Yoshihisa Kitamura

Targeting 5-HT1A receptors in astrocytes to protect dopaminergic neurons in parkinsonian models

Astrocytes are abundant neuron-supporting glial cells that harbor a powerful arsenal of neuroprotective antioxidative molecules and neurotrophic factors. Here we examined whether enrichment with healthy striatal astrocytes can provide neuroprotection against progressive dopaminergic neurodegeneration. Serotonin 1A (5-HT1A) agonist 8-OH-DPAT induced astrocyte proliferation and increased metallothionein-1/-2 (MT-1/-2), antioxidative molecules, in cultured astrocytes and the striatum of mice. Primary cultured mesencephalic dopamine neurons were protected against oxidative stress by preincubation with conditioned media from 8-OH-DPAT-treated astrocytes. These protective effects were canceled by 5-HT1A antagonist or MT-1/-2-specific antibody. Furthermore, reduction of nigrostriatal dopaminergic neurons in 6-hydroxydopamine-lesioned parkinsonian model mice was significantly abrogated by repeated injections of 8-OH-DPAT. Treatment with 8-OH-DPAT markedly increased the expression of MT in striatal astrocytes in the hemi-parkinsonian mice. Our study provides a promising therapeutic strategy of neuroprotection against oxidative stress and progressive dopaminergic neurodegeneration by demonstrating the efficacy of targeting 5-HT1A receptors in astrocytes.

Neuroprotective effects of levetiracetam target xCT in astrocytes in parkinsonian mice.

Astrocytes but not neurons express cystine/glutamate exchange transporter (xCT), which takes up cystine, and consequently supplies the substrate for GSH synthesis in neurons. It is recognized that GSH synthesis in neurons is dependent on the expression of xCT in astrocytes. Previous studies reported that levetiracetam (LEV), an anti‐epileptic drug, increased xCT expression in vivo. The purpose of this study was to examine neuroprotective effects of LEV in parkinsonian models and demonstrate xCT in astrocytes as a target of neuroprotection against dopaminergic neurodegeneration. We identified striatal astrocytes cultured with LEV showed significant increase in xCT expression and GSH levels. Preincubation of primary cultured mesencephalic dopamine neurons with conditioned media from LEV‐treated astrocytes protected against 6‐hydroxydopamine (6‐OHDA)‐induced neurotoxicity. These protective effects were canceled by xCT inhibitor. Furthermore, reduction of nigrostriatal dopaminergic neurons in 6‐OHDA‐lesioned parkinsonian mice was significantly abrogated by repeated injections of LEV. Treatment with LEV significantly increased the expression of xCT in striatal astrocytes in the hemi‐parkinsonian mice. In conclusion, LEV exerts neuroprotective effects against neurodegeneration via up‐regulation of xCT and GSH in astrocytes. Thus, xCT in astrocytes could be a potential target in novel neuroprotective approaches to prevent degeneration of dopaminergic neurons.

Incidence and Risk Factors of Osteonecrosis of the Jaw in Advanced Cancer Patients after Treatment with Zoledronic Acid or Denosumab: A Retrospective Cohort Study

Zoledronic acid and denosumab are two antiresorptive drugs currently in use for treating osteoporosis. They have different mechanisms of action, but both have been shown to delay the onset of skeletal-related events in patients with advanced cancer. However, medication-related osteonecrosis of the jaw (MRONJ) has been reported in cancer patients treated with zoledronic acid or denosumab. We studied 155 patients with several types of advanced cancer who were treated with zoledronic acid or denosumab in our hospital during the period from April 2010 through March 2013. Thirteen of these 155 patients (8.4%) developed MRONJ. MRONJ development was significantly associated with the number of zoledronic acid or denosumab infusions (p<0.001) and the duration of zoledronic acid or denosumab therapy (p<0.001). Logistic regression analysis showed that diabetes [odds ratio (OR)=6.699, 95% confidence interval (CI), 1.435-31.277, p=0.016], anemia [OR=14.559, 95% CI, 2.161-98.069, p=0.006], and pus discharge [OR=6.491, 95% CI, 1.514-27.835, p=0.012] significantly increased the risk of developing MRONJ. However, the risk of MRONJ was significantly lower [OR=0.137, 95% CI, 0.020-0.944, p=0.043] when patients received periodical dentistry maintenance. Diabetes, anemia, and pus discharge may also play roles in its development. These findings suggest that the active inclusion of dentistry maintenance in bisphosphonate or denosumab treatment of cancer patients can reduce MRONJ development.

Doxorubicin and cyclophosphamide treatment produces anxiety-like behavior and spatial cognition impairment in rats: Possible involvement of hippocampal neurogenesis via brain-derived neurotrophic factor and cyclin D1 regulation

Many patients who have received chemotherapy to treat cancer experience depressive- and anxiety-like symptoms or cognitive impairment. However, despite the evidence for this, the underlying mechanisms are still not understood. This study investigated behavioral and biochemical changes upon treatment with doxorubicin and cyclophosphamide, focusing on mental and cognitive systems, as well as neurogenesis in male rats. Doxorubicin (2 mg/kg), cyclophosphamide (50 mg/kg), and the combination of doxorubicin and cyclophosphamide were injected intraperitoneally once per week for 4 weeks. In particular, the co-administration of doxorubicin and cyclophosphamide produced anhedonia-like, anxiety-like, and spatial cognitive impairments in rats. It also reduced both the number of proliferating cells in the subgranular zone of the hippocampal dentate gyrus and their survival. Serum brain-derived neurotrophic factor (BDNF) levels were decreased along with chemotherapy-induced decreases in platelet levels. However, hippocampal BDNF levels and Bdnf mRNA levels were not decreased by this treatment. On the other hand, hippocampal cyclin D1 levels were significantly decreased by chemotherapy. These results suggest that the co-administration of doxorubicin and cyclophosphamide induces psychological and cognitive impairment, in addition to negatively affecting hippocampal neurogenesis, which may be related to hippocampal cyclin D1 levels, but not hippocampal BDNF levels.

Imipramine-Induced c-Fos Expression in the Medial Prefrontal Cortex is Decreased in the ACTH-Treated Rats

Previous studies have shown that the antidepressive‐like effect of tricyclic antidepressants is blocked by repeated treatments with adrenocorticotropic hormone (ACTH). However, little is known about the neuroanatomy underlying the mechanism of the imipramine treatment‐resistant depression model. In the present study, first experimental evidence showed no significant difference of the serum imipramine concentrations between the saline and ACTH‐treated rats. In further study, imipramine produced significant increases in the c‐Fos expression in the medial prefrontal cortex (mPFC), the dentate gyrus of the hippocampus (DGH), and the central nucleus of the amygdala (CeA), in rats repeatedly treated with saline. The imipramine‐increased c‐Fos immunoreactivity was suppressed in the mPFC of rats repeatedly treated with ACTH. However, there was no significant difference in c‐Fos expression in the DGH and CeA between ACTH‐ and saline‐treated rats. These results suggest that the mPFC is maybe involved in effects of the imipramine in the ACTH‐treated rats.

A cross-sectional study of psychological distress, burnout, and the associated risk factors in hospital pharmacists in Japan

BackgroundOpportunities for face-to-face communication with patients is increasing in modern hospital pharmacist practice. This may impose new burdens on hospital pharmacists. We performed a cross-sectional study to examine the prevalence of psychological distress, burnout, and compassion fatigue among hospital pharmacists. We also investigated possible relevant factors, such as sex, years of experience, hospital size, interpersonal work hours, and personality traits related to communication.MethodsWe mailed self-administered questionnaires to all pharmacists (n = 823) belonging to the prefectural society of hospital pharmacists in Japan. The questionnaires were the General Health Questionnaire (GHQ-12), Burnout (BO) and Compassion Fatigue and Secondary Traumatic Stress (CF/STS) subscales of the Professional Quality of Life Scale, the Autism Spectrum Quotient (AQ), and the Adult ADHD (attention deficit hyperactivity disorder) Self-Report Scale (ASRS). We examined associations between personality traits (AQ, ASRS) and psychological burden (GHQ-12, BO, CF/STS) using rank ANCOVA or multivariate logistic regression analyses.ResultsComplete responses were obtained from 380 pharmacists (46.2 % response rate). A substantial number of participants obtained scores that were higher than the cutoff points of the GHQ-12 (54.7 %), BO (49.2 %), and CF/STS (29.2 %). The GHQ-12 scores were negatively affected by years of experience (p < 0.001), and positively affected by AQ (p < 0.001) and ASRS (p < 0.001) scores. The BO scores was positively affected by AQ (p < 0.001) and ASRS (p = 0.001) scores, while the CF/STS (p = 0.023) score was negatively affected by years of experience, and positively affected by AQ (p < 0.001) and ASRS (p < 0.001) scores.ConclusionsThere is a high prevalence of psychological distress and work-related burnout/CF among hospital pharmacists. Additionally, two common personality traits, such as autistic-like traits and ADHD-like symptoms, which might be related to communication style, could increase the risk of psychological distress and burnout/CF. Early risk assessment and preventive interventions that are specialized for these characteristics could protect individuals with these specific traits from burnout.

Photoinitiators enhanced 1,2-dichloropropane-induced cytotoxicity in human normal embryonic lung fibroblasts cells in vitro

Dichloromethane (DCM) and 1,2-dichloropsropane (DCP) have various uses, including being solvents for paint removers. Photoinitiators are also used in a wide range of commercial applications such as printing. These chemicals have been shown to induce cytotoxic effects. In the present study, we evaluated the combined effects of DCM or DCP from paint removers and photoinitiators used in printing on normal human embryonic lung fibroblasts with the aim of preventing occupational injuries. We showed that DCP, 2,2-dimethoxy-2-phenylacetophenone (2,2-DMPAP), 2-ethylhexyl-4-(dimethylamino) benzoate (2-EHDAB), 1-hydroxycyclohexyl phenyl ketone (1-HCHPK), and methyl 2-benzoylbenzoate (MBB) induced cytotoxicity, whereas DCM and 2-isopropylthioxanthone (2-ITX) did not. In addition, 2-methyl-4′-(methylthio)-2-morpholinopropiophenone (MTMP) caused a slight increase in cytotoxicity. The combination of DCP and the four photoinitiators (2,2-DMPAP, 2-EHDAB, MBB, and MTMP) significantly induced cytotoxicity and also led to apoptosis. In conclusion, the combination of DCP and photoinitiators may increase the risk of respiratory diseases.

Yes1 signaling mediates the resistance to Trastuzumab/Lap atinib in breast cancer.

Background Overexpression of human epidermal growth factor receptor 2 (HER2) is observed in approximately 15–23% of breast cancers and these cancers are classified as HER2-positive breast cancer. Trastuzumab is the first-line targeted therapeutic drug for HER2-positive breast cancer and has improved patient overall survival. However, acquired resistance to trastuzumab is still a critical issue in breast cancer treatment. We previously established a trastuzumab-resistant breast cancer cell line (named as BT-474-R) from a trastuzumab-sensitive HER2-amplified cell line BT-474. Lapatinib is also a molecular-targeted drug for HER2-positive breast cancer, which acquired the resistance to trastuzumab. Acquired resistance to lapatinib is also an issue to be conquered. Methods We established trastuzumab/lapatinib-dual resistant cell line (named as BT-474-RL2) by additionally treating BT-474-R with lapatinib. We analyzed the mechanisms of resistance to trastuzumab and lapatinib. Besides, we analyzed the effect of the detected resistance mechanism in HER2-positive breast cancer patients. Results Proto-oncogene tyrosine-protein kinase Yes1, which is one of the Src family members, was amplified, overexpressed and activated in BT-474-R and BT-474-RL2. Silencing of Yes1 by siRNA induced both BT-474-R and BT-474-RL2 to restore the sensitivity to trastuzumab and lapatinib. Pharmaceutical inhibition of Yes1 by the Src inhibitor dasatinib was also effective to restore the sensitivity to trastuzumab and lapatinib in the two resistant cell lines. Combination treatment with dasatinib and trastuzumab induced down-regulation of signaling molecules such as HER2 and Akt. Moreover, the combination treatments induced G1-phase cell-cycle arrest and apoptosis. Consistent with cell line data, high expression of Yes1 mRNA was correlated with worse prognosis in patients with HER2-positive breast cancer. Conclusion Yes1 plays an important role in acquired resistance to trastuzumab and lapatinib in HER2-positive breast cancer. Our data suggest that pharmacological inhibition of Yes1 may be an effective strategy to overcome resistance to trastuzumab and lapatinib.

Effects of (+)-8-OH-DPAT on the duration of immobility during the forced swim test and hippocampal cell proliferation in ACTH-treated rats.

In the present study, we examined the effect of ACTH on the immobilization of rats in the forced swim test and hippocampal cell proliferation after administration of the 5-HT1A receptor agonist, R-(+)-8-hydroxy-2-di-n-propylamino tetralin ((+)-8-OH-DPAT). Chronic treatment with (+)-8-OH-DPAT (0.01-0.1 mg/kg, s.c.) significantly decreased the duration of immobility in saline- and ACTH-treated rats. Chronic administration of ACTH caused a significant decrease in hippocampal cell proliferation. However, (+)-8-OH-DPAT significantly normalized cell proliferation in ACTH-treated rats. We then investigated the effects of (+)-8-OH-DPAT on the expression of brain-derived neurotrophic factor (BDNF) and cyclin D1 (elements of cyclic adenosine monophosphate response element-binding protein (CREB)-BDNF and Wnt signaling pathways, respectively) in the hippocampus of saline- and ACTH-treated rats. ACTH treatment significantly decreased the expression of cyclin D1, while treatment with (+)-8-OH-DPAT normalized the expression of cyclin D1 in ACTH-treated rats. However, the expression of BDNF did not change in either saline- or ACTH-treated rats. These findings suggest that the antidepressant effects of (+)-8-OH-DPAT in treatment-resistant animals may be attributed to an enhancement of hippocampal cell proliferation, at least in part due to an enhancement of cyclin D1 expression.

Exploring autistic-like traits relating to empathic attitude and psychological distress in hospital pharmacists

Background Pharmacists are expected to play a key role in modern cancer care. Research suggests that an empathic approach and attitude in medical staff improves the quality of patient care. An empathic attitude and psychological distress are thought to be associated with autistic-like traits, but little is known about such traits. Objective In this study, we aimed to clarify the associations among autistic-like traits, empathic attitude in a medical context, and psychological health in hospital pharmacists. Setting Eligibility criteria for inclusion were certified pharmacists working at hospitals for patient care who returned their questionnaires. Method Eight hundred and twenty-three hospital pharmacists completed a number of self-administered questionnaires anonymously by mail. Main outcome measures Scores were obtained on the Autism-Spectrum Quotient, the Jefferson Scale of Empathy, the General Health Questionnaire-12, and subscales of the Interpersonal Reactivity Index (Perspective Taking, IRI-Empathic Concern, IRIPersonal Distress). We performed correlation and mediation analyses to confirm that the empathy and general health questionnaires were associated with autism-spectrum quotient scores, and with each IRI subscale. Results Complete responses were obtained from 379 pharmacists comprising 151 males (39.8xa0%) with a mean age of 37.7xa0±xa010.8xa0years (missing data, nxa0=xa013) and a median of 11xa0years after qualification as a pharmacist. Autism-Spectrum Quotient scores were inversely correlated with empathy (rxa0=xa0−0.22, pxa0<xa00.001) and positively correlated with general health scores (rxa0=xa00.40, pxa0<xa00.001). In the models with mediation, the inverse correlation between autism-spectrum quotient and empathy scores was mediated indirectly by IRI-Perspective Taking and IRI-Empathic Concern, and the positive correlation between autism-spectrum quotient and general health was mediated indirectly by IRI-Personal Distress. There were also direct effects, with significant effects of autism-spectrum quotient on empathy and general health scores. Conclusion Our findings suggest that autistic-like traits affect both empathic attitude in a medical context and the psychological health of pharmacists. We recommend that to improve empathy in those with high levels of autistic-like traits, we may need to develop specialized interventions, such as improving communication skills training.