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Steroid hormones are important modulators of many physiological processes, and measurements of steroids in blood, saliva, and urine matrices are widely used to assess endocrine pathologies and stress. However, these matrices cannot be used to retrospectively assess early-life stress and developmental endocrine pathologies, because they do not integrate steroid levels over the long term. A novel biological matrix in which to measure steroids is primary teeth (or "baby teeth"). Primary teeth develop early in life and accumulate various endogenous molecules during their gradual formation. Here, we developed and validated the first assay to measure steroids in human primary teeth using liquid chromatography-tandem spectrometry (LC-MS/MS). Our assay is highly sensitive, specific, accurate, and precise. It allows for the simultaneous quantification of 17 steroids in primary teeth (16 of which have not been examined previously in primary teeth). Overall, steroid levels in primary teeth were relatively low, and 8 steroids were quantifiable. Levels of dehydroepiandrosterone, cortisol, and progesterone were the highest of the 17 steroids examined. Next, we used this assay to perform steroid profiling in primary teeth from males and females. The same 8 steroids were quantifiable, and no sex differences were found. Levels of androgens (androstenedione and testosterone) were positively correlated, and levels of glucocorticoids (cortisol, cortisone, corticosterone, 11-dehydrocorticosterone) were also positively correlated. These data demonstrate that multiple steroids can be quantified by LC-MS/MS in human primary teeth, and this method potentially provides a powerful new way to retrospectively assess early-life stress and developmental endocrine pathologies. [ABSTRACT FROM AUTHOR]

INTRODUCTION: Biomarkers of TDP‐43 pathology are needed to distinguish frontotemporal lobar degeneration with TDP‐43 pathology (FTLD‐TDP) from phenotypically related disorders. While normal physiological TDP‐43 is not a promising biomarker, low‐resolution techniques have suggested truncated forms of TDP‐43 may be specific to TDP‐43 pathology. To advance biomarker efforts for FTLD‐TDP, we employed a high‐resolution structural technique to characterize TDP‐43 post‐translational modifications in FTLD‐TDP. METHODS: High‐resolution mass spectrometry was used to characterize TDP‐43 proteoforms in brain tissue from FTLD‐TDP, non‐TDP‐43 dementias and neuropathologically unaffected cases. Findings were then verified in a larger cohort of FTLD‐TDP and non‐TDP‐43 dementias via targeted quantitative mass spectrometry. RESULTS: In the discovery phase, truncated TDP‐43 identified FTLD‐TDP with 85% sensitivity and 100% specificity. The verification phase revealed similar findings, with 83% sensitivity and 89% specificity. DISCUSSION: The concentration of truncated TDP‐43 proteoforms—in particular, in vivo generated C‐terminal fragments—have high diagnostic accuracy for FTLD‐TDP. Highlights: Discovery: Truncated TDP‐43 differentiates FTLD‐TDP from related dementias.Verification: Truncated TDP‐43 concentration has high accuracy for FTLD‐TDP.TDP‐43 proteoforms <28 kDa have highest discriminatory power for TDP‐43 pathology. [ABSTRACT FROM AUTHOR]

Glucocorticoids (GCs) are critical modulators of the immune system. The hypothalamic-pituitary-adrenal (HPA) axis regulates circulating GC levels and is stimulated by endotoxins. Lymphoid organs also produce GCs; however, it is not known how lymphoid GC levels are regulated in response to endotoxins. We assessed whether an acute challenge of lipopolysaccharide (LPS) increases lymphoid levels of progesterone and GCs, and expression of steroidogenic enzymes and key HPA axis components (eg, corticotropin-releasing hormone [CRH], adrenocorticotropic hormone [ACTH]). We administered LPS (50 µg/kg intraperitoneally) or vehicle control to male and female C57BL/6J neonatal (postnatal day [PND] 5) and adult (PND90) mice and collected blood, bone marrow, thymus, and spleen 4 hours later. We measured progesterone, 11-deoxycorticosterone, corticosterone, and 11-dehydrocorticosterone via liquid chromatography–tandem mass spectrometry. We measured gene expression of key steroidogenic enzymes (Cyp11b1 , Hsd11b1 , and Hsd11b2) and HPA axis components (Crh , Crhr1 , Pomc , and Mc2r) via quantitative polymerase chain reaction. At PND5, LPS induced greater increases in steroid levels in lymphoid organs than in blood. In contrast, at PND90, LPS induced greater increases in steroid levels in blood than in lymphoid organs. Steroidogenic enzyme transcripts were present in all lymphoid organs, and LPS altered steroidogenic enzyme expression predominantly in the spleen. Lastly, we detected transcripts of key HPA axis components in all lymphoid organs, and there was an effect of LPS in the spleen. Taken together, these data suggest that LPS regulates GC production by lymphoid organs, similar to its effects on the adrenal glands, and the effects of LPS might be mediated by local expression of CRH and ACTH. [ABSTRACT FROM AUTHOR]

Despite recent advances in understanding the connection between the gut microbiota and the adult brain, there remains a wide knowledge gap in how gut inflammation impacts brain development. We hypothesized that intestinal inflammation in early life would negatively affect neurodevelopment through dysregulation of microbiota communication to the brain. We therefore developed a novel pediatric chemical model of inflammatory bowel disease (IBD), an incurable condition affecting millions of people worldwide. IBD is characterized by chronic intestinal inflammation, and has comorbid symptoms of anxiety, depression and cognitive impairment. Significantly, 25% of patients with IBD are diagnosed during childhood, and the effect of chronic inflammation during this critical period of development is largely unknown. This study investigated the effects of early-life gut inflammation induced by DSS (dextran sulfate sodium) on a range of microbiota, endocrine, and behavioral outcomes, focusing on sex-specific impacts. DSS-treated mice exhibited increased intestinal inflammation, altered microbiota membership, and changes in microbiota-mediated circulating metabolites. The majority of behavioral measures were unaffected, with the exception of impaired mate-seeking behaviors in DSS-treated males. DSS-treated males also showed significantly smaller seminal vesicles, lower circulating androgens, and decreased intestinal hormone-activating enzyme activity. In the brain, microglia morphology was chronically altered with DSS treatment in a sex-specific manner. The results suggest that early-life gut inflammation causes changes in gut microbiota composition, affecting short-chain fatty acid (SCFA) producers and glucuronidase (GUS) activity, correlating with altered SCFA and androgen levels. The findings emphasize the developmental sensitivity to inflammation-induced changes in endocrine signalling and underscore long-lasting physiological and microbiome changes associated with juvenile IBD., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Introduction: Biomarkers of TDP-43 pathology are needed to distinguish frontotemporal lobar degeneration with TDP-43 pathology (FTLD-TDP) from phenotypically related disorders. While normal physiological TDP-43 is not a promising biomarker, low-resolution techniques have suggested truncated forms of TDP-43 may be specific to TDP-43 pathology. To advance biomarker efforts for FTLD-TDP, we employed a high-resolution structural technique to characterize TDP-43 post-translational modifications in FTLD-TDP., Methods: High-resolution mass spectrometry was used to characterize TDP-43 proteoforms in brain tissue from FTLD-TDP, non-TDP-43 dementias and neuropathologically unaffected cases. Findings were then verified in a larger cohort of FTLD-TDP and non-TDP-43 dementias via targeted quantitative mass spectrometry., Results: In the discovery phase, truncated TDP-43 identified FTLD-TDP with 85% sensitivity and 100% specificity. The verification phase revealed similar findings, with 83% sensitivity and 89% specificity., Discussion: The concentration of truncated TDP-43 proteoforms-in particular, in vivo generated C-terminal fragments-have high diagnostic accuracy for FTLD-TDP., Highlights: Discovery: Truncated TDP-43 differentiates FTLD-TDP from related dementias. Verification: Truncated TDP-43 concentration has high accuracy for FTLD-TDP. TDP-43 proteoforms <28 kDa have highest discriminatory power for TDP-43 pathology., (© 2023 The Authors. Alzheimer's & Dementia published by Wiley Periodicals LLC on behalf of Alzheimer's Association.)