Control of nutrient stress-induced metabolic reprogramming by PKCζ in tumorigenesis.

Tumor cells have high-energetic and anabolic needs and are known to adapt their metabolism to be able to survive and keep proliferating under conditions of nutrient stress. We show that PKCζ deficiency promotes the plasticity necessary for cancer cells to reprogram their metabolism to utilize glutamine through the serine biosynthetic pathway in the absence of glucose. PKCζ represses the expression of two key enzymes of the pathway, PHGDH and PSAT1, and phosphorylates PHGDH at key residues to inhibit its enzymatic activity. Interestingly, the loss of PKCζ in mice results in enhanced intestinal tumorigenesis and increased levels of these two metabolic enzymes, whereas patients with low levels of PKCζ have a poor prognosis. Furthermore, PKCζ and caspase-3 activities are correlated with PHGDH levels in human intestinal tumors. Taken together, this demonstrates that PKCζ is a critical metabolic tumor suppressor in mouse and human cancer.

Growth, puberty and testicular function in boys born small for gestational age with a nonspecific disorder of sex development.

OBJECTIVE: Being born small for gestational age (SGA) is frequently associated with unexplained disorders of sex development (nonspecific DSD) in boys. Little is known about their future growth, puberty and testicular function. Our objective is to determine the long-term endocrine outcome of boys born SGA who have a nonspecific DSD. DESIGN: Boys with a nonspecific DSD born SGA and appropriate for GA (AGA) were retrieved through the International Disorders of Sex Development registry and retrospective data collected, based on a spreadsheet containing 102 items. PATIENTS AND MEASUREMENTS: In total, 179 boys were included, of which 115 were born SGA and 64 were born AGA. Their growth and pubertal development were compared. Serum LH, FSH, testosterone, AMH and inhibin B levels in infancy and puberty were analysed to assess testicular function. RESULTS: At 2 years of age, 30% of SGA boys had incomplete or absent catch-up growth. Boys born SGA also had higher LH during minipuberty and lower testosterone in stimulation tests (p = 0.037 and 0.040, respectively), as compared to boys born AGA. No differences were observed in timing or course of puberty or end-pubertal hormone levels. CONCLUSIONS: Almost one out of three SGA boys with a nonspecific DSD experiences insufficient catch-up growth. In addition, our data suggest dysfunction of infantile Leydig cells or altered regulation of the hypothalamic-pituitary-gonadal axis in SGA boys during childhood. Sex steroid production during puberty seems unaffected.

Effects of the short stitch technique for midline abdominal closure on incisional hernia (ESTOIH): randomized clinical trial.

BACKGROUND: Incisional hernia remains a frequent problem after midline laparotomy. This study compared a short stitch to standard loop closure using an ultra-long-term absorbent elastic suture material. METHODS: A prospective, multicentre, parallel-group, double-blind, randomized, controlled superiority trial was designed for the elective setting. Adult patients were randomly assigned by computer-generated sequence to fascial closure using a short stitch (5 to 8 mm every 5 mm, USP 2-0, single thread HR 26 mm needle) or long stitch technique (10 mm every 10 mm, USP 1, double loop, HR 48 mm needle) with a poly-4-hydroxybutyrate-based suture material (Monomax®). Incisional hernia assessed by ultrasound 1 year after surgery was the primary outcome. RESULTS: The trial randomized 425 patients to short (n = 215) or long stitch technique (n = 210) of whom 414 (97.4 per cent) completed 1 year of follow-up. In the short stitch group, the fascia was closed with more stitches (46 (12 s.d.) versus 25 (7 s.d.); P < 0.001) and higher suture-to-wound length ratio (5.3 (2.2 s.d.) versus 4.0 (1.3 s.d.); P < 0.001). At 1 year, seven of 210 (3.3 per cent) patients in the short and 13 of 204 (6.4 per cent) patients in the long stitch group developed incisional hernia (odds ratio 1.97, 95 per cent confidence interval 0.77 to 5.05; P = 0.173). CONCLUSION: The 1-year incisional hernia development was relatively low with clinical but not statistical difference between short and long stitches. Registration number: NCT01965249 (http://www.clinicaltrials.gov).

Structure of a HOIP/E2~ubiquitin complex reveals RBR E3 ligase mechanism and regulation.

Ubiquitination is a central process affecting all facets of cellular signalling and function. A critical step in ubiquitination is the transfer of ubiquitin from an E2 ubiquitin-conjugating enzyme to a substrate or a growing ubiquitin chain, which is mediated by E3 ubiquitin ligases. RING-type E3 ligases typically facilitate the transfer of ubiquitin from the E2 directly to the substrate. The RING-between-RING (RBR) family of RING-type E3 ligases, however, breaks this paradigm by forming a covalent intermediate with ubiquitin similarly to HECT-type E3 ligases. The RBR family includes Parkin and HOIP, the central catalytic factor of the LUBAC (linear ubiquitin chain assembly complex). While structural insights into the RBR E3 ligases Parkin and HHARI in their overall auto-inhibited forms are available, no structures exist of intact fully active RBR E3 ligases or any of their complexes. Thus, the RBR mechanism of action has remained largely unknown. Here we present the first structure, to our knowledge, of the fully active human HOIP RBR in its transfer complex with an E2~ubiquitin conjugate, which elucidates the intricate nature of RBR E3 ligases. The active HOIP RBR adopts a conformation markedly different from that of auto-inhibited RBRs. HOIP RBR binds the E2~ubiquitin conjugate in an elongated fashion, with the E2 and E3 catalytic centres ideally aligned for ubiquitin transfer, which structurally both requires and enables a HECT-like mechanism. In addition, three distinct helix-IBR-fold motifs inherent to RBRs form ubiquitin-binding regions that engage the activated ubiquitin of the E2~ubiquitin conjugate and, surprisingly, an additional regulatory ubiquitin molecule. The features uncovered reveal critical states of the HOIP RBR E3 ligase cycle, and comparison with Parkin and HHARI suggests a general mechanism for RBR E3 ligases.

Adolescent and Young Adult Urogenital Outcome following Childhood Hypospadias Repair: Perfection Revisited.

PURPOSE: We assessed the long-term surgical, functional urinary and sexual outcomes of adolescent and young adult men who underwent childhood hypospadias repair. MATERIALS AND METHODS: Men born with nonsyndromic hypospadias and healthy male controls aged 16-21 years old were recruited, and their surgical, urinary, sexual functional and aesthetic outcomes assessed. Good outcome was defined as a patent and orthotopic meatus without fistulas, and straight erections (<30 degree curvature) without erectile or ejaculatory problems. Statistics included regression analyses, chi-square/Fisher exact tests and Student's t/Mann-Whitney U and Kruskal-Wallis tests. RESULTS: A total of 193 patients and 50 controls participated 16.4 years (range 8.2-21.2) after initial repair. At least 1 reintervention was performed in 39.2%. The highest reintervention rate was found in those younger than 12 months at initial repair, even when excluding proximal hypospadias cases. A disturbed urinary and/or suboptimal sexual functional outcome was seen in 52.9% of cases. Suboptimal voiding was found in 22.1%, although few had relevant residual urine. More reinterventions and proximal hypospadias cases were associated with suboptimal urinary outcome, and the latter also with impaired sexual function. Poor inter-observer agreements were found between physician and patient genital appraisal. CONCLUSIONS: In 52.9% of cases, at least 1 concern was identified that required long-term followup. Hypospadias repair below 12 months was associated with more reinterventions. Adopting a restrictive attitude toward aesthetic refinement, unless on the patient's own request, could improve urinary outcomes.

Rosetta Stone of NLR Innate Immunity.

The formation of NLR inflammasomes is a central step in the initiation of the innate immune response. Two recent publications describe the structure of the NAIP2-NLRC4 inflammasome and derive an elegant model of NLR inflammasome formation, whereby binding of the pathogen-molecule-bound NLR NAIP2 to NLRC4 leads to the activation of NLRC4 and initiation of self-propagating NLRC4 inflammasome formation.

Psychosexual Outcome, Sexual Function, and Long-Term Satisfaction of Adolescent and Young Adult Men After Childhood Hypospadias Repair.

BACKGROUND: The psychosexual outcome in adolescents and young adults (AYA) men born with hypospadias is precarious. However, the factors responsible for impaired outcome in some AYA men have been understudied. AIM: To explore the outcome after hypospadias repair in childhood of AYA men aged 16-21 years and examine their opinion and their parents' opinion about this type of surgery. METHODS: Cross-sectional assessment of 193 AYA men born with hypospadias and 50 male controls was performed. Questionnaires such as the Decision Regret Scale, Pediatric Penile Perception Score, Sexual Quality of Life-Male, International Index of Erectile Function, and a custom-made questionnaire were used. The Decision Regret Scale and a custom-made questionnaire were also completed by the participants' parents. Physical examination including Hypospadias Objective Penile Evaluation and measuring stretched penile length was performed. OUTCOMES: This study reports the psychosexual functioning (ie, social, relational, and sexual), erectile and sexual function after childhood hypospadias repair, using ad hoc measures. In addition, the opinion about hypospadias repair of patients and their parents is represented. RESULTS: The number of surgeries and satisfaction regarding penile appearance were the most important factors associated with the opinion on hypospadias repair and the psychosexual outcome. Most AYA men were more satisfied with their penile appearance than the physician. 80% of men were satisfied with having had a childhood hypospadias repair, even though they had not been able to consent to surgery themselves. Erectile and ejaculation problems were mild and seen in approximately 10% of the population. CLINICAL IMPLICATIONS: Based on our data, deferring hypospadias repair until the patient can decide himself is not warranted. However, physicians who accept a suboptimal esthetic outcome and withdraw from repeated surgery may contribute importantly to the patient's well-being, especially in proximal forms of hypospadias. STRENGTHS & LIMITATIONS: This is one of the rare studies addressing the AYA's psychosexual outcome after childhood hypospadias repair. Strengths include the combination of clinical and psychosexual data from a very large cohort of men and their parents to provide a more holistic view. By entering this study, participants might have a different comfort level regarding their sexuality or have a different body image than the overall population of young men. CONCLUSION: Uncomplicated hypospadias surgery results in equal psychosexual outcome as controls and in high satisfaction rates; multiple surgeries are a risk factor for poorer outcomes. 80% of men are satisfied with childhood hypospadias repair. Tack LJW, Springer A, Riedl S, et al. Psychosexual Outcome, Sexual Function, and Long-Term Satisfaction of Adolescent and Young Adult Men After Childhood Hypospadias Repair. J Sex Med 2020;17:1665-1675.

Functional analysis of novel desert hedgehog gene variants improves the clinical interpretation of genomic data and provides a more accurate diagnosis for patients with 46,XY differences of sex development.

BACKGROUND: Desert hedgehog (DHH) gene variants are known to cause 46,XY differences/disorders of sex development (DSD). We have identified six patients with 46,XY DSD with seven novel DHH gene variants. Many of these variants were classified as variants of uncertain significance due to their heterozygosity or associated milder phenotype. To assess variant pathogenicity and to refine the spectrum of DSDs associated with this gene, we have carried out the first reported functional testing of DHH gene variant activity. METHODS: A cell co-culture method was used to assess DHH variant induction of Hedgehog signalling in cultured Leydig cells. Protein expression and subcellular localisation were also assessed for DHH variants using western blot and immunofluorescence. RESULTS: Our co-culture method provided a robust read-out of DHH gene variant activity, which correlated closely with patient phenotype severity. While biallelic DHH variants from patients with gonadal dysgenesis showed significant loss of activity, variants found as heterozygous in patients with milder phenotypes had no loss of activity when tested with a wild type allele. Taking these functional results into account improved clinical interpretation. CONCLUSION: Our findings suggest heterozygous DHH gene variants are unlikely to cause DSD, reaffirming that DHH is an autosomal recessive cause of 46,XY gonadal dysgenesis. Functional characterisation of novel DHH variants improves variant interpretation, leading to greater confidence in patient reporting and clinical management.

[Children's Rights in Health Care: The Views of Ombudsman Offices for Children and Youth and Patient Advocacies in Austria]. / Kinderrechte im Gesundheitswesen ­ die Sicht der Kinder- und Jugendanwaltschaften und der Patientenanwaltschaften in Österreich.

AIM: The aim of the survey was to obtain a rough estimate of the number and type of reported violations of children's rights in the health care system, as well as an expert evaluation of the problem by the responsible institutions. METHODS: A written survey of all Austrian Ombudsman offices for Children and Youth (OCYs) and Patient Advocacy offices (PAs) asked for the number and type of potential violations of children's rights and their significance. RESULTS: Both institutions are consulted very rarely regarding children's rights in health care. OCYs report a higher awareness about children's rights, even though health care issues are legally incorporated in the PA offices. PAs report incoming complaints regarding children's health care even less often. Cooperation between the 2 institutions is insufficient. Participation rights/consent issues and health care service deficiencies have been identified as the main children's rights problems. CONCLUSIONS: The low number of reported complaints as well the available literature indicates an insufficient awareness of supporting services and institutions for children's rights in health care in Austria. There is room for improvement in this area with more intensive cooperation between the responsible institutions, remediation of deficiencies in care, improved communication, and training and further education of personnel.

Functional characterization of novel NR5A1 variants reveals multiple complex roles in disorders of sex development.

Variants in the NR5A1 gene encoding SF1 have been described in a diverse spectrum of disorders of sex development (DSD). Recently, we reported the use of a targeted gene panel for DSD where we identified 15 individuals with a variant in NR5A1, nine of which are novel. Here, we examine the functional effect of these changes in relation to the patient phenotype. All novel variants tested had reduced trans-activational activity, while several had altered protein level, localization, or conformation. In addition, we found evidence of new roles for SF1 protein domains including a region within the ligand binding domain that appears to contribute to SF1 regulation of Müllerian development. There was little correlation between the severity of the phenotype and the nature of the NR5A1 variant. We report two familial cases of NR5A1 deficiency with evidence of variable expressivity; we also report on individuals with oligogenic inheritance. Finally, we found that the nature of the NR5A1 variant does not inform patient outcomes (including pubertal androgenization and malignancy risk). This study adds nine novel pathogenic NR5A1 variants to the pool of diagnostic variants. It highlights a greater need for understanding the complexity of SF1 function and the additional factors that contribute.

Association of the breast cancer antiestrogen resistance protein 1 (BCAR1) and BCAR3 scaffolding proteins in cell signaling and antiestrogen resistance.

Most breast cancers are estrogen receptor-positive and treated with antiestrogens, but aberrant signaling networks can induce drug resistance. One of these networks involves the scaffolding protein BCAR1/p130CAS, which regulates cell growth and migration/invasion. A less investigated scaffolding protein that also confers antiestrogen resistance is the SH2 domain-containing protein BCAR3. BCAR1 and BCAR3 bind tightly to each other through their C-terminal domains, thus potentially connecting their associated signaling networks. However, recent studies using BCAR1 and BCAR3 interaction mutants concluded that association between the two proteins is not critical for many of their interrelated activities regulating breast cancer malignancy. We report that these previously used BCAR mutations fail to cause adequate loss-of-function of the complex. By using structure-based BCAR1 and BCAR3 mutants that lack the ability to interact, we show that BCAR3-induced antiestrogen resistance in MCF7 breast cancer cells critically depends on its ability to bind BCAR1. Interaction with BCAR3 increases the levels of phosphorylated BCAR1, ultimately potentiating BCAR1-dependent antiestrogen resistance. Furthermore, antiestrogen resistance in cells overexpressing BCAR1/BCAR3 correlates with increased ERK1/2 activity. Inhibiting ERK1/2 through overexpression of the regulatory protein PEA15 negates the resistance, revealing a key role for ERK1/2 in BCAR1/BCAR3-induced antiestrogen resistance. Reverse-phase protein array data show that PEA15 levels in invasive breast cancers correlate with patient survival, suggesting that PEA15 can override ERK1/2 activation by BCAR1/BCAR3 and other upstream regulators. We further uncovered that the BCAR3-related NSP3 can also promote antiestrogen resistance. Thus, strategies to disrupt BCAR1-BCAR3/NSP3 complexes and associated signaling networks could ultimately lead to new breast cancer therapies.

The Fas-FADD death domain complex structure unravels signalling by receptor clustering.

The death inducing signalling complex (DISC) formed by Fas receptor, FADD (Fas-associated death domain protein) and caspase 8 is a pivotal trigger of apoptosis. The Fas-FADD DISC represents a receptor platform, which once assembled initiates the induction of programmed cell death. A highly oligomeric network of homotypic protein interactions comprised of the death domains of Fas and FADD is at the centre of DISC formation. Thus, characterizing the mechanistic basis for the Fas-FADD interaction is crucial for understanding DISC signalling but has remained unclear largely because of a lack of structural data. We have successfully formed and isolated the human Fas-FADD death domain complex and report the 2.7 A crystal structure. The complex shows a tetrameric arrangement of four FADD death domains bound to four Fas death domains. We show that an opening of the Fas death domain exposes the FADD binding site and simultaneously generates a Fas-Fas bridge. The result is a regulatory Fas-FADD complex bridge governed by weak protein-protein interactions revealing a model where the complex itself functions as a mechanistic switch. This switch prevents accidental DISC assembly, yet allows for highly processive DISC formation and clustering upon a sufficient stimulus. In addition to depicting a previously unknown mode of death domain interactions, these results further uncover a mechanism for receptor signalling solely by oligomerization and clustering events.

The CARD plays a critical role in ASC foci formation and inflammasome signalling.

The ASC (apoptosis speck-like protein) is a key component of multimeric protein complexes that mediate inflammation and host defence. Comprising a PYD (Pyrin) domain and a CARD (caspase activation and recruitment domain), ASC functions downstream of NLRs (nucleotide-binding domain, leucine-rich repeat-containing receptors) and AIM2 (absent in melanoma 2) through the formation of supramolecular structures termed inflammasomes. However, the mechanism underlying ASC signalling and its dependency on oligomeric arrangements in inflammasome formation remain poorly understood. When expressed in cells, ASC forms discrete foci (called 'specks') typically with one speck per cell. We employed a BiFC (bimolecular fluorescence complementation) system to investigate and visualize ASC foci formation in living cells. We demonstrated that the CARD of ASC plays a central role in ASC inflammasome assembly, representing the minimal unit capable of forming foci in conjunction with the caspase 1 CARD. Mutational studies point to multiple surfaces on the ASC CARD and two predominant areas on the caspase 1 CARD mediating the formation of ASC/caspase 1 foci. The lack of foci formation for ASC CARD mutants correlates with a loss of IL-1ß (interleukin 1ß) processing in response to NLRP (NLR family, PYD domain-containing) 3 or AIM2 agonists in RAW264.7 cell reconstitution assays. Analogously, we show that productive formation of the Salmonella typhimurium-induced NLRC4 (NLR family CARD domain-containing protein 4) inflammasome is dependent on ASC-CARD-mediated platform formation. Thus the results of the present study depict a central role of CARDs in the formation of ASC signalling platforms and provide an important tool for investigation of CARD-dependent networks.

Body Mass Index Distributions and Obesity Prevalence in a Transgender Youth Cohort - A Retrospective Analysis.

PURPOSE: To evaluate differences in auxological parameters between transgender and cisgender adolescents. METHODS: Retrospective analysis of auxological data of 269 transgender and gender diverse patients (75% assigned female at birth or AFAB, 25% assigned male at birth or AMAB) at the outpatient clinic for Pediatric Endocrinology at the Vienna General Hospital. All were treatment naïve at initial measurement. Height and weight data were compared to current World Health Organization (WHO) standards, defining a standard deviation score (SDS) of ≥ 1 ≤ 2 as overweight and > 2 as obese. RESULTS: In our untreated transgender population (mean age 15.7 years), 20% were overweight and 17% obese. Mean BMI was 0.64 SDS above the WHO average (p < .001). This result was more pronounced in the AFAB subgroup (+0.73 SDS, p < .001) than in the AMAB group (+0.37 SDS, p = .07). The AMAB group showed markedly higher BMI variance compared to WHO standards (p < .001) and to the AFAB group (p = .03), due to a higher relative number of underweight observations. When correcting for psychiatric diagnosis, transgender patients were still significantly overweight (p < .001). In patients for whom data both pregender-affirming hormone therapy and during gender-affirming hormone therapy was available (n = 133), BMI SDS did not change significantly over time (p = .22). DISCUSSION: We observed significantly higher rates of overweight and obesity in our adolescent transgender cohort. The reasons are likely complex and multifactorial. This makes eating and exercise behaviors central in both transgender care and future research.

Treatment trajectories of gender incongruent Austrian youth seeking gender-affirming hormone therapy.

Objective: The aim of this study was to describe the treatment trajectories of Austrian children and adolescents with gender incongruence seeking gender-affirming medical care. Methods: Patients who presented with gender incongruence at the pediatric outpatient clinic for differences in sex development at a large university hospital in Austria from January 2008 to December 2022 were included in a retrospective chart review, and analyzed regarding referral numbers, patient characteristics, treatment trajectories, fertility preservation, and legal gender marker changes. Results: Of 310 eligible patients, 230 (74.2%) were assigned female at birth (AFAB), and 80 (25.8%) were assigned male at birth (AMAB). The number of referrals increased steeply from 2008 to 2018, whereafter it stabilized at around 50 per year. At the time of initial presentation, the median age of patients was 15.6 years (IQR 14.3-16.8). AMAB individuals tended to be younger (median 14.9 years, IQR 13.9-16.8) than AFAB individuals (median 15.8 years, IQR 14.4-16.8; p= 0.012). 207 (66,8%) completed the assessment process and were eligible for gender affirming medical treatment (GAMT). Of those, 89% (186/207) commenced gender affirming hormone therapy in the pediatric outpatient clinic (79/186 received GnRHa monotherapy, 91/186 GnRHa and sex steroids, and 16/186 sex steroid monotherapy). Of the 54 AMAB individuals receiving GAMT, 6 (11.1%) completed fertility preservation prior to therapy initiation. Only 1/132 AFAB adolescents receiving GAMT completed fertility preservation. Chest masculinization surgery was performed in 22 cases (16.7%), and breast augmentation in two cases (3.7%) between the ages of 16 and 18. Changes in legal gender marker were common, with 205 individuals (66.1%) having changed their legal gender marker. Conclusion: This is the first time that treatment trajectories, fertility preservation rates, and changes of legal gender marker have been described in Austrian adolescents with gender incongruence seeking GAMT. The majority received GAMT and changed their legal gender marker, while gender affirming surgery rates were low, and utilization of fertility preservation treatment options was rare.

Whole-exome-sequencing-based discovery of human FADD deficiency.

Germline mutations in FASL and FAS impair Fas-dependent apoptosis and cause recessively or dominantly inherited autoimmune lymphoproliferative syndrome (ALPS). Patients with ALPS typically present with no other clinical phenotype. We investigated a large, consanguineous, multiplex kindred in which biological features of ALPS were found in the context of severe bacterial and viral disease, recurrent hepatopathy and encephalopathy, and cardiac malformations. By a combination of genome-wide linkage and whole-exome sequencing, we identified a homozygous missense mutation in FADD, encoding the Fas-associated death domain protein (FADD), in the patients. This FADD mutation decreases steady-state protein levels and impairs Fas-dependent apoptosis in vitro, accounting for biological ALPS phenotypes in vivo. It also impairs Fas-independent signaling pathways. The observed bacterial infections result partly from functional hyposplenism, and viral infections result from impaired interferon immunity. We describe here a complex clinical disorder, its genetic basis, and some of the key mechanisms underlying its pathogenesis. Our findings highlight the key role of FADD in Fas-dependent and Fas-independent signaling pathways in humans.

Design, synthesis and evaluation of inhibitor of apoptosis protein (IAP) antagonists that are highly selective for the BIR2 domain of XIAP.

We recently reported the systematic ligand-based rational design and synthesis of monovalent Smac mimetics that bind preferentially to the BIR2 domain of the anti-apoptotic protein XIAP. Expanded structure-activity relationship (SAR) studies around these peptidomimetics led to compounds with significantly improved selectivity (>60-fold) for the BIR2 domain versus the BIR3 domain of XIAP. The potent and highly selective IAP antagonist 8q (ML183) sensitized TRAIL-resistant prostate cancer cells to apoptotic cell death, highlighting the merit of this probe compound as a valuable tool to investigate the biology of XIAP.

Distinctive binding of three antagonistic peptides to the ephrin-binding pocket of the EphA4 receptor.

The EphA4 receptor tyrosine kinase interacts with ephrin ligands to regulate many processes, ranging from axon guidance and nerve regeneration to cancer malignancy. Thus antagonists that inhibit ephrin binding to EphA4 could be useful for a variety of research and therapeutic applications. In the present study we characterize the binding features of three antagonistic peptides (KYL, APY and VTM) that selectively target EphA4 among the Eph receptors. Isothermal titration calorimetry analysis demonstrated that all three peptides bind to the ephrin-binding domain of EphA4 with low micromolar affinity. Furthermore, the effects of a series of EphA4 mutations suggest that the peptides interact in different ways with the ephrin-binding pocket of EphA4. Chemical-shift changes observed by NMR spectroscopy upon binding of the KYL peptide involve many EphA4 residues, consistent with extensive interactions and possibly receptor conformational changes. Additionally, systematic replacement of each of the 12 amino acids of KYL and VTM identify the residues critical for EphA4, binding. The peptides exhibit a long half-life in cell culture medium which, with their substantial binding affinity and selectivity for EphA4, makes them excellent research tools to modulate EphA4 function.

Mental Health of Transgender Youth: A Comparison of Assigned Female at Birth and Assigned Male at Birth Individuals.

Gender dysphoric adolescents report a gender identity which is incongruent with their assigned sex at birth, whereby the experienced incongruence is accompanied by clinically relevant distress. The aim of the study was to assess and compare the mental health of transgender youth by assigned sex at birth. A total of n = 49 adolescents (n = 29 assigned females at birth, n = 20 assigned male at birth) aged 12 to 18 years with the diagnosis of gender dysphoria according to DSM-5 were included in the study. The adolescents underwent a psychological assessment in a child and adolescent psychiatry outpatient department prior to starting gender-affirming medical treatment, completing relevant mental health questionnaires. Although no differences were found in psychiatric disorders, more externalizing problems above the clinical threshold were reported by parents in assigned female at birth (AFAB) adolescents. On the other hand, internalizing problems, both in general and within the clinical range, were found to be more prevalent in assigned male at birth (AMAB) adolescents, as indicated by self-report. Our results suggest that a comprehensive assessment of mental health in gender dysphoric adolescents is crucial for understanding the diverse range of challenges they may face and tailoring appropriate interventions to address their specific needs.