.

Cellular and developmental patterns of expression of Ret and glial cell line-derived neurotrophic factor receptor alpha mRNAs

Glial cell line-derived neurotrophic factor (GDNF) has recently been shown to signal by binding to GDNF receptor-alpha (GDNFR-alpha), after which the GDNF-GDNFR-alpha associates with and activates the tyrosine kinase receptor Ret. We have localized Ret messenger RNA (mRNA) in the developing and adult rodent and compared with to the expression of GDNF and GDNFR-alpha mRNA. Ret mRNA is strongly expressed in dopamine neurons and alpha-motor neurons as well as in thalamus, ruber and occluomotor nuclei, the habenular complex, septum, cerebellum, and brain stem nuclei. Ret mRNA was also found in several sensory systems, in ganglia, and in nonneuronal tissues such as teeth and vibrissae. Very strong Ret mRNA signals are present in kidney and the gastrointestinal tract, where Ret and GDNF mRNA expression patterns are precisely complementary. The presence of Ret protein was confirmed in adult dopamine neurons using immunohistochemistry. GDNFR-alpha mRNA was strongly expressed in the developing and adult dopamine neurons. It was also found in neurons in deep layers of cortex cerebri, in hippocampus, septum, the dentate gyrus, tectum, and the developing spinal cord. In the kidney and the gastrointestinal tract, GDNFR-alpha mRNA and Ret mRNA distribution overlapped. Dorsal root ganglia, cranial ganglia, and developing peripheral nerves were also positive. GDNFR-alpha was additionally found in sensory areas and in developing teeth. Sensory areas included inner ear, eye, olfactory epithelium, and the vomeronasal organ, as well as developing tongue papillae. The temporospatial pattern of expression of GDNFR-alpha mRNA did not always match that of Ret mRNA. For instance, GDNFR-alpha mRNA was also found in the developing ventral striatum, including the olfactory tubercle, and in hippocampus. These areas seemed devoid of Ret mRNA, suggesting that GDNFR-alpha might also have functions unrelated to Ret.

Habrec1, a novel serine/threonine kinase TGF-beta type I-like receptor, has a specific cellular expression suggesting function in the developing organism and adult brain

Members of the TGF-beta superfamily signal through a dual receptor system consisting of a type II receptor protein kinase that binds the ligand, after which this complex associates with a type I receptor to mediate intracellular signaling. In mammals, six type I and five type II receptors mediating responses to different TGF-beta family members have been identified to date. Using primers from conserved regions of the protein kinase domain of the serine/threonine kinase receptors in a low-stringency polymerase chain reaction-based screening procedure, and deselecting known receptors with colony hybridization, we now report cloning a novel receptor member. The novel receptor was found in a cDNA library prepared from the habenular nucleus area and was designated Habrec1. Although only a partial sequence is available, it fits the criteria for a TGF-beta type I serine/threonine kinase receptor. In situ hybridization of Habrec1 reveals mRNA expression in several distinct areas of the developing central nervous system, including cortex cerebri, cerebellum, hippocampus, striatum, and thalamic nuclei. Expression is also seen in the anterior pituitary. In the periphery, strong expression prenatally includes brown fat, the gastrointestinal tract, liver, pancreas, thymus, and nasal cavity epithelium. In the adult brain Habrec1 mRNA is prominently found in cerebellum, cortex cerebri, and striatum, but at lower levels in several additional areas. We conclude that Habrec1 is a member of the TGF-beta type I receptor family with expression patterns in the developing animal, suggesting specific functions in and outside the nervous system, and in the adult CNS, suggesting roles in both cortical and subcortical brain circuitry.

Cellular expression of GDNF mRNA suggests multiple functions inside and outside the nervous system

Glial-cell-line-derived neurotrophic factor (GDNF) is a distant member of the transforming growth factor-beta family and has potent neurotrophic effects on several classes of neurons including dopamine neurons and motoneurons. Here, we have used in situ hybridization to describe the development of the cellular expression of GDNF mRNA pre- and postnatally. Consistent with dopaminotrophic activity, GDNF mRNA is expressed in the developing basal ganglia and the olfactory tubercle. It is also found in a thalamic nucleus, in neurons of the substantia innominata, in the developing Purkinje neurons and the developing locus coeruleus area, and in trigeminal brainstem nuclei. In the spinal cord, neuronal expression is found in Clarke's column. GDNF mRNA is also expressed in the dorsal horns during development. Additional GDNF mRNA expression in the head region includes the carotid body, the retina, the vibrissae, the inner ear, the ear canal, and epithelium in the nasal cavity. Prominent expression is also found in the developing teeth. The widespread expression of GDNF in developing skeletal muscle is consistent with trophic activity on alpha-motoneurons. The smooth muscle layers of the gastrointestinal tract are also strongly positive. A very strong signal is found in the outer mesenchyme of the developing metanephric kidney. We conclude that GDNF mRNA is expressed in many different cellular systems inside and outside the central nervous system during development, suggesting multiple functions of GDNF in the developing organism.

Retrograde axonal transport of glial cell line-derived neurotrophic factor in the adult nigrostriatal system suggests a trophic role in the adult

The recently cloned, distant member of the transforming growth factor beta (TGF-beta) family, glial cell line-derived neurotrophic factor (GDNF), has potent trophic actions on fetal mesencephalic dopamine neurons. GDNF also has protective and restorative activity on adult mesencephalic dopaminergic neurons and potently protects motoneurons from axotomy-induced cell death. However, evidence for a role for endogenous GDNF as a target-derived trophic factor in adult midbrain dopaminergic circuits requires documentation of specific transport from the sites of synthesis in the target areas to the nerve cell bodies themselves. Here, we demonstrate that GDNF is retrogradely transported by mesencephalic dopamine neurons of the nigrostriatal pathway. The pattern of retrograde transport following intrastriatal injections indicates that there may be subpopulations of neurons that are GDNF responsive. Retrograde axonal transport of biologically active 125I-labeled GDNF was inhibited by an excess of unlabeled GDNF but not by an excess of cytochrome c. Specificity was further documented by demonstrating that another TGF-beta family member, TGF-beta 1, did not appear to affect retrograde transport. Retrograde transport was also demonstrated by immunohistochemistry by using intrastriatal injections of unlabeled GDNF. GDNF immunoreactivity was found specifically in dopamine nerve cell bodies of the substantia nigra pars compacta distributed in granules in the soma and proximal dendrites. Our data implicate a specific receptor-mediated uptake mechanism operating in the adult. Taken together, the present findings suggest that GDNF acts endogenously as a target-derived physiological survival/maintenance factor for dopaminergic neurons.

Glial cell line-derived neurotrophic factor stimulates fiber formation and survival in cultured neurons from peripheral autonomic ganglia

Human recombinant glial cell line-derived neurotrophic factor (GDNF) was tested for its ability to stimulate fiber formation and neuron survival in primary cultures of peripheral ganglia dissected from the chicken embryo. GDNF, first characterized by its actions on central nervous system (CNS) neurons, had a marked stimulatory effect on fiber outgrowth in sympathetic and ciliary ganglia. Weaker responses were evoked in sensory spinal and nodose ganglia and in the ganglion of Remak. In addition, survival of neurons from the sympathetic and ciliary ganglia was stimulated by GDNF at 50 ng/ml. The effects were not mimicked by the distant but related protein transforming growth factor beta 1 (TGF beta 1). The profile of neurons stimulated by GDNF is also distinct from the patterns of stimulation shown by nerve growth factor (NGF), stimulating strongly sympathetic but not ciliary ganglia, and ciliary neurotrophic factor (CNTF), stimulating mainly the ciliary ganglion. Moreover, using in situ hybridization histochemistry, GDNF was demonstrated to be present in the pineal gland in the newborn rat, a target organ for sympathetic innervation. The present results suggest that GDNF is likely to act upon receptors present in several autonomic and sensory neuronal populations. GDNF may serve to support fiber outgrowth and cell survival in peripheral ganglia, adding yet one more trophic factor to the list of specific proteins controlling development and maintenance of the peripheral nervous system.

Protection and repair of the nigrostriatal dopaminergic system by GDNF in vivo

Glial-cell-line-derived neurotrophic factor (GDNF), a recently cloned new member of the transforming growth factor-beta superfamily, promotes survival of cultured fetal mesencephalic dopamine neurons and is expressed in the developing striatum. There have, however, been no reports about effects of GDNF in situ. We have used the dopaminergic neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), which produces parkinsonian symptoms in man, to determine whether GDNF might exert protective or regenerative effects in vivo in the adult nigrostriatal dopamine system in C57/B1 mice. GDNF injected over the substantia nigra or in striatum before MPTP potently protects the dopamine system, as shown by numbers of mesencephalic dopamine nerve cell bodies, dopamine nerve terminal densities and dopamine levels. When GDNF is given after MPTP, dopamine levels and fibre densities are significantly restored. In both cases, motor behaviour is increased above normal levels. We conclude that intracerebral GDNF administration exerts both protective and reparative effects on the nigrostriatal dopamine system, which may have implications for the development of new treatment strategies for Parkinson's disease.

Glial cell-line derived neurotrophic factor (GDNF) mRNA upregulation in striatum and cortical areas after pilocarpine-induced status epilepticus in rats

Glial cell-line derived neurotrophic factor (GDNF) has recently been cloned and shown to have trophic effects on dopaminergic nigral neurons. However, GDNF mRNA has not been detected in striatum or other forebrain areas of adult rat. Using limbic motor status epilepticus induced by pilocarpine to activate neurons in motor and limbic areas, we now demonstrate GDNF mRNA signals in the striatum, hippocampus and cortex using in situ hybridisation. The finding of GDNF mRNA in the stimulated striatum opens the possibility that GDNF may be a target-derived, trophic factor in the nigro-striatal system. This expression of GDNF mRNA may be linked to excitatory cortical input. Increases in GDNF mRNA after status epilepticus in hippocampus and neocortex indicate additional roles for GDNF.

Glial cell line-derived neurotrophic factor is expressed in the developing but not adult striatum and stimulates developing dopamine neurons in vivo

The potential role of glial cell line-derived neurotrophic factor (GDNF) as a trophic molecule for midbrain dopamine neurons was examined using two different approaches: in situ hybridization and intraocular transplantation. The presence of mRNA for GDNF was noted in striatal and ventral limbic dopaminergic target areas in the developing (E20-P7) rat, but not the adult rat. Signals were also found in nondopaminergic areas during maturation, such as the cerebellar anlage, spinal cord, and thalamus. Lesions of the nigrostriatal pathway in neonatal or adult rats, using 6-hydroxydopamine injected into the medial forebrain bundle, did not elicit upregulation of mRNA for GDNF. Grafts of fetal ventral mesencephalon in the anterior eye chamber were exposed to repeated injections of GDNF, which elicited a marked and dose-dependent increase in transplant volume. A low (0.1 microgram/eye) and high (1 microgram/eye) dose of GDNF both led to a somewhat larger mean area of dopamine fiber outgrowth into host irides. In the transplants, cell counts of tyrosine hydroxylase (TH)-immunoreactive neurons revealed a doubling of cell numbers in the low-dose group and about four times as many cells in the high-GDNF-dose group compared to controls. Moreover, the density of TH-immunoreactive nerve fibers was markedly and significantly higher in transplants treated with the high GDNF dose. Since the volumes of these transplants were also larger, the total amount of both TH-positive cells and TH-positive nerve fibers was many-fold greater in the high-GDNF group than that in the controls. Taken together, these data support the concept that GDNF functions as a dopaminotrophic factor in vivo.