BACKGROUND: Mitochondria, which harbor their own genome (mtDNA), have attracted attention due to the potential of mtDNA copy number (mtDNA-CN) as an indicator of mitochondrial dysfunction. Although mtDNA-CN has been proposed as a simple and accessible biomarker for metabolic disorders such as metabolic dysfunction-associated steatotic liver disease, the underlying mechanisms and the causal relationship remain insufficiently elucidated. In this investigation, we combined longitudinal epidemiological data, animal studies, and in vitro assays to elucidate the potential causal relationship between reduced mtDNA-CN and the development of steatotic liver disease (SLD). METHODS: We conducted a longitudinal study using data from a health examination cohort initiated in 1981 in Yakumo, Hokkaido, Japan. Data from examinations performed in 2015 and 2022 were analyzed, focusing on 76 subjects without SLD at baseline (2015) to assess the association between baseline mtDNA-CN and subsequent risk of SLD development. In addition, 28-day-old SD rats were fed ad libitum on a 45% high-fat diet and dissected at 2 and 8 weeks of age. Blood and liver mtDNA-CN were measured and compared at each feeding period. Additionally, in vitro experiments were performed using HepG2 cells treated with mitochondrial function inhibitors to induce mtDNA-CN depletion and to examine its impact on intracellular lipid accumulation. RESULTS: Epidemiological analysis showed that the subjects with low mtDNA-CN had a significantly higher odds ratio for developing SLD compared to high (odds ratio [95% confidence interval]: 4.93 [1.08-22.50]). Analysis of the animal model showed that 8 weeks of high-fat diet led to the development of fatty liver and a significant decrease in mtDNA-CN. A further 2 weeks of high-fat diet consumption resulted in a significant decrease in hepatic mtDNA-CN, despite the absence of fatty liver development, and a similar trend was observed for blood. Complementary in vitro experiments revealed that pharmacologically induced mitochondrial dysfunction led to a significant reduction in mtDNA-CN and was associated with increases in intracellular lipid accumulation in HepG2 cells. CONCLUSIONS Our findings suggest that reduced mtDNA-CN may contribute causally to SLD development and could serve as a convenient, noninvasive biomarker for early detection and risk assessment.
Animals ; DNA, Mitochondrial/genetics* ; Humans ; Male ; DNA Copy Number Variations ; Female ; Fatty Liver/blood* ; Rats ; Middle Aged ; Longitudinal Studies ; Rats, Sprague-Dawley ; Adult ; Japan/epidemiology* ; Aged ; Biomarkers/blood* ; Hep G2 Cells ; Diet, High-Fat/adverse effects*

Recent advances in long-read next-generation sequencing (NGS) have enabled researchers to identify several pathogenic variants overlooked by short-read NGS, array-based comparative genomic hybridization, and other conventional methods. Long-read NGS is particularly useful in the detection of structural variants and repeat expansions. Furthermore, it can be used for mutation screening in difficultto- sequence regions, as well as for DNA-methylation analyses and haplotype phasing. This mini-review introduces the usefulness of long-read NGS in the molecular diagnosis of pediatric endocrine disorders.

Objective: The long-term efficacy of deep brain stimulation (DBS) for motor fluctuations in advanced Parkinson’s disease (PD) has been well established; however, motor fluctuations may recur over time despite multiple adjustments of DBS settings and medications. Methods: We conducted a retrospective chart review of three patients for whom levodopa-carbidopa intestinal gel (LCIG) was additionally administered as a rescue therapy for secondary DBS failure due to the recurrence of motor fluctuations. Results: The three patients had advanced PD with a disease duration of 14–19 years, and had undergone DBS for motor fluctuations refractory to standard medical management. LCIG was administered to the patients because of symptom recurrence years after DBS and provided complementary effects in all patients. Conclusion The cases presented here show that rescue LCIG therapy may be a complementary treatment option for patients with post-DBS advanced PD who have a recurrence of troublesome motor complications.

A 74-year-old woman was referred to our unit with a chief complaint of dysphagia. Enhanced CT showed a Kommerell diverticulum with a maximum diameter of 46 mm, associated with a right-sided aortic arch and aberrant left subclavian artery. We performed two-staged operations : left subclavian-common carotid artery bypass followed by total arch, and descending aortic replacement by an antero-lateral thoracotomy with partial sternotomy (ALPS). The postoperative course was uneventful. Total arch and descending aortic replacement for a Kommerell diverticulum by an ALPS approach is rare. ALPS approach for Kommerell diverticulum achieves safe surgery with good exposure.

A 25-year-old man was admitted with high fever and heart murmur. Echocardiogram showed left ventricular chamber dilatation and vegetations attached to the aortic valve. Blood cultures obtained on admission revealed Streptococcus viridans. Despite adequate antibiotic therapy, congestive heart failure progressively worsened and large splenic abscesses were detected by computed tomography. Urgent aortic valve replacement and splenectomy were performed. The aortic valve was bicuspid and markedly destroyed. Pathology of the spleen showed findings consistent with large infarct and abscesses due to septic emboli. The postoperative course was uneventful.