AIMTo analyze the relationship between sperm mitochondrial membrane potential and sperm motility parameters by means of a computer-assisted sperm analyzer (CASA) and in-vitro fertilization rate(%FR).

METHODSSemen samples were obtained from 26 men undergoing in vitro fertilization-embryo transfer (IVF-ET). Informed consent was obtained from all men prior to the study. Samples were prepared using wash and swim-up method in HEPES-HTF medium. The sperm motility (%MOT), progressive motility (%PMOT), average path velocity (VAP) microm/s), straight line velocity (VSL) (micro m/s), curvilinear velocity (VCL) (microm/s) and %hyperactivated sperm (%HA), and the %FR were assessed. The samples were incubated in the presence of 2.0 mciromol/L of 5,5',6,6'-tetra-chloro-1,1',3,3'-tetraethylbenzimidazolyl-carbocyanine iodide (JC-1) for 30 min at 37 degrees C in air and washed in PBS before flow cytometry (FACSCalibur: Becton Dickinson) analysis. The mitochondrial probe JC-1 was used to identify the mitochondrial membrane potential. The sperm was divided into three populations according to the fluorescence pattern as follows: the high mitochondrial membrane potential group (n=8), the moderate group (n=5), and the low group (n=13). Statistical analysis was performed using unpaired t-test.

RESULTSSignificant differences were found between the high and the low groups in %MOT (91.1+/-8.5 vs 63.0+/-32.7, mean+/-SD), VAP (73.0+/-14.2 vs 52.1+/-12.5), VCL (127.0+/-28.1 vs 87.0+/-22.6), %HA (27.3+/-23.6 vs 7.2+/-9.0) and %FR [73.2 (48/56) vs 59.0 (69/117)]. No significant differences were found in other CASA parameters.

CONCLUSIONWhen the sperm mitochondrial membrane potential increases, sperm motility parameters and fertility potential will also increase. The JC-1 dye method is useful to predict sperm fertility potential.

Embryo Transfer ; Female ; Fertility ; physiology ; Fertilization in Vitro ; Flow Cytometry ; Humans ; Intracellular Membranes ; physiology ; Male ; Membrane Potentials ; physiology ; Mitochondria ; physiology ; ultrastructure ; Semen ; physiology ; Sperm Motility ; Spermatozoa ; physiology

OBJECTIVETo probe the changes of fast component of brainstem auditory evoked potentials (FC-BAEP), slow component of brainstem auditory evoked potentials (SC-BAEP) and the mitochondrial ultrastructures of the neurons in the brainstem in the rat pups with hyperbilirubinemia.

METHODS7 days old SD rat pups were randomly divided into control group (C, 17 rat pups) and two test groups (T1, 17 rat pups and T2, 17 rat pups). Bilirubin solutions (2 g/L) were injected into the abdominal cavity of the rat pups in the group T1 and T2 at the postnatal day 7 and 10. Six hours after the second injection, seven rat pups of each group were randomly selected to test serum bilirubin concentration via a micro-gauge. FC-BAEP and SC-BAEP were examined with an evoked potential recorder in the rest rat pups of each group at postnatal day 17 and 20. At the postnatal day 20, the endocardial perfusion was performed in these rat pups for the fixation of the brain, and then the brains were taken out. The cochlear nuclei were used for observation via electron microscope.

RESULTSSix hours after the injection of bilirubin solution at the postnatal day 10, the serum bilirubin concentrations of the rat pups in group T1 and T2 were increased significantly. Except for II-IV inter-peak latency(IPL), all the peak latency(PL) and IPL of FC-BAEP evoked via three sound stimulating rates (10/s, 40/s,80/s) at the postnatal day 17 prolonged significantly in the rat pups of group T1 and T2, and the PL in group T2 were much longer than that in group T1. Except for II-IV IPL of FC-BAEP evoked via sound stimulating rates of 10/s and 40/s, all the PL and IPL at the postnatal day 20 prolonged significantly in the rat pups of group T1 and T2. The PL of SC-BAEP evoked via sound stimulating rate of 10/s at the postnatal day 17 and 20 in the rat pups of group T1 and T2 prolonged significantly, and the PL at the postnatal day 17 in group T2 were much longer than that of group T1. The changes of mitochondria of the neurons in the cochlear nuclei at the postnatal day 20 in the rat pups of group T1 and T2 were characterized by swell, the slurred membranes, the broken crista and so on.

CONCLUSIONThere were the abnormal changes of FC-BAEP, SC-BAEP and the mitochondrial ultrastructures of the neurons in the brainstem in the rat pups with hyperbilirubinemia. The PL and IPL of FC-BAEP and SC-BAEP could be taken as the objective and sensitive indexes for early monitoring the bilirubin-induced hearing loss and brain injury.

Animals ; Animals, Newborn ; Brain Stem ; pathology ; Evoked Potentials, Auditory, Brain Stem ; physiology ; Hearing Loss ; etiology ; physiopathology ; Hyperbilirubinemia ; complications ; physiopathology ; Male ; Mitochondria ; ultrastructure ; Neurons ; ultrastructure ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo preliminarily investigate the long-term structural and functional injuries of mitochondria in rat brain caused by sepsis.

METHODSWistar rats were randomly assigned into sepsis and control groups. A rat model of sepsis was prepared by an intraperitoneal injection of 10 mg/kg lipopolysaccharide (LPS) of gram-negative bacteria, and the survival assay was performed. Eight rats in the sepsis group were sacrificed at 12, 24, 48, or 72 hours after LPS injection, while rats in the control group were sacrificed after an intraperitoneal injection of an equal volume of normal saline. Mitochondria were extracted from rat brain tissue. Mitochondrial membrane potential (MMP) and mitochondrial swelling level were determined by flow cytometry, and the activities of electron transport chain complexes (I-V) were measured using enzyme assay kits. Hematoxylin-eosin (HE) staining and electron microscopy were used to observe morphological changes in brain tissue and mitochondria.

RESULTSThe sepsis group had a significantly lower survival rate than the control group (P<0.01). The MMP and activities of electron transport chain complexes (I-V) in the sepsis group, which were significantly lower than those in the control group (P<0.05), were reduced to the lowest levels at 48 hours and partially recovered at 72 hours. The mitochondrial swelling level in the sepsis group, which was significantly higher than that in the control group (P<0.05), increased to the peak level at 48 hours and partially recovered at 72 hours. Hematoxylin and Eosin staining revealed substantial damages in the structure of brain tissue, and electron microscopy showed mitochondrial swelling, and vacuolization in a few mitochondria.

CONCLUSIONSIn the rat model of LPS-induced sepsis, both structural and functional injuries are found in cerebral mitochondria, and achieve the peak levels probably at around 48 hours.

Animals ; Brain ; pathology ; physiopathology ; ultrastructure ; Lipopolysaccharides ; toxicity ; Male ; Membrane Potential, Mitochondrial ; Mitochondria ; physiology ; ultrastructure ; Rats ; Rats, Wistar ; Sepsis ; chemically induced ; mortality ; physiopathology

Mitochondrial biogenesis is known to accompany adipogenesis to complement ATP and acetyl-CoA required for lipogenesis. Here, we demonstrated that mitochondrial proteins such as ATP synthase alpha and beta, and cytochrome c were highly expressed during the 3T3-L1 differentiation into adipocytes. Fully-differentiated adipocytes showed a significant increase of mitochondria under electron microscopy. Analysis by immunofluorescence, cellular fractionation, and surface biotinylation demonstrated the elevated levels of ATP synthase complex found not only in the mitochondria but also on the cell surface (particularly lipid rafts) of adipocytes. High rate of ATP (more than 30 micrometer) synthesis from the added ADP and Pi in the adipocyte media suggests the involvement of the surface ATP synthase complex for the exracellular ATP synthesis. In addition, this ATP synthesis was significantly inhibited in the presence of oligomycin, an ATP synthase inhibitor, and carbonyl cyanide m-chlorophenylhydrazone (CCCP), an ATP synthase uncoupler. Decrease of extracellular ATP synthesis in acidic but not in basic media further indicates that the surface ATP synthase may also be regulated by proton gradient through the plasma membrane.
Adenosine Triphosphate/analysis/*biosynthesis ; Adipocytes/*enzymology/ultrastructure ; Animals ; Cell Differentiation/physiology ; Cell Membrane/chemistry ; Cells, Cultured ; Humans ; Membrane Microdomains/chemistry/*enzymology ; Mice ; Mitochondria/metabolism/ultrastructure ; Mitochondrial Proton-Translocating ATPases/analysis/*physiology ; Research Support, Non-U.S. Gov't

Peroxynitrite is a highly reactive nitrogen species and a potent inducer of apoptosis and necrosis in somatic cells. Peroxynitrite-induced nitrosative stress has emerged as a major cause of impaired sperm function; however, its ability to trigger cell death has not been described in human spermatozoa. The objective here was to characterize biochemical and morphological features of cell death induced by peroxynitrite-mediated nitrosative stress in human spermatozoa. For this, spermatozoa were incubated with and without (untreated control) 3-morpholinosydnonimine (SIN-1), in order to generate peroxynitrite. Sperm viability, mitochondrial permeability transition (MPT), externalization of phosphatidylserine, DNA oxidation and fragmentation, caspase activation, tyrosine nitration, and sperm ultrastructure were analyzed. The results showed that at 24 h of incubation with SIN-1, the sperm viability was significantly reduced compared to untreated control (P < 0.001). Furthermore, the MPT was induced (P < 0.01) and increment in DNA oxidation (P < 0.01), DNA fragmentation (P < 0.01), tyrosine nitration (P < 0.0001) and ultrastructural damage were observed when compared to untreated control. Caspase activation was not evidenced, and although phosphatidylserine externalization increased compared to untreated control (P < 0.001), this process was observed in <10% of the cells and the gradual loss of viability was not characterized by an important increase in this parameter. In conclusion, peroxynitrite-mediated nitrosative stress induces the regulated variant of cell death known as MPT-driven necrosis in human spermatozoa. This study provides a new insight into the pathophysiology of nitrosative stress in human spermatozoa and opens up a new focus for developing specific therapeutic strategies to better preserve sperm viability or to avoid cell death.
Adult ; Caspases/metabolism* ; Cell Death ; Enzyme Activation ; Humans ; Male ; Mitochondria/pathology* ; Necrosis ; Nitrosative Stress/physiology* ; Permeability ; Peroxynitrous Acid/pharmacology* ; Phosphatidylserines/metabolism* ; Spermatozoa/ultrastructure*

A vast portion of human disease results when the process of apoptosis is defective. Disorders resulting from inappropriate cell death range from autoimmune and neurodegenerative conditions to heart disease. Conversely, prevention of apoptosis is the hallmark of cancer and confounds the efficacy of cancer therapeutics. In the search for optimal targets that would enable the control of apoptosis, members of the BCL-2 family of anti- and pro-apoptotic factors have figured prominently. Development of BCL-2 antisense approaches, small molecules, and BH3 peptidomimetics has met with both success and failure. Success-because BCL-2 proteins play essential roles in apoptosis. Failure-because single targets for drug development have limited scope. By examining the activity of the BCL-2 proteins in relation to the mitochondrial landscape and drawing attention to the significant mitochondrial membrane alterations that ensue during apoptosis, we demonstrate the need for a broader based multi-disciplinary approach for the design of novel apoptosis-modulating compounds in the treatment of human disease.
Apoptosis/*drug effects/physiology ; BH3 Interacting Domain Death Agonist Protein/physiology ; Drug Design ; Genes, bcl-2 ; Humans ; Mitochondria/physiology/ultrastructure ; Mitochondrial Membranes/*metabolism/physiology ; Multigene Family ; Proto-Oncogene Proteins c-bcl-2/*antagonists & inhibitors ; Signal Transduction

Apoptosis/*drug effects/physiology ; BH3 Interacting Domain Death Agonist Protein/physiology ; Drug Design ; Genes, bcl-2 ; Humans ; Mitochondria/physiology/ultrastructure ; Mitochondrial Membranes/*metabolism/physiology ; Multigene Family ; Proto-Oncogene Proteins c-bcl-2/*antagonists & inhibitors ; Signal Transduction

BACKGROUNDRecent studies in adult hearts have indicated that KATP channels in the inner mitochondrial membrane are responsible for the protection. And we investigated whether opening of mitochondrial KATP channels (mKATP) could provide myocardial protection for immature rabbits and determined its role in cardioprotection.

METHODSThirty-four 3-4-week-old rabbits, weighing 300 - 350 g, were divided randomly into five groups: Group I (control group, n = 8); Group II [diazoxide preconditioning group; n = 8; the hearts were pretreated with 100 micromol/L diazoxide for 5 minutes followed by 10-minute wash out with Krebs-Henseleit buffer (KHB)]; Group III [diazoxide + 5-hydroxydeconate (5-HD) preconditioning group; n = 5; the hearts were pretreated with 100 micromol/L diazoxide and 100 micromol/L 5-HD); Group IV (diazoxide + cardioplegia group; n = 8; cardioplegia containing 100 micromol/L diazoxide perfused the hearts for 5 minutes before ischemia); Group V (diazoxide + 5-HD + cardioplegia group; n = 5; the cardioplegia contained 100 micromol/L diazoxide and 100 micro mol/L 5-HD). All hearts were excised and connected to langendrff perfusion system and passively perfused with KHB at 38 degrees C under a pressure of 70 cmH(2)O. After reperfusion, the recovery rate of left ventricular diastolic pressure (LVDP), +/-dp/dtmax, coronary flow (CF), the creatinine kinase (CK), lactate dehydrogenase (LDH), aspartate aminotransferase (AST) in coronary sinus venous effluent and the tissue ATP were measured. Mitochondria were evaluated semiquantitatively by morphology.

RESULTSAfter ischemia and reperfusion (I/R), the two groups that were treated by diazoxide only (Groups II and IV) had a significant improvement in LVDP, +/-dp/dtmax, and CF recovery. AST, LDH, and CK were decreased, and the levels of tissue ATP in the two groups were higher. Mitochondria was protected better in Group IV than in other groups.

CONCLUSIONSActivating mKATP channels before and during ischemia can similarly protect immature rabbit hearts, and the mechanism is related to the direct protective effect on mitochondria. Opening of mKATP channel during ischemia provides a better protection for mitochondria than it does before ischemia.

Adenosine Triphosphate ; metabolism ; Animals ; Diazoxide ; pharmacology ; Female ; Ischemic Preconditioning, Myocardial ; Male ; Membrane Proteins ; physiology ; Mitochondria, Heart ; physiology ; ultrastructure ; Myocardial Ischemia ; physiopathology ; Potassium Channels ; Rabbits ; Time Factors ; Ventricular Function, Left ; drug effects

OBJECTIVETo investigate the effect of diazoxide (DE) on the myocardial ultrastructure and opening of maitochondrial permeability transition pore (MPTP) in donor rat heart suffered from long-term hypothermic preservation.

METHODSThe Langendorff model of isolated rat heart was used. The hearts were stored in 4 degrees C Celsior solution containing different concentration of DE (15, 30, or 45 micromol/L) for 9 h followed by 60 min of reperfusion. The recovery of rate-pressure product (RPP) was observed. The opening of MPTP and myocardial mitochondria ultrastructure were also evaluated.

RESULTS(1) As compared with the celsior solution preserved group, DE (30 micromol/L) increased recovery of RPP during reperfusion and inhibited the opening of MPTP. DE also alleviated the myocardial mitochondrial ultrastucture damage induced by long-term hypothermic preservation. (2) The above effects of DE were attenuated by a mitoK(ATP) channel inhibitor 5-hydroxydecanoate and a MPTP opener atractyloside.

CONCLUSIONIn the donor rat heart, DE protects myocardial mitochondria ultrastructure against long-term hypothermic preservation injury via inhibiting the opening of MPIP.

Animals ; Cryopreservation ; Diazoxide ; pharmacology ; Heart ; In Vitro Techniques ; Male ; Mitochondria, Heart ; physiology ; ultrastructure ; Mitochondrial Membrane Transport Proteins ; drug effects ; metabolism ; Organ Preservation Solutions ; pharmacology ; Potassium Channels ; metabolism ; Random Allocation ; Rats ; Rats, Sprague-Dawley

BACKGROUNDLymphocyte function and homeostasis is associated with immune defence to infection. Apoptosis of lymphocytes might be a considerably important component which has an impact on immunity to infections in people with hyperglycemia. The aim of this study was to explore the mitochondrial apoptosis pathway of lymphocyte in diabetic patients.

METHODSSixty patients with type 2 diabetes mellitus and fifty healthy volunteers were included in this study. Annexin V and propidiumiodide (PI) were joined in the isolated lymphocytes and the rate of lymphocyte apoptosis was calculated with flow cytometry. Observation of the lymphocytes was done using transmission electron microscopy; mitochondria had been extracted and then mitochondrial membrane potential (MMP) was detected to assess mitochondrial function; the mRNA level of Bcl-2, cytochrome c (Cyt-C), caspase-9 and caspase-3 were analyzed by real-time reverse transcription-polymerase chain reaction (RT-PCR).

RESULTSApoptosis rate of lymphocyte was significantly higher in diabetic group than that in normal control group (P < 0.05). Transmission electron microscopy showed lymphocyte shrinkage and breakage, chromatin condensation and less mitochondria; a fall in MMP levels was also evident; Bcl-2 concentration was reduced and the expressions of caspase-9, caspase-3 and Cyt-C were elevated (P < 0.05) in diabetic patients.

CONCLUSIONSThe rate of lymphocyte apoptosis was significantly higher in type 2 diabetic patients than that in normal population. Mitochondrial apoptosis pathway may play a very important role in decreasing function of lymphocyte in diabetes.

Aged ; Aged, 80 and over ; Apoptosis ; physiology ; Caspase 3 ; genetics ; Caspase 9 ; genetics ; Diabetes Mellitus, Type 2 ; metabolism ; Female ; Humans ; Lymphocytes ; cytology ; metabolism ; ultrastructure ; Male ; Microscopy, Electron, Transmission ; Mitochondria ; metabolism ; Real-Time Polymerase Chain Reaction ; bcl-2-Associated X Protein ; genetics