Nagisa Miyazaki

Intravenous Administration of Endothelial Colony-Forming Cells Overexpressing Integrin β1 Augments Angiogenesis in Ischemic Legs

When injected directly into ischemic tissue in patients with peripheral artery disease, the reparative capacity of endothelial progenitor cells (EPCs) appears to be limited by their poor survival. We, therefore, attempted to improve the survival of transplanted EPCs through intravenous injection and gene modification. We anticipated that overexpression of integrin β1 will enable injected EPCs to home to ischemic tissue, which abundantly express extracellular matrix proteins, the ligands for integrins. In addition, integrin β1 has an independent angiogenesis‐stimulating function. Human endothelial colony‐forming cells (ECFCs; late‐outgrowth EPCs) were transduced using a lentiviral vector encoding integrin β1 (ITGB1) or enhanced green fluorescent protein (GFP). We then locally or systemically injected phosphate‐buffered saline or the genetically modified ECFCs (GFP‐ECFCs or ITGB1‐ECFCs; 1 × 105 cells each) into NOD/Shi‐scid, IL‐2Rγnull mice whose right femoral arteries had been occluded 24 hours earlier. Upregulation of extracellular matrix proteins, including fibronectin, was apparent in the ischemic legs. Four weeks later, blood perfusion of the ischemic limb was significantly augmented only in the ITGB1‐ECFC group. Scanning electron microscopy of vascular casts revealed increases in the perfused blood vessels in the ischemic legs of mice in the ITGB1‐ECFC group and significant increases in the density of both capillaries and arterioles. Transplanted ECFC‐derived vessels accounted for 28% ± 4.2% of the vessels in the ITGB1‐ECFC group, with no cell fusion. Intravenous administration of ECFCs engineered to home to ischemic tissue appears to efficiently mediate therapeutic angiogenesis in a mouse model of peripheral artery disease.

Electron Microscopic Findings Are an Important Aid for Diagnosing Mitochondrial Cardiomyopathy With Mitochondrial DNA Mutation 3243A>G.

Mitochondrial disease can be caused by defects in either mitochondrial or nuclear DNA, but mtDNA mutations are the most common cause in adult.1 Among these mutations, m.3243A>G mutation (MTTL) was first identified in patients with mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes syndrome.2 The mutation is located in the gene encoding tRNALeu and results in impaired protein synthesis and electron transport chain dysfunction.2 Cardiomyopathy is seen in 40% of the symptomatic individuals, usually left ventricular hypertrophy with hypokinesis,3 which however is often overlooked when the patients show few phenotypes typical for mitochondrial disease. The patient (case 1) was a 60-year-old man admitted to Nara Medical University Hospital because of dyspnea due to congestive heart failure. He had hypertension and diabetes mellitus for nearly 10 years and had been hard of hearing for 2 years. His mother also …

Ultrastructural Alteration of Pulmonary Capillary Endothelial Glycocalyx During Endotoxemia

Background The most recent diagnostic criteria for sepsis include organ failure. Microvascular endothelial injury is believed to lead to the multiple organ failure seen in sepsis, although the precise mechanism is still controversial. ARDS is the primary complication during the sequential development of multiple organ dysfunction in sepsis, and endothelial injury is deeply involved. Sugar‐protein glycocalyx coats all healthy vascular endothelium, and its disruption is one factor believed to contribute to microvascular endothelial dysfunction during sepsis. The goal of this study was to observe the three‐dimensional ultrastructural alterations in the pulmonary capillary endothelium, including the glycocalyx, during sepsis‐induced pulmonary vasculitis. Methods This study investigated the three‐dimensional ultrastructure of pulmonary vascular endothelial glycocalyx in a mouse lipopolysaccharide‐induced endotoxemia model. Lungs were fixed with lanthanum‐containing alkaline fixative to preserve the glycocalyx. Results On both scanning and transmission electron microscopic imaging, the capillary endothelial glycocalyx appeared as a moss‐like structure entirely covering the endothelial cell surface in normal mice. In the septic lung following liposaccharide injection, however, this structure was severely disrupted; it appeared to be peeling away and coagulated. In addition, syndecan‐1 levels were significantly reduced in the septic lung, and numerous spherical structures containing glycocalyx were observed on the endothelial surface. Conclusions It appears that endothelial glycocalyx in the lung is markedly disrupted under experimental endotoxemia conditions. This finding supports the notion that disruption of the glycocalyx is causally related to the microvascular endothelial dysfunction that is characteristic of sepsis‐induced ARDS.

Anti-apoptosis in nonmyocytes and pro-autophagy in cardiomyocytes: two strategies against postinfarction heart failure through regulation of cell death/degeneration

Anti-apoptotic therapy for cardiomyocytes could be an effective strategy for preventing or treating heart failure. Notably, however, morphological evidence definitively demonstrating cardiomyocyte apoptosis has been very rare in actual heart diseases such as acute myocardial infarction and heart failure. By contrast, within the postinfarction heart, interstitial noncardiomyocytes such as granulation tissue cells do die via apoptosis to form scar tissue. Blockade of this apoptosis improves survival and mitigates ventricular remodeling and dysfunction during the chronic stage. Possible mechanisms to explain this benefit might be preservation of infarcted wall thickness and preservation of myofibroblasts, which could promote infarct shrinkage; both would reduce wall stress through Laplace’s law. On the other hand, autophagy is an intracellular degradation mechanism that compensates for energy insufficiency by digesting and recycling intracellular components, and is often observed in cardiomyocytes within failing hearts with various origins including postinfarction. Starvation strongly induces and activates autophagic degeneration within cardiomyocytes. When that activation is inhibited, the starved animals suffer from heart failure. Promoting autophagy through caloric restriction or several reagents not only reduces the acute infarct size but also mitigates postinfarction cardiac remodeling and dysfunction during chronic stages. Moreover, augmenting autophagy by the treatment with resveratrol or exercise can bring about reverse remodeling in failing hearts with a large old myocardial infarction. In conclusion, we propose two strategies for managing postinfarction heart failure through control of cell death/degeneration: (1) anti-apoptosis in granulation tissue noncardiomyocytes; and (2) pro-autophagy in salvaged cardiomyocytes.

Acupuncture and Traditional Herbal Medicine Therapy Prevent Deliriumin Patients with Cardiovascular Disease in Intensive Care Units.

The aim of this study was to determine the effect of combination therapy consisting of acupuncture and traditional herbal medicine (Kampo medicine) for reducing the incidence rate of delirium in patients with cardiovascular (CV) disease in ICUs. Twenty-nine patients who had been urgently admitted to the ICU in the control period were treated with conventional intensive care. Thirty patients in the treatment period received conventional therapy plus a combination therapy consisting of acupuncture and herbal medicine. Acupuncture treatment was performed once a day, and the herbal formula was administered orally three times a day during the first week of the ICU stay. The standard acupuncture points were GV20, Ex-HN3, HT7, LI4, Liv3, and KI3, and the main herbal preparation was Kamikihito. The incident rates of delirium, assessed using the confusion assessment method for ICU, in the treatment and control period were compared. The incidence rate of delirium was significantly lower in the treatment group than in the control group (6.6% vs. 37.9%, [Formula: see text]). Moreover, sedative drugs and non-pharmacological approaches against aggressive behavior of patients who were delirious were used less in the treatment group than in the control group. No serious adverse events were observed in the treatment group. Combination therapy consisting of acupuncture and herbal medicine was found to be effective in lowering the incidence of delirium in patients with CV disease in ICUs. Further studies with a large sample size and parallel randomized controlled design would be required to establish the effects of this therapy.

Mitochondrial deformity confined to a single cardiomyocyte in human endomyocardial biopsy specimens: Report of 4 cases

During electron microscopic examination of 156 consecutive human endomyocardial biopsy specimens, we found marked mitochondrial deformity within a single cardiomyocyte in each of 4 specimens. The deformed mitochondria were unevenly distributed, but the deformities were confined to the one cardiomyocyte. Those affected cardiomyocytes were accompanied by nonspecific degenerative changes such as nuclear hypertrophy and/or rarefaction of the myofibrils. Mitochondria in all other cells within the specimens appeared normal. Such an abnormality has never been reported to date. Each of the four cases was diagnosed with a different ailment: post-myocarditis, dilated cardiomyopathy, amyloidosis, and tachycardia-induced heart failure. However, all four cases were accompanied by left ventricular systolic dysfunction at biopsy. The very limited mitochondrial deformation may thus reflect a type of degenerative change that accompanies heart failure. <Learning objective: A marked mitochondrial deformity must have been overlooked to date, which is confined to a single cardiomyocyte in an endomyocardial biopsy specimen. Its etiology is still unknown but may reflect a type of degenerative change that accompanies heart failure.>.

Ultrastructural aspects of vacuolar degeneration of cardiomyocytes in human endomyocardial biopsies

Vacuolar degeneration of cardiomyocytes is a histological finding commonly encountered during routine light microscopic examination of human endomyocardial biopsy specimens. The vacuoles appear as intracellular clear areas lacking myofibers. By itself, this finding has little diagnostic value, but may have important clinical implications when the vacuolar contents are of etiological significance (e.g., accumulation of abnormal metabolites), and the clinical importance is increased when the disease is treatable. Thanks to its great resolving power, electron microscopy can often reveal the contents of the vacuoles and lead to a correct diagnosis. It can be used to differentially diagnose lysosomal storage diseases such as Fabry, Danon, and Pompe disease, doxorubicin cardiomyopathy, mitochondrial cardiomyopathy, autophagic degeneration, and accumulation of subcellular organelles (mitochondria, lipofuscin, glycogen granules, endoplasmic reticulum, etc.) as a nonspecific finding in failing cardiomyocytes. Nonetheless, undiagnosed cases certainly remain. It is strongly recommended that small pieces of tissue samples be fixed for electron microscopy at every endomyocardial biopsy procedure, and electron microscopic examination should be performed when a marked vacuolar degeneration is found.

Substitution of Chronic Insulin Therapy with Dipeptidyl Peptidase-4 Inhibitors and Sodium-Glucose Co-transporter-2 Inhibitors

Page 77 Insulin is a very useful and widely used treatment for diabetes. Temporary insulin therapy improves glucose toxicity due to improved β-cell function of the pancreas. Upon achieving glycemic control, insulin treatment could be discontinued and substituted with oral hypoglycemic agents. Nevertheless, insulin therapy is associated with side effects such as hypoglycemia, allergic reactions, and angioneurotic edema. Over this past decade, there have been rapid advances in diabetes treatment, including the introduction of Dipeptidyl peptidase-4 (DPP-4) inhibitors and Sodium-glucose cotransporter-2 (SGLT2) inhibitors. We present here the case of a patient with type 2 diabetes who discontinued insulin therapy after more than 20 years by switching to oral hypoglycemic agents including a DPP-4 inhibitor and a SGLT2 inhibitor.

Phenotype and Physiological Significance of the Endocardial Smooth Muscle Cells in Human Failing Hearts

Background—Extravascular smooth muscle cells are often observed in the endocardium of human failing hearts. Here, we characterized the phenotype of those cells and investigated their physiological significance. Methods and Results—We examined left ventricular biopsy specimens obtained from 44 patients with dilated cardiomyopathy and 6 nonfailing hearts. In Masson trichrome–stained histological preparations, bundles of smooth muscle cells were seen localized in the endocardium in 23 of the 44 specimens (none of the 6 controls). These cells were immunopositive for &agr;-smooth muscle actin, type 2 smooth muscle myosin, desmin, and calponin, but were negative for embryonic smooth muscle myosin, vimentin, fibronectin, and periostin. This profile is indicative of a late differentiation (contractile) smooth muscle phenotype. Electron microscopy confirmed that phenotype, revealing the cells to contain abundant myofilaments with dense bodies but little rough endoplasmic reticulum or Golgi apparatus. In the endocardial smooth muscle–positive group, the left ventricular end-systolic volume index (73±34 versus 105±50 mL/m2; P=0.021), left ventricular peak wall stress (164±47 versus 196±43 dynes 103/cm2; P=0.023), and left ventricular end-systolic meridional wall stress (97±38 versus 121±37 dynes 103/cm2; P=0.036) were all significantly smaller, and the ejection fraction was larger (41±8.8 versus 33±9.3%; P=0.005) than in the endocardial smooth muscle–negative group. However, no histological parameters differed between the 2 groups. Conclusions—Endocardial smooth muscle cell bundles in hearts with dilated cardiomyopathy exhibit a mature contractile phenotype and may play a compensatory role mitigating heart failure by reducing left ventricular wall stress and systolic dysfunction.