Knockdown of Fibromodulin Inhibits Proliferation and Migration of RPE Cell via the VEGFR2-AKT Pathway

FMOD Alleviates Depression-Like Behaviors by Targeting the PI3K/AKT/mTOR Signaling After Traumatic Brain Injury

Depression frequently occurs following traumatic brain injury (TBI). However, the role of Fibromodulin (FMOD) in TBI-related depression is not yet clear. Previous studies have suggested FMOD as a potential key factor in TBI, yet its association with depression post-TBI and underlying mechanisms are not well understood. Serum levels of FMOD were measured in patients with traumatic brain injury using qPCR. The severity of depression was assessed using the self-depression scale (SDS). Neurological function, depressive state, and cognitive function in mice were assessed using the modified Neurological Severity Score (mNSS), forced swimming test (FST), tail suspension test (TST), Sucrose Preference Test (SPT), and morris water maze (MWM). The morphological features of mouse hippocampal synapses and neuronal dendritic spines were revealed through immunofluorescence, transmission electron microscopy, and Golgi-Cox staining. The protein expression levels of FMOD, MAP2, SYP, and PSD95, as well as the phosphorylation levels of the PI3K/AKT/mTOR signaling pathway, were detected through Western blotting. FMOD levels were decreased in TBI patients' serum. Overexpression of FMOD preserved neuronal function and alleviated depression-like behaviour, increased synaptic protein expression, and induced ultrastructural changes in hippocampal neurons. The increased phosphorylation of PI3K, AKT, and mTOR suggested the involvement of the PI3K/AKT/mTOR signaling pathway in FMOD's protective effects. FMOD exhibits potential as a therapeutic target for depression related to TBI, with its protective effects potentially mediated through the PI3K/AKT/mTOR signaling pathway.

What's the situation with ocular inflammation? A cross-seasonal investigation of proteomic changes in ocular allergy sufferers' tears in Victoria, Australia

Background

Ocular allergy (OA) is a localized subset of allergy characterized by ocular surface itchiness, redness and inflammation. Inflammation and eye-rubbing, due to allergy-associated itch, are common in OA sufferers and may trigger changes to the ocular surface biochemistry. The primary aim of this study is to assess the differences in the human tear proteome between OA sufferers and Healthy Controls (HCs) across peak allergy season and off-peak season in Victoria, Australia.

Methods

19 participants (14 OA sufferers, 5 HCs) aged 18-45 were recruited for this study. Participants were grouped based on allergy symptom assessment questionnaire scoring. Proteins were extracted from human tear samples and were run on an Orbitrap Mass Spectrometer. Peaks were matched to a DIA library. Data was analyzed using the software MaxQuant, Perseus and IBM SPSS.

Results

1267 proteins were identified in tear samples of OA sufferers and HCs. 23 proteins were differentially expressed between peak allergy season OA suffers vs HCs, and 21 were differentially expressed in off-peak season. Decreased proteins in OA sufferers related to cell structure regulation, inflammatory regulation and antimicrobial regulation. In both seasons, OA sufferers were shown to have increased expression of proteins relating to inflammation, immune responses and cellular development.

Conclusion

Tear protein identification showed dysregulation of proteins involved in inflammation, immunity and cellular structures. Proteins relating to cellular structure may suggest a possible link between OA-associated itch and the subsequent ocular surface damage via eye-rubbing, while inflammatory and immune protein changes highlight potential diagnostic and therapeutic biomarkers of OA.

In vitro laboratory models of proliferative vitreoretinopathy

Proliferative vitreoretinopathy (PVR), the most common cause of recurrent retinal detachment, is characterized by the formation and contraction of fibrotic membranes on the surface of the retina. There are no Food and Drug Administration (FDA)-approved drugs to prevent or treat PVR. Therefore, it is necessary to develop accurate in vitro models of the disease that will enable researchers to screen drug candidates and prioritize the most promising candidates for clinical studies. We provide a summary of recent in vitro PVR models, as well as avenues for model improvement. Several in vitro PVR models were identified, including various types of cell cultures. Additionally, novel techniques that have not been used to model PVR were identified, including organoids, hydrogels, and organ-on-a-chip models. Novel ideas for improving in vitro PVR models are highlighted. Researchers may consult this review to help design in vitro models of PVR, which will aid in the development of therapies to treat the disease.

Effect of NK-5962 on Gene Expression Profiling of Retina in a Rat Model of Retinitis Pigmentosa

Purpose: NK-5962 is a key component of photoelectric dye-coupled polyethylene film, designated Okayama University type-retinal prosthesis (OUReP™). Previously, we found that NK-5962 solution could reduce the number of apoptotic photoreceptors in the eyes of the Royal College of Surgeons (RCS) rats by intravitreal injection under a 12 h light/dark cycle. This study aimed to explore possible molecular mechanisms underlying the anti-apoptotic effect of NK-5962 in the retina of RCS rats. Methods: RCS rats received intravitreal injections of NK-5962 solution in the left eye at the age of 3 and 4 weeks, before the age of 5 weeks when the speed in the apoptotic degeneration of photoreceptors reaches its peak. The vehicle-treated right eyes served as controls. All rats were housed under a 12 h light/dark cycle, and the retinas were dissected out at the age of 5 weeks for RNA sequence (RNA-seq) analysis. For the functional annotation of differentially expressed genes (DEGs), the Metascape and DAVID databases were used. Results: In total, 55 up-regulated DEGs, and one down-regulated gene (LYVE1) were found to be common among samples treated with NK-5962. These DEGs were analyzed using Gene Ontology (GO) term enrichment, Kyoto Encyclopedia of Genes and Genomes (KEGG), and Reactome pathway analyses. We focused on the up-regulated DEGs that were enriched in extracellular matrix organization, extracellular exosome, and PI3K–Akt signaling pathways. These terms and pathways may relate to mechanisms to protect photoreceptor cells. Moreover, our analyses suggest that SERPINF1, which encodes pigment epithelium-derived factor (PEDF), is one of the key regulatory genes involved in the anti-apoptotic effect of NK-5962 in RCS rat retinas. Conclusions: Our findings suggest that photoelectric dye NK-5962 may delay apoptotic death of photoreceptor cells in RCS rats by up-regulating genes related to extracellular matrix organization, extracellular exosome, and PI3K–Akt signaling pathways. Overall, our RNA-seq and bioinformatics analyses provide insights in the transcriptome responses in the dystrophic RCS rat retinas that were induced by NK-5962 intravitreal injection and offer potential target genes for developing new therapeutic strategies for patients with retinitis pigmentosa.

The HDAC/HSP90 Inhibitor G570 Attenuated Blue Light-Induced Cell Migration in RPE Cells and Neovascularization in Mice through Decreased VEGF Production

Age-related macular degeneration (AMD) occurs due to an abnormality of retinal pigment epithelium (RPE) cells that leads to gradual degeneration of the macula. Currently, AMD drug pipelines are endowed with limited options, and anti-VEGF agents stand as the dominantly employed therapy. Despite the proven efficacy of such agents, the evidenced side effects associated with their use underscore the need to elucidate other mechanisms involved and identify additional molecular targets for the sake of therapy improvement. The previous literature provided us with a solid rationale to preliminarily explore the potential of selective HDAC6 and HSP90 inhibitors to treat wet AMD. Rather than furnishing single-target agents (either HDAC6 or HSP90 inhibitor), this study recruited scaffolds endowed with the ability to concomitantly modulate both targets (HDAC6 and HSP90) for exploration. This plan was anticipated to accomplish the important goal of extracting amplified benefits via dual inhibition (HDAC6/HSP90) in wet AMD. As a result, G570 (indoline-based hydroxamate), a dual selective HDAC6-HSP90 inhibitor exerting its effects at micromolar concentrations, was pinpointed in the present endeavor to attenuate blue light-induced cell migration and retinal neovascularization by inhibiting VEGF production. In addition to the identification of a potential chemical tool (G570), the outcome of this study validates the candidate HDAC6-HSP90 as a compelling target for the development of futuristic therapeutics for wet AMD.

PODNL1 promotes cell proliferation and migration in glioma via regulating Akt/mTOR pathway

Background and Aims: Emerging studies have determined that the small leucine-rich proteoglycan (SLRP) family can aggravate tumor progression. However, the biological function of podocan-like protein 1 (PODNL1), a novel member of the SLRP family, has not been investigated. Therefore, our study focused on the function and regulatory mechanism of PODNL1 in glioma.

Methods: Both the Gene Expression Profiling Interactive Analysis (GEPIA) and the Chinese Glioma Genome Atlas (CGGA) database were used to analyze the expression level and survival risk of PODNL1 in glioma. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot were applied to detect the mRNA and protein expression, respectively. Celltiter-Glo and colony formation assays were used to evaluate cell proliferation. Migration capacity was measured by Transwell and wound healing assays. Flow cytometry was utilized to assess the apoptotic rate.

Results: The expression of PODNL1 predicted the poor prognosis in glioma patients. Silencing of PODNL1 inhibited cell proliferation, migration, and induced epithelial-like phenotype. In addition, knockdown of PODNL1 also induced cell apoptosis. Moreover, the cell growth and migration inhibited by PODNL1 knockdown could be partially rescued with Akt activator. Conversely, PODNL1 overexpression promoted cell growth and migration, which were suppressed by Akt inhibitor.

Conclusions: PODNL1, a promising predictive indicator of poor prognosis, resulted in greater proliferation, migration and epithelial-mesenchymal transition (EMT) process. Moreover, PODNL1 promoted aggressive glioma behavior by activating Akt/mTOR pathway, providing a novel therapeutic target for glioma.

Fibromodulin Modulates Chicken Skeletal Muscle Development via the Transforming Growth Factor-β Signaling Pathway

Simple Summary

Fibromodulin (Fmod) plays critical roles in skeletal muscle development and maintenance, but the roles of Fmod in skeletal muscle atrophy and development in chickens are unclear. Here, we demonstrate that Fmod plays important roles in the differentiation and atrophy of chicken skeletal muscle by regulating the transforming growth factor-β signaling pathway. These results suggest that Fmod plays important roles in skeletal muscle growth and development in chickens.

Abstract

Fibromodulin (Fmod), which is an extracellular matrix protein, belongs to the extracellular matrix small-leucine-rich proteoglycan family. Fmod is abundantly expressed in muscles and connective tissues and is involved in biological regulation processes, including cell apoptosis, cell adhesion, and modulation of cytokine activity. Fmod is the main regulator of myostatin, which controls the development of muscle cells, but its regulatory path is unknown. Chicken models are ideal for studying embryonic skeletal muscle development; therefore, to investigate the mechanism of Fmod in muscle development, Fmod-silenced and Fmod-overexpressed chicken myoblasts were constructed. The results showed that Fmod plays a positive role in differentiation by detecting the expression of myogenic differentiation markers, immunofluorescence of MyHC protein, and myotube formation in myoblasts. Fmod regulates expression of atrophy-related genes to alleviate muscle atrophy, which was confirmed by histological analysis of breast muscles in Fmod-modulated chicks in vivo. Additionally, genes differentially expressed between Fmod knockdown and normal myoblasts were enriched in the signaling pathway of transforming growth factor β (TGF-β). Both Fmod-silenced and Fmod-overexpressed myoblasts regulated the expression of TGFBR1 and p-Smad3. Thus, Fmod can promote differentiation but not proliferation of myoblasts by regulating the TGF-β signaling pathway, which may serve a function in muscular atrophy.