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Tear secretion from the lacrimal gland is essential for maintaining ocular surface homeostasis, and its insufficiency causes aqueous-deficient dry eye. Unlike the well-established parasympathetic neuronal regulation, the role of sympathetic nervous system (SNS) in tear secretion remains controversial. Here, we demonstrate the intact sympathetic innervation in lacrimal gland and its activation under multiple dry eye stresses. Pharmacological, surgical, and genetic blockade of SNS increases tear secretion and alleviates dry eye signs. Mechanistically, SNS-driven noradrenaline (NA) release activates α1a-adrenergic receptor (Adra1a) in acinar and myoepithelial cells to regulate mitochondrial Ucp2 and tear secretion. Systemic and local delivery of Adra1a antagonists, including silodosin and tamsulosin, improves tear secretion and reduces corneal lesions in multiple dry eye mouse models. In addition, we identify the brain locus coeruleus as an upstream driver orchestrating sympathetic regulation of lacrimal secretion. Overall, these findings reveal a gatekeeper role of SNS in tear secretion and offer potential therapeutic strategies for dry eye disease.
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http://dx.doi.org/10.1038/s41467-025-60476-z | DOI Listing |
Acta Neuropathol Commun
September 2025
Department of Neurology, TUM University Hospital Munich, Munich, Germany.
The diagnosis of Amyotrophic Lateral Sclerosis (ALS) remains challenging, particularly in early stages, where characteristic symptoms may be subtle and nonspecific. The development of disease-specific and clinically validated biomarkers is crucial to optimize diagnosis. Here, we explored tear fluid (TF) as a promising ALS biomarker source, given its accessibility, anatomical proximity to the brainstem as an important site of neurodegeneration, and proven discriminative power in other neurodegenerative diseases.
View Article and Find Full Text PDFRheumatol Int
September 2025
Department of General and Specialistic Medicine Rheumatology Unit, Azienda Ospedaliero Universitaria Città della Salute e della Scienza di Torino, Turin, Italy.
Polymyalgia rheumatica (PMR) is a common inflammatory disorder in the elderly, characterized by pain and stiffness in the shoulder and pelvic girdles. The diagnosis of PMR may be challenging due to its nonspecific clinical features and overlap with other musculoskeletal conditions, such as degenerative rotator cuff tendinopathy (dRCT). Although subacromial-subdeltoid bursitis (bSAD) is included in the 2012 ACR/EULAR classification criteria for PMR, its diagnostic specificity is limited unless further ultrasound (US) parameters are considered.
View Article and Find Full Text PDFTransl Vis Sci Technol
September 2025
Vision Science Group, Herbert Wertheim School of Optometry and Vision Science, University of California - Berkeley, Berkeley, CA, USA.
Purpose: The purpose of this study was to compare the diurnal patterns of tear meniscus height (TMH), traditional Schirmer strip test (TSST) wetted length, modified Schirmer strip test (MSST) wetted length, and tear aqueous production (TAP) rate.
Methods: One hundred fourteen subjects were evaluated between 7:00 and 16:00 hours. TMH (mm) was measured with the Oculus Keratograph 5M.
J Nanobiotechnology
September 2025
Department of Ophthalmology, People's Hospital of Zhengzhou University, Henan Provincial People's Hospital, Zhengzhou, China.
Sleep deprivation (SD) and exposure to engineered nanomaterials such as silica nanoparticles (SiNPs) are emerging risk factors for ocular surface disorders, particularly dry eye disease. However, the molecular mechanisms underlying their combined impact on lacrimal gland function remain unclear. In this study, we investigated the synergistic effects of SD and SiNPs exposure on circadian regulation, oxidative stress, inflammation, and structural integrity of the extraorbital lacrimal glands (ELGs) in C57BL/6J mice.
View Article and Find Full Text PDFBMC Ophthalmol
September 2025
Experimental Ophthalmo-Biology Group, Department of Cell Biology and Histology, University of the Basque Country UPV/EHU, Barrio Sarriena S/N, Leioa, E-48940, Spain.
Background: The tear-film lipid layer (TFLL) constitutes the outermost barrier of the ocular surface, reducing evaporation and stabilising the tear film. In aqueous-deficient dry eye (ADDE) and Meibomian-gland dysfunction (MGD), compositional changes in the TFLL compromise this protective role. The present study was designed to characterise the tear-lipid fingerprints associated with ADDE and MGD, to compare them with those of healthy subjects, and to assess the impact of intense pulsed-light (IPL) therapy on the tear lipidome in MGD.
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