Fine needle aspirates of kidneys: a promising tool for RNA sequencing in native and transplanted kidneys

Longitudinal liver sampling in patients with chronic hepatitis B starting antiviral therapy reveals hepatotoxic CD8+ T cells

Accumulation of activated immune cells results in nonspecific hepatocyte killing in chronic hepatitis B (CHB), leading to fibrosis and cirrhosis. This study aims to understand the underlying mechanisms in humans and to define whether these are driven by widespread activation or a subpopulation of immune cells. We enrolled CHB patients with active liver damage to receive antiviral therapy and performed longitudinal liver sampling using fine-needle aspiration to investigate mechanisms of CHB pathogenesis in the human liver. Single-cell sequencing of total liver cells revealed a distinct liver-resident, polyclonal CD8+ T cell population that was enriched at baseline and displayed a highly activated immune signature during liver damage. Cytokine combinations, identified by in silico prediction of ligand-receptor interaction, induced the activated phenotype in healthy liver CD8+ T cells, resulting in nonspecific Fas ligand-mediated killing of target cells. These results define a CD8+ T cell population in the human liver that can drive pathogenesis and a key pathway involved in their function in CHB patients.

Repeatable and objective method for evaluating angiogenesis using real-time RT-PCR of endoglin expression in canine tumours

Anti-angiogenic therapy is a cancer treatment strategy targeting new blood vessel formation. Microvessel density (MVD) is a histopathological method for evaluating angiogenesis and endoglin is used as an activated endothelial marker in human medicine. The assessment of the treatment effect using MVD is difficult because it is a non-repeatable method. To develop a repeatable method for evaluating angiogenesis, we investigated correlations among MVD, mRNA transcription levels of endothelial markers and angiogenesis factors, and confirmed the agreement of mRNA transcription levels between tissue samples and small samples obtained by fine needle aspiration (FNA). The various types of spontaneous tumours were collected from 51 dogs. MVD was assessed by immunostaining for von Willebrand factor (vWF). mRNA transcription levels of vWF, endoglin, vascular endothelial growth factor (VEGF) and VEGF receptor-2 (VEGFR2) were analysed using real-time reverse transcription polymerase chain reaction (real-time RT-PCR). There were significant correlations between MVD and mRNA transcription levels of vWF, endoglin and VEGFR2. VEGFR2 was more strongly correlated with endoglin (P <.01, Rs = 0.649) than vWF (P <.01, Rs = 0.512), indicating that angiogenesis can be evaluated more accurately by the measurement of mRNA transcription levels of endoglin. The mRNA transcription levels in tissue and FNA samples were strongly correlated, suggesting that evaluating angiogenesis using FNA samples is possible. In conclusion, we developed a repeatable and objective method for angiogenesis evaluation using mRNA transcription levels of endothelial markers by FNA sampling.

Suitability of ultrasound-guided fine-needle aspiration biopsy for transcriptome sequencing of the canine prostate

Ultrasound-guided fine-needle aspiration (US-FNA) biopsy is a widely used minimally invasive sampling procedure for cytological diagnosis. This study investigates the feasibility of using US-FNA samples for both cytological diagnosis and whole transcriptome RNA-sequencing analysis (RNA-Seq), with the ultimate aim of improving canine prostate cancer management. The feasibility of the US-FNA procedure was evaluated intra vitam on 43 dogs. Additionally, aspirates from 31 euthanised dogs were collected for standardising the procedure. Each aspirate was separated into two subsamples: for cytology and RNA extraction. Additional prostate tissue samples served as control for RNA quantity and quality evaluation, and differential expression analysis. The US-FNA sampling procedure was feasible in 95% of dogs. RNA isolation of US-FNA samples was successfully performed using phenol-chloroform extraction. The extracted RNA of 56% of a subset of US-FNA samples met the quality requirements for RNA-Seq. Expression analysis revealed that only 153 genes were exclusively differentially expressed between non-malignant US-FNAs and tissues. Moreover, only 36 differentially expressed genes were associated with the US-FNA sampling technique and unrelated to the diagnosis. Furthermore, the gene expression profiles clearly distinguished between non-malignant and malignant samples. This proves US-FNA to be useful for molecular profiling.