Editorial for the IJMS Special Issue on "Neurodevelopmental Disorders: From Epigenetic Basis to Therapeutic Perspectives".

In this Special Issue, we focus on the complex mechanisms underlying neurodevelopmental disorders (as delineated in the DSM-5), which are a group of neurological disorders that begin in childhood but significantly impact adult life [...].

Soluble Triggering Receptors Expressed on Myeloid Cells (sTREM) in Acute Ischemic Stroke: A Potential Pathway of sTREM-1 and sTREM-2 Associated with Disease Severity.

In 2022, stroke emerged as the most significant cerebrovascular disorder globally, causing 6.55 million deaths. Microglia, crucial for CNS preservation, can exacerbate brain damage in ischemic stroke by triggering neuroinflammation. This process is mediated by receptors on microglia, triggering receptors expressed on myeloid cells (TREM-1 and TREM-2), which have contrasting roles in neuroinflammation. In this study, we recruited 38 patients within 4.5 h from the onset of ischemic stroke. The degree of severity was evaluated by means of the National Institutes of Health Stroke Scale (NIHSS) at admission (T0) and after one week of ischemic events (TW) and the Modified Rankin Scale (mRS) at three months. The plasma concentration of TREMs (sTREM) was analyzed by next-generation ELISA at T0 and TW. The sTREM-1 concentrations at T0 were associated with mRS, while the sTREM-2 concentrations at T0 were associated with both the NIHSS at T0 and the mRS. A strong correlation between sTREM-1 and sTREM-2 was observed, suggesting a dependent modulation of the levels. This study provides insights into the potential pathway of TREM-1 and TREM-2 as a future biomarker for stratifying high-risk patients with ischemic stroke.

The Use of Human Amniotic Membrane (hAM) as a Treatment Strategy of Medication-Related Osteonecrosis of the Jaw (MRONJ): A Systematic Review and Meta-Analysis of the Literature.

Background and objectives: Although it is very uncommon, medication-induced osteonecrosis of the jaw (also known as MRONJ) can have serious consequences. Traditionally, this adverse event has been recognised in patients who were treated with bisphosphonate (BP) drugs. Nevertheless, in recent years, it has been established that individuals having treatment with various types of medications, such as a receptor activator of nuclear factor kappa-Β ligand inhibitor (denosumab) and antiangiogenic agents, have had the same issue. The purpose of this research is to determine if the application of human amniotic membrane (hAM) may be used as a therapy for MRONJ. Material and Methods: A multi-source database (MEDLINE, EMBASE, AMED, and CENTRAL) systematic search was performed. The major objective of this study is to obtain an understanding of the efficacy of hAM when it is employed as a treatment modality for MRONJ. The protocol of this review was registered in the INPLASY register under the number NPLASY202330010. Results: The authors were able to include a total of five studies for the quality analysis, whereas for the quantity evaluation, only four studies were eligible. A total of 91 patients were considered for the investigation. After treatment with human amniotic membrane (hAM), a recurrence of osteonecrosis was observed in n = 6 cases (8.8%). The combined efficacy of surgical therapy and the use of hAM resulted in an overall success rate of 91.2%. Intraoperative complications were only documented in one article, and they were mostly caused by the positioning of the hAM, which led to wound breakdown at the surgical site. Conclusions: Based on the small amount of data and low-quality research included in this study, using human amniotic membranes to treat MRONJ might represent a feasible option. Nevertheless, further studies with a wider patient population are required to understand the long-term impacts.

The Interplay of Raloxifene and Sonochemical Bio-Oss in Early Maxillary Sinus Bone Regeneration: A Histological and Immunohistochemical Analysis in Rabbits.

The study aimed to assess the efficacy of using Raloxifene with ultrasonic processing to enhance Bio-Oss®, a bone graft substitute, for maxillary sinus bone height reconstruction. A total of 24 rabbit maxillary sinuses were distributed into three groups, each receiving different treatments: Bio-Oss® only, sonicated Bio-Oss, and sonicated Bio-Oss® with Raloxifene. Surgical procedures and subsequent histomorphometric and immunohistochemistry analyses were conducted to evaluate the bone formation, connective tissue, and remaining biomaterial, as well as the osteoblastic differentiation and maturation of collagen fibers. Results indicated that the sonicated Bio-Oss® and Bio-Oss® groups showed similar histological behavior and bone formation, but the Raloxifene group displayed inflammatory infiltrate, low bone formation, and disorganized connective tissue. The statistical analysis confirmed significant differences between the groups in terms of bone formation, connective tissue, and remaining biomaterial. In conclusion, the study found that while sonicated Bio-Oss® performed comparably to Bio-Oss® alone, the addition of Raloxifene led to an unexpected delay in bone repair. The findings stress the importance of histological evaluation for accurate bone repair assessment and the necessity for further investigation into the local application of Raloxifene. Future research may focus on optimizing bone substitutes with growth factors to improve bone repair.

The Use of Hydroxyapatite Loaded with Doxycycline (HADOX) in Dentoalveolar Surgery as a Risk-Reduction Therapeutic Protocol in Subjects Treated with Different Bisphosphonate Dosages.

Medication-related osteonecrosis of the jaw (MRONJ) is considered as a severe adverse side effect of specific drugs such as anti-resorptive and anti-angiogenic medications. Evidence suggests that MRONJ is linked to invasive dental procedures, mainly dentoalveolar surgery. Several preventive strategies to minimize the risk of developing MRONJ have been investigated. However, no investigation has been attempted to evaluate the therapeutic effect of local drug-delivery technology as a preventive strategy protocol. The aim of this study is to evaluate the efficacy of hydroxyapatite-containing doxycycline (HADOX) in rats with high-risk MRONJ development. All the rats used in this study were divided into seven groups. Six groups of rats out of seven were exposed to two different doses of antiresorptive drug therapy for four weeks before undergoing an upper incisor extraction. After 28 days, all the animals were euthanized, and the bone blocks were processed for histological and histomorphometrical evaluation. The histomorphometric analysis confirmed that newly formed bone (NFB) was present in all groups, with significant differences. NFB in the HADOX group treated with zoledronic acid at 4% showed (28.38; C.I. 22.29-34.48), which represents a significant increase compared to HA (15.69; C.I. 4.89-26.48) (p = 0.02). A similar pattern was observed in the HADOX group treated with zoledronic acid 8% ZA treatment (p = 0.001). Conclusions: HADOX did not inhibit any bone repair and reduced early inflammatory response. Hence, HADOX could promote bone healing in patients undergoing antiresorptive drug therapy.

Does Melatonin Associated with Nanostructured Calcium Phosphate Improve Alveolar Bone Repair?

Background and objectives: Calcium phosphates have been widely used as bone substitutes, but their properties are limited to osteoconduction. The association of calcium phosphates with osteoinductive bioactive molecules has been used as a strategy in regenerative medicine. Melatonin has been studied due to its cell protection and antioxidant functions, reducing osteoclastic activity and stimulating newly formed bone. This study aimed to evaluate the effect of topical application of melatonin associated with nanostructured carbonated hydroxyapatite microspheres in the alveolar bone repair of Wistar rats through histological and histomorphometric analysis. Materials and Methods: Thirty female Wistar rats (300 g) were used, divided randomly into three experimental groups (n = 10), G1: nanostructured carbonated hydroxyapatite microspheres associated with melatonin gel (CHA-M); G2: nanostructured carbonated hydroxyapatite (CHA); G3: blood clot (without alveolar filling). The animals were euthanized after 7 and 42 days of the postoperative period and processed for histological and histomorphometric evaluation. Kruskal-Wallis and Dunn's post-test were applied to investigate statistical differences between the groups at the same time point for new bone and connective tissue variables. Mann-Whitney was used to assess statistical differences between different time points and in the biomaterial variable. Results: Results showed a greater volume of residual biomaterial in the CHA-M than the CHA group (p = 0.007), and there were no significant differences in terms of newly formed bone and connective tissue between CHA and CHA-M after 42 days. Conclusions: This study concluded that both biomaterials improved alveolar bone repair from 7 to 42 days after surgery, and the association of CHA with melatonin gel reduced the biomaterial's biodegradation at the implanted site but did not improve the alveolar bone repair.

Evidence that ITGB3 promoter variants increase serotonin blood levels by regulating platelet serotonin transporter trafficking.

Elevated serotonin (5-HT) blood levels, the first biomarker identified in autism research, has been consistently found in 20-30% of patients with Autism Spectrum Disorder (ASD). Hyperserotonemia is mainly due to greater 5-HT uptake into platelets, mediated by the 5-HT transporter (SERT) located at the platelet plasma membrane. The protein complex involved in platelet SERT trafficking and externalization includes integrin ß3, the beta subunit of the platelet membrane adhesive GP IIb/IIIa. Integrin ß3 is encoded by the ITGB3 gene, previously identified as a quantitative trait locus (QTL) for 5-HT blood levels in ASD at single nucleotide polymorphism (SNP) rs2317385. The present study aims to identify the functional ITGB3 gene variants contributing to hyperserotonemia. ITGB3 gene sequencing in 20 individuals selected on the basis of rs2317385 genotypes defined four haplotypes encompassing six SNPs located in the ITGB3 gene promoter region, all in linkage disequilibrium with rs2317385. Luciferase assays in two hematopoietic cell lines, K-562 and HEL 92.1.7, demonstrate that ITGB3 gene promoter activity is enhanced by the presence of the C allele at rs55827077 specifically during differentiation into megakaryocytes (P < 0.01), with modulatory effects by flanking SNPs. This same allele is strongly associated with (a) higher 5-HT blood levels in 176 autistic individuals (P < 0.001), (b) greater platelet integrin ß3 protein expression (P < 0.05) and (c) enhanced SERT trafficking from the cytosol toward the platelet plasma membrane (P = 4.05 × 10-11). Our results support rs55827077 as the functional ITGB3 gene promoter variant contributing to elevated 5-HT blood levels in ASD and define a mechanistic chain of events linking ITGB3 to hyperserotonemia.

Molecular biomarkers to track clinical improvement following an integrative treatment model in autistic toddlers.

OBJECTIVES: Identifying an objective, laboratory-based diagnostic tool (e.g. changes in gene expression), when used in conjunction with disease-specific clinical assessment, could increase the accuracy of the effectiveness of a therapeutic intervention. METHODS: We assessed the association between treatment outcome and blood RNA expression before the therapeutic intervention to post-treatment (after 1 year) of five autism spectrum disorder (ASD) toddlers who underwent an intensive cognitive-behavioural intervention integrated with psychomotor and speech therapy. RESULTS: We found 113 significant differentially expressed genes enriched for the nervous system, immune system, and transcription and translation-related pathways. Some of these genes, as MALAT-1, TSPO, and CFL1, appear to be promising candidates. CONCLUSIONS: Our findings show that changes in peripheral gene expression could be used in conjunction with clinical scales to monitor a rehabilitation intervention's effectiveness in toddlers affected by ASD. These results need to be validated in a larger cohort.

The role of antiresorptive drugs and medication-related osteonecrosis of the jaw in nononcologic immunosuppressed patients: A systematic review.

Medication related osteonecrosis of the jaw (MRONJ) is a severe condition affecting the jaws of patients exposed to specific drugs, and is primarily described in patients receiving bisphosphonate (BP) therapy. However, more recently it has been observed in patients taking other medications, such as the RANK ligand inhibitor (denosumab) and antiangiogenic drugs. It has been proposed that the existence of other concomitant medical conditions may increase the incidence of MRONJ. The primary aim of this research was to analyze all available evidence and evaluate the reported outcomes of osteonecrosis of the jaws (ONJ) due to antiresorptive drugs in immunosuppressed patients. A multi-database (PubMed, MEDLINE, EMBASE and CINAHL) systematic search was performed. The search generated twenty-seven studies eligible for the analysis. The total number of patients included in the analysis was two hundred and six. All patients were deemed to have some form of immunosuppression, with some patients having more than one disorder contributing to their immunosuppression. Within this cohort the commonest trigger for MRONJ was a dental extraction (n=197). MRONJ complications and recurrence after treatment was sparsely reported in the literature, however a total of fourteen cases were observed. The data reviewed have confirmed that an invasive procedure is the commonest trigger of MRONJ with relatively high frequency of post-operative complications or recurrence following management. However, due to low-quality research available in the literature it is difficult to draw a definitive conclusion on the outcomes analysed in this systematic review.

Phenotypic spectrum of NRXN1 mono- and bi-allelic deficiency: A systematic review.

Neurexins are presynaptic cell adhesion molecules critically involved in synaptogenesis and vesicular neurotransmitter release. They are encoded by three genes (NRXN1-3), each yielding a longer alpha (α) and a shorter beta (ß) transcript. Deletions spanning the promoter and the initial exons of the NRXN1 gene, located in chromosome 2p16.3, are associated with a variety of neurodevelopmental, psychiatric, neurological and neuropsychological phenotypes. We have performed a systematic review to define (a) the clinical phenotypes most associated with mono-allelic exonic NRXN1 deletions, and (b) the phenotypic features of NRXN1 bi-allelic deficiency due to compound heterozygous deletions/mutations. Clinically, three major conclusions can be drawn: (a) incomplete penetrance and pleiotropy do not allow reliable predictions of clinical outcome following prenatal detection of mono-allelic exonic NRXN1 deletions. Newborn carriers should undergo periodic neuro-behavioral observations for the timely detection of warning signs and the prescription of early behavioral intervention; (b) the presence of additional independent genetic risk factors should always be sought, as they may influence prognosis; (c) children with exonic NRXN1 deletions displaying early-onset, severe psychomotor delay in the context of a Pitt-Hopkins-like syndrome 2 phenotype, should undergo DNA sequencing of the spared NRXN1 allele in search for mutations or very small insertions/deletions.

Particulate Air Pollution, Clock Gene Methylation, and Stroke: Effects on Stroke Severity and Disability.

Circadian rhythm disturbances have been consistently associated with the development of several diseases, particularly cardiovascular diseases (CVDs). A central clock in the brain maintains the daily rhythm in accordance with the external environment. At the molecular level, the clock is maintained by "clock genes", the regulation of which is mainly due to DNA methylation, a molecular mechanism of gene expression regulation, able to react to and be reprogrammed by environmental exposure such as exposure to particulate matter (PM). In 55 patients with a diagnosis of acute ischemic stroke, we showed that PM2.5 exposure experienced before the event influenced clock genes methylation (i.e., circadian locomotor output cycles protein kaput CLOCK, period 2 PER2, cryprochrome 1 CRY1, Neuronal PAS Domain Protein 2 NPAS2), possibly modulating the patient prognosis after the event, as cryptochrome 1 CRY1 and period 1 PER1 methylation levels were associated with the Rankin score. Moreover, if PM2.5 annual average was low, CRY1/CRY2 methylation levels were positively associated with the National Institutes of Health Stroke Scale (NIHSS) score, whereas they were negatively associated if PM2.5 exposure was high. Whether epigenetic changes in clock genes need to be considered as a prognostic marker of stroke or rather a causal agent in stroke development remains to be determined. Further studies are needed to determine the role of clock gene methylation in regulating the response to and recovery after a stroke event.

Developmental and behavioral profile in a domestic adoptees sample: a new challenge for the pediatrician.

BACKGROUND: The aim of this study is to investigate the changes of developmental and behavioral profile in a domestic adoptees sample. METHODS: Thirty-six domestic adoptive families were recruited, resulting in a sample of 39 children. Families were sent a general questionnaire for collecting data related to the children demographic variables, infant's background (time spent in institutional care, age at adoption), children's health status and anthropometric measures at T0, T1, T2, and T3. Moreover, the Infant Behavior Questionnaire-Revised Very Short Form and a modified version of parent-report of Child Behavior Checklist were used to assess temperament and to detect behavioral problems. RESULTS: As regards the psychopathological evaluation, behavior problems were more common in older children, especially among girls. In particular they exhibited a higher frequency of internalizing problems versus externalizing. CONCLUSIONS: Children in foster care suffer discontinuity of care that negatively affects their emotional and physical development. It is important for pediatricians to be aware of the special needs of adopted children, providing adequate support to adoptive families.

Huntingtin gene CAG repeat size affects autism risk: Family-based and case-control association study.

The Huntingtin (HTT) gene contains a CAG repeat in exon 1, whose expansion beyond 39 repeats consistently leads to Huntington's disease (HD), whereas normal-to-intermediate alleles seemingly modulate brain structure, function and behavior. The role of the CAG repeat in Autism Spectrum Disorder (ASD) was investigated applying both family-based and case-control association designs, with the SCA3 repeat as a negative control. Significant overtransmission of "long" CAG alleles (≥17 repeats) to autistic children and of "short" alleles (≤16 repeats) to their unaffected siblings (all p < 10-5 ) was observed in 612 ASD families (548 simplex and 64 multiplex). Surprisingly, both 193 population controls and 1,188 neurological non-HD controls have significantly lower frequencies of "short" CAG alleles compared to 185 unaffected siblings and higher rates of "long" alleles compared to 548 ASD patients from the same families (p < .05-.001). The SCA3 CAG repeat displays no association. "Short" HTT alleles seemingly exert a protective effect from clinically overt autism in families carrying a genetic predisposition for ASD, while "long" alleles may enhance autism risk. Differential penetrance of autism-inducing genetic/epigenetic variants may imply atypical developmental trajectories linked to HTT functions, including excitation/inhibition imbalance, cortical neurogenesis and apoptosis, neuronal migration, synapse formation, connectivity and homeostasis.

Characterization of host proteins interacting with the lymphocytic choriomeningitis virus L protein.

RNA-dependent RNA polymerases (RdRps) play a key role in the life cycle of RNA viruses and impact their immunobiology. The arenavirus lymphocytic choriomeningitis virus (LCMV) strain Clone 13 provides a benchmark model for studying chronic infection. A major genetic determinant for its ability to persist maps to a single amino acid exchange in the viral L protein, which exhibits RdRp activity, yet its functional consequences remain elusive. To unravel the L protein interactions with the host proteome, we engineered infectious L protein-tagged LCMV virions by reverse genetics. A subsequent mass-spectrometric analysis of L protein pulldowns from infected human cells revealed a comprehensive network of interacting host proteins. The obtained LCMV L protein interactome was bioinformatically integrated with known host protein interactors of RdRps from other RNA viruses, emphasizing interconnected modules of human proteins. Functional characterization of selected interactors highlighted proviral (DDX3X) as well as antiviral (NKRF, TRIM21) host factors. To corroborate these findings, we infected Trim21-/- mice with LCMV and found impaired virus control in chronic infection. These results provide insights into the complex interactions of the arenavirus LCMV and other viral RdRps with the host proteome and contribute to a better molecular understanding of how chronic viruses interact with their host.

Viral immune modulators perturb the human molecular network by common and unique strategies.

Viruses must enter host cells to replicate, assemble and propagate. Because of the restricted size of their genomes, viruses have had to evolve efficient ways of exploiting host cell processes to promote their own life cycles and also to escape host immune defence mechanisms. Many viral open reading frames (viORFs) with immune-modulating functions essential for productive viral growth have been identified across a range of viral classes. However, there has been no comprehensive study to identify the host factors with which these viORFs interact for a global perspective of viral perturbation strategies. Here we show that different viral perturbation patterns of the host molecular defence network can be deduced from a mass-spectrometry-based host-factor survey in a defined human cellular system by using 70 innate immune-modulating viORFs from 30 viral species. The 579 host proteins targeted by the viORFs mapped to an unexpectedly large number of signalling pathways and cellular processes, suggesting yet unknown mechanisms of antiviral immunity. We further experimentally verified the targets heterogeneous nuclear ribonucleoprotein U, phosphatidylinositol-3-OH kinase, the WNK (with-no-lysine) kinase family and USP19 (ubiquitin-specific peptidase 19) as vulnerable nodes in the host cellular defence system. Evaluation of the impact of viral immune modulators on the host molecular network revealed perturbation strategies used by individual viruses and by viral classes. Our data are also valuable for the design of broad and specific antiviral therapies.

Topographic indices and pachymetry in healthy adolescents obtained with Sirius topographer.

PURPOSE: To determine the normal values for the Sirius corneal topography, of some topographic indices and corneal pachymetry, in a healthy young adolescent population. METHODS: A total of 176 students (mean age 12.95 ± 0.82 years) took part in this study. 352 eyes were imaged through Sirius topographer. Anterior and posterior meridians, mean pupillary power, central corneal thickness, minimum corneal thickness, and anterior and posterior asymmetry indices were analyzed. Correlations between corneal parameters and differences between anterior and posterior corneal surfaces were evaluated. RESULTS: Average anterior meridian was 43.37 D (± 1.46); average posterior meridian was 6.16 D (± 0.24); central corneal thickness was 550.81 ± 29.88 micron, minimum corneal thickness was 547.36 ± 29.93 micron; mean pupillary power was 42.95 ± 1.46 D, SIf was - 0.035 ± 0.46, and SIb was 0.012 ± 0.091. Anterior and posterior corneal curvatures correlated negatively with MPP (r = - 0.99; p = 0.000 and r = - 0.85 p = 0.000, respectively). Anterior curvature correlated positively with posterior curvature (r = 0.891; p = 0.000). Positive correlations were found for SIf and SIb (r = 0.58; p = 0.000). Negative correlations were found for SIf and corneal pachymetry (r = - 0.23; p = 0.000) and for SIb and corneal pachymetry (r = - 0.19; p = 0.012). The difference between anterior meridian average and posterior meridian average was 1.29 ± 0.12 and was significative (p < 0.001). No differences between genders were found. CONCLUSIONS: These results provide normal standards for corneal values in adolescents and could represent a useful tool for future comparative studies in this age-group population.

Are reprogrammed cells a useful tool for studying dopamine dysfunction in psychotic disorders? A review of the current evidence.

Since 2006, reprogrammed cells have increasingly been used as a biomedical research technique in addition to neuro-psychiatric methods. These rapidly evolving techniques allow for the generation of neuronal sub-populations, and have sparked interest not only in monogenetic neuro-psychiatric diseases, but also in poly-genetic and poly-aetiological disorders such as schizophrenia (SCZ) and bipolar disorder (BPD). This review provides a summary of 19 publications on reprogrammed adult somatic cells derived from patients with SCZ, and five publications using this technique in patients with BPD. As both disorders are complex and heterogeneous, there is a plurality of hypotheses to be tested in vitro. In SCZ, data on alterations of dopaminergic transmission in vitro are sparse, despite the great explanatory power of the so-called DA hypothesis of SCZ. Some findings correspond to perturbations of cell energy metabolism, and observations in reprogrammed cells suggest neuro-developmental alterations. Some studies also report on the efficacy of medicinal compounds to revert alterations observed in cellular models. However, due to the paucity of replication studies, no comprehensive conclusions can be drawn from studies using reprogrammed cells at the present time. In the future, findings from cell culture methods need to be integrated with clinical, epidemiological, pharmacological and imaging data in order to generate a more comprehensive picture of SCZ and BPD.

Copy number variation in 19 Italian multiplex families with autism spectrum disorder: Importance of synaptic and neurite elongation genes.

Autism Spectrum Disorder (ASD) is endowed with impressive heritability estimates and high recurrence rates. Its genetic underpinnings are nonetheless very heterogeneous, with common, and rare contributing variants located in hundreds of different loci, each characterized by variable levels of penetrance. Multiplex families from single ethnic groups represent a useful means to reduce heterogeneity and enhance genetic load. We screened 19 Italian ASD multiplex families (3 triplets and 16 duplets, total N = 41 ASD subjects), using array-CGH (Agilent 180 K). Causal or ASD-relevant CNVs were detected in 36.6% (15/41) of ASD probands, corresponding to 36.8% (7/19) multiplex families with at least one affected sibling genetically positive. However, only in less than half (3/7) of positive families, affected siblings share the same causal or ASD-relevant CNV. Even in these three families, additional potentially relevant CNVs not shared by affected sib pairs were also detected. These results provide further evidence of genetic heterogeneity in ASD even within multiplex families belonging to a single ethnic group. Differences in CNV burden may likely contribute to the substantial clinical heterogeneity observed between affected siblings. In addition, Gene Ontology enrichment analysis indicates that most potentially causal or relevant ASD genes detected in our cohort belong to nervous system-specific categories, especially involved in neurite elongation and synaptic structure/function. These findings point toward the existence of genomic instability in these families, whose underlying genetic and epigenetic mechanisms deserve further scrutiny.

Expanding the Interactome of the Noncanonical NF-κB Signaling Pathway.

NF-κB signaling is a central pathway of immunity and integrates signal transduction upon a wide array of inflammatory stimuli. Noncanonical NF-κB signaling is activated by a small subset of TNF family receptors and characterized by NF-κB2/p52 transcriptional activity. The medical relevance of this pathway has recently re-emerged from the discovery of primary immunodeficiency patients that have loss-of-function mutations in the MAP3K14 gene encoding NIK. Nevertheless, knowledge of protein interactions that regulate noncanonical NF-κB signaling is sparse. Here we report a detailed state-of-the-art mass spectrometry-based protein-protein interaction network including the noncanonical NF-κB signaling nodes TRAF2, TRAF3, IKKα, NIK, and NF-κB2/p100. The value of the data set was confirmed by the identification of interactions already known to regulate this pathway. In addition, a remarkable number of novel interactors were identified. We provide validation of the novel NIK and IKKα interactor FKBP8, which may regulate processes downstream of noncanonical NF-κB signaling. To understand perturbed noncanonical NF-κB signaling in the context of misregulated NIK in disease, we also provide a differential interactome of NIK mutants that cause immunodeficiency. Altogether, this data set not only provides critical insight into how protein-protein interactions can regulate immune signaling but also offers a novel resource on noncanonical NF-κB signaling.