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SUMMARYAndrogen deprivation therapy (ADT) induces regression of recurrent and advanced prostate cancer (PrCa), but many tumors recur. To understand the response to ADT, changes in tumor volume were imaged after castration of murine PrCa models. While mouse (non-tumor) prostate begins to regress within two days of castration, murine PrCa regresses after a delay of 3-14 days in two distinct mouse models. Intra-tumoral androgens are undetectable after castration, but tumor cells proliferate during this period. Intratumoral glucocorticoids and glucocorticoid receptor (GR) protein increase, as does GR mRNA and a set of GR-regulated genes specifically in tumor epithelial cells identified using scRNAseq. A selective GR antagonist (CORT125281, relacorilant), in clinical trials for late-state PrCa, eliminates the delayed regression phenotype in both models. Thus, activated GR signaling and murine tumor proliferation following castration resembles the GR-dependent escape mechanism of castrate resistant PrCa. These results suggest simultaneous inhibition of GR and androgen receptor signaling could improve PrCa therapy.In briefAndrogen deprivation therapy for high risk and recurrent prostate cancers is initially effective, but ultimately fails; better understanding the mechanisms should improve therapy. In two murine prostate cancer models, GR signaling is activated immediately following castration, substituting for the acute reduction in AR signaling, and allowing for continued tumor growth. This continued growth is blocked by relacorilant, selective GR antagonist in clinical trials for late-state PrCa.HighlightsAndrogen deprivation therapy induces regression of prostate cancer, but tumors recurMurine PrCa continues to proliferate for 3-14 days in two distinct mouse prostate cancer modelsTumor cells proliferate during this period, and intratumoral glucocorticoids and glucocorticoid receptor (GR) protein increase, as does GR mRNA and a set of GR-regulated genesRelacorilant, a selective GR antagonist in clinical trials for late-state PrCa, eliminates the delayed regression

Metacaspases are cysteine-dependent proteases, which play essential roles in programmed cell death (PCD), and caspase-3-like protease is the crucial executioner. However, its response mechanism to aluminum (Al)-induced PCD is still elusive. Here, the type I metacaspase gene in peanut (Arachis hypoganea L.), AhMC1, was cloned from the Al-sensitive cultivar ZH2. Physiological and biochemical methods, as well as gene expression analyses, were employed to explore its function in Al-induced PCD in peanut root tips. AhMC1 had a 1068-bp open reading frame, encoding a peptide of 355 amino acids, and the purified protein exhibited a high caspase-3-like protease activity. Its expression levels in different tissues of peanut varieties ZH2 and 99–1507 (Al-tolerant) varied under Al-stress conditions. The subcellular localization indicated that AhMC1 was transferred from mitochondria into the cytoplasm. Furthermore, overexpressing AhMC1 reduced the resistance to Al stress. Sense transgenic plants showed a low relative root growth rate, and reduced superoxide dismutase, peroxidase, and catalase activities, compared with wild-type and antisense transgenic plants under Al-stress conditions, but had a high root-cell death rate, and increased Al and maleic dialdehyde contents. The data suggest that metacaspase AhMC1 is a positive factor in Al-induced PCD in peanut root tips.

Highlights • SARS-CoV-2 virus was present in the air in the ICU. • Virus may be discharged in aerosol for days after patients test negative. • The finding may be one of the reasons for patients` re-detectable positive. • The clinical guidelines for recovered COVID-19 patients need to be improved., As coronavirus disease 2019 (COVID-19) is spreading worldwide, there have been arguments regarding the aerosol transmission of its causative agent, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Moreover, some re-detectable positive (RP) patients have been reported. However, little attention has been given to the follow-up of recovered patients, and there is no environmental evidence to determine whether these patients continue to shed the virus after they test negative. Therefore, with an objective to test the hypothesis of airborne transmission of SARS-CoV-2, it is necessary to 1) determine whether SARS-CoV-2 particles are present in the indoor air and 2) determine whether recovered patients are still shedding virus, thus providing much-needed environmental evidence for the management of COVID-19 patients during the recovery period. In this study, surface and air samples were collected from an intensive care unit (ICU) containing one ready-for-discharge patient. All surface samples tested negative, but the air samples tested positive for SARS-CoV-2. This implies that SARS-CoV-2 particles may be shed in aerosol form for days after patients test negative. This finding may be one of the reasons for the observation of RP patients; therefore, there is a need for improved clinical and disease management guidelines for recovered COVID-19 patients.

Tissue infiltration and elevated peripheral circulation of granulocytic myeloid-derived cells is associated with poor outcomes in prostate cancer and other malignancies. Although myeloid-derived cells have the ability to suppress T-cell function, little is known about the direct impact of these innate cells on prostate tumor growth. Here, it is reported that granulocytic myeloid-derived suppressor cells (MDSC) are the predominant tumor-infiltrating cells in prostate cancer xenografts established in athymic nude mice. MDSCs significantly increased in number in the peripheral circulation as a function of xenograft growth and were successfully depleted in vivo by Gr-1 antibody treatment. Importantly, MDSC depletion significantly decreased xenograft growth. We hypothesized that granulocytic MDSCs might exert their protumorigenic actions in part through neutrophil elastase (ELANE), a serine protease released upon granulocyte activation. Indeed, it was determined that NE is expressed by infiltrating immune cells and is enzymatically active in prostate cancer xenografts and in prostate tumors of prostate-specific Pten-null mice. Importantly, treatment with sivelestat, a small-molecule inhibitor specific for NE, significantly decreased xenograft growth, recapitulating the phenotype of Gr-1 MDSC depletion. Mechanistically, NE activated MAPK signaling and induced MAPK-dependent transcription of the proliferative gene cFOS in prostate cancer cells. Functionally, NE stimulated proliferation, migration, and invasion of prostate cancer cells in vitro. IHC on human prostate cancer clinical biopsies revealed coexpression of NE and infiltrating CD33+ MDSCs. Implications: This report suggests that MDSCs and NE are physiologically important mediators of prostate cancer progression and may serve as potential biomarkers and therapeutic targets. Mol Cancer Res; 15(9); 1138–52. ©2017 AACR.

First line treatment for recurrent and metastatic prostate cancer is androgen deprivation therapy (ADT). Use of ADT has been increasing in frequency and duration, such that side effects increasingly impact patient quality of life. One of the most significant side effects of ADT is sarcopenia, which leads to a loss of skeletal muscle mass and function, resulting in a clinical disability syndrome known as obese frailty. Using aged mice, we developed a mouse model of ADT-induced sarcopenia that closely resembles the phenotype seen in patients, including loss of skeletal muscle strength, reduced lean muscle mass, and increased adipose tissue. Sarcopenia onset occurred about 6 weeks after castration and was blocked by a soluble receptor (ActRIIB-Fc) that binds multiple TGFβ superfamily members, including myostatin, growth differentiation factor 11, activin A, activin B, and activin AB. Analysis of ligand expression in both gastrocnemius and triceps brachii muscles demonstrates that each of these proteins is induced in response to ADT, in 1 of 3 temporal patterns. Specifically, activin A and activin AB levels increase and decline before onset of strength loss at 6 weeks after castration, and myostatin levels increase coincident with the onset of strength loss and then decline. In contrast, activin B and growth differentiation factor 11 levels increase after the onset of strength loss, 8-10 weeks after castration. The observed patterns of ligand induction may represent differential contributions to the development and/or maintenance of sarcopenia. We hypothesize that some or all of these ligands are targets for therapy to ameliorate ADT-induced sarcopenia in prostate cancer patients.

Recent evidence has proved that caspase protease activities are detected in both mammals and plants during programmed cell death (PCD). The characteristics and functions of caspase-like proteases play important roles in understanding the mechanisms of PCD in plants. In this work, we report firstly the involvement of caspase-like protease activities and effects in aluminum (Al) stress in two contrasting peanut genotypes. Caspase-like activities in the root tip cells of ‘Zhonghua 2’ (Al-sensitive) and ‘99-1507’ (Al-tolerant) were detected using synthetic caspase substrates during Al-triggered PCD. Caspase-1-, -2-, -3-, -4-, -5-, -6-, -8- and -9-like proteases were found in peanut root tip cells. VDQQDase (caspase-2-like) and WEHD (caspase-5-like) were the first detected in the plants, and almost all of the caspase-like proteases were activated during Al-induced PCD, especially caspase-3-like and caspase-1-like, which was higher in ‘Zhonghua 2’ than in ‘99-1507’. The highest activity levels of caspase-3- and caspase-1-like proteases occurred 8 and 4 h after 100 µM Al treatment, respectively. Compared with 100 µM AlCl3 treatment alone, specific caspase-3 protease inhibitor Ac-DEVD-CHO inhibited the increase of caspase-3-like protease activity, Al content, Hsr203j expression, cell death and DNA fragmentation, and the decrease in root growth induced by 100 µM AlCl3 treatment, but it was more obvious in ‘Zhonghua 2’ than in ‘99-1507’. In conclusion, there were different caspase-like proteases in root tips of peanut, and caspase-3-like protease was a crucial executioner in Al-induced PCD. Its effects in the ‘Zhonghua 2’ genotype were higher than in ‘99-1507’. An improved model of the mechanism of Al-induced PCD and Al tolerance differences in different genotypes is proposed.

Taurine, as a free amino acid, is found at high levels in many tissues including brain, heart and skeletal muscle and is known to demonstrate neuroprotective effects in a range of disease conditions including stroke and neurodegenerative disease. Using in vitro culture systems we have demonstrated that taurine can elicit protection against endoplasmic reticulum stress (ER stress) from glutamate excitotoxicity or from excessive reactive oxygen species in PC12 cells or rat neuronal cultures. In our current investigation we hypothesized that taurine treatment after stroke in the rat middle cerebral artery occlusion (MCAO) model would render protection against ER stress processes as reflected in decreased levels of expression of ER stress pathway components. We demonstrated that taurine elicited high level protection and inhibited both ATF-6 and IRE-1 ER stress pathway components. As ischemic stroke has a complex pathology it is likely that certain combination treatment approaches targeting multiple disease mechanisms may have excellent potential for efficacy. We have previously employed the partial NMDA antagonist DETC-MeSO to render protection against in vivo ischemic stroke using a rat cerebral ischemia model. Here we tested administration of subcutaneous administration of 0.56 mg/kg DETC-MeSO or 40 mg/kg of taurine separately or as combined treatment after a 120 min cerebral ischemia in the rat MCAO model. Neither drug alone demonstrated protection at the low doses employed. Remarkably however the combination of low dose DETC-MeSO plus low dose taurine conferred a diminished infarct size and an enhanced Neuroscore (reflecting decreased neurological deficit). Analysis of ER stress markers pPERK, peIF-2-alpha and cleaved ATF-6 all showed decreased expression demonstrating that all 3 ER stress pathways were inhibited concurrent with a synergistic protective effect by the post-stroke administration of this DETC-MeSO-taurine combination treatment.

Ischemic stroke is one of the greatest contributors to death and long term disability in developed countries. Ischemia induced brain injury arises due to excessive release of glutamate and involves cell death due to apoptosis and endoplasmic reticulum (ER) stress responses. Despite major research efforts there are currently no effective treatments for stroke. Taurine, a free amino acid found in high concentrations in many invertebrate and vertebrate systems can provide protection against a range of neurological disorders. Here we demonstrate that taurine can combat ER stress responses induced by glutamate or by hypoxia/re-oxygenation in neuronal cell lines and primary neuronal cultures. Taurine decreased expression of ER stress markers GRP78, CHOP, Bim and caspase 12 in primary neuronal cultures exposed to hypoxia/re-oxygenation. In analyzing individual ER stress pathways we demonstrated that taurine treatment can result in reduced levels of cleaved ATF6 and decreased p-IRE1 levels. We hypothesized that because of the complex nature of stroke a combination therapy approach may be optimal. For this reason we proceeded to test combination therapies using taurine plus low dose administration of an additional drug: either granulocyte colony stimulating factor (G-CSF) or sulindac a non-steroidal anti-inflammatory drug with potent protective functions through signaling via ischemic preconditioning pathways. When primary neurons were pretreated with 25 mM taurine and 25 ng/mL G-CSF for I hour and then exposed to high levels of glutamate, the taurine/G-CSF combination increased the protective effect against glutamate toxicity to 88% cell survival compared to 75% cell survival from an individual treatment with taurine or G-CSF alone. Pre-exposure of PC12 cells to 5 mM taurine or 25 μM sulindac did not protect the cells from hypoxia/re-oxygenation stress whereas at these concentrations the combination of taurine plus sulindac provided significant protection. In summary we have demonstrated the protective effect of taurine in primary neuronal cultures against hypoxia with re-oxygenation through inhibition of ATF6 or p-IRE-1 pathway but not the PERK pathway of ER stress. Furthermore the combinations of taurine plus an additional drug (either G-CSF or sulindac) can show enhanced potency for protecting PC 12 cells from glutamate toxicity or hypoxia/re-oxygenation through inhibition of ER stress responses.

In the present era, investigators seek to find therapeutic interventions that are multifaceted in their mode of action. Such targets provide the most advantageous routes for addressing the multiplicity of pathophysiological avenues that lead to neuronal dysfunction and death observed in neurological disorders and neurodegenerative diseases. Taurine, an endogenous amino acid, exhibits a plethora of physiological functions in the central nervous system. In this review, we describe the mode of action of taurine and its clinical application in the neurological diseases: Alzheimer's disease, Parkinson's disease and Huntington's disease.

One of the most significant side effects of androgen-deprivation therapy (ADT), the first-line therapy for recurrent and metastatic prostate cancer (PrCa), is sarcopenia (loss of skeletal muscle mass and function). ADT produces a significant disability syndrome in PrCa patients known as obese frailty. Use of ADT has been increasing such that side effects increasingly impact patient quality of life, and result in nursing home placement. The sarcopenia and functional loss of strength is recapitulated following castration of “middle-aged,” but not younger, male mice. In this model all five muscle-regulating TGFß superfamily members, known as myokines, are upregulated in distinctive temporal patterns during sarcopenia development. Complete myokine blockade fully restores muscle mass and strength in castrated mice. We castrated 6- to 9-month-old PbCre4 x PTENfl/fl PrCa-bearing mice and measured tumor volume (by high-frequency ultrasound), body composition (by NMR), muscle mass, fat mass, grip strength, and expression of TGFß family members. Tumor-bearing mice were treated with ActRIIB-Fc (or vehicle) to block myokine signaling; additional tumor-bearing mice were sacrificed biweekly to monitor myokine levels. In an autochthonous mouse model of PrCa, castration-induced changes closely resemble the loss of skeletal muscle strength and body composition that occurs in ADT treated patients. The reduction in muscle strength is comparable to that seen in patients. ADT reduces the mass of individual skeletal muscles, overall LBM, and grip strength. We examined the expression of myokines following castration and found that muscle levels of free dimeric myostatin, the activins, and GDF11 all increase over time, but with distinctive kinetics. Functionally, ActIIRB-Fc, which binds and blocks myokines, inhibits sarcopenia in our model, indicating that the myokines mediate ADT-induced sarcopenia. Surprisingly, this myokine inhibition also induced prostate tumor regression in the absence of ADT, suggesting a protumorigenic effect of myokines. Myokine inhibition also increased the rate of castration-induced prostate tumor regression in this model. In the tumor tissue and in the circulation, as in the muscle tissue of these mice, some of the myokines also increase post-castration. Myokines mediate the induction of sarcopenia following castration, and may also mediate tumor growth. These results suggest that myokines might be both biomarkers and potential targets for therapy to reduce this comorbidity in PrCa patients and may also control tumor growth directly. Citation Format: Chunliu Pan, Yanni Zulia, Kent L. Nasituk. Myokine signaling blockade prevents androgen deprivation therapy-induced sarcopenia and promotes prostate tumor regression [abstract]. In: Proceedings of the AACR Special Conference: Prostate Cancer: Advances in Basic, Translational, and Clinical Research; 2017 Dec 2-5; Orlando, Florida. Philadelphia (PA): AACR; Cancer Res 2018;78(16 Suppl):Abstract nr B092.

Background Genetically engineered mouse models are essential to the investigation of the molecular mechanisms underlying human prostate pathology and the effects of therapy on the diseased prostate. Serial in vivo volumetric imaging expands the scope and accuracy of experimental investigations of models of normal prostate physiology, benign prostatic hyperplasia and prostate cancer, which are otherwise limited by the anatomy of the mouse prostate. Moreover, accurate imaging of hyperplastic and tumorigenic prostates is now recognized as essential to rigorous pre-clinical trials of new therapies. Bioluminescent imaging has been widely used to determine prostate tumor size, but is semi-quantitative at best. Magnetic resonance imaging can determine prostate volume very accurately, but is expensive and has low throughput. We therefore sought to develop and implement a high throughput, low cost, and accurate serial imaging protocol for the mouse prostate. Methods We developed a high frequency ultrasound imaging technique employing 3D reconstruction that allows rapid and precise assessment of mouse prostate volume. Wild-type mouse prostates were examined (n = 4) for reproducible baseline imaging, and treatment effects on volume were compared, and blinded data analyzed for intra- and inter-operator assessments of reproducibility by correlation and for Bland-Altman analysis. Examples of benign prostatic hyperplasia mouse model prostate (n = 2) and mouse prostate implantation of orthotopic human prostate cancer tumor and its growth (n = 6) are also demonstrated. Results Serial measurement volume of the mouse prostate revealed that high frequency ultrasound was very precise. Following endocrine manipulation, regression and regrowth of the prostate could be monitored with very low intra- and interobserver variability. This technique was also valuable to monitor the development of prostate growth in a model of benign prostatic hyperplasia. Additionally, we demonstrate accurate ultrasound image-guided implantation of orthotopic tumor xenografts and monitoring of subsequent tumor growth from ~10 to ~750 mm3 volume. Discussion High frequency ultrasound imaging allows precise determination of normal, neoplastic and hyperplastic mouse prostate. Low cost and small image size allows incorporation of this imaging modality inside clean animal facilities, and thereby imaging of immunocompromised models. 3D reconstruction for volume determination is easily mastered, and both small and large relative changes in volume are accurately visualized. Ultrasound imaging does not rely on penetration of exogenous imaging agents, and so may therefore better measure poorly vascularized or necrotic diseased tissue, relative to bioluminescent imaging (IVIS). Conclusions Our method is precise and reproducible with very low inter- and intra-observer variability. Because it is non-invasive, mouse models of prostatic disease states can be imaged serially, reducing inter-animal variability, and enhancing the power to detect small volume changes following therapeutic intervention.

Taurine is an inhibitory neurotransmitter and is one of the most abundant amino acids present in the mammalian nervous system. Taurine has been shown to provide protection against neurological diseases, such as Huntington’s disease, Alzheimer’s disease, and stroke. Ischemic stroke is one of the leading causes of death and disability in the world. It is generally believed that ischemia-induced brain injury is largely due to excessive release of glutamate resulting in excitotoxicity and cell death. Despite extensive research, there are still no effective interventions for stroke. Recently, we have shown that taurine can provide effective protection against endoplasmic reticulum (ER) stress induced by excitotoxicity or oxidative stress in PC12 cell line or primary neuronal cell cultures. In this study, we employed hypoxia/reoxygenation conditions for primary cortical neuronal cell cultures as an in vitro model of stroke as well as the in vivo model of rat focal middle cerebral artery occlusion (MCAO). Our data showed that when primary neuronal cultures were first subjected to hypoxic conditions (0.3%, 24 h) followed by reoxygenation (21%, 24–48 h), the cell viability was greatly reduced. In the animal model of stroke (MCAO), we found that 2 h ischemia followed by 4 days reperfusion resulted in an infarct of 47.42 ± 9.86% in sections 6 mm from the frontal pole. Using taurine greatly increased cell viability in primary neuronal cell culture and decreased the infarct area of sections at 6 mm to 26.76 ± 6.91% in the MCAO model. Furthermore, levels of the ER stress protein markers GRP78, caspase-12, CHOP, and p-IRE-1 which were markedly increased in both the in vitro and in vivo models significantly declined after taurine administration, suggesting that taurine may exert neuroprotection functions in both models. Moreover, taurine could downregulate the ratio of cleaved ATF6 and full-length ATF6 in both models. In the animal model of stroke, taurine induced an upregulation of the Bcl-2/Bax ratio and downregulation of caspase-3 protein activity indicating that it attenuates apoptosis in the core of the ischemic infarct. Our results show not only taurine elicits neuroprotection through the activation of the ATF6 and the IRE1 pathways, but also it can reduce apoptosis in these models.

Stroke is one of the leading causes of mortality and disability worldwide. There is no effective treatment for stroke despite extensive research. Taurine is a free amino acid which is present at high concentrations in a range of organs including the brain, heart, and retina in mammalian systems. It had been shown that taurine can significantly increase cell survival under stroke conditions using both in vivo and in vitro models. Recently, we have found that several agents including granulocyte colony-stimulating factor (G-CSF), a stem cell enhancer and facilitator;S-methyl-N-diethylthiolcarbamate sulfoxide (DETC-MeSO), an NMDA receptor partial antagonist; sulindac, a potent antioxidant; and taurine, a neuroprotectant and calcium regulator, are effective in protecting against stroke-induced neuronal injury when used alone or in combination in both animal and tissue/cell culture models. In this chapter, we demonstrate that taurine can protect human neuroblastoma cells measured by ATP assay under conditions of hypoxia or oxygen/glucose deprivation (OGD). In addition, we found that taurine exerts its protective function by suppressing the OGD-induced upregulation of endoplasmic reticulum (ER) stress markers and proapoptotic proteins. A model depicting the mode of action of taurine in protecting neuroblastoma cells under OGD conditions is presented.

Taurine has many physiological functions in the central nervous system (CNS) such as maintaining the structural integrity of the membrane, in regulating calcium binding and transport, as an osmolyte, as a neurotransmitter and neuromodulator. Taurine also can serve as a trophic factor in the development of the CNS and a neuroprotective agent in glutamate-induced neuronal injury and H2O2-induced cell injury in PC12 cell cultures. In this review, we will describe taurine's multiple-faceted role in the CNS. Particular attention is paid to the most current developments regarding to the modes of taurine function in developing and adult brains and the related neuroprotective mechanisms of taurine's actions in the CNS.

s Background Both taurine, an inhibitory neurotransmitter and granulocyte colony-stimulating factor (G-CSF), a growth factor, possess neuroprotective and neurotrophic properties in vitro. However, the mechanisms of their underlying neuroprotective effects are not fully understood. Methods In the present study, we investigated the potential protective benefits of taurine, G-CSF and the combination of taurine and G-CSF against excitotoxicity induced by glutamate in primary cortical neuronal cultures. Results 25 mM taurine, 25 ng/ml G-CSF and the combination of 25 mM taurine and 25 ng/ml G-CSF showed a protective effect reaching 75%, 75% and 88%, respectively. Furthermore, taurine exerted its protective effect through down-regulation of expression of GRP 78, CHOP, Bim and caspase 12. Conclusion The results showed that all of these treatments, taurine, G-CSF and the combination of taurine and G-CSF, protected primary cortical neurons against excitotoxicity induced by glutamate. ER stress is suppressed by taurine after glutamate toxicity.