57 research outputs found
A simplified method to quantitatively predict the effect of lenvatinib on hepatocellular carcinoma using contrast-enhanced ultrasound with perfluorobutane microbubbles
Contrast-enhanced computed tomography (CECT) is generally used to evaluate the response to treatment of hepatocellular carcinoma (HCC); however, CECT is unsuitable for the early prediction of therapeutic effects and frequent monitoring. We aimed to investigate the usefulness of our simplified method for the quantification of tumor vascularity using contrast-enhanced ultrasound (CEUS) with perfluorobutane microbubbles [Sonazoid® (GE Healthcare, Oslo, Norway)] to predict the therapeutic effect of lenvatinib. Among the 13 patients studied, nine who had more than a 20% reduction in tumor vascularity within 2 weeks of starting treatment experienced complete response or partial response at 8-12 weeks as assessed by CECT. In contrast, three patients without reductions and one patient with only a slight decrease in tumor vascularity had a poor response to lenvatinib. Quantitative assessment of tumor vascularity by our simplified CEUS-based method could be a useful predictor of therapeutic responses to lenvatinib in patients with HCC
DNA methyltransferase 3B plays a protective role against hepatocarcinogenesis caused by chronic inflammation via maintaining mitochondrial homeostasis
Most hepatocellular carcinomas (HCCs) develop on the basis of chronic hepatitis, but the mechanism of epigenetic regulation in inflammatory hepatocarcinogenesis has yet to be elucidated. Among de novo DNA methyltransferases (DNMTs), DNMT3B has lately been reported to act specifically on actively transcribed genes, suggesting the possibility that it plays a role in the pathogenesis of cancer. We confirmed that DNMT3B isoforms lacking its catalytic domain were highly expressed in HCCs compared with non-tumorous liver tissue. To elucidate the role of DNMT3B in hepatocarcinogenesis, we generated a genetically engineered mouse model with hepatocyte-specific Dnmt3b deletion. The liver of the Dnmt3b-deficient mice exhibited an exacerbation of thioacetamide-induced hepatitis, progression of liver fibrosis and a higher incidence of HCC compared with the liver of the control mice. Whole-genome bisulfite sequencing verified a lower CG methylation level in the Dnmt3b-deficient liver, demonstrating differentially methylated regions throughout the genome. Transcriptome analysis revealed decreased expression of genes related to oxidative phosphorylation in the Dnmt3b-deficient liver. Moreover, primary hepatocytes isolated from the Dnmt3b-deficient mice showed reduced mitochondrial respiratory capacity, leading to the enhancement of oxidative stress in the liver tissue. Our findings suggest the protective role of DNMT3B against chronic inflammation and HCC development via maintaining mitochondrial homeostasis
Single-molecular real-time deep sequencing reveals the dynamics of multi-drug resistant haplotypes and structural variations in the hepatitis C virus genome
While direct-acting antivirals (DAAs) for hepatitis C virus (HCV) have dramatically progressed, patients still suffer from treatment failures. For the radical eradication of HCV, a deeper understanding of multiple resistance-associated substitutions (RASs) at the single-clone level is essential. To understand HCV quasispecies and their dynamics during DAA treatment, we applied single-molecule real-time (SMRT) deep sequencing on sera from 12 patients with genotype-1b HCV infections with DAA treatment failures, both pre- and post-treatment. We identified >3.2 kbp sequences between NS3 and NS5A genes of 187, 539 clones in total, classifying into haplotype codes based on the linkage of seven RAS loci. The number of haplotype codes during the treatment, per sample, significantly decreased from 14.67 ± 9.12 to 6.58 ± 7.1, while the number of nonsynonymous codons on the seven RAS loci, per clone, significantly increased from 1.50 ± 0.92 to 3.64 ± 0.75. In five cases, the minority multi-drug resistant haplotypes at pre-treatment were identical to the major haplotypes at relapse. Moreover, various structural variations (SVs) were detected and their dynamics analysed. These results suggest that SMRT deep sequencing is useful for detecting minority haplotypes and SVs, and to evaluate the dynamics of viral genomes at the single-clone level
Evolutional transition of HBV genome during the persistent infection determined by single-molecule real-time sequencing
BACKGROUND: Although HBV infection is a serious health issue worldwide, the landscape of HBV genome dynamics in the host has not yet been clarified. This study aimed to determine the continuous genome sequence of each HBV clone using a single-molecule real-time sequencing platform, and clarify the dynamics of structural abnormalities during persistent HBV infection without antiviral therapy. PATIENTS AND METHODS: Twenty-five serum specimens were collected from 10 untreated HBV-infected patients. Continuous whole-genome sequencing of each clone was performed using a PacBio Sequel sequencer; the relationship between genomic variations and clinical information was analyzed. The diversity and phylogeny of the viral clones with structural variations were also analyzed. RESULTS: The whole-genome sequences of 797, 352 HBV clones were determined. The deletion was the most common structural abnormality and concentrated in the preS/S and C regions. Hepatitis B e antibody (anti-HBe)-negative samples or samples with high alanine aminotransferase levels have significantly diverse deletions than anti-HBe-positive samples or samples with low alanine aminotransferase levels. Phylogenetic analysis demonstrated that various defective and full-length clones evolve independently and form diverse viral populations. CONCLUSIONS: Single-molecule real-time long-read sequencing revealed the dynamics of genomic quasispecies during the natural course of chronic HBV infections. Defective viral clones are prone to emerge under the condition of active hepatitis, and several types of defective variants can evolve independently of the viral clones with the full-length genome
アンジオテンシン受容体拮抗薬は、肝硬変ラットの骨格筋萎縮に対して、分岐鎖アミノ酸製剤による保護効果を増強する。
Scope: This study investigated the combined effect of the angiotensin II
(AT-II) receptor blocker losartan and branched-chain amino acids (BCAAs) on
skeletal muscle atrophy in rats with cirrhosis and steatohepatitis.
Method and Results: Fischer 344 rats are fed a choline-deficient l-amino
acid-defined (CDAA) diet for 12 weeks and treated with oral losartan (30 mg
kg−1 day−1) and/or BCAAs (Aminoleban EN, 2500 mg kg−1 day−1). Treatment
with losartan and BCAAs attenuated hepatic inflammation and fibrosis and
improved skeletal muscle atrophy and strength in CDAA-fed rats. Both agents
reduced intramuscular myostatin and pro-inflammatory cytokine levels,
resulting in inhibition of the ubiquitin–proteasome system (UPS) through
interference with the SMAD and nuclear factor-kappa B pathways,
respectively. Losartan also augmented the BCAA-mediated increase of skeletal
muscle mass by promoting insulin growth factor-I production and
mitochondrial biogenesis. Moreover, losartan decreased the intramuscular
expression of transcription factor EB (TFEB), a transcriptional inducer of E3
ubiquitin ligase regulated by AT-II. In vitro assays illustrated that losartan
promoted mitochondrial biogenesis and reduced TFEB expression in
AT-II-stimulated rat myocytes, thereby potentiating the inhibitory effects of
BCAAs on the UPS and caspase-3 cleavage.
Conclusion: These results indicate that this regimen could serve as a novel
treatment for patients with sarcopenia and liver cirrhosis.博士(医学)・甲第861号・令和5年3月15
Feasibility study of two schedules of sunitinib in combination with pemetrexed in patients with advanced solid tumors
Background Sunitinib is an oral multitargeted tyrosine kinase inhibitor of vascular endothelial growth factor and platelet-derived growth factor receptors, as well as of other receptor types. We have performed a feasibility study to investigate the safety of sunitinib in combination with pemetrexed for treatment of advanced refractory solid tumors. Methods Sunitinib was administered once daily on a continuous daily dosing (CDD) schedule (37.5 mg/day) or a 2-weeks-on, 1-week-off treatment schedule (50 mg/day, Schedule 2/1) in combination with pemetrexed at 500 mg/m2 on day 1 of repeated 21-day cycles. Results Twelve patients were enrolled in the study: six on the CDD schedule and six on Schedule 2/1. None of the treated patients experienced a dose-limiting toxicity. Toxicities were manageable and similar in type to those observed in monotherapy studies of sunitinib and pemetrexed. Pharmacokinetic analysis did not reveal any substantial drug–drug interaction. One patient with squamous cell lung cancer showed a partial response and five patients had stable disease. Conclusions Combination therapy with sunitinib administered on Schedule 2/1 (50 mg/day) or a CDD schedule (37.5 mg/day) together with standard-dose pemetrexed (500 mg/m2) was well tolerated in previously treated patients with advanced solid tumors
酢酸亜鉛とリファキシミンの併用療法による腸管バリアー機能維持によるエタノール誘発性肝線維化予防効果
BACKGROUND
Hepatic overload of gut-derived lipopolysaccharide dictates the progression of
alcoholic liver disease (ALD) by inducing oxidative stress and activating Kupffer
cells and hepatic stellate cells through toll-like receptor 4 signaling. Therefore,
targeting the maintenance of intestinal barrier integrity has attracted attention for
the treatment of ALD. Zinc acetate and rifaximin, which is a nonabsorbable
antibiotic, had been clinically used for patients with cirrhosis, particularly those
with hepatic encephalopathy, and had been known to improve intestinal barrier
dysfunction. However, only few studies focused on their efficacies in preventing
the ALD-related fibrosis development.
AIM
To investigate the effects of a combined zinc acetate with rifaximin on liver
fibrosis in a mouse ALD model.
METHODS
To induce ALD-related liver fibrosis, female C57BL/6J mice were fed a 2.5% (v/v)
ethanol-containing Lieber-DeCarli liquid diet and received intraperitoneal carbon
tetrachloride (CCl4) injection twice weekly (1 mL/kg) for 8 wk. Zinc acetate (100
mg/L) and/or rifaximin (100 mg/L) were orally administered during experimental
period. Hepatic steatosis, inflammation and fibrosis as well as intestinal
barrier function were evaluated by histological and molecular analyses. Moreover,
the direct effects of both agents on Caco-2 barrier function were assessed by in
vitro assays.RESULTSIn the ethanol plus CCl4-treated mice, combination of zinc acetate and rifaximin
attenuated oxidative lipid peroxidation with downregulation of Nox2 and Nox4.
This combination significantly inhibited the Kupffer cells expansion and the
proinflammatory response with blunted hepatic exposure of lipopolysaccharide
and the toll-like receptor 4/nuclear factor kB pathway. Consequently, liver
fibrosis and hepatic stellate cells activation were efficiently suppressed with
downregulation of Mmp-2, -9, -13, and Timp1. Both agents improved the atrophic
changes and permeability in the ileum, with restoration of tight junction proteins
(TJPs) by decreasing the expressions of tumor necrosis factor α and myosin light
chain kinase. In the in vitro assay, both agents directly reinforced ethanol or
lipopolysaccharide-stimulated paracellular permeability and upregulated TJPs in
Caco-2 cells.
CONCLUSION
Dual therapy with zinc acetate and rifaximin may serve as a strategy to prevent
ALD-related fibrosis by maintaining intestinal barrier integrity.博士(医学)・甲第862号・令和5年3月15
リファキシミンは腸-肝臓-筋肉軸の調節により肝硬変ラットの骨格筋萎縮に対するL-カルニチンを介した予防効果を増強する
The gut‑liver‑muscle axis is associated with the
development of sarcopenia in liver cirrhosis. The present
study aimed to illustrate the combined effects of rifaximin
and L‑carnitine on skeletal muscle atrophy in cirrhotic rats
with steatohepatitis. For this purpose, a total of 344 Fischer
rats were fed a choline‑deficient L‑amino acid‑defined
(CD AA) diet with the daily oral administration of rifaximin
(100 mg/kg) and/or L‑carnitine (200 mg/kg), and measurements
of psoas muscle mass index and forelimb grip strength
were performed. After feeding for 12 weeks, blood samples,
and liver, ileum and gastrocnemius muscle tissues were
harvested. The effects of L‑carnitine on rat myocytes were
assessed using in vitro assays. Treatment with rifaximin
attenuated hyperammonemia and liver fibrosis in the
CD AA‑fed rats. Moreover, it improved intestinal permeability
with the restoration of tight junction proteins and
suppressed the lipopolysaccharide (LPS)‑mediated hepatic
macrophage activation and pro‑inflammatory response. In
addition, rifaximin prevented skeletal muscle mass atrophy
and weakness by decreasing intramuscular myostatin and
pro‑inflammatory cytokine levels. Moreover, rifaximin
synergistically enhanced the L‑carnitine‑mediated improvement
of skeletal muscle wasting by promoting the production
of insulin‑like growth factor‑1 and mitochondrial biogenesis,
resulting in the inhibition of the ubiquitin‑proteasome system
(UPS). The in vitro assays revealed that L‑carnitine directly
attenuated the impairment of mitochondrial biogenesis,
thereby inhibiting the UPS in rat myocytes that were stimulated
with LPS or tumor necrosis factor‑α. On the whole, the
present study demonstrates that the combination of rifaximin
with L‑carnitine may provide a clinical benefit for liver
cirrhosis‑related sarcopenia.博士(医学)・甲第863号・令和5年3月15
リファキシミンとルビプロストンの併用は脂肪性肝炎ラットの腸管バリア機能を修復し肝線維化を抑制する
Background: Although gut-derived lipopolysaccharide (LPS) affects the progression of non-alcoholic steatohepatitis (NASH) pathogenesis, few studies have focused on this relationship to develop treatments for NASH. Aims: To explore the effects of combination with rifaximin and lubiprostone on NASH liver fibrosis through the modulation of gut barrier function. Methods: To induce steatohepatitis, F344 rats were fed a choline-deficient l -amino acid-defined (CDAA) diet for 12 weeks and received oral administration of rifaximin and/or lubiprostone. Histological, molec- ular, and fecal microbial analyses were performed. Barrier function in Caco-2 cells were assessed by in vitro assays. Results: Combination rifaximin/lubiprostone treatment significantly suppressed macrophage expansion, proinflammatory responses, and liver fibrosis in CDAA-fed rats by blocking hepatic translocation of LPS and activation of toll-like receptor 4 signaling. Rifaximin and lubiprostone improved intestinal perme- ability via restoring tight junction proteins (TJPs) with the intestinal activation of pregnane X receptor and chloride channel-2, respectively. Moreover, this combination increased the abundance of Bacteroides, Lactobacillus, and Faecalibacterium as well as decreased that of Veillonella resulting in an increase of fecal short-chain fatty acids and a decrease of intestinal sialidase activity. Both agents also directly suppressed the LPS-induced barrier dysfunction and depletion of TJPs in Caco-2 cells. Conclusion: The combination of rifaximin and lubiprostone may provide a novel strategy for treating NASH-related fibrosis.博士(医学)・甲第860号・令和5年3月15
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