NAcM-OPT protects keratinocytes from H2O2-induced cell damage by promoting autophagy.

This study aimed to investigate the protective effect of NAcM-OPT, a small molecule inhibitor of defective in cullin neddylation 1 (DCN1), on H2O2-induced oxidative damage in keratinocytes. Immortalized human keratinocytes (HaCaT cells) were treated with NAcM-OPT and exposed to oxidative stress. CCK-8 assays were used to measure cell viability. The mGFP-RFP-LC3 dual fluorescent autophagy indicator system was utilized to evaluate changes in autophagic flux. Western blotting was used to measure the expression of the autophagy-related proteins LC3 and Beclin 1. Keratinocytes were treated with the autophagy activator rapamycin, and HaCaT cell supernatant was added to PIG1 cells (immortalized human melanocytes), followed by evaluation of tyrosinase (TYR) expression via qRT-PCR. NAcM-OPT increased cell viability and cell proliferation. Furthermore, this molecule promoted autophagic flux through increased expression of autophagy-related proteins under H2O2-induced oxidative stress. Additionally, rapamycin increased the mRNA levels of TYR in PIG1 cells. Moreover, NAcM-OPT alleviated mitochondrial damage, restored mitochondrial function, and upregulated the expression of NFE2L2, HO1, NQO1, and GCLM. Importantly, NAcM-OPT also increased epidermal thickness, follicle length, and melanin synthesis under oxidative stress in vivo. These findings suggest that NAcM-OPT may be a promising small molecule antioxidant drug for the treatment of vitiligo.

Systematic evaluation of single-cell RNA-seq analyses performance based on long-read sequencing platforms.

INTRODUCTION: The rapid development of next-generation sequencing (NGS)-based single-cell RNA sequencing (scRNA-seq) allows for detecting and quantifying gene expression in a high-throughput manner, providing a powerful tool for comprehensively understanding cellular function in various biological processes. However, the NGS-based scRNA-seq only quantifies gene expression and cannot reveal the exact transcript structures (isoforms) of each gene due to the limited read length. On the other hand, the long read length of third-generation sequencing (TGS) technologies, including Oxford Nanopore Technologies (ONT) and Pacific Biosciences (PacBio), enable direct reading of intact cDNA molecules. OBJECTIVES: Both ONT and PacBio have been used in conjunction with scRNA-seq, but their performance in single-cell analyses has not been systematically evaluated. METHODS: To address this, we generated ONT and PacBio data from the same single-cell cDNA libraries containing different amount of cells. RESULTS: Using NGS as a control, we assessed the performance of each platform in cell type identification. Additionally, the reliability in identifying novel isoforms and allele-specific gene/isoform expression by both platforms was verified, providing a systematic evaluation to design the sequencing strategies in single-cell transcriptome studies. CONCLUSION: Beyond gene expression analysis, which the NGS-based scRNA-seq only affords, TGS-based scRNA-seq achieved gene splicing analyses, identifying novel isoforms. Attribute to higher sequencing quality of PacBio, it outperforms ONT in accuracy of novel transcripts identification and allele-specific gene/isoform expression.

Etiologic evaluation and pregnancy outcomes of fetal growth restriction (FGR) associated with structural malformations.

This study aimed to evaluate the etiology and pregnancy outcomes of fetuses underwent invasive prenatal diagnosis for fetal growth restriction (FGR) accompanied by structural malformations. Data from 130 pregnancies referred for prenatal diagnosis for FGR accompanied by structural malformations were obtained between July 2011 and July 2023. Traditional karyotyping was conducted for all the subjects. A total of 37 (28.5%) cases of chromosomal abnormalities were detected by karyotyping, including 30 cases of numerical anomalies and seven cases of unbalanced structural anomalies. Trisomy 18 was the most common abnormalities, accounting for 51.4%, significantly higher than any other chromosomal abnormality. The cohort was predominantly comprised of early-onset FGR (88.5%) compared to late-onset FGR (11.5%). The incidences of chromosomal abnormalities in this two groups were 29.6% (34/115) and 20.0% (3/15), respectively (p > 0.05). The majority (74.6%, 97/130) of the cohort were affected by a single system malformation, with chromosomal abnormalities found in 19.6% (19/97) of cases. In pregnancies of structural malformations involving two and multiple systems, the frequencies were 56.5% (13/23), and 50.0% (5/10), respectively. Single nucleotide polymorphism array (SNP array) was performed in parallel for 65 cases, revealing additional 7.7% cases of copy number variants (CNVs) compared to karyotyping. Polymerase chain reaction (PCR) was used for detection of cytomegalovirus (CMV) DNA in 92 cases. All fetuses with FGR associated with two or more system malformations were either terminated or stillborn, irrespective of chromosomal aberrations. Conversely, 71.8% of pregnancies with a single-system malformation and normal genetic testing results resulted in live births. Furthermore, two (2.2%) cases tested positive for CMV DNA, leading to one termination and one case of serious developmental disorder after birth. Our study suggests that structural malformations associated with FGR are more likely to affect a single organ system. When multiple systems are involved, the incidence of chromosomal abnormalities and termination rates are notably high. We advocate for the use of CMA and CMV DNA examinations in FGR cases undergo invasive prenatal diagnosis, as these tests can provide valuable insights for etiological exploration and pregnancy management guidance.