Influence of the combination of SGLT2 inhibitors and GLP-1 receptor agonists on eGFR decline in type 2 diabetes: post-hoc analysis of RECAP study.

Accumulating evidence has demonstrated that both SGLT2 inhibitors (SGLT2i) and GLP-1 receptor agonists (GLP1Ra) have protective effects in patients with diabetic kidney disease. Combination therapy with SGLT2i and GLP1Ra is commonly used in patients with type 2 diabetes (T2D). We previously reported that in combination therapy of SGLT2i and GLP1Ra, the effect on the renal composite outcome did not differ according to the preceding drug. However, it remains unclear how the initiation of combination therapy is associated with the renal function depending on the preceding drug. In this post hoc analysis, we analyzed a total of 643 T2D patients (GLP1Ra-preceding group, n = 331; SGLT2i-preceding group, n = 312) and investigated the differences in annual eGFR decline. Multiple imputation and propensity score matching were performed to compare the annual eGFR decline. The reduction in annual eGFR decline in the SGLT2i-preceding group (pre: -3.5 ± 9.4 mL/min/1.73 m2/year, post: -0.4 ± 6.3 mL/min/1.73 m2/year, p < 0.001), was significantly smaller after the initiation of GLP1Ra, whereas the GLP1Ra-preceding group tended to slow the eGFR decline but not to a statistically significant extent (pre: -2.0 ± 10.9 mL/min/1.73 m2/year, post: -1.8 ± 5.4 mL/min/1.73 m2/year, p = 0.83) after the initiation of SGLT2i. After the addition of GLP1Ra to SGLT2i-treated patients, slower annual eGFR decline was observed. Our data raise the possibility that the renal benefits-especially annual eGFR decline-of combination therapy with SGLT2i and GLP1Ra may be affected by the preceding drug.

Repeated antibiotic drug treatment negatively affects memory function and glutamatergic nervous system of the hippocampus in mice.

The gut microbiota is associated with memory; however, the relationship between dysbiosis-induced memory deficits and hippocampal glutamatergic neurons remains unclear. In our study, a mouse dysbiosis model showed impaired memory-related behavior in the passive avoidance test; decreased expression levels of glutaminase, excitatory amino acid transporter (EAAT)1, EAAT2, vesicular glutamate transporter 2, synaptophysin, brain-derived neurotrophic factor, doublecortin, neuronal nuclear protein, glial fibrillary acidic protein, and S100ß; and decreased phosphorylation of N-methyl-D-aspartate receptor subunit 1, calmodulin-dependent protein kinase II, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor subunit 1, and cAMP response element-binding protein in the hippocampus. This suggests that dysbiosis-induced memory dysfunction is associated with the hippocampal glutamatergic nervous system.

Polarization to M1-type microglia in the hippocampus is involved in depression-like behavior in a mouse model of olfactory dysfunction.

Impaired olfactory function may be associated with the development of psychiatric disorders such as depression and anxiety; however, knowledge on the mechanisms underlying psychiatric disorders is incomplete. A reversible model of olfactory dysfunction, zinc sulfate (ZnSO4) nasal-treated mice, exhibit depression-like behavior accompanying olfactory dysfunction. Therefore, we investigated olfactory function and depression-like behaviors in ZnSO4-treated mice using the buried food finding test and tail suspension test, respectively; investigated the changes in the hippocampal microglial activity and neurogenesis in the dentate gyrus by immunohistochemistry; and evaluated the inflammation and microglial polarity related-proteins in the hippocampus using western blot study. On day 14 after treatment, ZnSO4-treated mice showed depression-like behavior in the tail suspension test and recovery of the olfactory function in the buried food finding test. In the hippocampus of ZnSO4-treated mice, expression levels of ionized calcium-binding adapter molecule 1 (Iba1), cluster of differentiation 40, inducible nitric oxide synthase, interleukin (IL)-1ß, IL-6, tumor necrosis factor-α, cleaved caspase-3, as well as the number of Iba1-positive cells and cell body size increased, and arginase-1 expression and neurogenesis decreased. Except for the increased IL-6, these changes were prevented by a microglia activation inhibitor, minocycline. The findings suggest that neuroinflammation due to polarization of M1-type hippocampal microglia is involved in depression accompanied with olfactory dysfunction.

Cytoprotective effects of Hangekobokuto against corticosterone-induced cell death in HT22 cells.

The hypothalamic-pituitary-adrenal (HPA) system plays an important role in stress response. Chronic stress is thought to induce neuronal damage and contribute to the pathogenesis of psychiatric disorders by causing dysfunction of the HPA system and promoting the production and release of glucocorticoids, including corticosterone and cortisol. Several clinical studies have demonstrated the efficacy of herbal medicines in treating psychiatric disorders; however, their effects on corticosterone-induced neuronal cell death remain unclear. Here, we used HT22 cells to evaluate the neuroprotective potential of herbal medicines used in neuropsychiatry against corticosterone-induced hippocampal neuronal cell death. Cell death was assessed using 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) reduction and Live/Dead assays. Hangekobokuto, Kamikihito, Saikokaryukotsuboreito, Kamishoyosan, and Yokukansan were supplied in the form of water-extracted dried powders. Exposure of HT22 cells to ≥ 100 µM corticosterone decreased MTT values. Exposure to 500 µM corticosterone alone reduced MTT values to 18%, while exposure to 10 µM Mifepristone (RU486)-a glucocorticoid receptor antagonist-restored values to 36%. Corticosterone-induced cell death was partially suppressed by treatment with RU486. At 100 µg/mL, Hangekobokuto significantly suppressed the decrease in MTT values (15-32%) and increase in the percentage of ethidium homodimer-1-positive dead cells caused by corticosterone exposure (78-36%), indicating an inhibitory effect on cell death. By contrast, Kamikihito, Saikokaryukotsuboreito, Kamishoyosan, and Yokukansan did not affect corticosterone-induced cell death. Therefore, our results suggest that Hangekobokuto may ameliorate the onset and progression of psychiatric disorders by suppressing neurological disorders associated with increased levels of glucocorticoids.

Hippocampal and gut AMPK activation attenuates enterocolitis-like symptoms and co-occurring depressive-like behavior in ulcerative colitis model mice: Involvement of brain-gut autophagy.

Patients with inflammatory bowel disease, including ulcerative colitis (UC) and Crohn's disease, have a high incidence of psychiatric disorders, including depression and anxiety. However, the underlying pathogenic mechanism remains unknown. Dextran sulfate sodium (DSS)-treated mice, a model of UC, exhibit depressive-like behavior and reduced adenosine monophosphate-activated protein kinase (AMPK) activity, which regulates various physiological functions in the brain and gut. However, comprehensive studies on UC pathophysiology with co-occurring depression focused on brain-gut AMPK activity are lacking. Therefore, we aimed to investigate whether resveratrol (RES), an AMPK activator, prevented DSS-induced UC-like symptoms and depressive-like behavior. DSS treatment induced UC-like pathology and depressive-like behavior, as assessed via the tail suspension test. Moreover, western blotting and immunohistochemical studies revealed that DSS increased p-p70S6 kinase (Thr389), p62, tumor necrosis factor-α, interleukin (IL)-1ß, IL-18, NLR family pyrin domain containing 3 (NLRP3), cleaved caspase-1, cleaved Gasdermin-D (GSDMD), and cleaved caspase-3 expression levels in the rectum and hippocampus, and increased CD40, iNOS, and Kelch-like ECH-associated protein 1 expression levels, and the number of Iba1-positive cells in the hippocampus, and decreased p-AMPK and LC3II/I expression levels, and the number of NF-E2-related factor 2 (Nrf2)-positive cells, and reduced neurogenesis in the hippocampus. These changes were reversed by the RES administration. RES also enhanced PGC1α and SOD1 expression in the hippocampus of DSS-treated male mice. Moreover, NLRP3 staining was observed in the neurons and microglia, and cleaved GSDMD staining in neurons in the hippocampus of DSS-treated mice. Notably, RES prevented UC-like pathology and depressive-like behavior and enhancement of autophagy, decreased rectal and hippocampal inflammatory cytokines and inflammasome, and induced the Nrf2-PGC1α-SOD1 pathway in the hippocampus, resulting in neurogenesis in the hippocampal dentate gyrus. Our findings suggest that brain-gut AMPK activation may be an important therapeutic strategy in patients with UC and depression.

Renoprotective effects of combination treatment with sodium-glucose cotransporter inhibitors and GLP-1 receptor agonists in patients with type 2 diabetes mellitus according to preceding medication.

AIMS: Combination therapy with sodium-glucose cotransporter inhibitors (SGLT2is) and GLP-1 receptor agonists (GLP1Ras) is now of interest in clinical practice. The present study evaluated the effects of the preceding drug type on the renal outcome in clinical practice. METHODS: We retrospectively extracted type 2 diabetes mellitus patients who had received both SGLT2i and GLP1Ra treatment for at least 1 year. A total of 331 patients in the GLP1Ra-preceding group and 312 patients in the SGLT2i-preceding group were ultimately analyzed. Either progression of the albuminuria status and/or a ≥30% decrease in the eGFR was set as the primary renal composite outcome. The analysis using propensity score with inverse probability weighting was performed for the outcome. RESULTS: The incidences of the renal composite outcome in the SGLT2i- and GLP1Ra-preceding groups were 28% and 25%, respectively, with an odds ratio [95% confidence interval] of 1.14 [0.75, 1.73] (p = .54). A logistic regression analysis showed that the mean arterial pressure (MAP) at baseline, the logarithmic value of the urine albumin-to-creatinine ratio at baseline, and the change in MAP were independent factors influencing the renal composite outcome. CONCLUSION: With combination therapy of SGLT2i and GLP1Ra, the preceding drug did not affect the renal outcome.

Experimental Study: Interleukin-31 Augments Morphine-Induced Antinociceptive Activity and Suppress Tolerance Development in Mice.

Morphine-induced antinociception is partially reduced in interleukin-31 (IL-31) receptor A (IL-31RA)-deficient mice, indicating that IL-31RA is crucial for morphine-induced peripheral antinociception. Herein, we examined the combined effects of IL-31 and morphine on the antinociceptive activity and itch-associated scratching behavior (LLS) in mice and elucidated the regulatory mechanisms. A hot-plate test was used to assess antinociception. LLS was automatically detected and recorded via a computer. IL-31RA mRNA expression was assessed using real-time polymerase chain reaction. Repeated pre-treatment with IL-31 resulted in significant antinociceptive activity. Repeated administration of morphine decreased the morphine-induced antinociceptive activity, LLS counts, and regular dose and inhibited IL-31-induced LLS. These results suggested that the repeated administration of morphine depleted inter-neuronal IL-31RA levels, preventing morphine-induced antinociception. Therefore, IL-31 may be helpful as an adjunct analgesic to morphine. To explore the benefits of IL-31, its influence on morphine-induced antinociceptive tolerance in mice was examined. An IL-31 and morphine combination increased the analgesic action, which increased the expression of DRG neuronal IL-31RA, elucidating the site of peripheral antinociception of morphine. This site may induce exocytosis of IL-31RA in the sensory nervous system. Collectively, the suppressive effect of IL-31 on morphine-induced antinociceptive tolerance may result from IL-31RA supplementation in sensory nerves.

The concomitant use of sodium-glucose co-transporter 2 inhibitors improved the renal outcome of Japanese patients with type 2 diabetes treated with glucagon-like peptide 1 receptor agonists.

Aims: This study aimed to clarify the renal influence of glucagon-like peptide 1 receptor agonists (GLP1Ras) with or without sodium-glucose co-transporter 2 inhibitors (SGLT2is) on Japanese patients with type 2 diabetes mellitus (T2DM). Methods: We retrospectively extracted 547 patients with T2DM who visited the clinics of members of Kanagawa Physicians Association. The progression of albuminuria status and/or a ≥ 15% decrease in the estimated glomerular filtration rate (eGFR) per year was set as the renal composite outcome. Propensity score matching was performed to compare GLP1Ra-treated patients with and without SGLT2i. Results: After matching, 186 patients in each group were compared. There was no significant difference of the incidence of the renal composite outcomes (17% vs. 20%, P = 0.50); however, the annual decrease in the eGFR was significantly smaller and the decrease in the urine albumin-to-creatinine ratio was larger in GLP1Ra-treated patients with the concomitant use of SGLT2is than in those without it (-1.1 ±â€…5.0 vs. -2.8 ±â€…5.1 mL/min/1.73 m2, P = 0.001; and -0.08 ±â€…0.61 vs. 0.05 ±â€…0.52, P = 0.03, respectively). Conclusion: The concomitant use of SGLT2i with GLP1Ra improved the annual decrease in the eGFR and the urine albumin-to-creatinine ratio in Japanese patients with T2DM.

Possible involvement of inflammasomes on the post-stroke cognitive impairment in a mouse model of embolic cerebral infarct.

Post-stroke cognitive impairment (PSCI) of the complications after stroke has been shown to be involved in brain proinflammatory cytokines such as interleukin (IL)-1ß (IL-lß) and IL-18. In the present study, we examined using acetic acid-induced embolic cerebral infarct (ECI) mice whether post-stroke inflammasome activation is involved in the development of PSCI. In behavioral tests, long-term learning and memory assessed using the passive avoidance test were impaired after ECI. On the other hand, the impairment of short-term learning and memory assessed using the Y-maze test was not observed. Furthermore, the phosphorylated α-amino-3hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor subunit glutamate receptor 1 (GluR1) at Ser 831 and Ser 845 protein was found to be significantly decreased in the dorsal hippocampus of ECI mice. In addition, the expression levels of ionized calcium-binding adapter protein 1 (Iba1), glial fibrillary acidic protein (GFAP), apoptosis-associated speck-like protein containing a caspase recruitment domain / target of methylation-induced silencing 1 (ASC/TMS1), Caspase-1, IL-1ß, IL-18 and tumor necrosis factor-α (TNF-α) were significantly increased in the dorsal hippocampus of ECI mice. These results indicate that development of PSCI after embolic cerebral infarction is due to a decrease in AMPA receptor subunit GluR1 at Ser831 and Ser845 through the inflammasome activation pathway in the dorsal hippocampus.

Analyzing the Antinociceptive Effect of Interleukin-31 in Mice.

The theory that an itch inhibits pain has been refuted; however, previous research did not investigate this theory for an interleukin-31 (IL-31)-induced itch. Previously, we have found that morphine-induced antinociception was partially reduced in IL-31 receptor A (IL-31RA)-deficient (IL-31RAKI) mice, indicating that IL-31RA may play an important role in morphine-induced peripheral antinociception. In the present study, we evaluated the effect of IL-31-induced analgesia on a 2,4,6-trinitrochlorobenzene (TNCB)-sensitized mice using a hot-plate test. This test evaluated the antinociceptive activity of morphine and non-steroidal anti-inflammatory drugs (NSAIDs). Repeated pretreatment with IL-31 showed significant antinociceptive action. Furthermore, its combination with morphine, but not with NSAIDs, increased the analgesic action. In contrast, treatment with TNCB and capsaicin decreased antinociception. Moreover, TNCB increased IL-31RA expression in the dorsal root ganglia at 24 h, whereas capsaicin inhibited it. The comparative action of several analgesics on TNCB or capsaicin was evaluated using a hot-plate test, which revealed that the antinociceptive activity was decreased or disappeared in response to capsaicin-induced pain in IL-31RAKI mice. These results indicate that the analgesic action of IL-31 involves the peripheral nervous system, which affects sensory nerves. These results provide a basis for developing novel analgesics using this mechanism.

Role of p53 in Cisplatin-Induced Myotube Atrophy.

Chemotherapy-induced sarcopenia is an unfavorable prognostic factor implicated in the development of postoperative complications and reduces the quality of life of patients with cancer. Skeletal muscle loss due to cisplatin use is caused by mitochondrial dysfunction and activation of muscle-specific ubiquitin ligases Atrogin-1 and muscle RING finger 1 (MuRF1). Although animal studies suggest the involvement of p53 in age-, immobility-, and denervation-related muscle atrophy, the association between cisplatin-induced atrophy and p53 remains unknown. Herein, we investigated the effect of a p53-specific inhibitor, pifithrin-alpha (PFT-α), on cisplatin-induced atrophy in C2C12 myotubes. Cisplatin increased the protein levels of p53, phosphorylated p53, and upregulated the mRNA expression of p53 target genes PUMA and p21 in C2C12 myotubes. PFT-α ameliorated the increase in intracellular reactive oxygen species production and mitochondrial dysfunction, and also reduced the cisplatin-induced increase in the Bax/Bcl-2 ratio. Although PFT-α also reduced the cisplatin-induced increase in MuRF1 and Atrogin-1 gene expression, it did not ameliorate the decrease in myosin heavy chain mRNA and protein levels and muscle-specific actin and myoglobin protein levels. We conclude that cisplatin increases muscle degradation in C2C12 myotubes in a p53-dependent manner, but p53 has minimal involvement in the reduction of muscle protein synthesis.

Real-world effects of once-daily inhaled steroid (fluticasone furoate) combined with long-acting beta-2 agonist (vilanterol) and long-acting muscarinic antagonist (umeclidinium) on lung function tests of asthma patients in Japan.

Background: The Japanese drug use system allowed the once-daily use of inhaled corticosteroid fluticasone furoate (FF) combined with a long-acting beta-2 agonist vilanterol (VI) and a long-acting muscarinic antagonist umeclidinium (UMEC) against asthma on 18 February 2021. We investigated the real-world effects of these drugs (FF/UMEC/VI) mainly on lung function tests. Methods: This was an open-label, uncontrolled, within-group time-series (before-after) study. Prior asthma treatment (inhaled corticosteroid with/without a long-acting beta-2 agonist with/without a long-acting muscarinic antagonist) was switched to FF/UMEC/VI 200/62.5/25 µg. Subjects were evaluated by lung function tests prior to, and 1-2 months after, initiation of FF/UMEC/VI 200/62.5/25 µg. Patients were asked questions regarding the asthma control test and preference for drugs. Results: Overall, 114 asthma outpatients (97% Japanese) were enrolled from February 2021 to April 2022: 104 subjects completed the study. Forced expiratory volume in 1 s, peak flow, and asthma control test score of FF/UMEC/VI 200/62.5/25 µg-treated subjects were significantly increased (p < 0.001, p < 0.001, and p < 0.01, respectively). In contrast with FF/VI 200/25 µg, instantaneous flow at 25% of the forced vital capacity and expiratory reserve volume were significantly increased by FF/UMEC/VI 200/62.5/25 µg (p < 0.01, p < 0.05, respectively). Sixty-six percent of subjects declared they wanted to continue FF/UMEC/VI 200/62.5/25 µg in the future. Adverse effects, mainly local, were seen in 30% of patients, but no serious adverse effects were seen. Conclusion: Once-daily FF/UMEC/VI 200/62.5/25 µg was effective against asthma without serious adverse events. This is the first report that demonstrated FF/UMEC/VI dilated peripheral airways using lung function tests. This evidence on drug effects may improve our understanding of pulmonary physiology and the pathophysiology of asthma.

Drug discovery and development for fibromyalgia using practical biomarkers throughout the process from relevant animal models to patients.

INTRODUCTION: Fibromyalgia (FM) is a chronic pain condition characterized by widespread pain and complex comorbidities with a high unmet medical need. Given few past successes in the launch of analgesics with new mechanisms, the implementation of practical biomarkers for drug discovery and development would be necessary to rationally create innovative drugs for chronic pain conditions, including FM. AREAS COVERED: This review surveys the evidence on pathophysiology of FM and the findings regarding the pathophysiology-associated practical biomarker candidates in body fluids (e.g. blood) from the studies in FM patients. This review also summarizes the most commonly used animal models simulating key aspects of clinical FM features. Finally, a strategy for rationally creating innovative drugs for FM is discussed. EXPERT OPINION: Drug discovery and development for FM targeting immune dysregulation/inflammation would be a viable strategy based on the availability of the pathophysiology-associated practical biomarkers (e.g. serum interleukins), which monitor the efficacy of interventions and/or identify responders based on the matching pathophysiology throughout the process from animal models to patients. This strategy could lead to a breakthrough in the development of drugs for FM, a chronic pain condition.

Association between serum ferritin level and decreased diffusion capacity 3 months after the onset of COVID-19 pneumonia.

BACKGROUND: Coronavirus disease 2019 (COVID-19) pneumonia can have prolonged sequelae and lead to respiratory dysfunction, mainly because of impaired diffusion capacity for carbon monoxide (DLCO). The clinical factors associated with DLCO impairment, including blood biochemistry test parameters, remain unclear. METHODS: Patients with COVID-19 pneumonia who underwent inpatient treatment between April 2020 and August 2021 were included in this study. A pulmonary function test was performed 3 months after onset, and the sequelae symptoms were investigated. Clinical factors, including blood test parameters and abnormal chest shadows on computed tomography, of COVID-19 pneumonia associated with DLCO impairment were investigated. RESULTS: In total, 54 recovered patients participated in this study. Twenty-six patients (48%) and 12 patients (22%) had sequelae symptoms 2 and 3 months after, respectively. The main sequelae symptoms at 3 months were dyspnea and general malaise. Pulmonary function tests showed that 13 patients (24%) had both DLCO <80% predicted value (pred) and DLCO/alveolar volume (VA) <80% pred, and appeared to have DLCO impairment not attributable to an abnormal lung volume. Clinical factors associated with impaired DLCO were investigated in multivariable regression analysis. Ferritin level of >686.5 ng/mL (odds ratio: 11.08, 95% confidence interval [CI]: 1.84-66.59; p = 0.009) was most strongly associated with DLCO impairment. CONCLUSIONS: Decreased DLCO was the most common respiratory function impairment, and ferritin level was a significantly associated clinical factor. Serum ferritin level could be used as a predictor of DLCO impairment in cases of COVID-19 pneumonia.

Capillary responses to functional and pathological activations rely on the capillary states at rest.

Brain capillaries play a crucial role in maintaining cellular viability and thus preventing neurodegeneration. The aim of this study was to characterize the brain capillary morphology at rest and during neural activation based on a big data analysis from three-dimensional microangiography. Neurovascular responses were measured using a genetic calcium sensor expressed in neurons and microangiography with two-photon microscopy, while neural acivity was modulated by stimulation of contralateral whiskers or by a seizure evoked by kainic acid. For whisker stimulation, 84% of the capillary sites showed no detectable diameter change. The remaining 10% and 6% were dilated and constricted, respectively. Significant differences were observed for capillaries in the diameter at rest between the locations of dilation and constriction. Even the seizures resulted in 44% of the capillaries having no detectable change in diameter, while 56% of the capillaries dilated. The extent of dilation was dependent on the diameter at rest. In conclusion, big data analysis on brain capillary morphology has identified at least two types of capillary states: capillaries with diameters that are relatively large at rest and stable over time regardless of neural activity and capillaries whose diameters are relatively small at rest and vary according to neural activity.

Donepezil prevents olfactory dysfunction and α-synuclein aggregation in the olfactory bulb by enhancing autophagy in zinc sulfate-treated mice.

Alzheimer's disease is associated with marked olfactory dysfunction observed in the early stages. Clinical studies reported that acetylcholinesterase inhibitor donepezil (DNP) attenuated this deficit; however, the underlying mechanism remains unclear. Herein, we aimed to examine the effects and underlying mechanisms of DNP on olfactory deficits in zinc sulfate (ZnSO4) nasal-treated mice, which were used as a model of reversible olfactory impairment. We evaluated olfactory function using the buried food finding test and neurogenesis in the subventricular zone (SVZ) using immunohistochemistry. Finally, we measured the expression of doublecortin (DCX), neuronal nuclear antigen (NeuN), olfactory marker protein, tyrosine hydroxylase (TH), tryptophan hydroxylase 2, glutamic acid decarboxylase 67, p-α-synuclein (Ser129), α-synuclein, p-AMPK, p-p70S6 kinase (p70S6K) (Thr389), LC3 Ⅱ/Ⅰ, and p-p62 in the olfactory bulb (OB) by western blotting. On day 7 after treatment, ZnSO4-treated mice exhibited prolonged time to find the buried food, cell proliferation enhancement in the SVZ, increased NeuN, p-α-synuclein (Ser129), and α-synuclein levels, and decreased DCX and TH levels in the OB; except for TH, these changes normalized on day 14 after treatment. Repeated administration of DNP prevented the ZnSO4-induced changes on day 7 after treatment. Moreover, DNP increased p-AMPK and LC3 Ⅱ/Ⅰ, and decreased p-p70S6K and p-p62 (Ser351) levels in the OB, suggesting that DNP enhances autophagy in the OB. These findings indicate that DNP may help prevent olfactory dysfunction by autophagy that reduces α-synuclein aggregation via the AMPK/mTOC1 pathway.

Brexpiprazole prevents colitis-induced depressive-like behavior through myelination in the prefrontal cortex.

Patients with inflammatory bowel disease (IBD) have higher rates of psychiatric pathology including depression. The dextran sulfate sodium (DSS)-treated mice exhibit IBD- and depressive-like phenotypes. A disturbed intestinal environment causes a decrease in serotonin and abnormal myelination in the brain, along with depressive-like behavior in rodents. However, the involvement of these factors in DSS-induced depressive-like behavior in mice remains unclear. In this study, we examined whether myelin proteins in the prefrontal cortex (PFC) and hippocampi were altered in DSS-treated mice, along with the changes in the serotonergic system in the PFC by western blotting and HPLC. The effects of brexpiprazole (Brx), a serotonin modulator, on DSS-induced depressive-like behavior using the tail-suspension test were evaluated. Subsequently, we investigated Brx's effects on the levels of myelin, nodal proteins, and neurotrophic molecules in the PFC with western blotting, and examined the altered node of Ranvier formation by immunohistochemistry. DSS-treated mice showed a reduction in myelin and nodal proteins, dysfunction of the serotonergic system, and impaired formation of the nodes of Ranvier in the PFC. Brx administration prevented the DSS-induced depressive-like behavior and demyelination in the PFC. However, the Brx-mediated effects were inhibited by the selective 5-HT1A antagonist, WAY100635, or the selective TrkB antagonist, ANA-12. Brx decreased the phosphorylation of ERK, CREB, and TrkB along with the expression of BDNF in the PFC of DSS-treated mice. Moreover, the effects of Brx were blocked by WAY100635. These findings indicated that myelination regulated by the activation of the ERK1/2-CREB-BDNF-TrkB pathway in the PFC may be involved in mediating the antidepressant effects of Brx.

Effects of smoking cessation using varenicline on the serum concentrations of oxidized high-density lipoprotein: Comparison with high-density lipoprotein cholesterol.

BACKGROUND: The oxidized high-density lipoprotein (oxHDL) is a possible marker for cardiovascular diseases. This study investigated the effects of smoking cessation with varenicline (a partial agonist of nicotinic acetylcholine receptors) on the levels of oxHDL in the serum of subjects compared with those of high-density lipoprotein cholesterol (HDL-C). METHODS: Data of 99 nicotine-dependent adult subjects who visited the smoking cessation outpatient services at International University of Health and Welfare Shioya Hospital were reviewed. Each subject was treated with varenicline titrated up to 1.0 mg twice daily for 12 weeks. Serum levels of oxHDL and HDL-C were repeatedly measured by enzyme-linked immunosorbent assay and enzymatic method, respectively. RESULTS: The serum levels of oxHDL were significantly decreased from 163.2 ± 96.6 to 148.3 ± 80.7 U/mL (p = 0.034, n = 99). This effect was more prominent when the data of subjects in whom the treatment was objectively unsuccessful (exhaled carbon monoxide at 3 months ≥ 10 ppm) were omitted (from 166.6 ± 98.4 to 147.4 ± 80.6 U/mL; p = 0.0063, n = 93). In contrast, the serum levels of HDL-C were significantly increased (p = 0.0044, n = 99). There was a close relationship between the baseline levels of oxHDL and HDL-C (R = 0.45, p < 0.0001, n = 99). Changes in the levels of oxHDL were closely associated with changes in the levels of exhaled carbon monoxide in subjects in whom smoking cessation with varenicline was very effective (decrease in exhaled carbon monoxide by ≥ 15 ppm after treatment with varenicline; R = 0.42, p = 0.0052, n = 43). CONCLUSIONS: Although there was a close relationship between the baseline serum concentrations of oxHDL and HDL-C, smoking cessation decreased oxHDL and increased HDL-C. This effect on oxHDL may be associated with the effectiveness of smoking cessation.

Correlation between the reduction in hippocampal SirT2 expression and depressive-like behaviors and neurological abnormalities in olfactory bulbectomized mice.

Reduced activity of hippocampal silent information regulator protein 2 (SirT2) has been associated with the development of depression caused by disturbances in neuronal and synaptic plasticity. However, changes in the hippocampal SirTs in olfactory bulbectomized (OBX) mice, an animal model of depression, remain unknown. Therefore, this study examined depressive-like behaviors, hippocampal SirTs, synaptic plasticity-associated proteins, and cell proliferation in OBX mice. The OBX mice showed depressive-like behaviors; reduced SirT2, synaptophysin, and PSD95 levels; and reduced cell proliferation in the hippocampus. These data indicate that decreased hippocampal SirT2 may contribute to pathophysiological depression and strongly affect the psychological state.

Capsaicin suppresses interleukin-31-induced itching partially involved in inhibiting the expression of dorsal root ganglion interleukin-31 receptor A in male mice.

To elucidate the mechanisms underlying the antipruritic effect of capsaicin, we investigated how topical application of capsaicin (0.01, 0.1 and 1.0% w/v) affects spontaneous scratching in NC/Nga mice, inerleukin-31 (IL-31) induced in BALB/c mice, and IL-31 receptor A (IL-31RA) and transient receptor potential vanilloid member 1 (TRPV1) mRNA expression in dorsal root ganglia (DRG). Capsaicin concentration-dependently suppressed long-lasting scratching (over 1.0 s, itch-associated scratching) and short-lasting scratching (0.3-1.0 s, locomotor activity) immediately after the application. Total long-lasting scratching and short-lasting scratching counts for 24 h and IL-31RA mRNA expression in the DRG significantly decreased with increasing concentration of capsaicin. Furthermore, 1.0% capsaicin suppressed long-lasting scratching and short-lasting scratching for more than 72 h. At this point, DRG IL-31RAmRNA was significantly decreased, but there was no change in cutaneous IL-31RA and TRPV1 mRNA. Thus capsaicin suppresses long-lasting scratching by inhibiting IL-31RA mRNA expression in the DRG. Next, we examined the effect of capsaicin on IL-31-induced long-lasting scratching in BALB/c mice. Repeated administration of IL-31 (50 µg/kg, subcutaneous) every 12 h for 3 days apparently increased long-lasting scratching counts and IL-31RA mRNA in the DRG. These increases were significantly suppressed by pretreatment with 1.0% capsaicin. TRPV1 mRNA in the DRG was also decreased within 1-24 h after capsaicin application. These results suggest that the strong and prolonged antipruritic action for IL-31-induced itching of capsaicin was caused by desensitization of C-fibers, and, in addition, the long-lasting inhibition of IL-31RA mRNA expression in the DRG.