Chemiluminescence is among the most sensitive methods for achieving a high signal-to-noise ratio in various chemical and biological applications. We have developed a modular practical synthetic route ...for preparation of turn-ON fluorophore-tethered dioxetane chemiluminescent probes. The chemiluminescent emission of the probes was significantly amplified through an energy-transfer mechanism under physiological conditions. Two probes were composed with green and near-infrared (NIR) fluorescent dyes tethered to Schaap's dioxetane. While both probes were able to provide chemiluminescence in vivo images following subcutaneous injection, only the NIR probe could provide a chemiluminescence image following intraperitoneal injection. These are the first in vivo images produced by Schaap's dioxetane chemiluminescence probes with no need of an enhancer. Previously, chemiluminescence cell images could only be obtained with a luciferin-based probe. Our NIR probe was able to image cells transfected with β-galactosidase gene by chemiluminescence microscopy. We also report, for the first time, the instability of dioxetane-fluorophore conjugates to ambient light. Our synthetic route effectively overcomes this limitation through a late-stage functionalization of the dioxetane intermediate. We anticipate that our practical synthetic methodology will be useful for preparation of various chemiluminescent probes for numerous applications.
The most common site of breast cancer metastasis is the bone, occurring in approximately 70% of patients with advanced disease. Bone metastasis is associated with severe morbidities and high ...mortality. Therefore, deeper understanding of the mechanisms that enable bone-metastatic relapse are urgently needed. We report the establishment and characterization of a bone-seeking variant of breast cancer cells that spontaneously forms aggressive bone metastases following surgical resection of primary tumor. We characterized the modifications in the immune milieu during early and late stages of metastatic relapse and found that the formation of bone metastases is associated with systemic changes, as well as modifications of the bone microenvironment towards an immune suppressive milieu. Furthermore, we characterized the intrinsic changes in breast cancer cells that facilitate bone-tropism and found that they acquire mesenchymal and osteomimetic features. This model provides a clinically relevant platform to study the functional interactions between breast cancer cells and the bone microenvironment, in an effort to identify novel targets for intervention.
Molecular changes, caused by various environmental factors, affect the quality and developmental potential of oocytes. Oxidative stress (OS) is a major factor involved in various gynecologic ...disorders and/or in aging. Recent studies suggest that elevated reactive oxygen species (ROS) hamper oocyte quality and future embryonic development. Pigment epithelium‐derived factor (PEDF) is a pleiotropic protein, known for its antiangiogenic, anti‐inflammatory, and antioxidative properties. Our previous findings demonstrate the antioxidative role of rPEDF in maintaining granulosa cell viability. In the current study, we examined the ability of PEDF to negate the adverse impact of OS on oocytes. Maturation rate of oocytes exposed to OS was significantly lower than that of control oocytes. The number of mtDNA copies in OS‐exposed oocytes was significantly higher than in control oocytes (>3 times), whereas ATP concentration was significantly lower. Oocytes exposed to OS demonstrated impaired chromosome arrangement at the metaphase plate. PEDF significantly improved maturation rate of untreated OS‐exposed oocytes. Moreover, mtDNA copy number, ATP concentration, and chromosome arrangement at the metaphase plate in rPEDF‐treated OS‐exposed oocytes were restored to the level of control oocytes. Our findings demonstrate that OS hampers the ability of oocytes to undergo proper in vitro maturation. The energetic balance of OS‐exposed oocyte is characterized by excessive mtDNA replication and reduced ATP concentration; it hampers the ability of oocytes to perform high fidelity chromosome segregation. PEDF alleviates this damage, improves the rate of oocyte maturation, and preserves mtDNA level and ATP content, thus enabling oocytes to form proper metaphase plate and improve oocyte competence.
Glioblastoma is a highly aggressive brain tumor. Current standard-of-care results in a marginal therapeutic outcome, partly due to acquirement of resistance and insufficient blood-brain barrier (BBB) ...penetration of chemotherapeutics. To circumvent these limitations, we conjugated the chemotherapy paclitaxel (PTX) to a dendritic polyglycerol sulfate (dPGS) nanocarrier. dPGS is able to cross the BBB, bind to P/L-selectins and accumulate selectively in intracranial tumors. We show that dPGS has dual targeting properties, as we found that P-selectin is not only expressed on tumor endothelium but also on glioblastoma cells. We delivered dPGS-PTX in combination with a peptidomimetic of the anti-angiogenic protein thrombospondin-1 (TSP-1 PM). This combination resulted in a remarkable synergistic anticancer effect on intracranial human and murine glioblastoma via induction of Fas and Fas-L, with no side effects compared to free PTX or temozolomide. This study shows that our unique therapeutic approach offers a viable alternative for the treatment of glioblastoma.
Chemiluminescence offers advantages over fluorescence for bioimaging, since an external light source is unnecessary with chemiluminescent agents. This report demonstrates the first encapsulation of ...chemiluminescence phenoxy-adamantyl-1,2-dioxetane probes with trimethyl β-cyclodextrin. Clear proof for the formation of a 1 : 1 host-guest complex between the adamantyl-1,2-dioxetane probe and trimethyl β-cyclodextrin was provided by mass spectroscopy and NMR experiments. The calculated association constant of this host-guest system, 253 M
−1
, indicates the formation of a stable inclusion complex. The inclusion complex significantly amplified the light emission intensity relative to the noncomplexed probe under physiological conditions. Complexation of adamantyl-dioxetane with fluorogenic dye-tethered cyclodextrin resulted in light emission through energy transfer to a wavelength that corresponds to the fluorescent emission of the conjugated dye. Remarkably, the light emission intensity of this inclusion complex was approximately 1500-fold higher than that of the non-complexed adamantyl-dioxetane guest. We present the first demonstration of microscopic cell images obtained using a chemiluminescence supramolecular dioxetane probe and demonstrate the utility of these supramolecular complexes by imaging of enzymatic activity and bio-analytes
in vitro
and
in vivo
. We anticipate that the described chemiluminescence supramolecular dioxetane probes will find use in various biological applications.
Chemiluminescence offers advantages over fluorescence for bioimaging, since an external light source is unnecessary with chemiluminescent agents.
Polymer conjugation is an efficient approach to improve the delivery of drugs and biological agents, both by protecting the body from the drug (by improving biodistribution and reducing toxicity) and ...by protecting the drug from the body (by preventing degradation and enhancing cellular uptake). This review discusses the journey that polymer therapeutics make through the body, following the ADME (absorption, distribution, metabolism, excretion) concept. The biological factors and delivery system parameters that influence each stage of the process will be described, with examples illustrating the different solutions to the challenges of drug delivery systems in vivo.
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Amphiphilic tobramycin analogues with potent antibacterial activity against tobramycin‐resistant bacteria were synthesized. Most analogues were found to be less prone to deactivation by ...aminoglycoside‐modifying enzymes than tobramycin. These compounds target the bacterial membrane rather than the ribosome (see picture). The lipophilic residue of these analogues is key to their antibacterial potency and selectivity towards bacterial membranes.
Glioblastoma (GB) is the most lethal type of primary tumor in the central nervous system. Current treatments include surgical resection followed by chemotherapy and radiotherapy. With this ...therapeutic regimen, the median survival is less than two years. However, these treatments do not much improve the overall survival of GB patients. GBs are highly angiogenic and invasive tumors and often acquire resistance to therapy. The invasive nature of the disease limits the ability to achieve complete resection of the tumor and the majority of GB patients will experience disease relapse. Moreover, GB is highly heterogeneous, harboring different mutations and presenting different phenotypes. As the brain is considered to be an immune‐privileged tissue, GB is defined as a cold tumor for which current immunotherapies have not yet been demonstrated to improve survival. On top of these challenges, the blood brain barrier (BBB) restricts the uptake of drugs by the brain, thus limiting the therapeutic options. Therefore, enormous efforts are being dedicated to the development of novel nanomedicines, which will be able to cross the BBB and specifically target the cancer cells. Here, the current achievements in drug delivery and novel therapeutic approaches for GB therapy are discussed.
A comprehensive review is presented which describes the current achievements in nanomedicine and novel therapeutic approaches for glioblastoma. The illustration demonstrates the different nanotechnological platforms designed to cross the blood brain barrier and target glioblastoma cells specifically, alongside their surrounding supportive brain microenvironment stromal cells.
Cancer stem cells (CSC) form a specific population within the tumor that has been shown to have self-renewal and differentiation properties, increased ability to migrate and form metastases, and ...increased resistance to chemotherapy. Consequently, even a small number of cells remaining after therapy can repopulate the tumor and cause recurrence of the disease. CSCs in Wilms tumor, a pediatric renal cancer, were previously shown to be characterized by neural cell adhesion molecule (NCAM) expression. Therefore, NCAM provides a specific biomarker through which the CSC population in this tumor can be targeted. We have recently developed an NCAM-targeted nanosized conjugate of paclitaxel bound to a biodegradable polyglutamic acid polymer. In this work, we examined the ability of the conjugate to inhibit Wilms tumor by targeting the NCAM-expressing CSCs. Results show that the conjugate selectively depleted the CSC population of the tumors and effectively inhibited tumor growth without causing toxicity. We propose that the NCAM-targeted conjugate could be an effective therapeutic for Wilms tumor.
.
The Role of PEDF in Reproductive Aging of the Ovary Nemerovsky, Luba; Bar-Joseph, Hadas; Eldar-Boock, Anat ...
International journal of molecular sciences,
09/2022, Letnik:
23, Številka:
18
Journal Article
Recenzirano
Odprti dostop
Reproductive aging is characterized by a decline in ovarian function and in oocytes’ quantity and quality. Pigment epithelium-derived factor (PEDF), a pivotal player in ovarian angiogenic and ...oxidative balance, was evaluated for its involvement in reproductive aging. Our work examines the initial stage of reproductive aging in women and mice, and the involvement of PEDF in the process. Granulosa cells from reproductively-aged (RA) women and mice (36–44 years old and 9–10 months old, respectively) indicated an increase in the level of PEDF mRNA (qPCR), with yet unchanged levels of AMH and FSHR mRNAs. However, the PEDF protein level in individual women showed an intra-cellular decrease (ELISA), along with a decrease in the corresponding follicular fluid, which reflects the secreted fraction of the protein. The in vitro maturation (IVM) rate in the oocytes of RA mice was lower compared with the oocytes of young mice, demonstrated by a reduced polar body extrusion (PBE) rate. The supplementation of PEDF improved the hampered PBE rate, manifested by a higher number of energetically-competent oocytes (ATP concentration and mtDNA copy number of individual oocytes). Our findings propose PEDF as an early marker of reproductive aging, and a possible therapeutic in vitro agent that could enhance the number of good-quality oocytes in older IVF patients.
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