Poor survival of human pluripotent stem cells (hPSCs) following freezing, thawing, or passaging hinders the maintenance and differentiation of stem cells. Rho-associated kinases (ROCKs) play a crucial role in hPSC survival. To date, a typical ROCK inhibitor, Y-27632, has been the primary agent used in hPSC research. Here, we report that another ROCK inhibitor, fasudil, can be used as an alternative and is cheaper than Y-27632. It increased hPSC growth following thawing and passaging, like Y-27632, and did not affect pluripotency, differentiation ability, and chromosome integrity. Furthermore, fasudil promoted retinal pigment epithelium (RPE) differentiation and the survival of neural crest cells (NCCs) during differentiation. It was also useful for single-cell passaging of hPSCs and during aggregation. These findings suggest that fasudil can replace Y-27632 for use in stem research.

Presbycusis, also referred to as age-related hearing loss (ARHL), is a multifaceted condition caused by the natural aging process affecting the auditory system. Genome-wide association studies (GWAS) in human populations can identify potential genes linked to ARHL. Despite this, our knowledge of the biochemical and molecular mechanisms behind the condition remains incomplete. This study aims to evaluate a potential protective tool for ARHL treatment by comparing human blood-based target gene-miRNA associations regulated in ARHL. To identify promising target genes for ARHL, we utilized an mRNA assay. To determine the role of miRNA in ARHL, we investigated the expression profile of miRNA in whole blood in ARHL patients with real-time polymerase chain reaction (RT-qPCR). A reporter gene assay was performed to confirm the regulation of candidate genes by microRNA. Through RT-qPCR validation analysis, we finally confirmed the relationship between ARHL and the role of the interferon-gamma (IFNG) gene. This gene can be regarded as an age-related gene. Through gene ontology (GO) analysis, it has been found that these genes are enriched in pathways related to apoptosis. Among them, IFNG induces an inflammatory response, apoptotic cell death, and cellular senescence. We found that miR-409-3p downregulates the expression of the IFNG in vitro. In addition, the downregulation of the IFNG by miRNA 409-3p promoted cell apoptosis and suppressed proliferation. In conclusion, our study produced gene signatures and associated microRNA regulation that could be a protective key for ARHL patients. IFNG genes and miR-409-3p should be investigated for their usefulness as a new biomarker for treatment modality.

Bitnara Kim, Seongjun So, Jiwan Choi, Eunju Kang and Yeonmi Lee. Journal of Animal Reproduction and Biotechnology 2022;37:48-54. https://doi.org/10.12750/JARB.37.1.48

Objectives. This study evaluated the effects of sarpogrelate, a selective 5-hydroxytryptamine (5-HT) 2A receptor antagonist, on the preservation of residual hearing and modulation of inflammatory responses following cochlear implantation (CI) in an animal model.Methods. The damaging effects of CI were simulated in male albino guinea pigs using a dummy electrode. Animals were allocated to three groups: control (n=12, dummy electrode insertion only), SPG-1004 (n=7, low-capacity pump delivering sarpogrelate), and SPG-2004 (n=6, high-capacity pump delivering sarpogrelate). Sarpogrelate was administered via osmotic pumps at two different volumes, and its effects on hearing thresholds, histological outcomes, and expression of inflammation-related genes were assessed. Hearing was evaluated using auditory brainstem response (ABR) thresholds measured at baseline (preoperatively) and at 1, 7, and 30 days postoperatively.Results. Administration of sarpogrelate via an osmotic pump resulted in significant hearing preservation across all tested frequencies at 1 month post-surgery (P<0.05) compared with the control group, which underwent dummy electrode insertion only. Histological analysis revealed that cochlear fibrosis and inflammatory cell infiltration were markedly reduced in the sarpogrelate-treated groups, especially in the group receiving the higher pump volume. Gene expression analysis supported these findings by showing a significant reduction in inflammation-related markers in the sarpogrelate-treated groups.Conclusion. Sarpogrelate exhibited a protective effect against the loss of residual hearing after CI, likely due to its anti-inflammatory and antifibrotic properties. In addition, the osmotic pump enabled controlled, sustained delivery of the drug over time. These findings indicate that administering sarpogrelate via an osmotic pump represents a promising pharmacological strategy for improving postoperative outcomes in CI patients by preserving residual hearing.

Poor survival of human pluripotent stem cells (hPSCs) following freezing, thawing, or passaging hinders maintenance and differentiation in stem cell research. Rho-associated kinases (ROCKs) play a crucial role in hPSC survival. To date, a typical ROCK inhibitor, Y-27632, has been the primary agent used in hPSC research. Here, we report that another ROCK inhibitor, fasudil, can be used as an alternative. Fasudil increased hPSC growth due to survival rather than proliferation following thawing and passaging, similar to Y-27632. It did not affect pluripotency and genetic integrity including mitochondrial genome (mtDNA). Notably, the genes related to metabolism, mTORC1, and TP53 have mainly displayed a faster recovery pattern with ROCK inhibitors than control. Furthermore, fasudil was confirmed as useful for the single dissociation of hPSCs and for aggregation. It also increased retinal pigment epithelium (RPE) differentiation and the survival of neural crest cells during differentiation. These findings suggest that fasudil can replace Y-27632 for use in stem cell research.