The distribution of conjunctival goblet cells in mice

Ocular Surface Changes Differ Significantly Between Oxaliplatin- and Diabetes-Induced Polyneuropathy

Dry eye disease (DED) is often seen in patients with polyneuropathies (PNs), but the relationship between the different forms of PNs and DED is not known. In oxaliplatin (Ox-)-treated mice with PNs, morphological changes in the sciatic nerve (SN), dorsal root ganglia (DRG), trigeminal ganglia (TG), and the ocular tissues involved in tear formation were investigated. In addition, the tear proteomics and the gene expression of related proteins in the ocular surface tissues as well as inflammatory factors were analyzed. There were significant changes in six tear proteins compared to the controls, with respective changes in gene expression in the ocular tissues. Morphologically, there was a decrease in the number of conjunctival goblet cells and changes in the myofibroblasts surrounding the Meibomian glands. The lacrimal gland appeared normal. In the SN, there was a slight decrease in the number of mitochondria without signs of inflammation. In the DRG, 30-50% of the small- and medium-sized neuronal cells had swollen mitochondria. In contrast, the mitochondria of the TG were unremarkable. The changes in the tear film proteins and the ocular tissue morphology involved in tear formation in OPN differed significantly from those previously described in DPN mice, despite a similar mechanical hypersensitivity and similar morphological features of the DRG. In DPN, these changes led to aqueous-deficient dry eye disease, whereas in OPN, they resulted in evaporative DED. Furthermore, in contrast to DPN, the TG in OPN showed no morphological alterations, which indicates differences in the peripheral nerve changes and ocular nerve damage between the two conditions.

Ocular surface changes in mice with streptozotocin-induced diabetes and diabetic polyneuropathy

PURPOSE

Diabetes mellitus (DM) is a leading risk factor for corneal neuropathy and dry eye disease (DED). Another common consequence of DM is diabetic peripheral polyneuropathy (DPN). Both complications affect around 50 % of the DM patients but the relationship between DM, DED and DPN remains unclear.

METHODS

In this study, we examined mice with early onset of DM and PN after streptozotocin (STZ)-induced diabetes (DPN). We compared the early morphological changes of the sciatic nerve, dorsal root and trigeminal ganglia with the changes in the ocular surface, including tear proteomic and we also investigated respective changes in the gene expressions and morphological alterations in the eye tissues involved in tear production.

RESULTS

The lacrimal gland, conjunctival goblet cells and cornea showed morphological changes along with alterations in tear proteins without any obvious signs of ocular surface inflammation. The gene expression for respectively altered tear proteins i.e., of Clusterin in cornea, Car6, Adh3a1, and Eef1a1 in eyelids, and Pigr in the lacrimal gland also showed significant changes compared to control mice. In the trigeminal ganglia like in the dorsal root ganglia neuronal cells showed swollen mitochondria and, in the latter, there was a significant increase of NADPH oxidases and MMP9 suggestive of oxidative and neuronal stress. In the dorsal root ganglia and the sciatic nerve, there was an upregulation of a number of pro-inflammatory cytokines and pain-mediating chemokines.

CONCLUSION

The early ocular changes in DM Mice only affect the lacrimal gland. Which, is reflected in the tear film composition of DPN mice. Due to the high protein concentration in tear fluid in humans, proteomic analysis in addition to noninvasive investigation of goblet cells and cornea can serve as a tools for the early diagnosis of DPN, DED in clinical practice. Early treatment could delay or even prevent the ocular complications of DM such as DED and PN.

Noninvasive Imaging of Conjunctival Goblet Cells as a Method for Diagnosing Dry Eye Disease in an Experimental Mouse Model

Purpose

The purpose of this study was to evaluate a noninvasive conjunctival goblet cell (GC) imaging method for assessing dry eye disease (DED) in an experimental mouse model.

Methods

Moxifloxacin-based fluorescence microscopy (MBFM) was used to examine GCs noninvasively in 56 mice. Forty-two (42) DED-induced mice were divided into 2 groups and treated topically for 14 days with cyclosporine (CsA) or normal saline (NS). In vivo MBFM imaging and clinical DED evaluations were performed and goblet cell density (GCD) and goblet cell area (GCA) were obtained and compared with histological GCD using periodic acid-Schiff (PAS) staining. Correlation and receiver operating characteristic (ROC) analyses showed MBFM's high diagnostic value.

Results

The GCD and GCA of the DED mice obtained from in vivo MBFM imaging were highly correlated with clinical DED parameters and GCD obtained from PAS histology. The therapeutic effect of CsA, as observed by in vivo MBFM, was significant with respect to that of NS treatment. The ROC curves derived from in vivo MBFM showed high diagnostic value in assessing DED.

Conclusions

The proposed noninvasive method has high diagnostic value in assessing the severity of DED and the effect of treatment for this disease.

Translational Relevance

A noninvasive imaging method using moxifloxacin-based fluorescence microscopy was evaluated for assessing DED in an experimental mouse model. The method showed high diagnostic value in assessing the severity of DED and the effect of treatment, bridging the gap between basic research and clinical treatment. The study provides a promising tool for diagnosing and monitoring DED.

Topographical Distribution and Phenotype of Resident Meibomian Gland Orifice Immune Cells (MOICs) in Mice and the Effects of Topical Benzalkonium Chloride (BAK)

Meibomian gland orifices (MGOs) are located along the eyelid margin and secrete meibum into the tear film. The profile of resident innate immune cells (ICs) at this site is not well understood. The distribution and phenotype of resident ICs around MGOs in mice was investigated and herein defined as MGO-associated immune cells (MOICs). The effect of topical 0.1% benzalkonium chloride (BAK) on MOICs was also assessed. Eyelids from healthy CD11ceYFP and Cx3cr1gfp/gfp mice aged three or seven months were compared. ICs were identified as CD11c+, Cx3cr1+, and MHC-II+ using four-colour immunostaining and confocal microscopy. MOIC density was variable but clustered around MGOs. There were more CD11c+ MOICs in three-month-old compared with seven-month-old mice (three-month-old: 893 ± 449 cells/mm2 vs. seven-month-old: 593 ± 493 cells/mm2, p = 0.004). Along the eyelid margin, there was a decreasing gradient of CD11c+ MOIC density in three-month-old mice (nasal: 1003 ± 369 cells/mm2, vs. central: 946 ± 574 cells/mm2, vs. temporal: 731 ± 353 cells/mm2, p = 0.044). Cx3cr1-deficient mice had two-fold fewer MHC-II+ MOICs, suggesting a role for Cx3cr1 receptor signaling in meibomian gland surveillance. CD11c+ MOIC density was lower in BAK-exposed eyes compared to saline-treated controls, suggesting a change in homeostasis. This study provides novel insight into resident ICs located at MGOs, and their contribution to MG homeostasis.

The mystery behind the nostrils - technical clues for successful nasal epithelial cell cultivation

OBJECTIVES

Research involving the nose reveals important information regarding the morphology and physiology of the epithelium and its molecular response to agents. The role of nasal epithelial cells and other cell subsets within the nasal epithelium play an interesting translational split between experimental and clinical research studying respiratory disorders or pathogen reactions. With an additional technical manuscript including a detailed description of important technical aspects, tips, tricks, and nuances for a successful culturing of primary, human nasal epithelial cells (NAEPCs), we here aim to improve the process of communication between experimentalists and physicians, supporting the purpose of a fruitful work for future translational projects.

METHODS

Based on previous work on various complex culture models of subject-derived NAEPCs, this additional manuscript harmonizes previously published facts combined with own experiences for a trouble-free implementation in laboratories.

RESULTS

A well-designed experimental question is essential prior to the establishment of different NAEPCs culture models. The correct method of cell extraction from the nasal cavity is essential and represent an important basis for successful culture work. Prior enzymatic processing of biopsy specimens, cell culture materials, collagenization procedure, culture conditions, and choice of culture medium are some important practical notes that increase the quality of the culture. Moreover, protocols on imaging techniques including histologic and electron microscopy must be adapted for NAEPC culture. Adapted flow cytometric protocols and transepithelial electrical resistance measurements can add valuable information.

OUTLOOK

A successful culturing of NAEPCs can provide an important basis for genetic studies and the implementation of omics-science, which is increasingly receiving broad attention in the scientific community. The common aim of in vitro 'mini-noses' will be a breakthrough in laboratories aiming to perform research under in vivo conditions. Here, organoid models are interesting models presenting a basis for translational studies.