Protective effects of zoledronate after denosumab discontinuation

RESUMEN : Tras suspender el tratamiento con denosumab se produce un aumento de los marcadores bioquímicos de remodelado óseo por encima de los valores de partida, conocido como “efecto rebote”. Este se acompaña de una disminución de la densidad mineral ósea (DMO) y un aumento del riesgo de fracturas vertebrales, especialmente fracturas vertebrales múltiples. Se ha sugerido que la administración de fármacos antirresortivos podría prevenir este efecto rebote. Por tanto, hemos considerado importante verificar que la administración de antirresortivos tras la suspensión de denosumab previene realmente el incremento de los marcadores de remodelado óseo. Describimos los casos de trece pacientes con osteoporosis que habían recibido denosumab durante más de cuatro años. Aproximadamente 6 meses después de la última inyección de denosumab recibieron una infusión intravenosa de 5 mg de ácido zoledrónico, fármaco escogido por su elevada potencia y su posología. Fueron seguidos durante un periodo de dos años, en el que ninguno presentó fracturas clínicas. Además, ningún valor de CTX ni la DMO en la columna lumbar sobrepasó su nivel basal correspondiente en ningún momento. Por tanto, como resultado de nuestro estudio, podemos decir que una infusión de zoledronato tras la suspensión de denosumab parece prevenir adecuadamente el fenómeno rebote.ABSTRACT : Discontinuation of denosumab results in a marked increase in bone turnover markers (BTM) above baseline, known as “rebound phenomenon”. This is accompanied by a decrease in bone mineral density (BMD) and an increase in the risk of vertebral fractures, particularly multiple vertebral fractures. It has been suggested that the administration of antiresorptive drugs could prevent the turnover rebound. Therefore, we have considered important to verify that the administration of antiresorptives after denosumab discontinuation certainly prevents the rebound of BTM. We report here a case series of thirteen patients with osteoporosis who had received denosumab for more than four years. Approximately 6 months after the last denosumab injection, they were given a single infusion of zoledronate (5 mg), drug chosen due to its potency and posology. They were followed-up for over a two-year period, in which none of them presented any clinical fractures. Furthermore, no single value of CTX nor lumbar spine BMD surpassed their corresponding baseline at any time. So, as a result of our study we can confirm that an injection of zoledronate at denosumab discontinuation seems to adequately prevent the rebound phenomenon.Grado en Medicin

Drug-Loaded Hydrogels for Intraocular Lenses with Prophylactic Action against Pseudophakic Cystoid Macular Edema

Pseudophakic cystoid macular edema (PCME), caused by chronic inflammation, is the most common cause of visual impairment in the medium-term after cataract surgery. Therefore, the prophylactic topical administration of combined steroidal and non-steroidal anti-inflammatory drugs is commonly done. Drug-eluting intraocular lenses (IOLs) gained interest as an efficient way to overcome the compliance issues related to the use of ocular drops without the need for additional surgical steps. The incorporation of functional monomers and molecular imprinting were herein applied to design hydrogels suitable as IOLs and able to co-deliver steroidal (dexamethasone sodium phosphate) and non-steroidal (bromfenac sodium) drugs. The incorporation of N-(2-aminopropyl) methacrylamide (APMA) increased the drug uptake and improved the in vitro release kinetics. Imprinting with bromfenac resulted in a decreased drug release due to permanent drug bonding, while imprinting with dexamethasone increased the amount of dexamethasone released after dual-drug loading. The application of a mathematical model to predict the in vivo drug release behavior suggests the feasibility of achieving therapeutic drug concentrations of bromfenac and dexamethasone in the aqueous humor for about 2 and 8 weeks, respectively, which is compatible with the current topical prophylaxis after cataract surgeryThis project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement N° 813440 (OR-BITAL—Ocular Research by Integrated Training and Learning) and is also supported by Fundação para a Ciência e Tecnologia (FCT) [UID/QUI/00100/2019, UIDB/00100/2020, and UID/BIM/04585/2020].S

MK2 degradation as a sensor of signal intensity that controls stress-induced cell fate

Cell survival in response to stress is determined by the coordination of various signaling pathways. The kinase p38 alpha is activated by many stresses, but the intensity and duration of the signal depends on the stimuli. How different p38 alpha-activation dynamics may impact cell life/death decisions is unclear. Here, we show that the p38 alpha signaling output in response to stress is modulated by the expression levels of the downstream kinase MK2. We demonstrate that p38 alpha forms a complex with MK2 in nonstimulated mammalian cells. Upon pathway activation, p38 alpha phosphorylates MK2, the complex dissociates, and MK2 is degraded. Interestingly, transient p38 alpha activation allows MK2 reexpression, reassembly of the p38 alpha-MK2 complex, and cell survival. In contrast, sustained p38 alpha activation induced by severe stress interferes with p38 alpha-MK2 interaction, resulting in irreversible MK2 loss and cell death. MK2 degradation is mediated by the E3 ubiquitin ligase MDM2, and we identify four lysine residues in MK2 that are directly ubiquitinated by MDM2. Expression of an MK2 mutant that cannot be ubiquitinated by MDM2 enhances the survival of stressed cells. Our results indicate that MK2 reexpression and binding to p38 alpha is critical for cell viability in response to stress and illustrate how particular p38 alpha-activation patterns induced by different signals shape the stress-induced cell fate

Essential role of the Cdk2 activator RingoA in meiotic telomere tethering to the nuclear envelope

Cyclin-dependent kinases (CDKs) play key roles in cell cycle regulation. Genetic analysis in mice has revealed an essential role for Cdk2 in meiosis, which renders Cdk2 knockout (KO) mice sterile. Here we show that mice deficient in RingoA, an atypical activator of Cdk1 and Cdk2 that has no amino acid sequence homology to cyclins, are sterile and display meiotic defects virtually identical to those observed in Cdk2 KO mice including non-homologous chromosome pairing, unrepaired double-strand breaks, undetectable sex-body and pachytene arrest. Interestingly, RingoA is required for Cdk2 targeting to telomeres and RingoA KO spermatocytes display severely affected telomere tethering as well as impaired distribution of Sun1, a protein essential for the attachment of telomeres to the nuclear envelope. Our results identify RingoA as an important activator of Cdk2 at meiotic telomeres, and provide genetic evidence for a physiological function of mammalian Cdk2 that is not dependent on cyclins

A topical microemulsion for the prevention of allergic rhinitis symptoms: results of a randomized, controlled, double-blind, parallel group, multicentre, multinational clinical trial (Nares study)

Background: Since barrier protection measures to avoid contact with allergens are being increasingly developed, we assessed the clinical efficacy and tolerability of a topical nasal microemulsion made of glycerol esters in patients with allergic rhinitis. Methods: Randomized, controlled, double-blind, parallel group, multicentre, multinational clinical trial in which adult patients with allergic rhinitis or rhinoconjunctivitis due to sensitization to birch, grass or olive tree pollens received treatment with topical microemulsion or placebo during the pollen seasons. Efficacy variables included scores in the mini-RQLQ questionnaire, number and severity of nasal, ocular and lung signs and symptoms, need for symptomatic medications and patients" satisfaction with treatment. Adverse events were also recorded. Results: Demographic characteristics were homogeneous between groups and mini-RQLQ scores did not differ significantly at baseline (visit 1). From symptoms recorded in the diary cards, the ME group showed statistically significant better scores for nasal congestion (0.72 vs. 1.01; p = 0.017) and mean total nasal symptoms (0.7 vs. 0.9; p = 0.045). At visit 2 (pollen season), lower values were observed in the mini-RQLQ in the ME group, although there were no statistically significant differences between groups in both full analysis set (FAS) and patients completing treatment (PPS) populations. The results obtained in the nasal symptoms domain of the mini-RQLQ at visit 2 showed the highest difference (−0.43; 95% CI: -0.88 to 0.02) for the ME group in the FAS population. The topical microemulsion was safe and well tolerated and no major discomforts were observed. Satisfaction rating with the treatment was similar between the groups. Conclusions: The topical application of the microemulsion is a feasible and safe therapy in the prevention of allergic symptoms, particularly nasal congestion

Anemia y gammapatía oligoclonal en paciente con síndrome nefrótico

Visceral leishmaniasis is the most severe form of presentation of Leishmania infection. It is a multisystemic disease that often affects immunosuppressed patients. We present a case of a 72-year-old woman in chronic immunosuppressive therapy with steroids and cyclosporine who debuts with weight loss, asthenia, atypical pneumonia, splenomegaly, and polyclonal hypergammaglobulinemia with the diagnosis of visceral leishmaniasis and amastigotes of Leishmania in the bone marrowLa leishmaniasis visceral es la forma de presentación más grave de la infección por Leishmania, se trata de una enfermedad multisistémica que afecta más frecuentemente a pacientes inmunodeprimidos. A continuación, presentamos un caso de una paciente de 72 años en tratamiento inmunosupresor crónico con corticoides y ciclosporina que debuta con pérdida de peso, astenia, neumonía atípica, esplenomegalia e hipergammaglobulinemia policlonal con diagnóstico de leishmaniasis visceral, al objetivarse en el aspirado de médula ósea amastigotes de Leishmania

Multi-phosphorylation of the intrinsically disordered unique domain of c-Src studied by in-cell and real-time NMR

Intrinsically disordered regions (IDRs) are preferred sites for post-translational modifications essential for regulating protein function. The enhanced local mobility of IDRs facilitates their observation by NMR spectroscopy in vivo. Phosphorylation events can occur at multiple sites and respond dynamically to changes in kinase-phosphatase networks. Here we used real-time NMR spectroscopy to study the effect of kinases and phosphatases present in Xenopus oocytes and egg extracts on the phosphorylation state of the 'unique domain' of c-Src. We followed the phosphorylation of S17 in oocytes, and of S17, S69, and S75 in egg extracts by NMR spectroscopy, MS, and western blotting. Addition of specific kinase inhibitors showed that S75 and S69 are phosphorylated by CDKs (cyclin-dependent kinases) differently from Cdk1. Moreover, although PKA (cAMP-dependent protein kinase) can phosphorylate S17 in vitro, this was not the major S17 kinase in egg extracts. Changes in PKA activity affected the phosphorylation levels of CDK-dependent sites, thus suggesting indirect effects of kinase-phosphatase networks. This study provides a proof-of-concept of the use of real-time in vivo NMR spectroscopy to characterize kinase/phosphatase effects on intrinsically disordered regulatory domains

Quantification of pathway crosstalk reveals novel synergistic drug combinations for breast cancer

Combinatorial therapeutic approaches are an imperative to improve cancer treatment, because it is critical to impede compensatory signaling mechanisms that can engender drug resistance to individual targeted drugs. Currently approved drug combinations result largely from empirical clinical experience and cover only a small fraction of a vast therapeutic space. Here we present a computational network biology approach, based on pathway cross-talk inhibition, to discover new synergistic drug combinations for breast cancer treatment. In silico analysis identified 390 novel anticancer drug pairs belonging to 10 drug classes that are likely to diminish pathway cross-talk and display synergistic antitumor effects. Ten novel drug combinations were validated experimentally, and seven of these exhibited synergy in human breast cancer cell lines. In particular, we found that one novel combination, pairing the estrogen response modifier raloxifene with the c-Met/VEGFR2 kinase inhibitor cabozantinib, dramatically potentiated the drugs' individual antitumor effects in a mouse model of breast cancer. When compared with high-throughput combinatorial studies without computational prioritization, our approach offers a significant advance capable of uncovering broad-spectrum utility across many cancer types

Local delivery of optimized nanobodies targeting the PD-1/PD-L1 axis with a self-amplifying RNA viral vector induces potent antitumor responses

Despite the success of immune checkpoint blockade for cancer therapy, many patients do not respond adequately. We aimed to improve this therapy by optimizing both the antibodies and their delivery route, using small monodomain antibodies (nanobodies) delivered locally with a self-amplifying RNA (saRNA) vector based on Semliki Forest virus (SFV). We generated nanobodies against PD-1 and PD-L1 able to inhibit both human and mouse interactions. Incorporation of a dimerization domain reduced PD-1/PD-L1 IC50 by 8- and 40-fold for antiPD-L1 and anti-PD-1 nanobodies, respectively. SFV viral particles expressing dimeric nanobodies showed a potent antitumor response in the MC38 model, resulting in >50% complete regressions, and showed better therapeutic efficacy compared to vectors expressing conventional antibodies. These effects were also observed in the B16 melanoma model. Although a short-term expression of nanobodies was observed due to the cytopathic nature of the saRNA vector, it was enough to generate a strong proinflammatory response in tumors, increasing infiltration of NK and CD8+ T cells. Delivery of the SFV vector expressing dimeric nanobodies by local plasmid electroporation, which could be more easily translated to the clinic, also showed a potent antitumor effect