Cascadia Journal of Biomedical Research - Articles

Mori, T., Ayuse, T., Sato, S., Ichinomia, T., Yano, R., Shimakura, A., Nakao, Y., Takahashi, K., Fukushima, M., Haraguchi, M., Sasaki, R., Ozawa, E., Miuma, S., Tatkov, S., Hara, T., Miyaaki, H.

Objectives Nasal high flow (NHF) improves oxygenation, reduces the work of breathing, and stabilizes ventilation. In endoscopic retrograde cholangiopancreatography (ERCP) under dexmedetomidine‐based sedation, opioids are often required but increase the risk of respiratory depression and delayed recovery. This study tested the hypothesis that NHF therapy, compared with low‐flow oxygen (LFO), may reduce opioid requirements during ERCP. Methods This open‐label, single‐center, randomized controlled trial enrolled patients undergoing ERCP under dexmedetomidine‐based sedation. Patients were randomized to NHF or LFO. Sedation used dexmedetomidine, midazolam and pethidine with a standardized protocol. The primary endpoint was total pethidine dose. Secondary endpoints included transcutaneous carbon dioxide (TcCO2), oxygenation‐perfusion parameters, processed electroencephalography (EEG) parameters, sedative doses, and sedation depth. Results Enrollment ended early at a total of 94 of the planned 118 patients due to slow recruitment (NHF 47, LFO 47). Poisson regression demonstrated reduced opioid requirements with NHF (incidence rate ratio 0.77, 95% confidence interval, 0.62–0.96, p = 0.023). The total pethidine dose was lower in the NHF group (medians 43.75 mg vs. 70.00 mg, p = 0.004). The TcCO2 and oxygenation‐perfusion parameters were comparable between groups. EEG tests showed lower patient state index and electromyographic activity in the NHF group, indicating deeper sedation. No adverse events attributable to interventions were observed. Conclusion NHF reduced opioid requirements while maintaining oxygenation, ventilation, and sedation during ERCP. The ability of NHF to provide respiratory support, ensure adequate oxygenation, and allow monitoring of breathing makes it a promising modality during procedural sedation; however, further multi‐center studies are needed. Trial Registration 072210047 [jRCTs]

Alagbe, A., Little‐Ihrig, L., Mutchler, S., Jackson, E., Novelli, E., Tofovic, S.

Red blood cells (RBCs) contain the highest purine nucleoside phosphorylase (PNP) level per cell volume, yet the role of PNP in the pathogenesis of sickle cell disease (SCD) is incompletely understood, highlighting an important gap in our knowledge of the disease. Previously, we reported increased PNP release by RBCs and accelerated purine nucleoside metabolism with increased production of pro‐oxidant, pro‐inflammatory and vasculotoxic byproducts in children with SCD and animal models of hemolytic injury. Thus, we hypothesized that PNP inhibition would reduce hemolysis and attenuate end‐organ damage in SCD. In adult patients with SCD (n = 63), plasma PNP levels were markedly elevated compared to controls (n = 27; p < 0.001) and correlated positively with LDH (r = 0.6032, p < 0.0001) and negatively with haemoglobin (r = −0.4523, p = 0.0002). SCD mice also showed accelerated purine metabolism compared to controls. Treatment with the PNP inhibitor 8‐aminoguanosine (8‐AG) increased inosine and guanosine and reduced downstream vasculotoxic byproducts hypoxanthine (p = 0.036), xanthine (p = 0.004) and guanine (p = 0.047), indicating efficient PNP inhibition. 8‐AG treatment rebalanced the purine metabolome in SCD mice to favour protective over harmful purine metabolites without negatively affecting haematological parameters. This was associated with reduced hemolysis and decreased splenomegaly, hepatomegaly, and hepatic and renal injury. This study suggests that PNP is an important erythrocytic damage‐associated molecular pattern molecule involved in the complex pathophysiology of SCD and proposes PNP inhibitors as a new therapeutic option for SCD and other hemolytic diseases.

Zhao, Y., Wang, Q., Lin, W., Song, W., Zhang, Z., Yang, X., Huang, D., Wang, F., Wu, Q., Jiang, S., Li, Y., Tsukasaki, M., Yuan, Q., Yin, Q.

Periodontitis (PD) affects over 1 billion people globally, underscoring the need for valid animal models. This study aimed to (1) systematically compare single-cell immune landscapes between human PD and murine ligature models, and (2) evaluate whether Porphyromonas gingivalis (Pg) supplementation improves model translatability. Using single-cell RNA sequencing (scRNA-seq) of murine gingival tissues from ligature, ligature+Pg, and control groups, integrated with human data, distinct immune profiles between murine and human PD was identified: (1) Murine models showed significantly lower B/plasma cell Δ(PD-Ctrl) proportions than human (murine 0.10% vs. human 22.39%, p < 0.001) and attenuated activation states; (2) Conversely, the change in macrophages Δ(PD-Ctrl) is significantly greater in mice (murine 28.53% vs. human −6.603%, p < 0.0001) and exhibited hyperactivation; (3) Co-administration of Pg did not reduce the immunological distinctions between mice and humans. (p > 0.05). These findings reveal immunological disparities in murine ligature models from human PD, suggesting to approach with caution when using these models for studying immune interactions in PD.

Zhao, C., Li, P., Zhu, D., Xiao, Z., Jiao, J., Li, Y., Du, X., Wang, S.

Cronobacter sakazakii (C. sakazakii) is a foodborne pathogen whose initial process involves intestinal cell adhesion mediated by numerous virulence factors encoded in various genes. The key metabolic enzyme, glyceraldehyde-3-phosphate dehydrogenase (GAPDH, also known as GapA), is encoded by gapA in the glycolysis pathway and acts as an adhesin in some bacteria. In C. sakazakii, there is also a key enzyme in the gluconeogenesis pathway, Gap, with type I GAPDH and erythrose-4-phosphate dehydrogenase activities and encoded by gap. This study aimed to investigate the virulence properties of GapA and Gap of C. sakazakii in adhesion to and invasion of HCT-8 and HIEC-6 cells and damage to the colon and brain of neonatal rats, by gene silencing. In addition, the role of both recombinant proteins in intestinal cell adhesion and invasion was investigated, and their role in inducting inflammatory cytokine expression was assessed by ELISA and Western blot. Silencing gapA or gap decreased the viability and swimming motility of bacterial cells and reduced bacterial adhesion to and invasion of both types of intestinal cells. Both recombinant proteins contributed to C. sakazakii adhesion in both cells, enhanced protein phosphorylation of NF-κB, and induced inflammatory cytokine expression. Finally, silenced expression of GapA and Gap also weakened bacterial damage to the brain and colon of neonatal rats. In conclusion, we demonstrated for the first time the virulence properties of GapA and Gap in C. sakazakii adhesion to and invasion of intestinal cells and neonatal rats and induction of inflammatory responses.

Zhao, C., Li, P., Zhu, D., Xiao, Z., Jiao, J., Li, Y., Du, X., Wang, S.

Cronobacter sakazakii (C. sakazakii) is a foodborne pathogen whose initial process involves intestinal cell adhesion mediated by numerous virulence factors encoded in various genes. The key metabolic enzyme, glyceraldehyde-3-phosphate dehydrogenase (GAPDH, also known as GapA), is encoded by gapA in the glycolysis pathway and acts as an adhesin in some bacteria. In C. sakazakii, there is also a key enzyme in the gluconeogenesis pathway, Gap, with type I GAPDH and erythrose-4-phosphate dehydrogenase activities and encoded by gap. This study aimed to investigate the virulence properties of GapA and Gap of C. sakazakii in adhesion to and invasion of HCT-8 and HIEC-6 cells and damage to the colon and brain of neonatal rats, by gene silencing. In addition, the role of both recombinant proteins in intestinal cell adhesion and invasion was investigated, and their role in inducting inflammatory cytokine expression was assessed by ELISA and Western blot. Silencing gapA or gap decreased the viability and swimming motility of bacterial cells and reduced bacterial adhesion to and invasion of both types of intestinal cells. Both recombinant proteins contributed to C. sakazakii adhesion in both cells, enhanced protein phosphorylation of NF-κB, and induced inflammatory cytokine expression. Finally, silenced expression of GapA and Gap also weakened bacterial damage to the brain and colon of neonatal rats. In conclusion, we demonstrated for the first time the virulence properties of GapA and Gap in C. sakazakii adhesion to and invasion of intestinal cells and neonatal rats and induction of inflammatory responses.

Kashem, N., Ahmed, F., Tanu, S., Rahman, A., Sultana, R., Jui, Y., Asaduzzaman, M.

Obesity is linked to structural and functional cardiac changes. This study assessed the impact of body mass index (BMI) on left ventricular (LV) function. A cross‐sectional study included 100 adults (50 obese and 50 nonobese), matched for age and sex. Echocardiographic parameters, end‐diastolic volume (EDV), end‐systolic volume (ESV), ejection fraction (EF), E/A, E/e ratios, Interventricular Septal thickness in Diastole (IVSd), stroke volume (SV), and cardiac output (CO), were measured by a blinded cardiologist using American Society of Echocardiography (guidelines. Spearman's correlation and multivariable regression evaluated associations between BMI and LV parameters. Obese participants had higher EDV (100.0 ± 23.3 vs. 84.6 ± 25.8 mL), ESV (35.6 ± 10.0 vs. 30.4 ± 12.5 mL), IVSd (9.33 ± 1.53 vs. 8.37 ± 0.91 mm), and SV (67.7 ± 15.2 vs. 57.8 ± 13.9 mL) than nonobese participants (all p < 0.05). EF and E/A ratio were similar. BMI correlated positively with EDV and ESV, negatively with E/A ratio, and independently predicted higher EDV and ESV. Obesity is associated with increased LV volumes, septal thickness, and diastolic dysfunction while preserving systolic function, highlighting the importance of early cardiac evaluation in obese adults.

Chitre, S., Gharaibeh, R., Jobin, C.

The intestinal microbiota influences host susceptibility to Campylobacter jejuni (C. jejuni) infection. However, the interaction between specific intestinal bacteria and the C. jejuni-mediated host response is unclear. We established a defined consortium of bacteria to delineate C. jejuni-induced host responses. Three groups of germ-free (GF) Il10–/– mice were used in this study: 1) mice colonized with a defined consortium of 13 bacterial isolates (C13) representing the four most prominent phyla in the mouse gut. 2) C13 plus C. jejuni 81-176 and 3) GF alone. The C13 + C. jejuni group induced significant intestinal inflammation and inflammatory mRNA gene expression compared to mice colonized with C13. 16S rRNA gene sequencing revealed an increased relative abundance of Escherichia and Paraclostridium in C13 + C. jejuni. Fluorescence in situ hybridization (FISH) and RNAscope integrated with spatial transcriptomics provided a high-resolution map of infection-induced gene expression, revealing localized immune responses and epithelial remodeling in defined colonic regions. Region-specific analysis further demonstrated that tissue-associated C. jejuni differentially modulates host gene expression compared to tissue-associated Enterobacteriaceae. Collectively, these findings demonstrate the potential of defined microbial consortia and spatially resolved transcriptomics to dissect the complex interplay between host, microbiota, and pathogens during enteric infection.

Watanabe, A., Bianchi, R., Hayashi, W.

Chronic kidney disease is a major health issue and is gaining prevalence. Using a Drosophila model for chronic kidney disease, we show that a high-fat diet (HFD) disrupts the slit diaphragm filtration structure in nephrocytes, the fly functional equivalent of mammalian podocytes. The structural disruption resulted in reduced filtration function in the affected nephrocytes. We demonstrate that HFD activates the JAK-STAT pathway in nephrocytes, which has previously been linked to diabetic kidney disease. JAK-STAT activation was initiated by increased expression and release of the adipokine, Upd2, from the fat body. This leptin-like hormone is a known ligand of JAK-STAT. Both genetic and pharmacological inhibition of JAK-STAT restored nephrocyte HFD-associated dysfunction. Altogether, our study reveals the importance of the JAK-STAT signaling pathway in the adipose tissue−nephrocyte axis and its contribution to HFD-associated nephropathy. These findings open new avenues for intervention in treating diabetic nephropathy and chronic kidney disease. Updated in version 2 to clarify the scope of the analysis.

Singh, G., Vaishnav, B.

Guo, X., Du, G., Zhou, J., Fu, F., Yuan, Y., Liu, X., Chen, H., Wan, Q., Gong, B., Chen, H.

Aging disrupts intestinal stem cell (ISC) lineage fidelity, impairing epithelial barrier function and then promoting systemic health decline. In this study, we identify peroxisomal dysfunction as a critical driver of age-associated ISC mis-differentiation. Using Drosophila and mouse colonic organoids, we demonstrate that reduced PEX5 expression in aged ISCs impairs peroxisomal matrix protein import, leading to very long-chain fatty acids (VLCFAs) accumulation. In addition, we found that RAB7-dependent late endosome maturation and SOX21A were downstream of the peroxisome in controlling aged ISC differentiation. Aspirin, a classic anti-inflammatory drug, restores ISC lineage fidelity by enhancing PEX5-mediated peroxisomal β-oxidation of VLCFAs. Taken together, these findings highlight peroxisomal dysfunction and VLCFA metabolism as pivotal regulators of ISC aging and suggest new therapeutic strategies for combating age-related intestinal decline.