Changes in brain proteasome dynamics associated with aging.

In the nervous system, proteasomes are important for proteolysis and cellular homeostasis of neurons and glial cells and for brain health. Proteasome function declines with age in many tissues, including the nervous system, and this decline affects many of the nervous system processes important to brain health and may be related to age-related cognitive decline. Therefore, we analyzed the factors that contribute to this decline in function using the brain of mice from different months of life. Peptidase activity of proteasomes in crude extracts decreased with aging, while ubiquitinated proteins increased with aging. Additionally, there was a tendency for the number of subunits that form proteasomes to decrease slightly with age. On the other hand, ump1, which is required for proteasome formation, accumulated with age. Therefore, analysis of proteasome dynamics in each month revealed that proteasome formation decreased with aging. This study suggests that with aging, not only 20S proteasome function but also 26 proteasome function decreases, the decline in proteasome function is due to the lack of proteasome formation, the PA28-20S-PA700 complex, which is involved in immunity, increases in the brain, and one factor in this lack of proteasome formation is that the proteins called UMP1.

A Greater Increase in Complement C5a Receptor 1 Level at Onset and a Smaller Decrease in Immunoglobulin G Level after Recovery in Severer Coronavirus Disease 2019 Patients: A New Analysis of Existing Data with a New Two-Tailed t-Test.

(1) Background: It is our purpose to identify the differences in the changes in Complement C5a receptor 1 (C5aR1) levels showing the degree of inflammation at onset and Immunoglobulin G (IgG) levels showing the extent of survival of the virus fragments after recovery between coronavirus disease 2019 (COVID-19) and pneumonia coronavirus disease (non-COVID-19) for saving patients' lives. (2) Methods: First, the studies showing these markers' levels in individual patients before and after the passage of time were selected from the PubMed Central® databases with the keywords (((COVID-19) AND individual) NOT review) AND C5a/IgG. Then, no changes in these markers' levels with conventional analyses were selected from the studies. Finally, the no changes were reexamined with our new two-tailed t-test using the values on the regression line between initial levels and changed levels instead of the mean or median of changed levels as the expected values of changed levels. (3) Results: Not conventional analyses but our new t-test suggested a greater increase in C5aR1-levels at onset and a smaller decrease in IgG-levels after recovery in COVID-19 patients than non-COVID-19 patients. (4) Conclusion: Our new t-test also should be used in clinics for COVID-19 patients.

The effect of nutrient deprivation on proteasome activity in 4-week-old mice and 24-week-old mice.

Recently, we have begun to better understand the regulatory mechanisms of proteasome activity in response to the nutritional state. In this study, we analyzed the expression and function of proteasomes in the livers and brains where changes in the metabolic system occur in vivo during short-term starvation. In the livers of 4-week-old mice, proteasome activity decreased with fasting time, whereas brain proteasome activity remained unchanged by up to 24 h of fasting and then decreased. However, liver and brain proteasome activity in 24-week-old mice decreased by fasting for 24 h and then recovered. There was no significant change in the expression levels of the subunits that make up the proteasomes in livers and brains regardless of age, and there was no change in the molecular size of the formed proteasome. Interestingly, Ump1, a proteasome assembly protein, accumulated with changes in proteasome activity. When the fasted state returned to a fed state, the proteasome activity in the brain was restored to almost the same level as in the fed state, but the proteasome activity in the liver was not restored to that of the fed state. In this state, the assembly protein Ump1 continued to accumulate. These findings suggest that (1) the expression of Ump1 is controlled by the nutritional state, and (2) the proteasome formation mechanism may differ depending on the organ.

Acupuncture Treatment for Social Defeat Stress.

Depression is a mood disorder characterized by disordered affect, thoughts, cognition, and behavior. Antidepressant therapy is often the primary treatment for depression. However, antidepressant therapy may cause unwanted side effects, and its effects are slow. Therefore, some patients are seeking alternative treatments for depression, such as acupuncture. However, there are many unclear points regarding the mechanism of the effect of acupuncture on depression. In recent years, we have reported that acupuncture improves the symptoms of mild depression induced by water-immersion stress in a rat model and depression induced by forced swimming in a mouse model. In this study, we examined the effect of acupuncture on the symptoms of social defeat stress (SDS)-induced depression in mice that most closely resemble human symptoms. In this study, we investigated the preventive and therapeutic effects of acupuncture as part of GV20 "Bai-Hui" and Ex-HN3 "Yintang" on model mice with depression induced by SDS. To examine the mechanism of the preventive and therapeutic effects of acupuncture on depression model mice, we examined the expression of neurotrophic factors in the brains of SDS mice. Two weeks of simultaneous acupuncture stimulation as part of GV20 and Ex-HN3 restored SDS-reduced brain-derived neurotrophic factor (BDNF), neurotrophin (NT)-3, and NT-4/5 expression, which was not observed with antidepressants. In contrast, acupuncture stimulation suppressed nerve growth factor (NGF) expression induced by SDS. These results suggest that acupuncture treatment could be effective in correcting the imbalance in the expression of neurotrophic factors. Furthermore, the effects of acupuncture on the expression of neurotrophic factors appear earlier than those of antidepressants, suggesting that it may be a useful treatment for depression.

Search for Substances That Inhibit Histamine Production Using Used Tea Leaves.

ABSTRACT: As food waste has become a major problem in recent years, measures against food loss have become an urgent issue. When manufacturing or making green tea beverages, large quantities of tea leaves are subsequently disposed of, which results in potential food loss. Moreover, because many of the tea components remain in the used tea leaves, these continue to have value, as these leaves exhibit antibacterial action. Furthermore, histamine is produced from histidine via histidine decarboxylase that is produced by microorganisms, with histamine accumulation potentially causing histamine food poisoning. Although we have been trying to develop a simple method for detecting histamine, there has yet to be a quick detection method established. We examined whether a method using a low concentration of bromocresol indicator in the culture medium was capable of rapidly detecting histamine. Our results demonstrated that when using lower indicator concentrations, there was a faster detection of histamine production, within 4 h. Using this method, we also investigated whether used tea leaf components, which have antibacterial effects, could suppress histamine production. In this study, used leaves from green, oolong, and black teas were analyzed according to different extraction processes. Compared with green tea, oolong and black teas were able to suppress histamine production using lower concentrations, 25 and 12.5% extracts, respectively. In contrast, the inhibitory effect on histamine production by used green tea leaves required a high concentration of 50% used tea leaf extracts. Furthermore, our results suggested that used tea leaves suppress histamine production and that the inhibitory effects vary according to different extracts. Based on these findings, we propose that (i) a more rapid detection method for histamine should be established and (ii) used tea leaf extracts may have applications in the storage and processing of foods associated with an undesirable production of histamine.

Effect of Manual Acupuncture Stimulation at "Bai-Hui" (GV 20) or "Yintáng" (Ex-HN3) on Depressed Rats.

A previous study on rats showed that simultaneous acupuncture stimulation at the "Bai-Hui" (GV 20) and the "Yintáng" (Ex-HN3) acupoints alleviated the state of depression to an extent similar to that achieved by pharmacotherapy. This study investigated whether the alleviation of the depressed state required simultaneous acupuncture at these two acupuncture points. For the purposes of testing the effect of acupuncture on depressive symptoms, we treated a depression model rat, where depression had been induced by using a mild water-immersion stress technique, with either acupuncture stimulation at only one acupuncture point (GV 20 or Ex-HN3) or an antidepressant, and we measured the immobile time for evaluating the state of depression. Anxiety, as a symptom commonly associated with depression, was also evaluated by measuring the number of head dips. Neither the immobile time nor the number of head dips decreased upon acupuncture stimulation. From this study, single acupuncture stimulation at either "GV 20" or "Ex-HN3" alleviated neither the state of depression nor the anxiety. The water-immersion stress used to make the depression model rats was shown not to induce anxiety; however, the stress induced by immobilizing the rats for acupuncture stimulation did lead to anxiety.

Effect of acupuncture stimulation on rats with depression induced by water-immersion stress.

Depression is a kind of mood disorder. The incidence of depressed patients has demonstrated an upward trend in recent years. Symptoms may improve with treatments such as pharmacotherapy and cognitive-behavioral therapy, but such approaches may exert strong side effects, and therapeutic effects can be slow. We studied how acupuncture stimulation would affect depression as a method to reduce side effects. Mild depression was induced in rats by 1-week water-immersion stress. We treated these mildly depressed rats with either acupuncture stimulation at the "Bai-Hui" (GV 20) and "Yintáng" (Ex-HN3) points, or antidepressants. We then measured the immobile time and serum corticosterone level in rats. Immobile time and serum corticosterone level decreased on stimulation with acupuncture or antidepressants. These findings suggest that mild depression in rats was improved by stimulation with acupuncture The mechanisms underlying such improvement may effect HPA system activated by this stress, and inhibit the response to lead to the disorder of the hippocampal nerve cell.

Effects of manual acupuncture at GB34 on carbon tetrachloride-induced acute liver injury in rats.

Manual acupuncture at Yanglingquan (GB34) is reported to have a beneficial effect on chronic liver damage. We, therefore, studied the effect of manual acupuncture at GB34 on acute liver damage. Rats were administered carbon tetrachloride (CCl(4)) or olive oil, and direct manual acupuncture was subsequently performed at GB34 or at a sham point (a nonacupoint). In rats administered with CCl(4), the serum levels of aspartate aminotransferase and alanine aminotransferase, the total cholesterol concentration, and the levels of hepatic thiobarbituric-acid-reactive substances were suppressed by acupuncture at GB34 when compared with acupuncture at the sham point. By contrast, there was little histological difference in the liver between acupuncture at GB34 and that at the sham point in rats administered with CCl(4). These results suggest that manual acupuncture at GB34 tends to improve acute liver damage but is not sufficient by itself to completely resolve the hepatic injury.

An endogenous electrophile that modulates the regulatory mechanism of protein turnover: inhibitory effects of 15-deoxy-Delta 12,14-prostaglandin J2 on proteasome.

Prostaglandin D(2) (PGD(2)), a major cyclooxygenase product in a variety of tissues and cells, readily undergoes dehydration to yield electrophilic PGs, such as 15-deoxy-Delta(12,14)-PGJ(2) (15d-PGJ(2)). We have previously shown that 15d-PGJ(2) potently induces apoptosis of SH-SY5Y human neuroblastoma cells via accumulation of the tumor suppressor gene product p53. In the study presented here, we investigated the molecular mechanisms involved in the 15d-PGJ(2)-induced accumulation of p53. It was observed that 15d-PGJ(2) potently induced p53 protein expression but scarcely induced p53 gene expression. In addition, exposure of the cells to 15d-PGJ(2) resulted in an accumulation of ubiquitinated proteins and in a significant inhibition of proteasome activities, suggesting that 15d-PGJ(2) acted on the ubiquitin-proteasome pathway, a regulatory mechanism of p53 turnover. The effects of 15d-PGJ(2) on the protein turnover were attributed to its electrophilic feature, based on the observations that (i) the reduction of the double bond in the cyclopentenone ring of 15d-PGJ(2) virtually abolished the effects on protein turnover, (ii) overexpression of an endogenous redox regulator, thioredoxin 1, significantly retarded the inhibition of proteasome activities and accumulations of p53 and ubiquitinated proteins induced by 15d-PGJ(2), and (iii) treatment of SH-SY5Y cells with biotinylated 15d-PGJ(2) indeed resulted in the formation of a 15d-PGJ(2)-proteasome conjugate. These data suggest that the modulation of proteasome activity may be involved in the mechanism responsible for the accumulation of p53 and subsequent induction of apoptotic cell death induced by 15d-PGJ(2).

Conditional knockdown of proteasomes results in cell-cycle arrest and enhanced expression of molecular chaperones Hsp70 and Hsp40 in chicken DT40 cells.

The 26 S proteasome is an evolutionarily conserved ATP-dependent protease complex that degrades poly-ubiquitinated proteins and plays essential roles in a critical part of cellular regulation. In vertebrates, the roles of the proteasome have been widely studied by use of specific inhibitors, but not genetically. Here, we generated a cell line Z(-/-/-)/Z-HA, in which the expression of the catalytic subunit of the proteasome, Z (beta2) could be manipulated. This cell line expresses exogenous Z protein under the control of a tetracycline-repressible promoter in a Z-nullizygous genetic background. Treatment of these cells with doxycycline inhibited Z expression and, hence, the function of the proteasome. The latter resulted in accumulation of poly-ubiquitinated proteins and concomitant induction of molecular chaperones Hsp70 and Hsp40. These results suggest a synergistic role for the proteasome with these molecular chaperones to eliminate misfolded or damaged proteins in vivo. Furthermore, knockdown of the proteasome induced apoptotic cell death following cell-cycle arrest at G(2)/M phase. Our Z(-/-/-)/Z-HA cell line would be useful for evaluating proteolytic processes catalyzed by the proteasome in many biological events in vertebrate cells.

Selective proteasomal dysfunction in the hippocampal CA1 region after transient forebrain ischemia.

Delayed neuronal death in the hippocampal CA1 region after transient forebrain ischemia may share its underlying mechanism with neurodegeneration and other modes of neuronal death. The precise mechanism, however, remains unknown. In the postischemic hippocampus, conjugated ubiquitin accumulates and free ubiquitin is depleted, suggesting impaired proteasome function. The authors measured regional proteasome activity after transient forebrain ischemia in male Mongolian gerbils. At 30 minutes after ischemia, proteasome activity was 40% of normal in the frontal cortex and hippocampus. After 2 hours of reperfusion, it had returned to normal levels in the frontal cortex, CA3 region, and dentate gyrus, but remained low for up to 48 hours in the CA1 region. Thus, the 26S proteasome was globally impaired in the forebrain during transient ischemia and failed to recover only in the CA1 region after reperfusion. The authors also measured 20S and 26S proteasome activities directly after decapitation ischemia (at 5 and 20 minutes) by fractionating the extracts with glycerol gradient centrifugation. Without adenosine triphosphate (ATP), only 20S proteasome activity was detected in extracts from both the hippocampus and frontal cortex. When the extracts were incubated with ATP in an ATP-regenerating system, 26S proteasome activity recovered almost fully in the frontal cortex but only partially in the hippocampus. Thus, after transient forebrain ischemia, ATP-dependent reassociation of the 20S catalytic and PA700 regulatory subunits to form the active 26S proteasome is severely and specifically impaired in the hippocampus. The irreversible loss of proteasome function underlies the delayed neuronal death induced by transient forebrain ischemia in the hippocampal CA1 region.