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Ameloblasts are specialized epithelial cells in the jaw that have an indispensable role in tooth enamel formation-amelogenesis 1 . Amelogenesis depends on multiple ameloblast-derived proteins that function as a scaffold for hydroxyapatite crystals. The loss of function of ameloblast-derived proteins results in a group of rare congenital disorders called amelogenesis imperfecta 2 . Defects in enamel formation are also found in patients with autoimmune polyglandular syndrome type-1 (APS-1), caused by AIRE deficiency 3,4 , and in patients diagnosed with coeliac disease 5-7 . However, the underlying mechanisms remain unclear. Here we show that the vast majority of patients with APS-1 and coeliac disease develop autoantibodies (mostly of the IgA isotype) against ameloblast-specific proteins, the expression of which is induced by AIRE in the thymus. This in turn results in a breakdown of central tolerance, and subsequent generation of corresponding autoantibodies that interfere with enamel formation. However, in coeliac disease, the generation of such autoantibodies seems to be driven by a breakdown of peripheral tolerance to intestinal antigens that are also expressed in enamel tissue. Both conditions are examples of a previously unidentified type of IgA-dependent autoimmune disorder that we collectively name autoimmune amelogenesis imperfecta., (© 2023. The Author(s), under exclusive licence to Springer Nature Limited.)

Development of immunocompetent T cells in the thymus is required for effective defence against all types of pathogens, including viruses, bacteria and fungi. To this end, T cells undergo a very strict educational program in the thymus, during which both non-functional and self-reactive T cell clones are eliminated by means of positive and negative selection 1 .Thymic epithelial cells (TECs) have an indispensable role in these processes, and previous studies have shown the notable heterogeneity of these cells 2-7 . Here, using multiomic analysis, we provide further insights into the functional and developmental diversity of TECs in mice, and reveal a detailed atlas of the TEC compartment according to cell transcriptional states and chromatin landscapes. Our analysis highlights unconventional TEC subsets that are similar to functionally well-defined parenchymal populations, including endocrine cells, microfold cells and myocytes. By focusing on the endocrine and microfold TEC populations, we show that endocrine TECs require Insm1 for their development and are crucial to maintaining thymus cellularity in a ghrelin-dependent manner; by contrast, microfold TECs require Spib for their development and are essential for the generation of thymic IgA + plasma cells. Collectively, our study reveals that medullary TECs have the potential to differentiate into various types of molecularly distinct and functionally defined cells, which not only contribute to the induction of central tolerance, but also regulate the homeostasis of other thymus-resident populations., (© 2023. The Author(s), under exclusive licence to Springer Nature Limited.)

Patients with loss of function in the gene encoding the master regulator of central tolerance AIRE suffer from a devastating disorder called autoimmune polyendocrine syndrome type 1 (APS-1), characterized by a spectrum of autoimmune diseases and severe mucocutaneous candidiasis. Although the key mechanisms underlying the development of autoimmunity in patients with APS-1 are well established, the underlying cause of the increased susceptibility to Candida albicans infection remains less understood. Here, we show that Aire + MHCII + type 3 innate lymphoid cells (ILC3s) could sense, internalize and present C. albicans and had a critical role in the induction of Candida-specific T helper 17 (T H 17) cell clones. Extrathymic Rorc-Cre-mediated deletion of Aire resulted in impaired generation of Candida-specific T H 17 cells and subsequent overgrowth of C. albicans in the mucosal tissues. Collectively, our observations identify a previously unrecognized regulatory mechanism for effective defense responses against fungal infections., (© 2022. The Author(s), under exclusive licence to Springer Nature America, Inc.)

Objective: There is an unmet need for new, efficacious, well-tolerated, acute treatments for migraine in adolescents. Remote electrical neuromodulation (REN) is a novel, nonpharmacological treatment that provides significant symptom relief with good tolerability. The current post hoc analysis compared the efficacy of REN to that of standard-care medications for the acute treatment of migraine in adolescents., Design: Within-participant post hoc analysis of data from a clinical trial., Setting: Data from a clinical trial., Subjects: Data from 35 adolescent participants were analyzed., Methods: Efficacy was compared between a run-in phase, in which attacks were treated with standard-care medications (triptans or over-the-counter medications), and an intervention phase, in which attacks were treated with REN. Efficacy was compared within participants through the use of McNemar's test at four endpoints (2 hours after treatment): single-treatment pain freedom and pain relief, and consistency of pain freedom and pain relief (defined as response in at least 50% of the available first four treatments)., Results: At 2 hours after treatment, pain freedom was achieved by 37.1% of the participants with REN, vs 8.6% of the participants with medications (P = 0.004). Pain relief was achieved by 71.4% with REN, vs 57.1% with medications (P = 0.225). Consistency of pain freedom was achieved by 40% with REN, vs 8.6% with medications (P < 0.001). Consistency of pain relief was achieved by 80.0% with REN, vs 57.2% with medications (P = 0.033)., Conclusions: Our results suggest that REN may have higher efficacy than certain standard-care medications for the acute treatment of migraine in adolescents. A larger-scale, blinded comparative-effectiveness and tolerability study is needed., (© The Author(s) 2021. Published by Oxford University Press on behalf of the American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

The autoimmune regulator (AIRE) is essential for the establishment of central tolerance and prevention of autoimmunity. Interestingly, different AIRE mutations cause autoimmunity in either recessive or dominant-negative manners. Using engineered mouse models, we establish that some monoallelic mutants, including C311Y and C446G, cause breakdown of central tolerance. By using RNAseq, ATACseq, ChIPseq, and protein analyses, we dissect the underlying mechanisms for their dominancy. Specifically, we show that recessive mutations result in a lack of AIRE protein expression, while the dominant mutations in both PHD domains augment the expression of dysfunctional AIRE with altered capacity to bind chromatin and induce gene expression. Finally, we demonstrate that enhanced AIRE expression is partially due to increased chromatin accessibility of the AIRE proximal enhancer, which serves as a docking site for AIRE binding. Therefore, our data not only elucidate why some AIRE mutations are recessive while others dominant, but also identify an autoregulatory mechanism by which AIRE negatively modulates its own expression., Competing Interests: Disclosures: The authors declare no competing interests exist., (© 2021 Goldfarb et al.)

Objectives: Migraine is a common disabling neurological disorder. Current acute treatments for migraine in adolescents are mostly pharmacological and may have limited effectiveness, can cause side effects, and may lead to medication overuse. There is an unmet need for effective and well-tolerated treatments. Remote electrical neuromodulation (REN) is a novel acute treatment of migraine that stimulates upper arm peripheral nerves to induce conditioned pain modulation (CPM)-an endogenous analgesic mechanism. The REN device (Nerivio ® , Theranica Bio-Electronics Ltd., Israel) is a FDA-authorized device for acute treatment of migraine in adults. This study assessed the efficacy and safety of REN in adolescents with migraine., Design and Methods: This was an open-label, single-arm, multicenter study in adolescents (ages 12-17 years) with migraine. Participants underwent a 4-week run-in phase. Eligible participants continued to an 8-week treatment phase with the device. Pain severity, associated symptoms, and functional disability were recorded at treatment initiation, and 2 and 24 hours post-treatment. The primary endpoints of this study were related to the safety and tolerability of REN. The secondary endpoints were related to device efficacy and included the proportion of participants who achieved pain relief at 2 hours post-treatment and the proportion of participants who achieved pain freedom at 2 hours. The presented results reflect an interim analysis with subsequent stopping of the rest of the study., Results: Sixty participants were enrolled for the study; of these, 14 failed to meet the run-in criteria and 1 was lost to follow-up. Forty-five participants performed at least one treatment, of which 39 participants completed a test treatment with REN. One device-related adverse event (2%) was reported in which a temporary feeling of pain in the arm was felt. Pain relief and pain-free at 2 hours were achieved by 71% (28/39) and 35% (14/39) participants, respectively. At 2 hours, 69% (23/33) participants experienced improvement in functional ability., Conclusions: REN may offer a safe and effective non-pharmacological alternative for acute treatment in adolescents., (© 2020 American Headache Society.)

Background: There is a significant unmet need for new, effective and well tolerated acute migraine treatments. A recent study has demonstrated that a novel remote electrical neuromodulation (REN) treatment provides superior clinically meaningful pain relief with a low rate of device-related adverse events. The results reported herein compare the efficacy of REN with current standard of care in the acute treatments of migraine., Methods: We performed a post-hoc analysis on a subgroup of participants with migraine from a randomized, double-blind, parallel-group, sham-controlled, multicenter study on acute care. The original study included a 2-4 weeks run-in phase, in which migraine attacks were treated according to patient preference (i.e., usual care) and reported in an electronic diary; next, participants entered a double-blind treatment phase in which they treated the attacks with an active or sham device. The efficacy of REN was compared to the efficacy of usual care or pharmacological treatments in the run-in phase in a within-subject design that included participants who treated at least one attack with the active REN device and reported pain intensity at 2 h post-treatment., Results: Of the 252 patients randomized, there were 99 participants available for analysis. At 2 h post-treatment, pain relief was achieved in 66.7% of the participants using REN versus 52.5% participants with usual care (p < 0.05). Pain relief at 2 h in at least one of two attacks was achieved by 84.4% of participants versus 68.9% in usual care (p < 0.05). REN and usual care were similarly effective for pain-free status at 2 h. The results also demonstrate the non-inferiority of REN compared with acute pharmacological treatments and its non-dependency on preventive medication use., Conclusion: REN is an effective acute treatment for migraine with non-inferior efficacy compared to current acute migraine therapies. Together with a very favorable safety profile, these findings suggest that REN may offer a promising alternative for the acute treatment of migraine and could be considered first line treatment in some patients., Trial Registration: ClinicalTrials.gov NCT03361423 . Registered 18 November 2017.

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by cognitive deficits, deposition of amyloid-β (Aβ) plaques, intracellular neurofibrillary tangles, and neuronal cell death. Neuroinflammation is commonly believed to participate in AD pathogenesis. CD44 is an inflammation-related gene encoding a widely-distributed family of alternatively spliced cell surface glycoproteins that have been implicated in inflammation, metastases, and inflammation-linked neuronal injuries. Here we investigated the expression patterns of CD44S (which does not contain any alternative exon) and CD44 splice variants in postmortem hippocampal samples from AD patients and matched non-AD controls. The expression of CD44S and CD44 splice variants CD44V3, CD44V6, and CD44V10 was significantly higher in AD patients compared to non-AD controls. Immunohistochemistry of human hippocampal sections revealed that CD44S differentially localized to neuritic plaques and astrocytes, whereas CD44V3, CD44V6, and CD44V10 expression was mostly neuronal. Consistent with these findings, we found that the expression of CD44V6 and CD44V10 was induced by Aβ peptide in neuroblastoma cells and primary neurons. Furthermore, in loss of function studies we found that both CD44V10-specific siRNA and CD44V10 antibody protected neuronal cells from Aβ-induced toxicity, suggesting a causal relationship between CD44V10 and neuronal cell death. These data indicate that certain CD44 splice variants contribute to AD pathology and that CD44V10 inhibition may serve as a new neuroprotective treatment strategy for this disease.

Runx3 protein products that are translated from the distal (P1)- and proximal (P2)-promoter transcripts appear on Western blots as a 47-46kDa doublet corresponding to full-length proteins bearing the P1- and P2-N-termini respectively. An additional 44kDa protein band, the origin and nature of which was unclear, is also detected. Transfection of full-length Runx3 cDNA bearing the P2 N-terminus (P2-cDNA) into HEK293 cells resulted in expression of both 46 and 44kDa proteins. Sequence analysis of the P2-cDNA revealed an in-frame ATG 90bp downstream (+90ATG) of the proximal +1ATG. Insertion of an N-terminal HA-tag into P2-cDNA immediately downstream of the +1ATG produced HA-tagged 46kDa and untagged 44kDa proteins, consistent with the possibility that the latter was translated through initiation at the internal +90ATG site. Deleting or blocking the activity of the +1ATG, the natural cap-dependent translation initiation site in P2-cDNA, abrogated production of the 46kDa Runx3 protein while facilitating production of the 44kDa product. These findings supported the notion that Runx3 44kDa protein resulted from internal translation initiation at the +90ATG. Northern blot and RT-PCR analyses performed on RNA from P2-cDNA transfected cells showed a single transcript and product respectively, of the expected size, ruling out the possibility that the 44kDa protein was translated from transcripts originating at a cryptic promoter or produced by alternative splicing. Taken together, the data indicate that the 44kDa protein results from translation initiation at the internal ATG and that Runx3, like its family members Runx1 and Runx2, contains a mechanism for internal mRNA translation initiation., (2010 Elsevier Inc. All rights reserved.)

Iron uptake and storage are tightly regulated to guarantee sufficient iron for essential cellular processes and to prevent the production of damaging free radicals. The placenta is the entry site for iron, which is delivered to the developing embryo. Iron is taken up by syncytiotrophoblast cells and is transported unidirectionally from mother to fetus against a concentration gradient. Several iron transporters and regulators were recently characterized, including DMT1 and ferroportin/Ireg1 that transport iron through membranes, and HFE that regulates TfR-mediated iron uptake. In this study we demonstrate that in a differentiated choriocarcinoma cell line BeWo, HFE, and TfR are localized mainly in recycling endosomes and a small percentage of these complexes is observed in late endosomes with DMT1 while in trophoblast cells, the level of TfR is significantly lower and it is detected with HFE and DMT1 mainly in late endosomes. Most interestingly, TfR and HFE, as well as TfR and DMT1 interact in placental trophoblast cells. Based on previous and these data we suggest that the level of intracellular iron may regulate both TfR expression (on the post-transcriptional and the post-translational levels) and TfR trafficking/transcytosis in polarized cells., (Copyright 2005 Wiley-Liss, Inc.)