Ovariectomy drives increase of an ECM transcription signature in the posterior eye and retina.

Increased risk of developing glaucoma has recently been associated with early age of menopause. Here, we examined how age and surgically-induced menopause via ovariectomy (OVX) impacted gene expression in gene pathways previously linked to glaucoma, such as extracellular matrix (ECM) remodeling and TGF-ß signaling. Using bulk RNA sequencing, we analyzed changes in young (3-4 months) and middle-aged (9-10 months) Long-Evans rats. We focused on posterior pole tissues (sclera and optic nerve head) but also examined the retina to compare observed changes across different tissue regions. Our results demonstrated that aging and OVX significantly alter gene expression in the sclera and optic nerve head. Generally, OVX triggered the enrichment of immune-related processes. However, OVX in young rats also led to significant enrichment of ECM and TGF-ß gene sets. At the same time, these effects were diminished in middle-aged rats, indicating an age dependency of the effects of OVX on matrix-related pathways. Notably, the transcriptional factor Fos was downregulated in the posterior eye and retina in aged and OVX animals. Fos is a major regulator of cell proliferation and survival, and its dysregulation may play an important role in aging and menopause for women. These findings underscore the important role of menopause timing in modulating molecular pathways associated with glaucoma, which is consistent with clinical studies showing that early menopause may heighten the risk of developing this condition. This study also highlights the importance of considering women's health factors, such as menopause, in understanding and managing glaucoma risk.

A method for analyzing AFM force mapping data obtained from soft tissue cryosections.

Atomic force microscopy (AFM) is a valuable tool for assessing mechanical properties of biological samples, but interpretations of measurements on whole tissues can be difficult due to the tissue's highly heterogeneous nature. To overcome such difficulties and obtain more robust estimates of tissue mechanical properties, we describe an AFM force mapping and data analysis pipeline to characterize the mechanical properties of cryosectioned soft tissues. We assessed this approach on mouse optic nerve head and rat trabecular meshwork, cornea, and sclera. Our data show that the use of repeated measurements, outlier exclusion, and log-normal data transformation increases confidence in AFM mechanical measurements, and we propose that this methodology can be broadly applied to measuring soft tissue properties from cryosections.

A Method for Analyzing AFM Force Mapping Data Obtained from Soft Tissue Cryosections.

Atomic force microscopy (AFM) is a valuable tool for assessing mechanical properties of biological samples, but interpretations of measurements on whole tissues can be difficult due to the tissue's highly heterogeneous nature. To overcome such difficulties and obtain more robust estimates of tissue mechanical properties, we describe an AFM force mapping and data analysis pipeline to characterize the mechanical properties of cryosectioned soft tissues. We assessed this approach on mouse optic nerve head and rat trabecular meshwork, cornea, and sclera. Our data show that the use of repeated measurements, outlier exclusion, and log-normal data transformation increases confidence in AFM mechanical measurements, and we propose that this methodology can be broadly applied to measuring soft tissue properties from cryosections.

Glaucoma and biomechanics.

PURPOSE OF REVIEW: Biomechanics is an important aspect of the complex family of diseases known as the glaucomas. Here, we review recent studies of biomechanics in glaucoma. RECENT FINDINGS: Several tissues have direct and/or indirect biomechanical roles in various forms of glaucoma, including the trabecular meshwork, cornea, peripapillary sclera, optic nerve head/sheath, and iris. Multiple mechanosensory mechanisms and signaling pathways continue to be identified in both the trabecular meshwork and optic nerve head. Further, the recent literature describes a variety of approaches for investigating the role of tissue biomechanics as a risk factor for glaucoma, including pathological stiffening of the trabecular meshwork, peripapillary scleral structural changes, and remodeling of the optic nerve head. Finally, there have been advances in incorporating biomechanical information in glaucoma prognoses, including corneal biomechanical parameters and iridial mechanical properties in angle-closure glaucoma. SUMMARY: Biomechanics remains an active aspect of glaucoma research, with activity in both basic science and clinical translation. However, the role of biomechanics in glaucoma remains incompletely understood. Therefore, further studies are indicated to identify novel therapeutic approaches that leverage biomechanics. Importantly, clinical translation of appropriate assays of tissue biomechanical properties in glaucoma is also needed.