Biology subjects

Dela Cruz, C.

Publications and source records attributed to Dela Cruz, C..

5 recordsLinked to original sources

bioRxiv2026

Epithelial QKI Protects Against Emphysema by Maintaining Mitochondrial Integrity

Single-cell transcriptomic profiling of chronic obstructive pulmonary disease (COPD) lungs identified QKI, an RNA-binding protein, as a candidate emphysema-associated gene, but its epithelial role in COPD pathobiology remains unclear. We show that QKI expression is reduced in human COPD lungs and that alveolar type 2 epithelial (AT2) cell QKI protein levels correlate strongly with spirometric indices and diffusing capacity (DLCO). Lung epithelium-specific QKI knockout mice (QKI{Delta}/{Delta}) developed spontaneous airspace enlargement with emphysema-like mechanics, and QKI-deficient AT2 cells showed impaired spheroid colony formation and increased apoptosis. Integrated transcriptomic and proteomic analyses of primary AT2 cells revealed a selective reduction in functional mitochondrial (respiratory-chain and metabolic) protein abundance despite relatively preserved transcript levels, consistent with mitochondrial transcriptome-proteome discordance. QKI loss increased mtDNA abundance and TOMM20 staining but decreased ATP5A, indicating accumulation of structurally increased but functionally dysfunctional mitochondria. In human epithelial cells, CRISPR-mediated QKI deficiency reduced oxidative respiration, increased glycolytic reliance, elevated mitochondrial ROS and membrane potential, and increased apoptosis; these phenotypes were partially rescued by QKI re-expression. These findings identify epithelial QKI as a regulator of mitochondrial integrity and stress tolerance in COPD.

cell biology↗

bioRxiv2025

Integrative Single-Cell RNA and ATAC Sequencing Reveals the Impact of Chronic Cigarette Smoking on Lung Epithelial Responses to Influenza and Hyperoxia

Cigarette smoke (CS) is a significant risk factor for developing acute respiratory distress syndrome (ARDS), but the cellular and molecular mechanisms linking smoking to ARDS susceptibility remain unclear. Our goal was to improve our understanding of these mechanisms. To address this, we established a mouse model comparing long-term CS exposure to non-smoking controls, examining responses to influenza infection and hyperoxia-induced lung injury. The mice were divided into six groups (n=1 per group): control (CON), cigarette smoke (CS), hyperoxia (HYP), influenza infection (FLU), cigarette smoke plus hyperoxia (CS+HYP), and cigarette smoke plus influenza infection (CS+FLU). Single-cell RNA sequencing (scRNA-seq) and single-cell ATAC sequencing (scATAC-seq) were performed on lung tissues. Quality control analysis using Seurat (v5.1.0) and Signac (v1.13.1) retained 78,402 cells from scRNA-seq and 84,144 cells from scATAC-seq, with 32,305 matched cells identified across both datasets. Differential gene expression analysis revealed significant smoking-associated alterations in cellular responses to influenza infection and hyperoxia exposure. Pathway enrichment indicated heightened immune responses, inflammatory signaling, and cellular survival pathways in smoking-exposed animals. Integration of scRNA-seq and scATAC-seq identified key transcription factors (TFs), including those involved in immune regulation, tissue repair, and chromatin remodeling mediating these responses. Overall, this study underscores the role of chronic cigarette smoke exposure in exacerbating pathways critical to ARDS pathogenesis, providing potential targets for therapeutic intervention.

bioinformatics↗

bioRxiv2023

Bone quality following peripubertal growth in a mouse model of transmasculine gender-affirming hormone therapy

During peri-puberty, bone growth and the attainment peak bone mass is driven predominantly by sex steroids. This is important when treating transgender and gender diverse youth, who have become increasingly present at pediatric clinics. Analogues of gonadotropin-releasing hormone (GnRH) are commonly prescribed to transgender and gender diverse youth prior to starting gender-affirming hormone therapy (GAHT). However, the impact of GnRH agonists on long bones with the addition of GAHT is relatively unknown. To explore this, we developed a trans-masculine model by introducing either GnRHa or vehicle treatment to female-born mice at a pre-pubertal age. This treatment was followed by male GAHT (testosterone, T) or control treatment three weeks later. Six weeks after T therapy, bone quality was compared between four treatment groups: Control (vehicle only), GnRHa-only, GnRHa + T, and T-only. Bone length/size, bone shape, mechanical properties, and trabecular morphology were modulated by GAHT. Independent of GnRHa administration, mice treated with T had shorter femurs, larger trabecular volume and increased trabecular number, higher trabecular bone mineral density, and wider superstructures on the surface of bone (e.g., third trochanters) when compared to control or GnRHa-only mice. In conclusion, prolonged treatment of GnRHa with subsequent GAHT treatment directly affect the composition, parameters, and morphology of the developing long bone. These findings provide insight to help guide clinical approaches to care for transgender and gender diverse youth.

physiology↗

bioRxiv2021

No evidence of fetal defects or anti-syncytin-1 antibody induction following COVID-19 mRNA vaccination

The impact of coronavirus disease 2019 (COVID-19) mRNA vaccination on pregnancy and fertility has become a major topic of public interest. We investigated two of the most widely propagated claims to determine 1) whether COVID-19 mRNA vaccination of mice during early pregnancy is associated with an increased incidence of birth defects or growth abnormalities, and 2) whether COVID-19 mRNA-vaccinated human volunteers exhibit elevated levels of antibodies to the human placental protein syncytin-1. Using a mouse model, we found that intramuscular COVID-19 mRNA vaccination during early pregnancy at gestational age E7.5 did not lead to differences in fetal size by crown-rump length or weight at term, nor did we observe any gross birth defects. In contrast, injection of the TLR3 agonist and double-stranded RNA mimic polyinosinic-polycytidylic acid, or poly(I:C), impacted growth in utero leading to reduced fetal size. No overt maternal illness following either vaccination or poly(I:C) exposure was observed. We also found that term fetuses from vaccinated murine pregnancies exhibit high circulating levels of anti-Spike and anti-RBD antibodies to SARS-CoV-2 consistent with maternal antibody status, indicating transplacental transfer. Finally, we did not detect increased levels of circulating anti-syncytin-1 antibodies in a cohort of COVID-19 vaccinated adults compared to unvaccinated adults by ELISA. Our findings contradict popular claims associating COVID-19 mRNA vaccination with infertility and adverse neonatal outcomes.

immunology↗

bioRxiv2020

Detection of SARS-CoV-2 RNA by multiplex RT-qPCR

The current RT-qPCR assay recommended for SARS-CoV-2 testing in the United States requires analysis of three genomic targets per sample: two viral and one host. To simplify testing and reduce the volume of required reagents, we developed a multiplex RT-qPCR assay to detect SARS-CoV-2 in a single reaction. We used existing N1, N2, and RP primer and probe sets by the CDC, but substituted fluorophores to allow multiplexing of the assay. The cycle threshold (Ct) values of our multiplex RT-qPCR were comparable to those obtained by the singleplex assay adapted for research purposes. Low copies (>500 copies / reaction) of SARS-CoV-2 RNA were consistently detected by the multiplex RT-qPCR. Our novel multiplex RT-qPCR improves upon current singleplex diagnostics by saving reagents, costs, time and labor.

microbiology↗