Hypericin: A natural anthraquinone as promising therapeutic agent.

BACKGROUND: Hypericin is a prominent secondary metabolite mainly existing in genus Hypericum. It has become a research focus for a quiet long time owing to its extensively pharmacological activities especially the anti-cancer, anti-bacterial, anti-viral and neuroprotective effects. This review concentrated on summarizing and analyzing the existing studies of hypericin in a comprehensive perspective. METHODS: The literature with desired information about hypericin published after 2010 was gained from electronic databases including PubMed, SciFinder, Science Direct, Web of Science, China National Knowledge Infrastructure databases and Wan Fang DATA. RESULTS: According to extensive preclinical and clinical studies conducted on the hypericin, an organized and comprehensive summary of the natural and artificial sources, strategies for improving the bioactivities, pharmacological activities, drug combination of hypericin was presented to explore the future therapeutic potential of this active compound. CONCLUSIONS: Overall, this review offered a theoretical guidance for the follow-up research of hypericin. However, the pharmacological mechanisms, pharmacokinetics and structure activity relationship of hypericin should be further studied in future research.

A phase II study of bisantrene in patients with relapsed/refractory acute myeloid leukemia.

OBJECTIVES: To determine the current role of bisantrene, an anthracene with anthracycline-like activity which was shown in earlier studies to be effective therapy in relapsed/refractory acute myeloid leukemia with no discernible cardiotoxicity, in the treatment of patients with R/R AML. METHODS: This phase 2, single-center study (NCT03820908) enrolled adult R/R AML to receive bisantrene (250 mg/m2 daily for 7 days) which was administered via an intravenous infusion over 2 hours on days 1-7. Disease assessment included routine blood work and bone marrow studies. RESULTS: In all, 10 patients were enrolled with a median of 3 lines of prior therapy including seven patients who had relapsed following allogeneic stem cell transplantation. The most frequently reported grade ≥3 treatment-attributed hematologic AE was thrombocytopenia, whereas the most frequently reported grade ≥3 treatment-attributed non-hematologic AE was mucositis. Of the 10 patients, one (10%) achieved a complete remission and three patients achieved a partial remission resulting in an overall response rate of 40%. Next-generation sequencing of patient samples identified a wide array of mutations associated with activated signaling, splicing, and epigenetic modification. CONCLUSIONS: In view of the observed low toxicity, a follow-up study combining bisantrene with complementary anti-leukemic therapy is planned.

JNK signaling contributes to skeletal muscle wasting and protein turnover in pancreatic cancer cachexia.

Cancer cachexia patients experience significant muscle wasting, which impairs the quality of life and treatment efficacy for patients. Skeletal muscle protein turnover is imparted by increased expression of ubiquitin-proteasome pathway components. Mitogen-activated protein kinases p38 and ERK have been shown to augment E3 ubiquitin ligase expression. Utilizing reverse-phase protein arrays, we identified pancreatic cancer cell-conditioned media-induced activation of JNK signaling in myotubes differentiated from C2C12 myoblasts. Inhibition of JNK signaling with SP600125 reduced cancer cell-conditioned media-induced myotube atrophy, myosin heavy chain protein turnover, and mRNA expression of cachexia-specific ubiquitin ligases Trim63 and Fbxo32. Furthermore, utilizing an orthotopic pancreatic cancer cachexia mouse model, we demonstrated that treatment of tumor-bearing mice with SP600125 improved longitudinal measurements of forelimb grip strength. Post-necropsy measurements demonstrated that SP600125 treatment rescued body weight, carcass weight, and gastrocnemius muscle weight loss without impacting tumor growth. JNK inhibitor treatment also rescued myofiber degeneration and reduced the muscle expression of Trim63 and Fbxo32. These data demonstrate that JNK signaling contributes to muscle wasting in cancer cachexia, and its inhibition has the potential to be utilized as an anti-cachectic therapy.

A Novel Allosteric Inhibitor of Phosphoglycerate Mutase 1 Suppresses Growth and Metastasis of Non-Small-Cell Lung Cancer.

Phosphoglycerate mutase 1 (PGAM1) plays a pivotal role in cancer metabolism and tumor progression via its metabolic activity and interaction with other proteins like α-smooth muscle actin (ACTA2). Allosteric regulation is considered to be an innovative strategy to discover a highly selective and potent inhibitor targeting PGAM1. Here, we identified a novel PGAM1 allosteric inhibitor, HKB99, via structure-based optimization. HKB99 acted to allosterically block conformational change of PGAM1 during catalytic process and PGAM1-ACTA2 interaction. HKB99 suppressed tumor growth and metastasis and overcame erlotinib resistance in non-small-cell lung cancer (NSCLC). Mechanistically, HKB99 enhanced the oxidative stress and altered multiple signaling pathways including the activation of JNK/c-Jun and suppression of AKT and ERK. Collectively, the study highlights the potential of PGAM1 as a therapeutic target in NSCLC and reveals a distinct mechanism by which HKB99 inhibits both metabolic activity and nonmetabolic function of PGAM1 by allosteric regulation.

Release of IL-6 After Stroke Contributes to Impaired Cerebral Autoregulation and Hippocampal Neuronal Necrosis Through NMDA Receptor Activation and Upregulation of ET-1 and JNK.

The sole FDA-approved drug treatment for ischemic stroke is tissue-type plasminogen activator (tPA). However, upregulation of JNK mitogen-activated protein kinase (MAPK) and endothelin 1 (ET-1) by tPA after stroke contributes to impaired cerebrovascular autoregulation. Wild-type (wt) tPA can bind to the lipoprotein-related receptor (LRP), which mediates vasodilation, or NMDA receptors (NMDA-Rs), exacerbating vasoconstriction. Elevations in IL-6, a marker of inflammation that accompanies stroke, are reported to be an adverse prognostic factor. We hypothesized that IL-6 released into CSF after stroke by wt-tPA through activation of NMDA-Rs and upregulation of ET-1 and JNK contribute to impairment of cerebrovascular autoregulation and increased histopathology. Results show that IL-6 was increased post stroke in pigs, which was increased further by wt-tPA. Co-administration of the IL-6 antagonist LMT-28 with wt-tPA prevented impairment of cerebrovascular autoregulation and necrosis of hippocampal cells. wt-tPA co-administered with the JNK inhibitor SP 600125 and the ET-1 antagonist BQ 123 blocked stroke-induced elevation of IL-6. Co-administration of LMT-28 with wt-tPA blocked the augmentation of JNK and ET-1 post stroke. In conclusion, IL-6 released after stroke, which is enhanced by wt-tPA through activation of NMDA-Rs and upregulation of ET-1 and JNK, impairs cerebrovascular autoregulation and increases histopathology. Strategies that promote fibrinolysis while limiting activation of NMDA-Rs and upregulation of IL-6 may improve the benefit/risk ratio compared to wt-tPA in treatment of stroke.

Activation of CXCL5-CXCR2 axis promotes proliferation and accelerates G1 to S phase transition of papillary thyroid carcinoma cells and activates JNK and p38 pathways.

C-X-C motif chemokine ligand 5 (CXCL5) is initially identified to recruit neutrophils by interacting with its receptor, C-X-C motif chemokine receptor 2 (CXCR2). Our prior work demonstrated that the expression levels of CXCL5 and CXCR2 were higher in the papillary thyroid carcinoma (PTC) tumors than that in the non-tumors. This study was performed to further investigate how this axis regulates the growth of PTC cells. B-CPAP cells (BRAFV600E) and TPC-1 cells (RET/PTC rearrangement) expressing CXCR-2 were used as in vitro cell models. Our results showed that the recombinant human CXCL5 (rhCXCL5) promoted the proliferation of PTC cells. rhCXCL5 accelerated the G1/S transition, upregulated the expression of a group of S (DNA synthesis) or M (mitosis)-promoting cyclins and cyclin-dependent kinases (CDKs), and downregulated CDK inhibitors in PTC cells. The CDS region of homo sapiens CXCL5 gene was inserted into an eukaryotic expression vector to mediate the overexpression of CXCL5 in PTC cells. The phosphorylation of c-Jun N-terminal kinases (JNK) and p38, and the nuclear translocation of c-Jun were enhanced by CXCL5 overexpression, whereas attenuated by CXCR2 antagonist SB225002. Additionally, CXCL5/CXCR2 axis, JNK and p38 pathway inhibitors, SB225002, SP600125 and SB203580, suppressed the growth of PTC cells overexpressing CXCL5 in nude mice, respectively. Collectively, our study demonstrates a growth-promoting effect of CXCL5-CXCR2 axis in PTC cells in vitro and in vivo.

Synergetic and Antagonistic Molecular Effects Mediated by the Feedback Loop of p53 and JNK between Saikosaponin D and SP600125 on Lung Cancer A549 Cells.

We jointly analyzed the changes in cell cycle arrest and distribution, the accumulation of subphase cells, apoptosis, and proliferation in A549 cells treated with Saikosaponin D (Ssd) and JNK inhibitor SP600125 alone or in combination. Our results indicated that cell cycle arrest at G0/G1, S, and G2/M phases was coupled with the accumulation of subG1, subS, and subG2 cells, corresponding to early apoptosis, DNA endoreplication, and later inhibitory proliferation, respectively. Analyzing the expression of 18 cell cycle regulatory genes and JNK and phosphorylated JNK (pJNK) levels revealed an enhancement in these factors by Ssd. Additional SP600125 weakened or eliminated the Ssd-induced increase of these factors except that p53/p21 and Rassfia levels were further improved. Ingenuity Pathway Analysis (IPA) of the interactions of these factors revealed a negative synergistic effect on apoptosis while a positive synergistic effect on proliferative inhibition of the two drugs: (1) Ssd induced apoptosis via the activation of two axes, TGFα-JNK-p53 and TGFα-Rassfia-Mst1. By eliminating the Ssd-induced increase of JNK/pJNK, additional SP600125 weakened the Ssd-induced apoptotic axis of TGFα-JNK-p53 and simultaneously abolished Ssd-induced apoptosis; (2) Ssd inhibited proliferation by the activation of two axes, TGFß-p53/p21/p27/p15/p16 and TGFα-Rassfia-cyclin D1. By improving the Ssd-induced increase of p53/p21 and Rassfia, additional SP600125 enhanced the two axes of Ssd-induced inhibitory proliferation. Analyzing JNK/pJNK, p53, phospho-p53, and TNF-α levels revealed an opposite association of JNK/pJNK with p53 while consistent with phospho-p53 and TNF-α, which supported the proposals that JNK/pJNK negatively regulated p53 level, while it mediated p53 phosphorylation to transcriptionally activate TNF-α expression of apoptotic gene and trigger apoptosis. With the multiple roles, JNK/pJNK forms a synergetic and antagonistic feedback loop with phospho-p53/p53. Within the feedback loop, (1) Ssd-induced apoptosis depended on JNK/pJNK activities mediating phospho-p53 that activated TNF-α expression; (2) by weakening the negative regulation of JNK/pJNK in p53, SP600125 enhanced p53 level and the Ssd-induced inhibitory proliferation axes of TGFß-p53/p21/p27/p15/p16. The results indicated the central coordinating roles of the feedback loop in the synergistic and antagonistic effects of the two drugs in A549 cells and provided a rationale for the combination of Ssd with SP600125 in the treatment of lung cancer.

Barbaloin protects against lipopolysaccharide (LPS)-induced acute lung injury by inhibiting the ROS-mediated PI3K/AKT/NF-κB pathway.

Barbaloin is the major anthraquinone compound that is isolated from the leaf exudates of Aloe vera and is often used as a bittering agent in alcoholic beverages. Here, we investigated the potential protective role of barbaloin in a mouse model of lipopolysaccharide (LPS)-induced acute lung injury (ALI) and clarified the underlying mechanism in vitro. Histological analysis showed that barbaloin exhibited a certain protective effect on LPS-induced ALI. To further elucidate the mechanisms underlying the actions of barbaloin, LPS-stimulated macrophages were used in this study. The results showed that barbaloin decreased the phosphorylation levels of IκBα and NF-κB p65, leading to a reduction in the expression of pro-inflammatory cytokines (TNF-α, IL-1ß and IL-6). Furthermore, barbaloin also reduced the levels of intracellular reactive oxygen species (ROS) similarly to the antioxidant N­acetyl­l­cysteine (NAC), which alone repressed the LPS-induced phosphorylation of phosphoinositide 3-kinase (PI3K) and AKT. Additionally, a pharmacological inhibitor of PI3K/AKT, LY294002, also restrained the phosphorylation levels of IκBα and NF-κB p65 and thereby decreased the expression of pro-inflammatory cytokines. Together, these results show that barbaloin possesses a protective effect on LPS-induced ALI via suppressing the release of pro-inflammatory cytokines through the ROS-mediated PI3K/AKT/NF-κB pathway.

Oxygen-independent combined photothermal/photodynamic therapy delivered by tumor acidity-responsive polymeric micelles.

Tumor hypoxia strikingly restricts photodynamic therapy (PDT) efficacy and limits its clinical applications in cancer therapy. The ideal strategy to address this issue is to develop oxygen-independent PDT systems. Herein, the rationally designed tumor pH-responsive polymeric micelles are devised to realize oxygen-independent combined PDT and photothermal therapy (PTT) under near-infrared light (NIR) irradiation. The triblock copolymer, poly(ethylene glycol)-b-poly(ε-caprolactone)-b-poly(2-(piperidin-1-yl)ethyl methacrylate) (PEG-b-PCL-b- PPEMA), was prepared to co-encapsulate cypate and singlet oxygen donor (diphenylanthracene endoperoxide, DPAE) via self-assembly to obtain the micellar delivery system (C/O@N-Micelle). C/O@N-Micelle showed remarkable tumor accumulation and improved cellular internalization (2.1 times) as the pH value was changed from 7.4 during blood circulation to 6.8 in tumor tissues. The micelles could produce a potent hyperthermia for PTT of cypate under 808 nm NIR irradiation, which simultaneously induced thermal cycloreversion of DPAE generating abundant singlet oxygen for PDT without participation of tumor oxygen. Finally, the photothermally triggered PDT and PTT combination achieved efficient tumor ablation without remarkable systemic toxicity in an oxygen-independent manner. This work represents an efficient strategy for oxygen-independent combined PDT and PTT of cancers under NIR irradiation through co-encapsulation of cypate and DPAE into tumor pH-responsive polymeric micelles.

Endogenous c-Jun N-terminal kinase (JNK) activity marks the boundary between normal and malignant granulosa cells.

Granulosa cell tumor of the ovary (GCT) is a very rare tumor, accounting for only 2% of all ovarian tumors. It originates from sex cords in the ovary and can be divided into adult (95%) and juvenile (5%) types based on histologic findings. To date, no clear etiologic process has been identified other than a missense point mutation in the FOXL2 gene. Our previous works showed that c-Jun N-terminal kinase (JNK) pathway plays critical role in cell cycle progression and mitosis of normal and immortalized granulosa cells and follicle growth in rodent ovaries. These findings led us to investigate the role of JNK pathway in the granulosa cell tumor of the ovary. We used two different GCT cell lines (COV434 and KGN) and fresh GCT samples of adult and juvenile types obtained from the patients during surgery. We have discovered that endogenous kinase activity of JNK is markedly enhanced in the GCT samples and cell lines, whereas it was almost undetectable in mitotic non-malignant human granulosa cells. The inhibition of JNK pathway in GCT cell lines with two different pharmacologic inhibitors (SP600125 and AS601245) or siRNA resulted in a dose-dependent reduction in in vitro cell growth, increased apoptosis and diminished estradiol and AMH productions. JNK inhibition was also associated with a decrease in the number of cells positive for mitosis marker phospho-histone H3Ser 10 in the asynchronous cells; and diminished EdU uptake during S phase and cell cycle arrest at G2/M-phase transition in the synchronized cells. Ex vivo treatment of patient-derived GCT samples with JNK inhibitors for 24 h significantly decreased their in vitro growth and estradiol and AMH productions. Furthermore, in human GCT xenograft model, in vivo tumor growth was significantly reduced and plasma AMH levels were significantly decreased in SCID mice after administration of JNK inhibitors and siRNA. These findings suggest that targeting JNK pathway may provide therapeutic benefit in the treatment of granulosa cell tumors for which currently no curative therapy exists beyond surgery.

Conflicting evidence for the role of JNK as a target in breast cancer cell proliferation: Comparisons between pharmacological inhibition and selective shRNA knockdown approaches.

As a target, the JNK pathway has been implicated in roles including cell death, proliferation, and inflammation in variety of contexts which span cardiovascular disease, neurodegenerative pathologies, and cancer. JNK1 and JNK2 have recently been demonstrated to function independently, highlighting a new parameter in the study of the JNK pathway. In order for JNK1 and JNK2-specific roles to be defined, better tools need to be employed. Previous studies have relied upon the broad spectrum JNK inhibitor, SP600125, to characterize the role of JNK signaling in a number of cell lines, including the breast cancer cell line MCF-7. In line with previous literature, our study has demonstrated that SP600125 treatment inhibited c-Jun and JNK phosphorylation and MCF-7 proliferation. However, in addition to targeting JNK1, JNK2, and JNK3, SP600125 has been previously demonstrated to suppress the activity of a number of other serine/threonine kinases, making SP600125 an inadequate tool for JNK isoform-specific roles to be determined. In this study, lentiviral shRNA was employed to selectively knockdown JNK1, JNK2, and JNK1/2 in MCF-7 cells. Using this approach, JNK phosphorylation was fully inhibited following stable knockdown of respective JNK isoforms. Interestingly, despite suppression of JNK phosphorylation, MCF-7 cell proliferation, cell cycle progression, or cell death remained unaffected. These findings raise the question of whether JNK phosphorylation really is pivotal in MCF-7 cell growth and death or if suppression of these events is a result of one of the many off-targets cited for SP600125.

JNK1/2 inhibitor reduces dengue virus-induced liver injury.

High viral load with liver injury is exhibited in severe dengue virus (DENV) infection. Mitogen activated protein kinases (MAPKs) including ERK1/2 and p38 MAPK were previously found to be involved in the animal models of DENV-induced liver injury. However, the role of JNK1/2 signaling in DENV-induced liver injury has never been investigated. JNK1/2 inhibitor, SP600125, was used to investigate the role of JNK1/2 signaling in the BALB/c mouse model of DENV-induced liver injury. SP600125-treated DENV-infected mice ameliorated leucopenia, thrombocytopenia, hemoconcentration, liver transaminases and liver histopathology. DENV-induced liver injury exhibited induced phosphorylation of JNK1/2, whereas SP600125 reduced this phosphorylation. An apoptotic real-time PCR array profiler was used to screen how SP600125 affects the expression of 84 cell death-associated genes to minimize DENV-induced liver injury. Modulation of caspase-3, caspase-8 and caspase-9 expressions by SP600125 in DENV-infected mice suggests its efficiency in restricting apoptosis via both extrinsic and intrinsic pathways. Reduced expressions of TNF-α and TRAIL are suggestive to modulate the extrinsic apoptotic signals, where reduced p53 phosphorylation and induced anti-apoptotic Bcl-2 expression indicate the involvement of the intrinsic apoptotic pathway. This study thus demonstrates the pivotal role of JNK1/2 signaling in DENV-induced liver injury and how SP600125 modulates this pathogenesis.

Inhibition of c-Jun N-terminal kinase signaling suppresses skin flap apoptosis in a rat ischemia and/or reperfusion model.

BACKGROUND: The goals of this study were to validate the role of c-Jun N-terminal kinase (JNK) activation in skin flap apoptosis in a rat model of abdomen skin ischemia and/or reperfusion (IR) and to compare the protective effect of SP600125 and hydrogen-rich saline in skin IR injury. METHODS: Male Sprague-Dawley rats were divided into five groups: one sham surgery group and four surgery groups. Before undergoing 3 h of IR management, the surgery groups were treated with normal saline (IR), dimethyl sulfoxide, SP600125 (SP), and hydrogen-rich saline (H). On the third postoperative day, blood perfusion of the flap was measured using Laser Doppler flowmeters. Hematoxylin and eosin staining was used to observe morphologic changes. Early apoptosis was observed using TdT-mediated dUTP-X nick end-labeling staining. pASK-1, pJNK, Bcl-2, and Bax were examined by immunodetection. Caspase-3 activity was also measured 24 h after reperfusion. RESULTS: Compared to the IR group and the dimethyl sulfoxide group, the SP group and the H group had larger skin flap survival area, more blood perfusion and lower levels of caspase-3 activity. The SP and the H groups had high expression levels of Bcl-2 and low expression levels of pASK-1 and pJNK. Bax was significantly decreased in the SP group. In addition, cell apoptosis was decreased in both the sham surgery and the H groups. CONCLUSIONS: IR-induced JNK phosphorylation was reduced by SP600125, indicating that JNK mediates the apoptosis pathways in rat skin. In the SP and the H groups, the apoptotic factors measured showed similar expression levels, indicating that JNK inhibition during IR may be associated with H-mediated protection against skin IR apoptosis.

The Role of Platelet-Derived Growth Factor Receptor in Early Brain Injury Following Subarachnoid Hemorrhage.

OBJECTIVE: This study aims to observe encephaledema and cell apoptosis in rats following subarachnoid hemorrhage (SAH) and to explore the mechanism of platelet-derived growth factor receptor (PDGFR) in the development of early brain injury (EBI). METHODS: Adult and male Sprague-Dawley rats were randomly divided into 4 groups: sham operation, SAH, SAH + imatinib, and SAH + platelet-derived growth factor-BB (PDGF-BB). SAH model was established using intravascular silk puncture of the internal carotid artery crotch. The SAH + imatinib group was treated with intraperitoneal injection of imatinib 1 hour before establishing the model. The SAH + PDGF-BB group was administered with intracerebroventricular injection of PDGF-BB 1 hour before establishing the model. The mortality, encephaledema, and nerve functional scoring were observed after 24 hours in all groups. The expression of caspase-3 in hippocampus was tested by reverse transcription polymerase chain reaction and Western blotting. RESULTS: Mortality and encephaledema were the highest in the SAH + PDGF-BB group, which were alleviated when the rats were injected with imatinib (P < .01). CONCLUSION: PDGFR may participate in the pathogenesis of EBI following SAH. The antagonist of PDGFR, imatinib, can reduce brain damage to some degree.

Reduction of autophagy markers mediated protective effects of JNK inhibitor and bucladesine on memory deficit induced by Aß in rats.

Autophagy, the process of self-degradation of cellular components, has an important role in neurodegenerative diseases, such as Alzheimer's disease. In this study, we investigated the effects of SP600125 as c-Jun N-terminal kinase (JNK) inhibitor and bucladesine as a cyclic adenosine 3',5'-monophosphate (cAMP) analog on spatial memory and expression of autophagic factors in Aß-injected rats. Male Wistar rats were used. Rats were randomly allocated into five groups as following: amyloid beta (Aß)-only group, Aß + SP600125 (30 µg/1 µ/side, n = 7) and/or bucladesine (100 µM/1 µl/side, n = 7), and the normal control (vehicle only) group. The treatments were administered bilaterally to the CA1 sub-region of the hippocampus stereotaxically. Spatial reference memory was performed using Morris Water Maze 21 days later. The expression of authophagy markers (beclin1, Atg7, Atg12, and LC3 II/LC3 I) in the hippocampus was evaluated using western blotting. Compared to the vehicle group, Aß administration reduced spatial reference learning (P < 0.001) and memory (P < 0.01) and upregulated the expression of beclin1, Atg7, Atg12, and LC3 II/I (P < 0.0001). Compare to Aß-only group, the administration of SP600125 and/or bucladesine improved spatial reference learning (P < 0.001) and memory (P < 0.01). Compared to the Aß-only group, the treatment with SP600125 and/or bucladesine also reduced beclin1, Atg7, Atg12, and LC3 II/I (P < 0.0001) which was similar to amount of normal rats. In summary, it seems that the improvement of spatial memory by SP600125 and/or bucladesine in Aß-injected rats is in relation with normalizing of autophagy to the physiologic level, possibly through neuroprotection and/or neuroplasticity.

Discovery of antitumor anthra[2,3-b]furan-3-carboxamides: Optimization of synthesis and evaluation of antitumor properties.

Anthraquinones and their analogues, in particular heteroarene-fused anthracendiones, are prospective scaffolds for new compounds with improved antitumor characteristics. We herein report the use of a 'scaffold hopping' approach for the replacement of the core structure in the previously discovered hit compound naphtho[2,3-f]indole-5,10-dione 2 with an alternative anthra[2,3-b]furan-5,10-dione scaffold. Among 13 newly synthesized derivatives the majority of 4,11-dihydroxy-2-methyl-5,10-dioxoanthra[2,3-b]furan-3-carboxamides demonstrated a high antiproliferative potency against a panel of wild type and drug resistant tumor cell lines, a property superior over the reference drug doxorubicin or lead naphtho[2,3-f]indole-5,10-dione 2. At low micromolar concentrations the selected derivative of (R)-3-aminopyrrolidine 3c and its stereoisomer (S)-3-aminopyrrolidine 3d caused an apoptotic cell death preceded by an arrest in the G2/M phase. Studies of intracellular targets showed that 3c and 3d formed stable intercalative complexes with the duplex DNA as determined by spectral analysis and molecular docking. Both 3c and 3d attenuated topoisomerase 1 and 2 mediated unwinding of the supercoiled DNA via a mechanism different from conventional DNA-enzyme tertiary complex formation. Furthermore, 3d decreased the activity of selected human protein kinases in vitro, indicating multiple targeting by the new chemotype. Finally, 3d demonstrated an antitumor activity in a model of murine intraperitoneally transplanted P388 leukemia, achieving the increase of animal life span up to 262% at tolerable doses. Altogether, the 'scaffold hopping' demonstrated its productivity for obtaining new perspective antitumor drug candidates.

Inhibition of development of experimental abdominal aortic aneurysm by c-jun N-terminal protein kinase inhibitor combined with lysyl oxidase gene modified smooth muscle progenitor cells.

Chronic inflammation, imbalance between the extracellular matrix synthesis and degradation, and loss of vascular smooth muscle cells (SMCs) contribute to the development of abdominal aortic aneurysm (AAA). The purpose of this study was to investigate the effect of the therapy with periaortic incubation of c-Jun N-terminal protein kinase inhibitor SP600125 infused from an osmotic pump and subadventitial injection of lysyl oxidase (LOX) gene modified autologous smooth muscle progenitor cells (SPCs) on treatment of AAA in a rabbit model. Obvious dilation of the abdominal aorta in the control group was caused by periaortic incubation of calcium chloride and elastase. But the progression of aortic dilation was significantly decreased after the treatment with SP600125 and LOX gene modified SPCs compared to the treatment with phosphate-buffered saline. This therapy could inhibit matrix metalloproteinases expression, enhance elastin synthesis, improve preservation of elastic laminar integrity, benefit SPCs survival and restore SMCs population. It seemed that this method might provide a novel therapeutic strategy to treat AAA.

The Streptomyces metabolite anhydroexfoliamycin ameliorates hallmarks of Alzheimer's disease in vitro and in vivo.

Anhydroexfoliamycin (1) and undecylprodigiosin (2) have been previously described as neuroprotective molecules against oxidative stress in neurons. Since oxidative stress is strongly correlated with neurodegenerative diseases, we have evaluated their effects over the principal hallmarks of Alzheimer's disease (AD). Both compounds were tested in vitro in two different neuroblastoma cellular models, one for amyloid precursor protein metabolism studies (BE(2)-M17) and another one specific for taupathology in AD (SH-SY5Y-TMHT441). Amyloid-beta (Aß) levels, ß-secretase (BACE1) activity, tau phosphorylation, extracellular signal-regulated kinase (ERK) and glycogen synthase kinase-3beta (GSK3ß) expression were analyzed and while undecylprodigiosin (2) produced poor results, anhydroexfoliamycin (1) strongly inhibited GSK3ß, reducing tau phosphorylation in vitro (0.1 µM). A competitive assay of anhydroexfoliamycin (1) and the specific c-Jun N-terminal kinase (JNK) inhibitor, SP600125, showed that the reduction of the phosphorylated tau levels is mediated by the JNK pathway in SH-SY5Y-TMHT441 cells. Thus, this compound was tested in vivo by intraperitoneal administration in 3xTg-AD mice, confirming the positive results registered in the in vitro assays. This work presents anhydroexfoliamycin (1) as a promising candidate for further studies in drug development against neurodegenerative diseases.

Blockade of the JNK signalling as a rational therapeutic approach to modulate the early and late steps of the inflammatory cascade in polymicrobial sepsis.

Cecal ligation and puncture (CLP) is an experimental polymicrobial sepsis induced systemic inflammation that leads to acute organ failure. Aim of our study was to evaluate the effects of SP600125, a specific c-Jun NH2-terminal kinase (JNK) inhibitor, to modulate the early and late steps of the inflammatory cascade in a murine model of CLP-induced sepsis. CB57BL/6J mice were subjected to CLP or sham operation. Animals were randomized to receive either SP600125 (15 mg/kg) or its vehicle intraperitoneally 1 hour after surgery and repeat treatment every 24 hours. To evaluate survival, a group of animals was monitored every 24 hours for 120 hours. Two other animals were sacrificed 4 or 18 hours after surgical procedures; lung and liver samples were collected for biomolecular and histopathologic analysis. The expression of p-JNK, p-ERK, TNF-α, HMGB-1, NF-κB, Ras, Rho, Caspase 3, Bcl-2, and Bax was evaluated in lung and liver samples; SP600125 improved survival, reduced CLP induced activation of JNK, NF-κB, TNF-α, and HMGB-1, inhibited proapoptotic pathway, preserved Bcl-2 expression, and reduced histologic damage in both lung and liver of septic mice. SP600125 protects against CLP induced sepsis by blocking JNK signalling; therefore, it can be considered a therapeutic approach in human sepsis.

Lower susceptibility of female mice to acetaminophen hepatotoxicity: Role of mitochondrial glutathione, oxidant stress and c-jun N-terminal kinase.

UNLABELLED: Acetaminophen (APAP) overdose causes severe hepatotoxicity in animals and humans. However, the mechanisms underlying the gender differences in susceptibility to APAP overdose in mice have not been clarified. In our study, APAP (300mg/kg) caused severe liver injury in male mice but 69-77% lower injury in females. No gender difference in metabolic activation of APAP was found. Hepatic glutathione (GSH) was rapidly depleted in both genders, while GSH recovery in female mice was 2.6 fold higher in the mitochondria at 4h, and 2.5 and 3.3 fold higher in the total liver at 4h and 6h, respectively. This faster recovery of GSH, which correlated with greater induction of glutamate-cysteine ligase, attenuated mitochondrial oxidative stress in female mice, as suggested by a lower GSSG/GSH ratio at 6h (3.8% in males vs. 1.4% in females) and minimal centrilobular nitrotyrosine staining. While c-jun N-terminal kinase (JNK) activation was similar at 2 and 4h post-APAP, it was 3.1 fold lower at 6h in female mice. However, female mice were still protected by the JNK inhibitor SP600125. 17ß-Estradiol pretreatment moderately decreased liver injury and oxidative stress in male mice without affecting GSH recovery. CONCLUSION: The lower susceptibility of female mice is achieved by the improved detoxification of reactive oxygen due to accelerated recovery of mitochondrial GSH levels, which attenuates late JNK activation and liver injury. However, even the reduced injury in female mice was still dependent on JNK. While 17ß-estradiol partially protects male mice, it does not affect hepatic GSH recovery.