Hitoshi Shimano

• MD, PhD
• Professor at University of Tsukuba

Most mitochondrial proteins encoded in the nuclear genome are synthesized in the cytoplasm. These proteins subsequently undergo maturation through the cleavage of a signal sequence at the N-terminus by one or two mitochondrial signal peptidases, which is essential for their function within mitochondria. The present study demonstrates that adipocyte...

Objective: Checkpoint inhibitor-associated autoimmune diabetes mellitus (CIADM), a variant of type 1 diabetes, is a rare immune-related adverse events (irAEs) caused by antibody-based immune checkpoint inhibitors. CIADM typically manifests as fulminant or acute-onset type 1 diabetes in the insulin-depleted state. However, we encountered a patient w...

Low lean body mass increases fall risk. Some diabetes medications, specifically SGLT2 inhibitors and GLP-1RAs, can cause muscle and body mass loss. This study assessed their association on falls in type 2 diabetes patients. An annual fall survey was conducted for up to 5 years on individuals with type 2 diabetes admitted to our department. Fall ris...

Maturity-onset diabetes of the young type 5 (MODY5), causally associated with loss-of-function of the HNF1B gene, is a rare form of monogenic diabetes that has been underdiagnosed in part because microdeletions of chromosome 17q12 encompassing the HNF1B gene cannot be detected by sequencing-based approaches, which accounts for about 50% of MODY5 ca...

Recent success with the use of glucagon-like peptide-1 (GLP-1) receptor analogs and dipeptidyl peptidase-4 inhibitors for the treatment of patients with diabetes has highlighted the role of the intestine as an endocrine organ. Gut-derived hormones, including glucagon-like peptide-1, glucose-dependent insulinotropic polypeptide, and ghrelin, have im...

Diabetes mellitus, particularly type 2 diabetes mellitus (T2DM), is a pervasive chronic disease that affects millions of people worldwide. It predisposes individuals to a range of severe microvascular and macrovascular complications, which drastically impact the patient’s quality of life and increase mortality rates owing to various comorbidities....

A man in his late 30s with gait difficulty, dysarthria, impaired consciousness and polyuria was diagnosed with left thalamic infarction. Hypercalcaemia (3.52 mmol/L (2.15–2.52)), high intact-parathyroid hormone (i-PTH) levels (88.8 pmol/L (1.1–6.9)) and high D-dimer levels (14.7 mg/L (<1.0)) were identified, followed by a positive microbubble test...

Aims Many guidelines recommend increases in potassium intake. However, the relationship of dietary potassium intake with incident cardiovascular disease (CVD) has not been examined in those with type 2 diabetes (T2DM), including sodium acting antagonistically with potassium. We investigated these relationships in Japanese patients with T2DM. Mater...

Background To evaluate the seasonal variability of urinary albumin to creatinine ratio (UACR) and eGFR and these effects on three-year eGFR slope in persons with type 2 diabetes (T2D). Methods A total of 1135 persons with T2D were analyzed in this single-center, retrospective cohort study in Japan. The standard deviation (SD) of UACR (SD [UACR]) a...

Toll-like receptors (TLRs) on macrophages sense microbial components and trigger the production of numerous cytokines and chemokines that mediate the inflammatory response to infection. Although many of the components required for the activation of the TLR pathway have been identified, the mechanisms that appropriately regulate the magnitude and du...

Background Numerous epidemiological studies have shown that hypertriglyceridemia is a significant risk factor for cardiovascular diseases (CVD). However, large clinical studies on triglyceride‐lowering therapy have yielded inconsistent results. In the current review, we reassess the importance of triglyceride‐lowering therapy in preventing CVD base...

Objectives During fasting, liver pivotally regulates blood glucose levels through glycogenolysis and gluconeogenesis. Kidney also produces glucose through gluconeogenesis. Gluconeogenic genes are transactivated by fasting, but their expression patterns are chronologically different between the two organs. We find that renal gluconeogenic gene expre...

Aim: This study aimed to analyze two cases of marked hypo-high-density lipoprotein (HDL) cholesterolemia to identify mutations in ATP-binding cassette transporter A1 (ABCA1) and elucidate the molecular mechanism by which these novel pathological mutations contribute to hypo-HDL cholesterolemia in Tangier disease. Methods: Wild type and mutant expre...

Developing techniques to visualize the dynamics of cellular organization, which impacts the spatiotemporal functionality of biomolecules, is essential for elucidating mechanisms that govern cellular behavior. In this study, we demonstrated that label-free external apodization phase-contrast (ExAPC) microscopy is a valuable modality for this purpose...

Background: No consensus exists regarding which anthropometric measurements are related to bone mineral density (BMD), and this relationship may vary according to sex and age. A large Japanese cohort was analyzed to provide an understanding of the relationship between BMD and anthropometry while adjusting for known confounding factors. Methods: Our...

One of the extracellular matrix proteins, tenascin-C (TN-C), is known to be upregulated in age-related inflammatory diseases such as cancer and cardiovascular diseases. Expression of this molecule is frequently detected, especially in the macrophage-rich areas of atherosclerotic lesions; however, the role of TN-C in mechanisms underlying the progre...

Macrophages are essential for the proper inflammatory and reparative processes that lead to regeneration of skeletal muscle after injury. Recent studies have demonstrated close links between the function of activated macrophages and their cellular metabolism. Sterol regulatory element-binding protein 1 (SREBP1) is a key regulator of lipid metabolis...

Background The EMPA-KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad populat...

Background Sodium glucose co-transport 2 inhibitors (SGLT2i) reduce progression of chronic kidney disease (CKD) and the risk of cardiovascular morbidity and mortality in a wide range of patients. However, their effects on kidney disease progression in some patients with CKD are unclear because few clinical kidney outcomes occurred among such patien...

Aims: We attempted to clarify whether the multiple criteria for metabolic syndrome (MetS) can sufficiently predict cardiovascular disease, whether waist circumference (WC) should be required, and whether sex-specific thresholds for each component are necessary. Only a few large-scale studies among East Asians have addressed the ability of MetS to p...

The endoplasmic reticulum (ER)–embedded transcription factors, sterol regulatory element-binding proteins (SREBPs), master regulators of lipid biosynthesis, are transported to the Golgi for proteolytic activation to tune cellular cholesterol levels and regulate lipogenesis. However, mechanisms by which the cell responds to the levels of saturated o...

Type 2 diabetes is a progressive disorder denoted by hyperglycemia and impaired insulin secretion. Although a decrease in β-cell function and mass is a well-known trigger for diabetes, the comprehensive mechanism is still unidentified. Here, we performed single-cell RNA sequencing of pancreatic islets from prediabetic and diabetic db/db mice, an an...

Metabolism is one of the vital functions of cells and living organisms, and the systems to sense and respond to the metabolic alterations play pivotal roles in a plethora of biological processes, including cell proliferative activities, immune cell functions, aging processes, and neuronal functions. Recently, we have reported that a transcriptional...

During periods of fasting, the body undergoes a metabolic shift from carbohydrate utilization to the use of fats and ketones as an energy source, as well as the inhibition of de novo lipogenesis and the initiation of gluconeogenesis in the liver. The transcription factor sterol regulatory element‐binding protein‐1 (SREBP‐1), which plays a critical...

Background The studies evaluating patients’ characteristics and lipid-lowering therapy for patients with homozygous familial hypercholesterolemia (HoFH) are scarce. Objectives This study aims to evaluate the characteristics of and treatments for patients with HoFH. Methods This study included 201 patients who were diagnosed with definite or proba...

The adaptive increase in insulin secretion in early stages of obesity serves as a safeguard mechanism to maintain glucose homeostasis that cannot be sustained, and the eventual decompensation of β cells is a key event in the pathogenesis of diabetes. Here we describe a crucial system orchestrated by a transcriptional cofactor CtBP2. In cultured β c...

Many guidelines recommend increased potassium intake. However, the relationship between dietary potassium intake and incidence of CVD in persons with T2D has not been explored, nor is it known if this relationship varies with sodium intake in such persons. Therefore, we investigated these relationships as part of the JDCP study, a nationwide study...

Maintenance of metabolic homeostasis is secured by metabolite-sensing systems, which can be overwhelmed by constant macronutrient surplus in obesity. Not only the uptake processes but also the consumption of energy substrates determine the cellular metabolic burden. We herein describe a novel transcriptional system in this context comprised of pero...

We report a rare case of takotsubo cardiomyopathy caused by subacute thyroiditis in a man in his 50s. He went to the doctor with complaints of loss of appetite, diarrhoea, chills and general malaise. He had consciousness disturbance, thyrotoxicosis and thyroid-stimulating hormone (TSH) suppression. Thyroglobulin and C reactive protein levels in the...

Background Mild cognitive impairment (MCI) is not just a prodrome to dementia, but a very important intervention point to prevent dementia caused by Alzheimer's disease (AD). It has long been known that people with AD have a higher frequency of falls with some gait instability. Recent evidence suggests that vestibular impairment is disproportionate...

Insulin and its secretagogues are essential for some patients with type 2 diabetes (T2D) to maintain good glycemic control (GC), but severe hypoglycemia (SH) is a concern. This network meta-analysis aimed to find optimal glucose-lowering drug treatment regimens in terms of GC and SH in T2D patients. MEDLINE and EMBASE were used to identify trials t...

ELOVL fatty acid elongase 6 (ELOVL6) controls cellular fatty acid (FA) composition by catalyzing the elongation of palmitate (C16:0) to stearate (C18:0) and palmitoleate (C16:1n-7) to vaccinate (C18:1n-7). Although the transcriptional regulation of ELOVL6 has been well studied, the post-transcriptional regulation of ELOVL6 is not fully understood....

Purpose Prolonged lipid malabsorption occurs after small bowel resection (SBR). We aimed to clarify the underlying mechanism using a mouse model. Methods SBR mice were created by resecting 50% of the proximal intestine. In sham mice, the intestine was transected and re-anastomosed. Intravenous nutrition was not initiated and mice were fed a liquid...

In this study, we herein describe a 47-year-old Japanese woman who manifested inheritable non-alcoholic steatohepatitis (NASH) and severe dyslipidemia. Interestingly, her NASH progression was ameliorated by treatment with a sodium–glucose co-transporter 2 (SGLT2) inhibitor. This inheritability prompted us to comprehensively decode her genomic infor...

Background: Elongation of very-long-chain fatty acids protein 6 (ELOVL6), an enzyme regulating elongation of saturated and monounsaturated fatty acids with C12-C16 to those with C18, has been recently indicated to affect various immune and inflammatory responses; however, the precise process by which ELOVL6-related lipid dysregulation affects alle...

Introduction: Obesity is a risk factor for many diseases because it leads to a reduction in skeletal muscle mass and promotes insulin resistance. p62/Sqstm1-knockout mice are a model of metabolic syndrome; show obesity, insulin resistance, and non-alcoholic fatty liver (NAFL); and develop non-alcoholic steatohepatitis (NASH) in response to the feed...

Sterol regulatory element binding proteins (SREBPs) are master transcription factors for lipid synthesis, and SREBP-1 is important for fatty acid and triglyceride synthesis. SREBP-1 has two isoforms, SREBP-1a and SREBP-1c, which are splicing variants transcribed from the Srebf1 gene. Although SREBP-1a exhibits stronger transcriptional activity as c...

A 19-year-old male presented with fatigue and dyspnea on exertion. He was diagnosed with acute T-cell lymphoblastic leukemia. After following the Group for Research on Adult Acute Lymphoblastic Leukemia (GRAALL) 2003 protocol that incorporates L-asparaginase (L-Asp) treatment, blood glucose levels became elevated for more than one year and insulin...

Fibroblast growth factor 21 (FGF21), which is mainly synthesized and secreted by the liver, plays a crucial role in systemic glucose and lipid metabolism, ameliorating metabolic diseases. In this study, we screened the WAKANYAKU library derived from medicinal herbs to identify compounds that can activate Fgf21 expression in mouse hepatocyte AML12 c...

Although branched-chain amino acids (BCAA) are known to stimulate myofibrillar protein synthesis and affect insulin signaling and kynurenine metabolism (the latter being a metabolite of tryptophan associated with depression and dementia), the effects of BCAA supplementation on type 2 diabetes (T2D) are not clear. Therefore, a 24-week, prospective r...

A paired homeodomain transcription factor, PAX6 (paired-box 6), is essential for the development and differentiation of pancreatic endocrine cells as well as ocular cells. Despite the impairment of insulin secretion observed in PAX6-deficient mice, evidence implicating causal association between PAX6 gene mutations and monogenic forms of human diab...

We aimed to investigate the status of falls and to identify important risk factors for falls in persons with type 2 diabetes (T2D) including the non-elderly. Participants were 316 persons with T2D who were assessed for medical history, laboratory data and physical capabilities during hospitalization and given a questionnaire on falls one year after...

Renal cell carcinoma (RCC) features altered lipid metabolism and accumulated polyunsaturated fatty acid (PUFAs). Elongation of very-long-chain fatty acid (ELOVL) family enzymes catalyze fatty acid elongation, and ELOVL5 is indispensable for PUFAs elongation, but its role in RCC progression remains unclear. Here, we show that higher levels of ELOVL5...

Cardiovascular (CV) disease is the most alarming complication of diabetes mellitus (DM), and a strategy aiming at CV event prevention in DM has long been debated. Large landmark clinical trials have shown CV benefits of intensive glycemic control as a “legacy effect” in newly diagnosed type 2 DM (T2DM). In contrast, we have learned that excessive i...

Dyslipidemia is considered an essential component of the pathological process of amyotrophic lateral sclerosis (ALS), a fatal motor neuron disease. Although TAR DNA Binding Protein 43 kDa (TDP-43) links both familial and sporadic forms of ALS and cytoplasmic aggregates are a hallmark of most cases of ALS, the molecular mechanism and the in vivo rel...

The increasing prevalence of obesity worldwide has become an alarming public health concern because of dramatic increases in the incidence of obesity-associated diseases, including type 2 diabetes mellitus (T2DM). Peripheral insulin resistance and impaired insulin secretion remain the core defects in T2DM. Despite significant advances in unraveling...

Medical nutrition therapy and exercise therapy are the cornerstones of treatment for patients with type 2 diabetes; however, there has not been a nationwide study on the actual dietary intake and physical activity status of patients since the 2000s. We aimed to clarify this in Japanese patients with type 2 diabetes using data from the Japan Diabete...

Cyclic adenosine monophosphate-responsive element-binding protein H (CREBH) activates lipoprotein lipase (LPL) activity by modulating apolipoproteins. Activated LPL hydrolyzes triglyceride-rich lipoproteins, such as very low-density lipoprotein (VLDL) and chylomicrons, resulting in remnant lipoproteins. CREBH increases apolipoprotein E (ApoE), a li...

Aims/Introduction Recently, an increasing number of cohort studies have suggested using machine learning (ML) to predict type 2 diabetes mellitus (T2DM). However, its predictive ability remains inconclusive. This meta-analysis evaluated the current ability of ML algorithms for predicting incident T2DM. Material and methods We systematically search...

Dietary ω3 fatty acids have important health benefits and exert their potent bioactivity through conversion to lipid mediators. Here, we demonstrate that microbiota play an essential role in the body’s use of dietary lipids for the control of inflammatory diseases. We found that amounts of 10-hydroxy- cis -12- cis -15-octadecadienoic acid (αHYA) an...

The pancreatic islet vasculature is of fundamental importance to the β-cell response to obesity-associated insulin resistance. To explore islet vascular alterations in the pathogenesis of type 2 diabetes, we evaluated two insulin resistance models: ob/ob mice, which sustain large β-cell mass and hyperinsulinemia, and db/db mice, which progress to d...

We aimed to investigate the status of falls and to identify important risk factors for falls in persons with type 2 diabetes (T2D) including the non-elderly. Participants were 316 persons with T2D. They were assessed for medical history, laboratory data and physical capabilities during the hospitalization and given a questionnaire on falls one year...

Renal cell carcinoma (RCC) is an aggressive genitourinary malignancy which has been associated with a poor prognosis, particularly in patients with metastasis, its major subtypes being clear cell RCC (ccRCC), papillary PCC (pRCC) and chromophobe RCC (chRCC). The presence of intracellular lipid droplets (LDs) is considered to be a hallmark of ccRCC....

Biological systems to sense and respond to metabolic perturbations are critical for the maintenance of cellular homeostasis. Here we describe a hepatic system in this context orchestrated by the transcriptional corepressor C-terminal binding protein 2 (CtBP2) that harbors metabolite-sensing capabilities. The repressor activity of CtBP2 is reciproca...

KLF15 is a transcription factor that plays an important role in the activation of gluconeogenesis from amino acids as well as the suppression of lipogenesis from glucose. Here we identified the transcription start site of liver-specific KLF15 transcript and showed that FoxO1/3 transcriptionally regulate Klf15 gene expression by directly binding to...

Mild cognitive impairment (MCI) is not just a prodrome to dementia, but a very important intervention point to treat Alzheimer's disease (AD). It has long been known that AD patients have a higher frequency of falls with some gait instability. Recent evidence suggests that vestibular impairment is disproportionately prevalent among individuals with...

Aim: We investigated the relationship between cognitive function and olfactory and physical functions in middle-aged persons with and without type 2 diabetes (T2D) to examine the potential of olfactory and physical functions as biomarkers for early cognitive impairment. Methods: Enrolled were 70 T2D patients (age 40 to <65 y) and 81 age-matched...

High protein diet (HPD) is an affordable and positive approach in prevention and treatment of many diseases. It is believed that transcriptional regulation is responsible for adaptation after HPD feeding and Kruppel-like factor 15 (KLF15), a zinc finger transcription factor that has been proved to perform transcriptional regulation over amino acid,...

It is unclear whether genetic interactions are involved in the association between vegetable intake and reduced body mass index (BMI) or obesity. We conducted a comprehensive search for single nucleotide polymorphisms (SNPs) which are associated with the interaction between vegetable intake frequency and BMI or obesity. We performed a genome-wide a...

Cyclic AMP-responsive element-binding protein H (CREBH, encoded by CREB3L3) is a membrane-bound transcriptional factor expressed in the liver and small intestine. The activity of CREBH is regulated not only at the transcriptional level but also at the posttranslational level. CREBH governs triglyceride metabolism in the liver by controlling gene ex...

Disruption of mitochondrial morphology occurs during various diseases, but the biological significance is not entirely clear. Here, we describe a detailed step-by-step protocol for a chemically inducible dimerization system-based synthetic protein device, termed inducible counter mitochondrial morphology. This system allows artificial manipulation...

The Suppressors of Cytokine Signaling (SOCS) proteins are negative regulators of cytokine signaling required to prevent excessive cellular responses. In particular, SOCS3 is involved in the regulation of metabolic syndromes, such as obesity and diabetes, by suppressing leptin and insulin signals. SOCS3 also suppresses the inflammatory response asso...

Aims Most risk calculators that predict future cardiovascular disease (CVD) by baseline profiles are originally developed for primary prevention, but some studies applied the calculators to secondary prevention. We compared the impact of baseline profiles on the future CVD risk between patients with diabetes with and without a CVD history. Methods...

The ER-embedded transcription factors, sterol-regulatory element-binding proteins (SREBPs), master regulators of lipid biosynthesis, are transported to Golgi for proteolytic activation to tune cellular cholesterol levels and regulate lipogenesis. However, mechanisms by which the cell responds to the levels of saturated or unsaturated fatty acids re...

The high incidence of germline variants in pheochromocytoma and paraganglioma (PPGL) has been reported mainly in Europe, but not among Japanese populations in Asia. We aimed to study the prevalence of germline variants in Japanese PPGL patients and the genotype–phenotype correlation. We examined 370 PPGL probands, including 43 patients with family...

Aging causes loss of skeletal muscle mass and function, which is called sarcopenia. While sarcopenia impairs the quality of life of older adults and is a major factor in long-term hospitalization, its detailed pathogenic mechanism and preventive measures remain to be identified. Caloric restriction (CR) suppresses age-related physiological and path...

Engineered synthetic biomolecular devices that integrate elaborate information processing and precisely regulate living cell behavior have potential in various applications. Although devices that directly regulate key biomolecules constituting inherent biological systems exist, no devices have been developed to control intracellular membrane archit...

While molecular oxygen is essential for aerobic organisms, its utilization is inseparably connected with generation of oxidative insults. To cope with the detrimental aspects, cells evolved antioxidative defense systems, and insufficient management of the oxidative insults underlies the pathogenesis of a wide range of diseases. A battery of genes f...

Background The efficacy of small molecule inhibitors for intracellular signal mediators varies among the individuals, and their mechanism of action is broad. A phosphodiesterase 4 inhibitor apremilast shows a dramatic effect on a certain proportion of psoriatic patients by modulating the cellular metabolism and regulating the production of pro-infl...

Dyslipidemia is correlated with the prognosis of amyotrophic lateral sclerosis (ALS), a fatal motor neuron disorder characterized pathologically by TAR DNA binding protein (TDP-43) inclusions. We investigated molecular mechanisms of lipid metabolism regulated by TDP-43 in ALS. Expression microarray and RNA deep sequencing (RNA-Seq) were performed u...

A growing body of evidence indicates that cellular metabolism is involved in immune cell functions, including cytokine production. Serine is a nutritionally non-essential amino acid that can be generated by de novo synthesis and conversion from glycine. Serine contributes to various cellular responses, but the role in inflammatory responses remains...

cAMP responsive element‐binding protein H (CREBH) is a hepatic transcription factor to be activated during fasting. We generated CREBH knock‐in flox mice, and then generated liver‐specific CREBH transgenic (CREBH L‐Tg) mice in an active form. CREBH L‐Tg mice showed a delay in growth in the postnatal stage. Plasma growth hormone (GH) levels were sig...

Familial hypercholesterolemia (FH) is an inherited disorder with retarded clearance of plasma LDL caused by mutations of the genes involved in the LDL receptor-mediated pathway and most of them exhibit autosomal dominant inheritance. Homozygotes of FH (HoFH) may have plasma LDL-C levels, which are at least twice as high as those of heterozygous FH...

Background Although type 2 diabetes mellitus (T2DM) is a known risk factor for hepatocellular carcinoma (HCC) development, the annual incidence in diabetes patients is far below the threshold of efficient surveillance. This study aimed to elucidate the risk factors for HCC in diabetic patients and to determine the best criteria to identify surveill...

It is known that first-principles based fragment molecular orbital (FMO) theory can be used to study protein–ligand interactions quantitatively. This includes obtaining amino acid residue-wise interactions with the ligand and detailed interaction components such as electrostatic, dispersion, charge-transfer, and exchange-repulsion. This chapter dis...

To determine associations between severity of hypertension and risk of starting dialysis in the presence or absence of diabetes mellitus (DM). A nationwide database with claims data on 258 874 people with and without DM aged 19–72 years in Japan was used to elucidate the impact of severity of hypertension on starting dialysis. Initiation of dialysi...

Background & Aims cAMP responsive element-binding protein 3 like 3 (CREB3L3) is a membrane-bound transcription factor involved in the maintenance of lipid metabolism in the liver and small intestine. CREB3L3 controls hepatic triglyceride and glucose metabolism by activating plasma fibroblast growth factor 21 (FGF21) and lipoprotein lipase. In this...

Background & aims: The incidence of NASH-related HCC is progressively increasing. However, the pathophysiology and etiology of NASH progression to HCC are unknown. We hypothesized that steatosis was the key factor in NASH-related hepatocarcinogenesis and aimed to evaluate the effects of long-term LXR agonist stimulation on hepatic steatosis induce...

Abstract Despite mounting evidence of the positive relationship between diabetes mellitus (DM) and heart failure (HF), the entire context of the magnitude of risk for HF in relation to DM remains insufficiently understood. The principal reason is because new‐onset HF (HF occurring in participants without a history of HF) and recurrent HF (HF re‐occ...

Caloric restriction (CR) improves whole body metabolism, suppresses age-related pathophysiology, and extends lifespan in rodents. Metabolic remodeling, including fatty acid (FA) biosynthesis and mitochondrial biogenesis, in white adipose tissue (WAT) plays an important role in the beneficial effects of CR. We have proposed that CR-induced mitochond...