Vortioxetine Reverses Impairment of Visuospatial Memory and Cognitive Flexibility Induced by Degarelix as a Model of Androgen Deprivation Therapy in Rats.

INTRODUCTION: Androgen deprivation therapy (ADT) is a mainstay treatment for prostate cancer, but many patients experience cognitive impairment in domains mediated by the medial prefrontal cortex (mPFC) and hippocampus. Prostate cancer typically occurs in older patients (>65 years). As age is often accompanied by cognitive decline, it may impact the efficacy of any treatment aimed at restoring cognitive impairment induced by ADT. Vortioxetine, a multimodal antidepressant that improves cognition in depression, has been shown to be efficacious in elderly patients. Therefore, vortioxetine may improve cognition in older patients who experience cognitive decline after ADT. METHODS: Young (3 months) and middle-aged (13 months) rats were used to investigate the influence of age on treating ADT-induced cognitive decline. As our previous studies used surgical castration, we tested if vortioxetine would reverse cognitive deficits associated with more translationally relevant chemical castration using degarelix. Vortioxetine was given in the diet for 21 days. Animals underwent behavioral testing to assess visuospatial memory mediated by the hippocampus and cognitive flexibility mediated by the mPFC. We also investigated changes in afferent-evoked responses in these regions in middle-aged rats. RESULTS: Degarelix induced impairments in both visuospatial memory and cognitive flexibility that were reversed by vortioxetine. Vortioxetine also rescued afferent-evoked responses in the mPFC and hippocampus. However, modest age-related reductions in baseline visuospatial memory limited our ability to detect further decreases induced by degarelix in middle-aged rats due to a floor effect. CONCLUSION: These results suggest that vortioxetine may be a treatment option for older prostate cancer patients who experience cognitive decline after ADT.

Cryopreserved mesenchymal stem cells regain functional potency following a 24-h acclimation period.

BACKGROUND: Mesenchymal stem cells (MSCs) are attractive cell-therapy candidates. Despite their popularity and promise, there is no uniform method of preparation of MSCs. Typically, cells are cryopreserved in liquid nitrogen, thawed, and subsequently administered to a patient with little to no information on their function post-thaw. We hypothesized that a short acclimation period post-thaw will facilitate the recovery of MSC's functional potency. METHODS: Human bone-marrow-derived MSCs were divided into 3 groups: FC (fresh cells; from existing culture); TT (thawed + time; acclimated for 24 h post-thaw); and FT (freshly thawed; thawed and immediately used). The 3 groups were analyzed for their cellular and functional potency. RESULTS: Phenotypic analysis demonstrated a decrease in CD44 and CD105 surface markers in FT MSCs, with no change in the other two groups. All MSCs were able to differentiate down the osteogenic and chondrogenic lineages. In FT cells, metabolic activity and apoptosis was significantly increased with concomitant decrease in cell proliferation; clonogenic capacity; and key regenerative genes. Following 24-h acclimation, apoptosis was significantly reduced in TT cells with a concomitant upregulation in angiogenic and anti-inflammatory genes. While all MSCs significantly arrested T-cell proliferation, the TT MSCs were significantly more potent. Similarly, although all MSCs maintained their anti-inflammatory properties, IFN-γ secretion was significantly diminished in FT cells. CONCLUSIONS: These data demonstrate that FT MSCs maintain their multipotent differentiation capacity, immunomodulatory function, and anti-inflammatory properties; yet, various aspects of cell characteristics and function are deleteriously affected by cryopreservation. Importantly, a 24-h acclimation period 'reactivates' thawed cells to recover their diminished stem-cell function.

Preconditioning in an Inflammatory Milieu Augments the Immunotherapeutic Function of Mesenchymal Stromal Cells.

Multipotent mesenchymal stromal cells (MSCs) have emerged as potent therapeutic agents for multiple indications. However, recent evidence indicates that MSC function is compromised in the physiological post-injury milieu. In this study, bone marrow (BM)- and adipose-derived (AD)-MSCs were preconditioned in hypoxia with or without inflammatory mediators to potentiate their immunotherapeutic function in preparation for in vivo delivery. Human MSCs were cultured for 48 hours in either normoxia (21% O2) or hypoxia (2% O2) with or without the addition of Cytomix, thus creating 4 groups: 1) normoxia (21%); 2) Cytomix-normoxia (+21%); 3) hypoxia (2%); and 4) Cytomix-hypoxia (+2%). The 4 MSC groups were subjected to comprehensive evaluation of their characteristics and function. Preconditioning did not alter common MSC surface markers; nonetheless, Cytomix treatment triggered an increase in tissue factor (TF) expression. Moreover, the BM-MSCs and AD-MSCs from the +2% group were not able to differentiate to chondrocytes and osteoblasts, respectively. Following Cytomix preconditioning, the metabolism of MSCs was significantly increased while viability was decreased in AD-MSCs, but not in BM-MSCs. MSCs from both tissues showed a significant upregulation of key anti-inflammatory genes, increased secretion of IL-1 receptor antagonist (RA), and enhanced suppression of T-cell proliferation following the Cytomix treatment. Similarly, following a lipopolysaccharide challenge, the Cytomix-treated MSCs suppressed TNF-α secretion, while promoting the production of IL-10 and IL-1RA. These preconditioning approaches facilitate the production of MSCs with robust anti-inflammatory properties. AD-MSCs preconditioned with Cytomix under normoxia appear to be the most promising therapeutic candidates; however, safety concerns, such as thrombogenic disposition of cells due to TF expression, should be carefully considered prior to clinical translation.

Short-term physiological hypoxia potentiates the therapeutic function of mesenchymal stem cells.

BACKGROUND: In the bone marrow, MSCs reside in a hypoxic milieu (1-5% O2) that is thought to preserve their multipotent state. Typically, in vitro expansion of MSCs is performed under normoxia (~ 21% O2), a process that has been shown to impair their function. Here, we evaluated the characteristics and function of MSCs cultured under hypoxia and hypothesized that, when compared to normoxia, dedicated hypoxia will augment the functional characteristics of MSCs. METHODS: Human and porcine bone marrow MSCs were obtained from fresh mononuclear cells. The first study evaluated MSC function following both long-term (10 days) and short-term (48 h) hypoxia (1% O2) culture. In our second study, we evaluated the functional characteristics of MSC cultured under short-term 2% and 5% hypoxia. MSCs were evaluated for their metabolic activity, proliferation, viability, clonogenicity, gene expression, and secretory capacity. RESULTS: In long-term culture, common MSC surface marker expression (CD44 and CD105) dropped under hypoxia. Additionally, in long-term culture, MSCs proliferated significantly slower and provided lower yields under hypoxia. Conversely, in short-term culture, MSCs proliferated significantly faster under hypoxia. In both long-term and short-term cultures, MSC metabolic activity was significantly higher under hypoxia. Furthermore, MSCs cultured under hypoxia had upregulated expression of VEGF with concomitant downregulation of HMGB1 and the apoptotic genes BCL-2 and CASP3. Finally, in both hypoxia cultures, the pro-inflammatory cytokine, IL-8, was suppressed, while levels of the anti-inflammatories, IL-1ra and GM-CSF, were elevated in short-term hypoxia only. CONCLUSIONS: In this study, we demonstrate that hypoxia augments the therapeutic characteristics of both porcine and human MSCs. Yet, short-term 2% hypoxia offers the greatest benefit overall, exemplified by the increase in proliferation, self-renewing capacity, and modulation of key genes and the inflammatory milieu as compared to normoxia. These data are important for generating robust MSCs with augmented function for clinical applications.