Genetic variants, neurocognitive outcomes, and functional neuroimaging in survivors of childhood acute lymphoblastic leukemia.

BACKGROUND: Genetic predispositions may modulate risk for developing neurocognitive late effects in childhood acute lymphoblastic leukemia (ALL) survivors. METHODS: Long-term ALL survivors (n = 212; mean = 14.3 [SD = 4.77] years; 49% female) treated with chemotherapy completed neurocognitive testing and task-based functional neuroimaging. Based on previous work from our team, genetic variants related to the folate pathway, glucocorticoid regulation, drug metabolism, oxidative stress, and attention were included as predictors of neurocognitive performance, using multivariable models adjusted for age, race, and sex. Subsequent analyses evaluated the impact of these variants on task-based functional neuroimaging. Statistical tests were 2-sided. RESULTS: Survivors exhibited higher rates of impaired attention (20.8%), motor skills (42.2%), visuo-spatial memory (49.3%-58.3%), processing speed (20.1%), and executive function (24.3%-26.1%) relative to population norms (10%; P < .001). Genetic variants implicated in attention deficit phenotypes predicted impaired attention span (synaptosome associated protein 25, F(2,172) = 4.07, P = .019) and motor skills (monoamine oxidase A, F(2,125) = 5.25, P = .007). Visuo-spatial memory and processing speed varied as a function of genetic variants in the folate pathway (methylenetetrahydrofolate reductase [MTHFRrs1801133], F(2,165) = 3.48, P = .033; methylenetetrahydrofolate dehydrogenase 1 [MTHFD1rs2236225], F(2,135) = 3.8, P = .025; respectively). Executive function performance was modulated by genetic variants in the folate pathway (MTHFD1rs2236225, F(2,158) = 3.95, P = .021; MTHFD1rs1950902, F(2,154) = 5.55, P = .005) and glucocorticoid regulation (vitamin D receptor, F(2,158) = 3.29, P = .039; FKBP prolyl isomerase 5, F(2,154) = 5.6, P = .005). Additionally, MTHFD1rs2236225 and FKBP prolyl isomerase 5 were associated with altered brain function during attention and working memory (P < .05; family wise error corrected). CONCLUSIONS: Results extend previous findings of genetic risk of neurocognitive impairment following ALL therapy and highlight the importance of examining genetic modulators in relation to neurocognitive deficits.

FK506-Binding Protein like (FKBPL) Has an Important Role in Heart Failure with Preserved Ejection Fraction Pathogenesis with Potential Diagnostic Utility.

Heart failure (HF) is the leading cause of hospitalisations worldwide, with only 35% of patients surviving the first 5 years after diagnosis. The pathogenesis of HF with preserved ejection fraction (HFpEF) is still unclear, impeding the implementation of effective treatments. FK506-binding protein like (FKBPL) and its therapeutic peptide mimetic, AD-01, are critical mediators of angiogenesis and inflammation. Thus, in this study, we investigated-for the first time-FKBPL's role in the pathogenesis and as a biomarker of HFpEF. In vitro models of cardiac hypertrophy following exposure to a hypertensive stimulus, angiotensin-II (Ang-II, 100 nM), and/or AD-01 (100 nM), for 24 and 48 h were employed as well as human plasma samples from people with different forms of HFpEF and controls. Whilst the FKBPL peptide mimetic, AD-01, induced cardiomyocyte hypertrophy in a similar manner to Ang-II (p < 0.0001), when AD-01 and Ang-II were combined together, this process was abrogated (p < 0.01-0.0001). This mechanism appears to involve a negative feedback loop related to FKBPL (p < 0.05). In human plasma samples, FKBPL concentration was increased in HFpEF compared to controls (p < 0.01); however, similar to NT-proBNP and Gal-3, it was unable to stratify between different forms of HFpEF: acute HFpEF, chronic HFpEF and hypertrophic cardiomyopathy (HCM). FKBPL may be explored for its biomarker and therapeutic target potential in HFpEF.

Effects of immunophilin inhibitors and non-immunosuppressive analogs on coronavirus replication in human infection models.

Rationale: Human coronaviruses (HCoVs) seriously affect human health by causing respiratory diseases ranging from common colds to severe acute respiratory diseases. Immunophilins, including peptidyl-prolyl isomerases of the FK506-binding protein (FKBP) and the cyclophilin family, are promising targets for pharmaceutical inhibition of coronavirus replication, but cell-type specific effects have not been elucidated. FKBPs and cyclophilins bind the immunosuppressive drugs FK506 and cyclosporine A (CsA), respectively. Methods: Primary human bronchial epithelial cells (phBECs) were treated with CsA, Alisporivir (ALV), FK506, and FK506-derived non-immunosuppressive analogs and infected with HCoV-229E. RNA and protein were assessed by RT-qPCR and immunoblot analysis. Treatment with the same compounds was performed in hepatoma cells (Huh-7.5) infected with HCoV-229E expressing Renilla luciferase (HCoV-229E-RLuc) and the kidney cell line HEK293 transfected with a SARS-CoV-1 replicon expressing Renilla luciferase (SARS-CoV-1-RLuc), followed by quantification of luminescence as a measure of viral replication. Results: Both CsA and ALV robustly inhibited viral replication in all models; both compounds decreased HCoV-229E RNA in phBECs and reduced luminescence in HCoV-229E-RLuc-infected Huh7.5 and SARS-CoV-1-RLuc replicon-transfected HEK293. In contrast, FK506 showed inconsistent and less pronounced effects in phBECs while strongly affecting coronavirus replication in Huh-7.5 and HEK293. Two non-immunosuppressive FK506 analogs had no antiviral effect in any infection model. Conclusion: The immunophilin inhibitors CsA and ALV display robust anti-coronaviral properties in multiple infection models, including phBECs, reflecting a primary site of HCoV infection. In contrast, FK506 displayed cell-type specific effects, strongly affecting CoV replication in Huh7.5 and HEK293, but inconsistently and less pronounced in phBECs.

Duration of Reduction in Enduring Stress-Induced Hyperalgesia Via FKBP51 Inhibition Depends on Timing of Administration Relative to Traumatic Stress Exposure.

Chronic pain development is a frequent outcome of severe stressor exposure, with or without tissue injury. Enduring stress-induced hyperalgesia (ESIH) is believed to play a central role, but the precise mechanisms mediating the development of chronic post-traumatic pain, and the time-dependency of these mechanisms, remain poorly understood. Clinical and preclinical data suggest that the inhibition of FK506-binding protein 51 (FKBP51), a key stress system regulator, might prevent ESIH. We evaluated whether peritraumatic inhibition of FKBP51 in an animal model of traumatic stress exposure, the single prolonged stress (SPS) model, reversed ESIH evaluated via daily mechanical von Frey testing. FKBP51 inhibition was achieved using SAFit2, a potent and specific small molecule inhibitor of FKBP51, administered to male and female Sprague-Dawley rats via intraperitoneal injection. To assess timing effects, FKBP51 was administered at different times relative to stress (SPS) exposure. SAFit2 administration immediately after SPS produced a complete reversal in ESIH lasting >7 days. In contrast, SAFit2 administration 72 hours following SPS produced only temporary hyperalgesia reversal, and administration 120h following SPS had no effect. Similarly, animals undergoing SPS together with tissue injury (plantar incision) receiving SAFit2 immediately post-surgery developed acute hyperalgesia but recovered by 4 days and did not develop ESIH. These data suggest that: 1) FKBP51 plays an important, time-dependent role in ESIH pathogenesis, 2) time windows of opportunity may exist to prevent ESIH via FKBP51 inhibition after traumatic stress, with or without tissue injury, and 3) the use of inhibitors of specific pathways may provide new insights into chronic post-traumatic pain development. PERSPECTIVE: The current work adds to a growing body of literature indicating that FKBP51 inhibition is a highly promising potential treatment strategy for reducing hyperalgesia. In the case of post-traumatic chronic pain, we show that such a treatment strategy would be particularly impactful if administered early after traumatic stress exposure.

Peptidylprolyl Isomerases as In Vivo Carriers for Drugs That Target Various Intracellular Entities.

Analyses of sequences and structures of the cyclosporine A (CsA)-binding proteins (cyclophilins) and the immunosuppressive macrolide FK506-binding proteins (FKBPs) have revealed that they exhibit peculiar spatial distributions of charges, their overall hydrophobicity indexes vary within a considerable level whereas their points isoelectric (pIs) are contained from 4 to 11. These two families of peptidylprolyl cis/trans isomerases (PPIases) have several distinct functional attributes such as: (1) high affinity binding to some pharmacologically-useful hydrophobic macrocyclic drugs; (2) diversified binding epitopes to proteins that may induce transient manifolds with altered flexibility and functional fitness; and (3) electrostatic interactions between positively charged segments of PPIases and negatively charged intracellular entities that support their spatial integration. These three attributes enhance binding of PPIase/pharmacophore complexes to diverse intracellular entities, some of which perturb signalization pathways causing immunosuppression and other system-altering phenomena in humans.

The effects of PEP-1-FK506BP on dry eye disease in a rat model.

As FK506 binding proteins (FK506BPs) are known to play an important role in the regulation of a variety of biological processes related to cell survival, this study was designed to examined the protective effects of FK506 binding protein 12 (FK506BP) on low humidity air flow induced dry eye in a rat model using transduced PEP-1-FK506BP. After the topical application of PEP-1-FK506BP, tear volumes were markedly increased and significant prevention of cornea damage was observed compared with dry eye rats. Further, immunohistochemical analysis demonstrated that PEP-1-FK506BP markedly prevented damage to the cornea, the bulbar conjunctiva, and the palpebral conjunctiva epithelial lining compared with dry eye rats. In addition, caspase-3 and PARP expression levels were found to be decreased. These results demonstrated that topical application of PEP-1-FK506BP significantly ameliorates dry eye injury in an animal model. Thus, we suggest that PEP-1-FK506BP can be developed as a new ophthalmic drop to treat dry eye diseases.

Fenobam promoted the neuroprotective effect of PEP-1-FK506BP following oxidative stress by increasing its transduction efficiency.

We examined the ways in which fenobam could promote not only the transduction of PEP-1-FK506BP into cells and tissues but also the neuroprotective effect of PEP-1-FK506BP against ischemic damage. Fenobam strongly enhanced the protective effect of PEP-1-FK506BP against H2O2-induced toxicity and DNA fragmentation in C6 cells. In addition, combinational treatment of fenobam with PEP-1-FK506BP significantly inhibited the activation of Akt and MAPK induced by H2O2, compared to treatment with PEP-1-FK506BP alone. Interestingly, our results showed that fenobam significantly increased the transduction of PEP-1-FK506BP into both C6 cells and the hippocampus of gerbil brains. Subsequently, a transient ischemic gerbil model study demonstrated that fenobam pretreatment led to the increased neuroprotection of PEP-1-FK506BP in the CA1 region of the hippocampus. Therefore, these results suggest that fenobam can be a useful agent to enhance the transduction of therapeutic PEP-1-fusion proteins into cells and tissues, thereby promoting their neuroprotective effects.

Transduced PEP-1-FK506BP ameliorates atopic dermatitis in NC/Nga mice.

Immunophilin, FK506-binding protein 12 (FK506BP), is a receptor protein for the immunosuppressive drug FK506 by the FK506BP/FK506 complex. However, the precise function of FK506BP in inflammatory diseases remains unclear. Therefore, we examined the protective effects of FK506BP on atopic dermatitis (AD) in tumor necrosis factor-α (TNF-α)/interferon-γ (IFN-γ)-induced HaCaT cells and 2,4-dinitrofluorobenzene-induced AD-like dermatitis in Nishiki-nezumi Cinnamon/Nagoya (NC/Nga) mice using a cell-permeable PEP-1-FK506BP. Transduced PEP-1-FK506BP significantly inhibited the expression of cytokines, as well as the activation of NF-κB and mitogen-activated protein kinase (MAPK) in TNF-α/IFN-γ-induced HaCaT cells. Furthermore, topical application of PEP-1-FK506BP to NC/Nga mice markedly inhibited AD-like dermatitis as determined by a histological examination and assessment of serum IgE levels, as well as cytokines and chemokines. These results indicate that PEP-1-FK506BP inhibits NF-κB and MAPK activation in cells and AD-like skin lesions by reducing the expression levels of cytokines and chemokines, thus suggesting that PEP-1-FK506BP may be a potential therapeutic agent for AD.

An inducible caspase 9 safety switch for T-cell therapy.

The efficacy of adoptive T-cell therapy as treatment for malignancies may be enhanced by genetic modification of infused cells. However, oncogenic events due to vector/transgene integration, and toxicities due to the infused cells themselves, have tempered enthusiasm. A safe and efficient means of removing aberrant cells in vivo would ameliorate these concerns. We describe a "safety switch" that can be stably and efficiently expressed in human T cells without impairing phenotype, function, or antigen specificity. This reagent is based on a modified human caspase 9 fused to a human FK506 binding protein (FKBP) to allow conditional dimerization using a small molecule pharmaceutical. A single 10-nM dose of synthetic dimerizer drug induces apoptosis in 99% of transduced cells selected for high transgene expression in vitro and in vivo. This system has several advantages over currently available suicide genes. First, it consists of human gene products with low potential immunogenicity. Second, administration of dimerizer drug has no effects other than the selective elimination of transduced T cells. Third, inducible caspase 9 maintains function in T cells overexpressing antiapoptotic molecules. These characteristics favor incorporation of inducible caspase 9 as a safety feature in human T-cell therapies.

Hippocampal CA1 neuron survival and cytosolic FKBP12, the 12 kDa FK506-binding protein, after ischemia and tacrolimus treatment in gerbils.

To assess the neuroprotective effect of tacrolimus (FK506) in transient forebrain ischemia models in gerbils, 10.0 mg/kg of FK506 was injected intraperitoneally immediately following reperfusion and at intervals of 1, 3, 6, 9, and 12 h after reperfusion. FK506 produced a significant neuroprotective effect for up to 6 h after 5 min of ischemia. Immunoblot and immunohistochemistry revealed that the amount of FKBP12, the 12-kDa FK506-binding protein, in the cytosol remained unchanged until 12 h after reperfusion. Translocation of FKBP12 from the nucleus to the cytosol was not observed until 24 h after reperfusion. Administration of FK506 did not appear to induce the cytosolic increase in FKBP12. In this study, no correlation was apparent between the post-ischemic therapeutic efficacy of FK506 and the post-ischemic changes in the cytosolic FKBP12.