Profiling of cardiolipins and their hydroperoxides in HepG2 cells by LC/MS.

Cardiolipin (CL) exists as crucial functional phospholipid in mitochondria. The oxidation of CL is concerned with mitochondrial dysfunction and various diseases. As main oxidation products, CL hydroperoxide (CL-OOH) plays a key role in intermediating oxidative reaction. Thus, direct analysis of CL-OOH is of great interest. In the present study, CL and CL-OOH profiles were analyzed in oxidized HepG2 cell lipid via HPLC-Orbitrap MS/MS. Furthermore, the contents of individual molecular species were compared between intact and AAPH-oxidized HepG2 cells. In total, 46 CL and 18 CL-OOH were identified from oxidized cell lipids, while 21 CL and 9 CL-OOH were detected in AAPH-treated cells. Most CL depleted significantly after AAPH inducement, with percentages varying from 8.3% (CL70:7) to 73.7% (CL72:4), depending on fatty acyl composition. While almost all the CL-OOH remarkably increased, among them 68:6-, 72:6-, and 72:7-OOHs were only detected in AAPH-treated cells. CL68:5- and CL68:4-OOH were the most abundant species, while CL70:5-OOH among all the species expressed the highest oxidation percentage of the corresponding CL. Our results showed practical separation, identification, and semi-quantitation of CL-OOH species, which could contribute to approaches to lipidomic analysis of CL and CL-OOH, as well as tracing biomarkers in mitochondrial oxidative stress diagnosis. Graphical abstract Illustration represents cardiolipin hydroperoxide structure and its content increasing in AAPH-treated HepG2 cells by LC/MS analysis.

Molecular relationships between Australian annual wild rice, Oryza meridionalis, and two related perennial forms.

BACKGROUND: The perennial, Oryza rufipogon distributed from Asia to Australia and the annual O. meridionalis indigenous to Australia are AA genome species in the Oryza. However, recent research has demonstrated that the Australian AA genome perennial populations have maternal genomes more closely related to those of O. meridionalis than to those found in Asian populations of O. rufipogon suggesting that the Australian perennials may represent a new distinct gene pool for rice. RESULTS: Analysis of an Oryza core collection covering AA genome species from Asia to Oceania revealed that some Oceania perennials had organellar genomes closely related to that of O meridionalis (meridionalis-type). O. rufipogon accessions from New Guinea carried either the meridionalis-type or rufirpogon-type (like O. rufipogon) organellar genomes. Australian perennials carried only the meridionalis-type organellar genomes when accompanied by the rufipogon-type nuclear genome. New accessions were collected to better characterize the Australian perennials, and their life histories (annual or perennial) were confirmed by field observations. All of the material collected carried only meridionalis-type organellar genomes. However, there were two distinct perennial groups. One of them carried an rufipogon-type nuclear genome similar to the Australian O. rufipogon in the core collection and the other carried an meridionalis-type nuclear genome not represented in the existing collection. Morphologically the rufipogon-type shared similarity with Asian O. rufipogon. The meridionalis-type showed some similarities to O. meridionalis such as the short anthers usually characteristic of annual populations. However, the meridionalis-type perennial was readily distinguished from O. meridionalis by the presence of a larger lemma and higher number of spikelets. CONCLUSION: Analysis of current accessions clearly indicated that there are two distinct types of Australian perennials. Both of them differed genetically from Asian O. rufipogon. One lineage is closely related to O. meridionalis and another to Asian O. rufipogon. The first was presumed to have evolved by divergence from O. meridionalis becoming differentiated as a perennial species in Australia indicating that it represents a new gene pool. The second, apparently derived from Asian O. rufipogon, possibly arrived in Australia later.

[Clinical features of congenital myasthenic syndrome in Japan].

OBJECTIVE: We examined the clinical and neurophysiological features of Japanese patients with congenital myasthenic syndrome (CMS). METHOD: Subjects were five patients who were diagnosed with CMS on the basis of clinical course, repetitive nerve stimulation (RNS), and genetic analysis. RESULTS: Four patients manifested motor retardation within one year of birth, while one manifested motor intolerance at three years of age. The most characteristic symptom observed in all the patients was fluctuating muscle weakness, which varied on a daily basis or continued for several days after the late infancy period. Only one patient manifested daily fluctuation of muscle weakness. RNS of the accessory nerve evoked a decrementing response in three patients who were examined;however, RNS of the median, ulnar, and tibial nerves (one patient each) did not evoke such responses. After the edrophonium chloride test, no improvement was seen even if the patients manifested ptosis. For judgment of this test, improvement in decrementing rate observed while performing RNS was useful. All five patients who were administered medication based on the results of genetic analysis demonstrated an improvement in their symptoms. CONCLUSION: We suggest that CMS can be diagnosed based on careful examination and electrophysiological results. CMS is a treatable disorder, and therefore, correct diagnosis is important.