Global analysis of aging-related protein structural changes uncovers enzyme-polymerization-based control of longevity

Aging is associated with progressive phenotypic changes. Virtually all cellular phenotypes are produced by proteins, and their structural alterations can lead to age-related diseases. However, we still lack comprehensive knowledge of proteins undergoing structural-functional changes during cellular aging and their contributions to age-related phenotypes. Here, we conducted proteome-wide analysis of early age-related protein structural changes in budding yeast using limited proteolysis-mass spectrometry (LiP-MS). The results, compiled in online ProtAge catalog, unraveled age-related functional changes in regulators of translation, protein folding, and amino acid metabolism. Mechanistically, we found that folded glutamate synthase Glt1 polymerizes into supramolecular self-assemblies during aging, causing breakdown of cellular amino acid homeostasis. Inhibiting Glt1 polymerization by mutating the polymerization interface restored amino acid levels in aged cells, attenuated mitochondrial dysfunction, and led to lifespan extension. Altogether, this comprehensive map of protein structural changes enables identifying mechanisms of age-related phenotypes and offers opportunities for their reversal.

De novo seropositive rheumatoid arthritis during immunosuppressive treatment after kidney transplantation

We detected de novo seropositive erosive rheumatoid arthritis (RA) in a patient seven years after successful cadaveric kidney transplantation (RTx). RA developed in spite of treatment with cyclosporine A (CyA), methylprednisolon (MP) and azathioprine (Aza), compounds often also used for treatment of active RA. Renal failure was due to diabetes mellitus (DM) nephropathy. Besides a slight increase in C-reactive protein (CRP) concentration two years after RTx, the clinical symptoms of RA were observed seven years after RTx. RA was confirmed by X-ray examination, isotopic skeletal scan and positive serum RA factor. After switching Aza to methotrexate (Mtx) treatment, his symptoms disappeared and CRP concentration returned to normal. Our patient had HLA DRB1 *0101, *0401 alleles and DQB1 *0501, *0302 alleles which have strong genetic association with both DM and RA. To our best knowledge, this is the first case in which de novo seropositive erosive RA developed while on treatment with triple immunosuppression after RTx. The immunosuppressive treatment probably masked the inflammation and symptoms of RA.

Midline brain anomalies and schizophrenia in people with CATCH 22 syndrome

BACKGROUND

Since people with chromosome 22q11 deletion (CATCH 22 syndrome) have unexpectedly high incidence of major psychosis it has been suggested that 22q area might be involved in the pathogenesis of schizophrenia and bipolar disorders.

METHOD

A single case report.

RESULTS

A 32-year-old male patient with CATCH 22 syndrome and schizophrenia had extensive midline anomalies of the brain in the regions relevant to psychotic disorders.

CONCLUSIONS

22q11-dependent abnormalities in the midline structures of the brain may cause dysfunction in the limbic system and interfere with the interhemispheric information exchange thus predisposing people with CATCH 22 syndrome to psychotic disorders.

Sediment accumulation of organic halogens in pristine forest lakes: Tracking of a single defined discharge of pulp bleaching wastewater

Sediment accumulation of organic halogen was studied in two forest lakes, one pristine and one which received 30 m(3) of biologically purified bleaching wastewater from a kraft pulp mill in 1979 equivalent to ca. 2 kg of adsorbable organic halogen (AOX). Lake sediments were dated with(210)Pb,(134)Cs and(137)Cs and the annual deposition rates of organic halogens and organic matter were calculated. Organic bound halogen contents of the sediment aged 150 years was 180 microg Cl g(-1) d.w. in both lakes. The concentration of organic bound halogen at the topmost 6 cm of the sediments (less than 20-years-old) ranged from 45 to 80 microg Cl g(-1) d.w. This suggests that solvent extractable halogen had enriched in the older sediment layers. The deposition of extractable organic halogen (EOX) in the lakes in 1950's was 4 to 5 mg Cl m(-2) a(-1). Since then, the deposition of EOX doubled in both lakes. The deposition of organic matter increased concomitantly from 50 g m(-2) a(-1) to 110 g m(-2) a(-1) in Lake Mustalampi and from 35 g m(-2) a(-1) to 62 g m(-2) a(-1) in Lake Pyylampi suggesting that the increase in the deposition of organic halogen followed the increase in the deposition of organic matter. Of the 2 kg of organic halogen discharged into the lake, 5% or less was detected in the sediment in tetrahydrofuran extractable form 15 years later.

Schizophrenia: a scientific delusion with long-lasting computer virus-like action on human thought?

The recent report on dopamine D4 receptors in schizophrenia by Seeman et al is briefly reviewed. It is suggested that these data, especially when published in a high-impact scientific journal, provide experimental support for my views of schizophrenia as a scientific delusion and corroborate the following principle of Ludvig Wittgenstein: 'It belongs to the logic of our scientific investigations that certain things are indeed not doubted.'

The secret of clozapine: to sleep while awake?

A dramatic increase in REM sleep time at the expense of slow wave sleep has been reported in patients on clozapine monotherapy (5). It is now suggested that this effect of clozapine on the sleep pattern could be due to a dissociation of the NREM/REM sleep cycle, and that the epileptogenic EEG abnormalities induced by clozapine in daytime recordings (2) would represent a dose-dependent activation on NREM sleep mechanism during wakefulness. The implications of this theory in relation to the concept of schizophrenia are discussed.

Long-term 'treatment' of schizophrenics with typical neuroleptics: a crime against humanity?

It is well documented that neuroleptics acting on dopamine receptors induce suppression of reward-directed behaviors in animals (1). Since the need for reward and pleasure is evidently also a powerful determinant of human behavior, it is suggested that compulsory treatment of schizophrenics in remission with anhedonic neuroleptics should be regarded as a crime against humanity, comparable with the scientifically approved use of frontal lobotomy in the management of poor psychotics before the advent of neuroleptics.

Prevention of AIDS in HIV-infected people by means of T cells stimulated with microbial superantigens?

It has been shown that neuroleukin, a secretary product of T cells, is partly homologous to HIV gp 120 envelope protein. Since HIV naive T cells sometimes induce the production of antibodies against HIV coat proteins in a new host, it is suggested that the development of AIDS in HIV-infected people could be prevented by means of T cells stimulated with superantigens of either bacterial or viral origin.

Are syntax errors due to the amino acid sequence of neuroleukin involved in the pathogenesis of the acquired immunodeficiency syndrome (AIDS) and insulin dependent diabetes mellitus (IDDM)?

The main principles of this hypothesis are very general: (i) signal-detection from background noise is one central issue in electronics; (ii) an important source of misunderstanding at different levels of communication is the fact that a given signal may have different meanings in different contexts; (iii) the unique role of chance in developmental biology is generally appreciated (37). In AIDS the basic defect would be the human specific inability to distinguish between the amino acid sequence of neuroleukin and peptides derived from the gp120 envelope protein of HIV, resulting in a slowly progressing failure of the CD4+ T cell-mediated immunity. In IDDM the postulated HLA class II-dependent hypersensitivity to immunological noise could predispose to random contacts between cells with a different signalling language. In the ensuing dialogue neuroleukin secreted by T cells would imply a continuous demand for insulin secretion to pancreatic beta cells resulting in diabetes. This hypothesis does not contradict with the provocative ideas proposed by Duesberg concerning the relationships between HIV and AIDS (24) and the known data on the genesis of IDDM.

Effects of partial food restriction on nocturnal meal size and feeding speed are counteracted by concurrent REM sleep deprivation in the rat

Effects of rapid eye movement (REM) sleep deprivation on meal size and feeding speed were investigated by means of the cuff pedestal technique in 9 male rats exposed to partial food restriction. Reduction of available food by 50% alone, when accomplished by providing the pellets at the beginning of each dark period, during 7 consecutive days, induced a quite linear increase both in the meal size and feeding speed. When the same feeding schedule was repeated in combination with REM sleep deprivation, the meal size remained smaller and the feeding time was prolonged (during the first 3-4 days) when compared to those during food restriction alone, although losses of body weight were almost doubled. These findings are in agreement with the effects of REM sleep deprivation on the meal pattern in rats on ad libitum diet and provide further support for the suggestion of the importance of REM sleep in the generation of the light/dark rhythm of feeding in the rat.

Increased aggression after rapid eye movement sleep deprivation in Wistar rats is not influenced by reduction of dimensions of enclosure

Twelve female and twelve male Wistar rats were assigned to home groups, platform-control groups, and rapid eye movement sleep deprivation groups. The deprivation was performed with the cuff-pedestal method. Rats were tested in pairs in a shrinking chamber to increase proximity of the rats and to provoke interaction between them. An increase in boxing behavior was noted in the sleep-deprived groups. The result confirms that deprivation of rapid eye movement sleep increases aggressive behavior in the rat. However, this behavior is not influenced by the area of the testing arena. The sleep-deprived females explored each other more than the controls; the males' behavior did not differ in this respect. The amount of genital exploration decreased with diminishing area of enclosure, whereas boxing was not area dependent.

Decision-making to initiate voluntary movements in the rat is altered during deprivation of rapid eye movement sleep

Eight male rats were deprived of rapid eye movement (REM) sleep for 6 days by means of a cuff pedestal which makes it possible to use the animal as its own control. In order to obtain access to food, the rat had to jump from its pedestal to a strip of wire mesh suspended from the ceiling of the deprivation chamber. The number as well as duration of hangings on the wire mesh was continuously recorded. An initial increase in jumping frequency was associated with decreased duration of hangings. This initial effect was totally reversed from the fourth day of deprivation onwards. It is suggested that the threshold in decision making to initiate voluntary movement is altered during the course of REM sleep deprivation.

Is the mental deterioration in Down's syndrome linked to impaired terminal degradation of neurofilaments?

Early detection of foetuses carrying the chromosomal anomaly typical of Down's syndrome provides an efficient means to solve both the social and medical problems inherent in this common form of mental deficiency likely to occur in offsprings to aged mothers. The routine use of this screening procedure, however, is limited to the Western culture. We hope that the present hypothesis suggesting an important role of neurofilament dysfunction in Down's syndrome will stimulate therapeutic approaches aimed at preventing the expression of mental stigmata in children unhappily born with this chromosomal anomaly.

Validation of the cuff pedestal technique for rapid eye movement sleep (REMs) deprivation by electrophysiological recordings

Twenty-four-hour recordings of electrophysiological correlates of the sleep-waking cycle in the rat were performed during different stages of cuff pedestal treatment. It was found that rats adapted to live on pedestals with the cuff raised displayed undisturbed patterns of sleep and wakefulness. Lowering the cuff for three days resulted in virtually total disappearance of rapid eye movement sleep (REMs), while slow wave sleep (SWs) was only slightly reduced. Raising the cuff induced a prominent rebound increase of REMs. These results accord with data obtained by means of the conventional flowerpot procedure and corroborate the validity of the cuff pedestal technique.

Focal irradiation of the brain: an alternative to temporal lobe resection in intractable focal epilepsy?

Reconciling the early promising results of radiation therapy in the treatment of epilepsy with the recent theory concerning the role of nonsynaptic mechanisms in focal epileptogenesis, it is suggested that the potential of irradiation as an alternative to temporal lobe resection in intractable epilepsy should be re-evaluated.

Antipyretic analgesics in patients on antiepileptic drug therapy

The effect of administration for three days of acetylsalicylic acid (1500 mg/day), phenylbutazone (300 mg/day), paracetamol (1500 mg/day) and tolfenamic acid (300 mg/day) on serum concentrations of phenytoin and carbamazepine were studied in a group of patients on continuous antiepileptic therapy. When measured 10 h after the last dose of the analgesics, the only significant effect was a decrease in total serum phenytoin after three days of phenylbutazone. When six patients on continuous phenytoin therapy took phenylbutazone for two weeks there was at two days an initial decrease, followed by a signficiant increase in total serum phenytoin and a concomitant increase in free phenytoin in serum. Even phenylbutazone was well tolerated by most of the patients. However, its use had to be discontinued on one patient due to obvious signs of phenytoin intoxication, with concomitant increases in the serum free and total phenytoin concentrations.

Do the peptide hormones common to intestine and brain participate in the genesis of epilepsy?

It is suggested that the peptide hormones common to the brain and intestine provide a physiological basis to the hypothesis that acute gastroenteritis during the first postnatal month may be associated with spontaneous epileptogenic activity in EEG and lowered seizure threshold in adult age.