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1.
Brain Behav ; 7(2): e00616, 2017 02.
Article in English | MEDLINE | ID: mdl-28239526

ABSTRACT

OBJECTIVES: To clarify whether weight change in patients with Parkinson's disease (PD) or progressive supranuclear palsy (PSP) is caused by the disease itself or secondarily by other factors. MATERIALS AND METHODS: We conducted a retrospective analysis of 51 patients with PD and 14 patients with PSP, especially during the early stage of their diseases. All patients were independent in terms of their activities of daily living and did not have any feeding difficulty. RESULTS: The body mass index measured within 3 years after the disease onset did not show a significant difference between the two diseases. However, the subsequent weight was stable in patients with PD and significantly decreased in patients with PSP. CONCLUSIONS: Weight loss begins in the early stage of PSP, whereas dopaminergic treatment may contribute to keep weight in the early stage of PD through reduction of energy expenditure and/or improvement in appetite.


Subject(s)
Body Mass Index , Disease Progression , Parkinson Disease/physiopathology , Supranuclear Palsy, Progressive/physiopathology , Weight Loss/physiology , Aged , Female , Humans , Male , Middle Aged , Retrospective Studies
2.
Intern Med ; 53(19): 2223-6, 2014.
Article in English | MEDLINE | ID: mdl-25274234

ABSTRACT

Recent randomized studies have failed to note any benefits to adding renal artery stenting to optimal medical therapy in patients with atherosclerotic renal artery stenosis (ARAS). We herein present the case of a 75-year-old woman with acute worsening of chronic renal failure in whom renal stenting was essential to saving the patient's life and avoiding dialysis. Although the long-term usefulness of renal artery stenting for ARAS remains controversial, this procedure should be kept in mind as a viable option for treating acute critical cases such as this.


Subject(s)
Glomerular Filtration Rate/physiology , Kidney Failure, Chronic/etiology , Recovery of Function , Renal Artery Obstruction/surgery , Renal Artery/surgery , Stents , Vascular Surgical Procedures/methods , Aged , Arteriosclerosis/complications , Arteriosclerosis/diagnosis , Arteriosclerosis/surgery , Female , Humans , Kidney Failure, Chronic/physiopathology , Kidney Failure, Chronic/surgery , Renal Artery Obstruction/complications , Renal Artery Obstruction/diagnosis
3.
Neuropathology ; 34(1): 58-63, 2014 Feb.
Article in English | MEDLINE | ID: mdl-23773010

ABSTRACT

A 64-year-old man noticed weakness in his arms and dyspnea upon exertion. Four months later he was admitted to our hospital, where muscle atrophy and hyperactive deep tendon reflexes in the arms were observed upon examination. A needle electromyograph study revealed acute and chronic denervation in the extremities, and he was diagnosed as having amyotrophic lateral sclerosis (ALS). Seven months after onset of the disease, he died of respiratory failure. Neuropathologically, neuronal cell loss was observed in the motor cortex, hypoglossal nuclei, cervical and lumbar anterior horns and Clarke's nuclei. Some of the remaining neurons contained neurofilamentous conglomerate inclusions (CIs). A small number of Lewy body-like hyaline inclusions (LBHIs) were also observed. No the Bunina bodies, skein-like inclusions or basophilic inclusions were detectable. Tract degeneration was moderate in the dorsal and ventral spinocerebellar tracts, mild in the pyramidal tract, but not discerned in the posterior column. Immunohistochemical examinations revealed that the CIs were strongly positive for phosphorylated neurofilament and moderately positive for ubiquitin and Cu/Zn superoxide dismutase 1 (SOD1). Moreover, a number of phosphorylated tau protein-positive globose neurofibrillary tangles (NFTs) and threads were observed in the periaqueductal gray matter, oculomotor nuclei and trochlear nuclei. Although the family history was negative for neuromuscular diseases, the neuropathological findings indicated features of familial ALS with a SOD1 mutation. In fact, DNA analysis of frozen-brain tissue revealed the presence of the I113T SOD1 mutation. This case represents the first one of this mutation in a patient who showed CIs as well as LBHIs in the motor neurons at the same time, in addition to the NFTs in the mesencephalic tegmentum.


Subject(s)
Amyotrophic Lateral Sclerosis/diagnosis , Amyotrophic Lateral Sclerosis/genetics , Amyotrophic Lateral Sclerosis/pathology , Humans , Male , Middle Aged , Mutation , Neurofibrillary Tangles/pathology , Superoxide Dismutase/genetics , Superoxide Dismutase-1
4.
Amyotroph Lateral Scler ; 12(6): 444-50, 2011 Nov.
Article in English | MEDLINE | ID: mdl-21745122

ABSTRACT

The major pathological hallmarks of amyotrophic lateral sclerosis (ALS) are neuronal cytoplasmic inclusions (NCIs) and swollen neurites. Superoxide dismutase (SOD)-1-immunopositive NCIs are observed in patients with familial ALS (FALS), and TAR DNA-binding protein 43kDa (TDP-43)-immunopositive NCIs are found in patients with sporadic ALS (SALS). Protein disulfide isomerase (PDI) is a member of the thioredoxin superfamily and is believed to accelerate the folding of disulfide-bonded proteins by catalyzing the disulfide interchange reaction, which is the rate-limiting step during protein folding in the luminal space of the endoplasmic reticulum. Post mortem spinal cord specimens from five patients with SALS and one with FALS (I113T), and five normal controls were utilized in this immunohistochemical study. We found PDI-immunopositive swollen neurites and NCIs in the patients with ALS. Furthermore, PDI was colocalized with TDP-43 and SOD1 in NCIs. The accumulation of misfolding proteins may disturb axon transport and make swollen neurites. As the motor neuron is the longest cell in the nervous system, the motor system may selectively be disturbed. In conclusion, we assume that PDI is S-nitrosylated in the affected neurons, which inhibits its enzymatic activity and thus allows protein misfolding to occur in ALS.


Subject(s)
Amyotrophic Lateral Sclerosis/enzymology , Amyotrophic Lateral Sclerosis/pathology , Inclusion Bodies/enzymology , Inclusion Bodies/pathology , Protein Disulfide-Isomerases/metabolism , Animals , DNA-Binding Proteins/chemistry , DNA-Binding Proteins/metabolism , Humans , Protein Disulfide-Isomerases/chemistry , Protein Folding
5.
J Orthop Res ; 27(12): 1652-8, 2009 Dec.
Article in English | MEDLINE | ID: mdl-19489046

ABSTRACT

It is assumed that there are systemic changes in mineral metabolism during fracture healing that may cause a predisposition to sequential fractures in osteoporotic patients who suffered from previous fractures. Initial therapies for patients with osteoporotic fractures are important to prevent disabilities in daily life consequent to bone and muscle atrophies, and sequential fractures, although systemic and local bone metabolism during fracture healing have not been well understood. We evaluated the effects of bone injury and elcatonin injection as an initial therapy on systemic and local bone turnover and bone wound healing. Two drill holes were made in the diaphysis of the left femur and tibia of 12-week-old male C57BL/6J mice. They were treated with three doses of elcatonin or a vehicle thrice a week until the end of the 28-day experiment. Urinary crosslinked C-telopeptide of type I collagen (CTX) increased and the bone mineral densities (BMDs) in the lumbar vertebrae decreased in the vehicle-treated mice. Elcatonin injection prevented increases in urinary CTX and reduction of the BMDs. In the noninjured femoral metaphysis, osteoclast surface increased until day 28, whereas elcatonin suppressed it. In the fracture site, elcatonin facilitated osteoblast proliferation and did not delay the healing of the bone defect. Bone injuries accelerated bone turnover systemically and locally, and the elcatonin injections suppressed the systemic acceleration of bone resorption without a delay of filling regenerated cortical bone in the bone defect.


Subject(s)
Bone Density Conservation Agents/pharmacology , Bone Regeneration/drug effects , Bone Resorption/drug therapy , Calcitonin/analogs & derivatives , Femur/drug effects , Absorptiometry, Photon , Animals , Biomarkers/metabolism , Body Weight/drug effects , Bone Regeneration/physiology , Bone Resorption/metabolism , Calcitonin/pharmacology , Collagen Type I/genetics , Collagen Type I/metabolism , Collagen Type I/urine , Collagen Type I, alpha 1 Chain , Disease Models, Animal , Femur/diagnostic imaging , Femur/injuries , Lumbar Vertebrae/diagnostic imaging , Lumbar Vertebrae/drug effects , Lumbar Vertebrae/metabolism , Male , Mice , Mice, Inbred C57BL , Osteocalcin/genetics , Osteocalcin/metabolism , Peptides/urine , RNA, Messenger/metabolism , Wound Healing/drug effects
6.
J Mol Cell Cardiol ; 40(4): 562-9, 2006 Apr.
Article in English | MEDLINE | ID: mdl-16483597

ABSTRACT

L-type Ca(2+) channels have a wide tissue distribution and play essential roles in physiological responses. Recent studies have indicated that regulation of L-type Ca(2+) channels involves the assembly of macromolecular signaling complexes such as the beta(2)-adrenergic receptor signaling complex, the small G-protein kir/Gem and the BK channel. Here, we report the previously unidentified role of another protein in binding to the II-III linker of the alpha(1C) subunit of the L-type Ca(2+) channel. This protein is COP9 signalosome subunit 5 (CSN5)/Jun activation domain-binding protein 1 (Jab1). We have demonstrated that CSN5 interacts specifically with the II-III linker of the alpha(1C) subunit in a yeast two-hybrid system. The alpha(1C) subunit and CSN5 were coimmunoprecipitated in rat heart and both proteins were colocalized in sarcolemmal membranes and transverse tubules of cardiac myocytes. Silencing of CSN5 mRNA using siRNA decreased the endogenous protein level of CSN5 and activated L-type Ca(2+) channels expressed in COS7 cells. These data indicate that CSN5 is a protein that plays a newly defined functional role in association with the cardiac L-type Ca(2+) channel.


Subject(s)
Calcium Channels, L-Type/metabolism , Gene Expression Regulation , Intracellular Signaling Peptides and Proteins/metabolism , Multiprotein Complexes/physiology , Myocytes, Cardiac/physiology , Peptide Hydrolases/physiology , Signal Transduction/physiology , Animals , COP9 Signalosome Complex , COS Cells , Calcium Channels, L-Type/genetics , Chlorocebus aethiops , Gene Expression Regulation/genetics , Intracellular Signaling Peptides and Proteins/genetics , Myocytes, Cardiac/cytology , Protein Binding/physiology , Protein Subunits/physiology , RNA Interference , Rats , Receptors, Adrenergic, beta-2/metabolism , Sarcolemma/metabolism
7.
Bone ; 39(1): 83-92, 2006 Jul.
Article in English | MEDLINE | ID: mdl-16487758

ABSTRACT

To clarify the role of cyclooxygenase-2 (COX-2) in acute recovery of trabecular bone in reloaded hindlimbs of tail-suspended mice, we administered a COX-2 selective inhibitor in the mice during the reloading period after unloading. Experiments were conducted on 140 male C57BL/6J mice (8 weeks old). They were divided into ground control (GC) and unloading by tail suspension (UL) groups. On day 7, Group GC was divided into Groups GC+Vehicle (Veh) and GC+Celecoxib (Cel), while Group UL mice were fed on the ground [reloading (RL)] after 7-day unloading and were then divided into Groups RL+Veh and RL+Cel. Bone histomorphometry, osteogenic cell development, and mRNA expression of osteogenic molecules were assessed. At 5 days after reloading, the increase of bone formation rate and the ratio of osteocalcin mRNA expression per CFU-f colony in Group RL+Cel were significantly decreased compared with those in Group RL+Veh, while alkaline phosphatase-positive (ALP+) CFU-f formation and the ratios of cbfa-1, osterix, and type 1 collagen mRNA expression per CFU-f colony increased to the same levels in both RL groups. At 14 days after reloading, decreased bone volume by unloading in RL+Veh recovered to the same level as that of GC+Veh, but that in RL+Cel did not recover completely. The increase of c-fos mRNA expression in bone marrow cells at 1, 24, and 48 h after reloading, osteocalcin mRNA at 6 h, and osterix mRNA at 24 h were suppressed by COX-2 inhibitor. These data indicate that the COX-2 selective inhibitor celecoxib suppresses the restoration of tibial trabecular bone formation and the acute recovery of trabecular bone. These actions are closely related to restriction of c-fos and osteocalcin mRNA expressions and osteoblast differentiation in bone marrow cells.


Subject(s)
Cyclooxygenase 2 Inhibitors/pharmacology , Hindlimb Suspension , Osteoblasts/drug effects , Pyrazoles/pharmacology , Sulfonamides/pharmacology , Tibia/cytology , Tibia/drug effects , Animals , Body Weight , Bone Development/drug effects , Celecoxib , Male , Mice , Mice, Inbred C57BL , Osteoblasts/metabolism , RNA, Messenger/metabolism , Random Allocation , Stress, Mechanical , Tibia/metabolism , Time Factors
8.
Bone ; 36(3): 502-11, 2005 Mar.
Article in English | MEDLINE | ID: mdl-15777685

ABSTRACT

We evaluated the effects of YM529, a nitrogen-containing bisphosphonate, on the repair of cortical bone after drill-hole injury at the tissue-, cell- and gene-levels in the femur of mice. Eight-week-old male C57BL/6N mice were treated with an intravenous injection of 0.01, 0.05 and 0.1 mg/kg body weight (BW) of YM529, or the vehicle (VC) once a week from 8 weeks of age until sacrifice. At 10 weeks of age (day 0), a drill-hole was made in the diaphysis of bilateral femurs. Femoral specimens were obtained at days 3, 5, 7, 10, 14, 21 and 28 after surgery. Histology and histomorphometry confirmed the early woven bone formation in 7 days after injury in all four groups, but the following lamellar bone repair in the cortical tissue area delayed only in the YM529-treated groups. Since the findings were not dose-dependent, following evaluations were performed in VC and YM529 0.1 mg/kg BW dose groups. Calcein-labeled surface of regenerated bone decreased at day 21 in the YM529 group. At day 0, CFU-f number and mineralized nodule area that developed from marrow cells were significantly smaller in YM529 group than in VC group. At day 5, however, these values increased to levels similar to those in VC group. The mRNA expression levels of BMP-2, cbfa1, osterix, type I collagen, and osteocalcin in the injured bone and marrow cells at days 3 and 5 were similar in the two groups, but were higher in YM529 group at day 7 compared with that in the VC group. At day 14, the levels of these mRNAs were still high, while that of osteocalcin was significantly reduced compared to the VC group. These data indicate that the action of YM529 on bone formation is bimodal, stimulatory on the developments of osteogenic cells for the woven bone regeneration and inhibitory on the terminal differentiation of osteoblasts for the later remodeling, consequently leading to a delay in the lamellar bone healing in the cortical tissue area.


Subject(s)
Bone Regeneration/drug effects , Cell Differentiation/drug effects , Diphosphonates/pharmacology , Femur/drug effects , Femur/injuries , Imidazoles/pharmacology , Osteoblasts/drug effects , Animals , Bone Regeneration/physiology , Cell Differentiation/physiology , Femur/cytology , Femur/physiology , Male , Mice , Mice, Inbred C57BL , Osteoblasts/cytology , Osteoblasts/physiology , Time Factors
9.
J Bone Miner Metab ; 22(6): 530-40, 2004.
Article in English | MEDLINE | ID: mdl-15490262

ABSTRACT

Estrogen deficiency causes reduction of bone mass and abnormal bone microarchitecture, consequently reducing bone strength. Human parathyroid hormone (hPTH) (1-34) increases bone mass and strength. To clarify the factors that determine the recovery of bone strength in the lumbar vertebrae of ovariectomized rats by intermittent hPTH administration, we analyzed the relationship between skeletal measurements and bone strength. Human PTH (1-34) administration resulted in recovery of cortical bone mineral content (BMC) and cortical bone area to sham the levels, but in resulted in a less pronounced recovery of trabecular BMC and no increase in the total cross-sectional area of the vertebral body. Of the three-dimensional (3D) trabecular bone parameters, hPTH (1-34) increased trabecular thickness (Tb.Th). The cortical shell area of L4, determined by histomorphometry, was also increased. In hPTH-treated rats, the only determinant of the compressive load of L5 was the cortical shell BMC, in the early recovery period (days 42-84). Our data suggest that increased cortical bone mass contributes more than trabecular bone mass and structure to the recovery of bone strength in response to hPTH therapy in the rat lumbar vertebral body after ovariectomy.


Subject(s)
Bone Density/drug effects , Bone Remodeling/drug effects , Lumbar Vertebrae/metabolism , Teriparatide/administration & dosage , Animals , Female , Humans , Lumbar Vertebrae/pathology , Osteocalcin/blood , Osteoporosis/blood , Osteoporosis/drug therapy , Osteoporosis/pathology , Ovariectomy , Rats , Rats, Sprague-Dawley
10.
Bone ; 34(6): 940-8, 2004 Jun.
Article in English | MEDLINE | ID: mdl-15193540

ABSTRACT

Prostaglandin E(2) (PGE(2)) is essential for fracture healing. Systemic administration of EP4 ligands such as PGE(2) and other synthetic EP4 agonists appears to transduce anabolic signals by binding to receptor EP4. Therefore, the present study was designed to test whether administration of EP4 agonist accelerates the healing of drill-hole injury in the femoral diaphysis. After surgery, a total of 128 Wistar rats, at the age of 12 weeks, were assigned to basal control (n = 8), and three groups with respective doses of 0 (vehicle control), 10 (low-dose), and 30 (high-dose) microg/kg body weight of the agent were subcutaneously injected twice a day. Femoral specimens were obtained at 0, 5, 7, 14, 21, and 28 days. In EP4 agonist-treated groups, the total bone volume of the regenerating bone in the defect did not significantly differ, but the regenerated cortical bone volume measured by histomorphometry and cortical bone mineral content (Ct. BMC) by pQCT dose-dependently increased at 14 and 21 days compared to the control. In the high-dose group, the value of osteoclast surface significantly increased compared with that in the control at 14 days. Expression levels of osteocalcin and TRAP mRNAs in the injured tissue increased at 14 days. Expression levels of EP4, BMP-2, and RANKL mRNAs increased at 7 days in the high-dose group. The bone mineral values of the lumbar bone at 28 days, measured by DXA, did not differ in the three groups. These data indicated that systemic administration of EP4 agonist ONO-4819.CD accelerated cortical bone healing after drill-hole injury by upregulating the local turnover of the regenerating bone.


Subject(s)
Bone Regeneration/drug effects , Femur/drug effects , Femur/injuries , Heptanoates/pharmacology , Receptors, Prostaglandin E/agonists , Up-Regulation/drug effects , Animals , Bone Regeneration/physiology , Bone Remodeling/drug effects , Bone Remodeling/physiology , Femur/physiology , Male , Rats , Rats, Wistar , Receptors, Prostaglandin E/physiology , Receptors, Prostaglandin E, EP4 Subtype , Up-Regulation/physiology
11.
Jpn J Physiol ; 54(1): 1-6, 2004 Feb.
Article in English | MEDLINE | ID: mdl-15040842

ABSTRACT

The excitation-contraction (E-C) coupling system during the development of heart can be investigated because of marked progression in electrophysiology and microfluorescence studies. During the developmental period, Ca2+ influx mediating the E-C coupling is mainly through the L-type Ca2+ channels. In the fetal period, T-type Ca2+ channels and the reverse mode of the Na-Ca exchange system also contribute to Ca2+ influx. These contributions probably reduce gradually until adulthood. The contraction of fetal cardiomyocytes has been thought to depend mainly on the Ca2+ influx. However, recent studies reveal that immature sarcoplasmic reticulum (SR) already works in the early fetal period. Ca2+ spark, a local and unitary movement of Ca2+, can be observed in adult cardiomyocytes by the use of a confocal microscope. On the other hand, no Ca2+ spark is observed in fetal cardiomyocytes. The frequency of Ca(2+)-spark evocation increases during the postnatal period. Therefore a close distance between the L-type Ca2+ channel and the SR Ca(2+)-release channel is essential to the establishment of the Ca2+ spark.


Subject(s)
Calcium Channels/physiology , Calcium Signaling/physiology , Heart/embryology , Heart/physiology , Myocardial Contraction/physiology , Myocytes, Cardiac/physiology , Animals , Humans , Models, Cardiovascular
12.
Eur J Pharmacol ; 487(1-3): 37-45, 2004 Mar 08.
Article in English | MEDLINE | ID: mdl-15033374

ABSTRACT

We recently cloned the beta(2c) subunit of the L-type Ca(2+) channel as a functional type of beta subunit from the rat heart. In order to clarify the contribution of the beta(2c) subunit to native Ca(2+) channel function, we investigated the single-channel properties of Ca(2+) channels reconstituted with beta(2a) or beta(2c) subunits and compared them with the properties of native channels. In contrast to the Ca(2+) channel with beta(2a) subunit, long-lasting closings were dominant in the Ca(2+) channel with beta(2c) subunit and the native channel. The ensemble-averaged current of the cells with beta(2c) subunits was comparable to that of the native cardiomyocytes. Many high P(o) sweeps (mode 2) were observed in the cells with beta(2a) subunits, while only a few high P(o) sweeps were observed in the cells with beta(2c) subunits and the native cells. These findings suggest that the beta(2c) subunit is one of the functional beta subunits in the rat heart.


Subject(s)
Calcium Channels, L-Type/metabolism , Myocardium/metabolism , 3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester/pharmacology , Animals , COS Cells , Calcium Channel Agonists/pharmacology , Calcium Channels, L-Type/drug effects , Calcium Channels, L-Type/genetics , Chlorocebus aethiops , Electrophysiology , Heart/drug effects , Ion Channel Gating/drug effects , Rats , Transfection
13.
J Mol Cell Cardiol ; 35(9): 1073-82, 2003 Sep.
Article in English | MEDLINE | ID: mdl-12967630

ABSTRACT

The Ca(2+)-independent, voltage-gated transient outward current (I(to)) displays a marked increase during development of cardiomyocytes. However, the molecular mechanism remained unclear. In rat adult ventricular myocytes, I(to) can be divided into a fast (I(to,f)) and a slow (I(to,s)) component by recovery process from inactivation. Voltage-gated K(+) channel-interacting proteins 2 (KChIP2) has recently been shown to modify membrane expressions and current densities of I(to,f). Here we examined the developmental change of I(to) and the putative molecular correlates of I(to,f) (Kv4.2 and Kv4.3) and KChIP2 in rat ventricular myocytes. Even in rat embryonic day 12 (E12) myocytes, we detected I(to). However, I(to) in E12 was solely composed of I(to,s). In postnatal day 10 (P10), we recorded much increased I(to) composed of two components (I(to,f) and I(to,s)), and I(to,f) was dominant. Thus, the developmental increase of I(to) from E12 to P10 can be explained by the dramatic appearance of I(to,f). Real-time RT-PCR revealed that Kv4.2 and Kv4.3 mRNA levels were slightly changed. By contrast, KChIP2 mRNA level increased from E12 to P10 by 731-fold. Therefore, the huge increase of KChIP2 expression was likely to be the cause of the great increase of I(to,f). In order to confirm that KChIP2 is crucial to induce I(to,f), we used adenoviral gene transfer technique. When KChIP2 was over-expressed in E12 myocytes, a great amplitude of I(to,f) appeared. Immunocytochemical experiments also demonstrated that KChIP2 enhanced the trafficking of Kv4.2 channels to cell surface. These results indicate that KChIP2 plays an important role in the generation of functional I(to,f) channels during development.


Subject(s)
Calcium-Binding Proteins/metabolism , Heart Ventricles/metabolism , Potassium Channels, Voltage-Gated , Adenoviridae/genetics , Aging , Animals , Animals, Newborn , Cells, Cultured , Fetus , Fluorescent Antibody Technique, Indirect , Heart Ventricles/cytology , Ion Channel Gating , Kv Channel-Interacting Proteins , Myocardium/cytology , Patch-Clamp Techniques , Polymerase Chain Reaction , Potassium Channels/metabolism , RNA, Messenger/analysis , Rats , Rats, Wistar , Shal Potassium Channels , Time Factors
14.
Cardiovasc Res ; 58(3): 535-48, 2003 Jun 01.
Article in English | MEDLINE | ID: mdl-12798426

ABSTRACT

OBJECTIVE: The aim of this study was to characterize the spatio-temporal dynamics of [Ca(2+)](i) in rat heart in the fetal and neonatal periods. METHODS: Using confocal scanning laser microscopy and the Ca(2+) indicator fluo-3, we investigated Ca(2+) transients and Ca(2+) sparks in single ventricular myocytes freshly isolated from rat fetuses and neonates. T-tubules were labeled with a membrane-selective dye (di-8-ANEPPS). Spatial association of dihydropyridine receptors (DHPR) and ryanodine receptors (RyR) was also examined by double-labeling immunofluorescence. RESULTS: Ca(2+) transients in the fetal myocytes were characterized by slower upstroke and decay of [Ca(2+)](i) compared to those in adult myocytes. The magnitude of fetal Ca(2+) transients was decreased after application of ryanodine (1 microM) or thapsigargin (1 microM). However, Ca(2+) sparks were rarely detected in the fetal myocytes. Frequent ignition of Ca(2+) sparks was established in the 6-9-day neonatal period, and was predominantly observed in the subsarcolemmal region. The developmental change in Ca(2+) sparks coincided with development of the t-tubule network. The immunofluorescence study revealed colocalization of DHPR and RyR in the postnatal period, which was, however, not observed in the fetal period. In the adult myocytes, Ca(2+) sparks disappeared after disruption of t-tubules by glycerol incubation (840 mM). CONCLUSIONS: The sarcoplasmic reticulum (SR) of rat ventricular myocytes already functions early in the fetal period. However, ignition of Ca(2+) sparks depends on postnatal t-tubule formation and resultant colocalization of DHPR and RyR.


Subject(s)
Calcium Channels/metabolism , Calcium/metabolism , Heart Conduction System/physiology , Heart/embryology , Myocytes, Cardiac/metabolism , 3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester/pharmacology , Analysis of Variance , Calcium Channel Agonists/pharmacology , Calcium Channels/drug effects , Calcium Channels, L-Type/metabolism , Electrophysiology , Enzyme Inhibitors/pharmacology , Fluorescent Antibody Technique, Indirect , Heart/growth & development , Humans , Microscopy, Confocal , Microscopy, Fluorescence , Myocytes, Cardiac/ultrastructure , Ryanodine/pharmacology , Ryanodine Receptor Calcium Release Channel/metabolism , Sarcoplasmic Reticulum/metabolism , Thapsigargin/pharmacology
15.
Bone ; 32(5): 491-501, 2003 May.
Article in English | MEDLINE | ID: mdl-12753865

ABSTRACT

In this study, we investigated the expression of vascular endothelial growth factor (VEGF) mRNA along with its receptors in the healing process following rat femoral drill-hole injury. The cellular events involved in the differential expression of VEGF were studied by reverse transcription-polymerase chain reaction, immunocytochemistry, and in situ hybridization. Abundant alkaline phosphatase-positive osteoprogenitor cells were present in the bone marrow cavity surrounding the wound region at day 3. Some of the cells were immunoreactive for Flk-1, a marker of angioblasts. At day 5, osteoblasts expressing osteocalcin mRNA actively participated in bone formation. After day 11, medullary bone gradually decreased and hematopoietic cells covered the wound region. The expressions of the VEGF splice variants VEGF120 and VEGF164 were detected at days 1 and 3, and VEGF188 mRNA began to appear from day 5. The expressions of the three VEGF splice variants gradually decreased after day 11. VEGF immunoreactivity and mRNA expression were strongly detected in angioblasts, osteoprogenitor cells, and osteoblasts between days 3 and 7, but gradually decreased after day 11. Immunoreactivity for Flt-1 was also detected in endothelial cells, osteoprogenitor cells, and osteoblasts between days 3 and 7. However, immunoreactivity for Flk-1 was not detected on osteoblasts but rather on endothelial cells. These findings indicate that the differential expression of VEGF splicing isoforms along with its receptors may play an important role in the healing process after rat femoral drill-hole injury.


Subject(s)
Bone Marrow/injuries , Femur/injuries , Fracture Healing/physiology , Vascular Endothelial Growth Factor A/genetics , Vascular Endothelial Growth Factor Receptor-1/genetics , Vascular Endothelial Growth Factor Receptor-2/genetics , Animals , Bone Marrow/physiology , Bony Callus/cytology , Bony Callus/physiology , Extracellular Matrix Proteins/genetics , Female , Femur/physiology , Gene Expression/physiology , Immunohistochemistry , In Situ Hybridization , Osteocalcin/genetics , RNA, Messenger/analysis , Rats , Rats, Wistar , Reverse Transcriptase Polymerase Chain Reaction
16.
Biochem Biophys Res Commun ; 294(2): 199-204, 2002 Jun 07.
Article in English | MEDLINE | ID: mdl-12051693

ABSTRACT

KCNQ1 encodes a pore-forming subunit of potassium channels. Mutations in this gene cause inherited diseases, i.e., Romano-Ward syndrome and Jervell and Lange-Nielsen syndrome. A truncated isoform of KCNQ1 was reported to be expressed physiologically and to suppress a delayed rectifier potassium current dominant-negatively in human heart. However, it is not known whether this way of modulation occurs in other species. We cloned another truncated splice variant of KCNQ1 (tr-rKCNQ1) from rat heart. Judging from the deleted sequence of the tr-rKCNQ1, the genomic structure of rat in this portion might be different from those of human and mouse. Otherwise, an unknown exon might exist. RT-PCR analysis demonstrated that the tr-rKCNQ1 was expressed in fetal and neonatal hearts. When this gene was expressed along with a full-length KCNQ1, it suppressed potassium currents, whether a regulatory subunit minK was co-expressed or not.


Subject(s)
Alternative Splicing/genetics , Myocardium/metabolism , Potassium Channels, Voltage-Gated , Potassium Channels/biosynthesis , Potassium Channels/genetics , Aging , Animals , Animals, Newborn , Blotting, Northern , Cloning, Molecular , Gene Expression , Heart/embryology , Humans , In Vitro Techniques , KCNQ Potassium Channels , KCNQ1 Potassium Channel , Mice , Microinjections , Molecular Sequence Data , Oocytes/metabolism , Patch-Clamp Techniques , Potassium/metabolism , RNA, Complementary/administration & dosage , RNA, Complementary/metabolism , Rats , Reverse Transcriptase Polymerase Chain Reaction , Sequence Alignment , Sequence Deletion , Sequence Homology, Amino Acid , Xenopus
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