RESUMEN
Purpose: Exosomes are membrane vesicles secreted by various cells and play a crucial role in intercellular communication. They can be excellent delivery vehicles for oligonucleotide drugs, such as microRNAs, due to their high biocompatibility. MicroRNAs have been shown to be more stable when incorporated into exosomes; however, the lack of targeting and immune evasion is still the obstacle to the use of these microRNA-containing nanocarriers in clinical settings. Our goal was to produce functional exosomes loaded with target ligands, immune evasion ligand, and oligonucleotide drug through genetic engineering in order to achieve more precise medical effects. Methods: To address the problem, we designed engineered exosomes with exogenous cholecystokinin (CCK) or somatostatin (SST) as the targeting ligand to direct the exosomes to the brain, as well as transduced CD47 proteins to reduce the elimination or phagocytosis of the targeted exosomes. MicroRNA-29b-2 was the tested oligonucleotide drug for delivery because our previous research showed that this type of microRNA was capable of reducing presenilin 1 (PSEN1) gene expression and decreasing the ß-amyloid accumulation for Alzheimer's disease (AD) in vitro and in vivo. Results: The engineered exosomes, containing miR29b-2 and expressing SST and CD47, were produced by gene-modified dendritic cells and used in the subsequent experiments. In comparison with CD47-CCK exosomes, CD47-SST exosomes showed a more significant increase in delivery efficiency. In addition, CD47-SST exosomes led to a higher delivery level of exosomes to the brains of nude mice when administered intravenously. Moreover, it was found that the miR29b-2-loaded CD47-SST exosomes could effectively reduce PSEN1 in translational levels, which resulted in an inhibition of beta-amyloid oligomers production both in the cell model and in the 3xTg-AD animal model. Conclusion: Our results demonstrated the feasibility of the designed engineered exosomes. The application of this exosomal nanocarrier platform can be extended to the delivery of other oligonucleotide drugs to specific tissues for the treatment of diseases while evading the immune system.
Asunto(s)
Enfermedad de Alzheimer , Péptidos beta-Amiloides , Encéfalo , Antígeno CD47 , Exosomas , MicroARNs , Presenilina-1 , Receptores de Somatostatina , Animales , Exosomas/metabolismo , Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/genética , MicroARNs/genética , MicroARNs/administración & dosificación , Presenilina-1/genética , Encéfalo/metabolismo , Receptores de Somatostatina/genética , Receptores de Somatostatina/metabolismo , Péptidos beta-Amiloides/metabolismo , Ratones , Antígeno CD47/genética , Antígeno CD47/metabolismo , Somatostatina , Humanos , Modelos Animales de EnfermedadRESUMEN
Two novel lanthanide mercury materials, [Gd(IA)3(H3O)2Hg3Br6]n·2nCl (1) and [La(IA)3(H3O)2Hg3Br6]n·2nCl (2) (IA = isonicotinic anion), have been prepared under solvothermal conditions and characterized by single-crystal X-ray diffraction techniques. They are isomorphic and characterized by a three-dimensional (3-D) framework structure. The lanthanide ions are bound by eight oxygen atoms to exhibit a square antiprismatic geometry. The solid-state photoluminescence experiment discovers that compound 1 shows a strong emission in the red region. Compound 1 possesses CIE (Commission Internationale de I'Éclairage) chromaticity coordinates of 0.7347 and 0.2653. Its CCT (correlated color temperature) is 6514 K. Compound 2 displays yellow photoluminescence and it has CIE chromaticity coordinates of 0.4411 and 0.5151. The CCT of compound 2 is 3633 K. Solid-state UV/Vis diffuse reflectance spectra revealed that their semiconductor band gaps are 2.16 eV and 2.85 eV, respectively.
RESUMEN
Although mechanical loading is essential for maintaining bone health and combating osteoporosis, its practical application is limited to a large extent by the high variability in bone mechanoresponsiveness. Here, we found that gut microbial depletion promoted a significant reduction in skeletal adaptation to mechanical loading. Among experimental mice, we observed differences between those with high and low responses to exercise with respect to the gut microbial composition, in which the differential abundance of Lachnospiraceae contributed to the differences in bone mechanoresponsiveness. Microbial production of L-citrulline and its conversion into L-arginine were identified as key regulators of bone mechanoadaptation, and administration of these metabolites enhanced bone mechanoresponsiveness in normal, aged, and ovariectomized mice. Mechanistically, L-arginine-mediated enhancement of bone mechanoadaptation was primarily attributable to the activation of a nitric-oxide-calcium positive feedback loop in osteocytes. This study identifies a promising anti-osteoporotic strategy for maximizing mechanical loading-induced skeletal benefits via the microbiota-metabolite axis.
Asunto(s)
Arginina , Huesos , Microbioma Gastrointestinal , Ratones Endogámicos C57BL , Animales , Arginina/metabolismo , Ratones , Femenino , Huesos/metabolismo , Adaptación Fisiológica , Osteocitos/metabolismoRESUMEN
Knowledge about the effect of different prostate biopsy approaches on the prostate cancer detection rate (CDR) in patients with gray-zone prostate-specific antigen (PSA) is limited. We performed this study to compare the CDR among patients who underwent different biopsy approaches and had rising PSA levels in the gray zone. Two hundred and twenty-two patients who underwent transrectal prostate biopsy (TRB) and 216 patients who underwent transperineal prostate biopsy (TPB) between June 2016 and September 2022 were reviewed in this study. In addition, 110 patients who received additional targeted biopsies following the systematic TPB were identified. Clinical parameters, including age, PSA derivative, prostate volume (PV), and needle core count, were recorded. The data were fitted via propensity score matching (PSM), adjusting for potential confounders. TPB outperformed TRB in terms of the CDR (49.6% vs 28.3%, P = 0.001). The clinically significant prostate cancer (csPCa) detection rate was not significantly different between TPB and TRB (78.6% vs 68.8%, P = 0.306). In stratified analysis, TPB outperformed TRB in CDR when the age of patients was 65-75 years (59.0% vs 22.0%, P < 0.001), when PV was 25.00-50.00 ml (63.2% vs 28.3%, P < 0.001), and when needle core count was no more than 12 (58.5% vs 31.5%, P = 0.005). The CDR ( P = 0.712) and detection rate of csPCa ( P = 0.993) did not significantly differ among the systematic, targeted, and combined biopsies. TPB outperformed TRB in CDR for patients with gray-zone PSA. Moreover, performing target biopsy after systematic TPB provided no additional benefits in CDR.
Asunto(s)
Antígeno Prostático Específico , Próstata , Neoplasias de la Próstata , Humanos , Masculino , Neoplasias de la Próstata/patología , Neoplasias de la Próstata/sangre , Neoplasias de la Próstata/diagnóstico , Antígeno Prostático Específico/sangre , Anciano , Persona de Mediana Edad , Próstata/patología , Perineo , Estudios Retrospectivos , Biopsia/métodos , Recto/patología , Biopsia con Aguja Gruesa/métodos , Biopsia Guiada por Imagen/métodosRESUMEN
Key Clinical Message: In a patient with metastatic breast cancer, an acquired BRCA mutation in the BRCA gene was detected, resulting in benefits from olaparib treatment. This underscores the importance of ongoing genetic phenotype testing after paclitaxel chemotherapy. Abstract: Triple-negative breast cancer (TNBC) is associated with a poor prognosis and elevated mortality risk. BRCA mutations are commonly regarded as prevalent mutations in TNBC patients, strongly associated with congenital familial heredity. Dynamic changes in mutation sites, however, are rarely reported. In this case report, we report a 59-year-old TNBC patient who developed pulmonary metastases post-chemoradiotherapy. No BRCA mutations were detected through NGS. After 7.6 months of nab-paclitaxel treatment, the patient experienced progression of lung metastases, and BRCA mutations were detected through NGS testing. Subsequent administration of olaparib resulted in a reduction in lung metastasis, demonstrating significant therapeutic efficacy. This case underscores the infrequent occurrence of treatment-induced BRCA mutations and emphasizes the significance of dynamic NGS genetic testing for real-time assessment of a patient's mutational status.
RESUMEN
Background: The Scn3b gene encodes for Navß3, a pivotal regulatory subunit of the fast sodium channel in cardiomyocytes. However, its mutation status in the Chinese population suffering from Brugada Syndrome (BrS) has not been characterized, and the contributory pathophysiological mechanisms to disease pathology remain undefined. Methods and Results: A Scn3b (c.260C>T, p.P87l) mutation was identified in a patient with BrS of Chinese descent. Functional analyses demonstrated that sodium channel activation for the wild type, mutant samples, and co-expression of both commenced at -55â mv and peaked at -25â mv. The mutant group exhibited a notable reduction, approximately 60%, in peak sodium channel activation current (INa) at -25â mv. The parameters for half-maximal activation voltages (V1/2) and slope factors (k) showed no significant differences when comparing wild type, mutant, and combined expression groups (P = 0.98 and P = 0.65, respectively). Additionally, no significant disparities were evident in terms of the steady-state sodium channel inactivation parameters V1/2 and k (with P-values of 0.85 and 0.25, respectively), nor were there significant differences in the activation time constant τ (P = 0.59) and late sodium current density (P = 0.23) across the wild-type, mutant, and co-expressed groups. Confocal imaging and Western blot analysis demonstrated decreased plasma membrane localization of SCN3B and SCN5A in the P87l group. Computational simulations of cardiac action potentials suggested that SCN3B P87l can alter the morphology of the action potentials within the endocardium and epicardium while reducing the peak of depolarization. Conclusions: The pathogenic impact of the Scn3b P87l mutation predominantly originates from a reduction in peak INa activation current coupled with decreased cell surface expression of Nav1.5 and Navß3. These alterations may influence cardiac action potential configurations and contribute to the risk of ventricular arrhythmias in individuals with BrS.
RESUMEN
Type 2 diabetes (T2D)-related fragility fractures represent an increasingly tough medical challenge, and the current treatment options are limited. Mechanical loading is essential for maintaining bone integrity, although bone mechano-responsiveness in T2D remains poorly characterized. Herein, we report that exogenous cyclic loading-induced improvements in bone architecture and strength are compromised in both genetically spontaneous and experimentally-induced T2D mice. T2D-induced reduction in bone mechano-responsiveness is directly associated with the weakened Ca2+ oscillatory dynamics of osteocytes, although not those of osteoblasts, which is dependent on PPARα-mediated specific reduction in osteocytic SERCA2 pump expression. Treatment with the SERCA2 agonist istaroxime was demonstrated to improve T2D bone mechano-responsiveness by rescuing osteocyte Ca2+ dynamics and the associated regulation of osteoblasts and osteoclasts. Moreover, T2D-induced deterioration of bone mechano-responsiveness is blunted in mice with osteocytic SERCA2 overexpression. Collectively, our study provides mechanistic insights into T2D-mediated deterioration of bone mechano-responsiveness and identifies a promising countermeasure against T2D-associated fragility fractures.
Asunto(s)
Diabetes Mellitus Tipo 2 , Osteocitos , Animales , Ratones , Huesos , Calcio/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Osteoblastos/metabolismo , Osteocitos/metabolismoRESUMEN
Acute liver injury (ALI) is a complex, life-threatening inflammatory liver disease, and persistent liver damage leads to rapid decline and even failure of liver function. However, the pathogenesis of ALI is still not fully understood, and no effective treatment has been discovered. Recent evidence shows that many circular RNAs (circRNAs) are associated with the occurrence of liver diseases. In this study we investigated the mechanisms of occurrence and development of ALI in lipopolysaccharide (LPS)-induced ALI mice. We found that expression of the circular RNA circDcbld2 was significantly elevated in the liver tissues of ALI mice and LPS-treated RAW264.7 cells. Knockdown of circDcbld2 markedly alleviates LPS-induced inflammatory responses in ALI mice and RAW264.7 cells. We designed and synthesized a series of hesperidin derivatives for circDcbld2, and found that hesperetin derivative 2a (HD-2a) at the concentrations of 2, 4, 8 µM effectively inhibited circDcbld2 expression in RAW264.7 cells. Administration of HD-2a (50, 100, 200 mg/kg. i.g., once 24 h in advance) effectively relieved LPS-induced liver dysfunction and inflammatory responses. RNA sequencing analysis revealed that the anti-inflammatory and hepatoprotective effects of HD-2a were mediated through downregulating circDcbld2 and suppressing the JAK2/STAT3 pathway. We conclude that HD-2a downregulates circDcbld2 to inhibit the JAK2/STAT3 pathway, thereby inhibiting the inflammatory responses in ALI. The results suggest that circDcbld2 may be a potential target for the prevention and treatment of ALI, and HD-2a may have potential as a drug for the treatment of ALI.
Asunto(s)
Lesión Pulmonar Aguda , Hesperidina , Animales , Ratones , Lipopolisacáridos/farmacología , Hesperidina/efectos adversos , Regulación hacia Abajo , Lesión Pulmonar Aguda/inducido químicamente , Lesión Pulmonar Aguda/tratamiento farmacológico , Lesión Pulmonar Aguda/metabolismo , Hígado/metabolismoRESUMEN
OBJECTIVE: Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune-mediated disorder with aquaporin 4-immunoglobulin G (AQP4-IgG) in most settings. Soluble programmed death-1 (sPD-1) and soluble programmed death ligand 1 (sPD-L1) play key roles in immunomodulation. We aim to assess the association of sPD-1 and sPD-L1 with cytokines and their clinical significance in AQP4-IgG (+) NMOSD. METHOD: We measured plasma sPD-1, sPD-L1, and 10 cytokines levels of 66 AQP4-IgG (+) NMOSD patients, including 40 patients in attack (attack-NMOSD) and 26 patients in remission (remission-NMOSD) phases, and 28 healthy controls through ultrasensitive Simoa and SP-X platform, respectively. We also performed >2 years (median) of follow-up after testing and analyzed the relationship between the detection index and current and future clinical parameters. RESULT: Plasma sPD-1 level discriminated attack-NMOSD from remission-NMOSD (AUC = 0.692, p = 0.009). sPD-1 and sPD-L1 levels positively correlated with IL-6 (rsPD-1 = 0.313; rsPD-L1 = 0.508), IFN-γ (rsPD-1 = 0.331; rsPD-L1 = 0.456), and TNF-α (rsPD-1 = 0.451; rsPD-L1 = 0.531) expression, as well as clinical indicators, including the EDSS score (rsPD-1 = 0.331; rsPD-L1 = 0.402), number of attacks (rsPD-1 = 0.431) and segments of spinal cord involvement (rsPD-1 = 0.462; rsPD-L1 = 0.508). The risk of relapse within 2 years after sampling was associated with higher sPD-1/sPD-L1 ratio in attack-NMOSD (p = 0.022; Exp(B) = 1.589). INTERPRETATION: Plasma sPD-1 and sPD-L1 levels reflected current disease severity and activity, and predicted future relapses in AQP4-IgG (+) NMOSD, suggesting that they hold the potential to guide timely and targeted treatment.
Asunto(s)
Neuromielitis Óptica , Humanos , Acuaporina 4 , Inmunoglobulina G , Antígeno B7-H1 , Citocinas , Enfermedad CrónicaRESUMEN
BACKGROUND: COVID-19 caused by SARS-CoV-2 is a great threat to public health. We present the safety and immunogenicity data from a phase I trial in China of an mRNA vaccine (LVRNA009). METHODS: In the single-centre, double-blind, placebo-controlled and dose-escalation study, 72 healthy unvaccinated adults aged 18-59 years were randomized (3:1) to receive LVRNA009 with one of three vaccine dosage (25, 50 and 100 µg) or placebo, to evaluate for the safety, tolerability and immunogenicity of LVRNA009. RESULTS: All these participants received two injections 28 days apart. No adverse events higher than grade 2 were reported during the study. A total of 30 participants (42 %) reported solicited adverse reactions during the first 14 days after vaccinations. Of the events reported, fever (n = 11, 15 %) was the most common systemic adverse reaction, and pain at the injection site (n = 17, 24 %) was the most frequent solicited local adverse reaction. Anti-S-protein IgG and neutralising antibodies were observed to have been induced 14 days after the first dose, significantly increased 7 days after the second dose, and remained at a high level 28 days after the second dose. Specific T-cell responses peaked 7 days and persisted 28 days after second vaccination. CONCLUSION: LVRNA009 has demonstrated promising results in safety and tolerability at all three dose levels among Chinese adults. LVRNA009 at three dose levels could rapidly induce strong humoral and cellular immune responses, including binding and neutralising antibody production and IFN- γ secretion, which showed good immunogenicity. CLINICAL TRIAL REGISTRATION NUMBER: Clinicaltrials.gov NCT05364047; Chictr.org.cn ChiCTR2100049349.
Asunto(s)
Vacunas contra la COVID-19 , COVID-19 , Adulto , Humanos , Anticuerpos Neutralizantes , Anticuerpos Antivirales , COVID-19/prevención & control , Vacunas contra la COVID-19/uso terapéutico , Método Doble Ciego , Pueblos del Este de Asia , Inmunogenicidad Vacunal , SARS-CoV-2 , Vacunas de ARNmRESUMEN
Bone stress injuries are common overuse injuries, especially in soldiers, athletes, and performers. In contrast to various post-injury treatments, early protection against bone stress injuries can provide greater benefit. This study explored the early protection strategies against bone stress injuries by mobilization of endogenous targeted bone remodeling. The effects of various pharmaceutical/biophysical approaches, individual or combinational, were investigated by giving intervention before fatigue loading. We optimized the dosage and administration parameters and found that early intervention with pulsed electromagnetic field and parathyroid hormone (i.e., PEMF+PTH) resulted in the most pronounced protective effects among all the approaches against the bone stress injuries. In addition, the mechanisms by which the strategy mobilizes targeted bone remodeling and enhances the self-repair capacity of bone were systematically investigated. This study proposes strategies to reduce the incidence of bone stress injuries in high-risk populations (e.g., soldiers and athletes), particularly for those before sudden increased physical training.
RESUMEN
INTRODUCTION: Contrast-induced encephalopathy (CIE) is a rare complication associated with the use of contrast media. New contrast agents make contrast complications increasingly rare. The diagnosis of CIE is challenging, particularly in patients with acute ischemic stroke. Neuroimaging results for patients with CIE can also be highly variable. PATIENT CONCERNS: A 63-year-old man with severe internal carotid artery stenosis who experienced several symptoms, including dizziness, nausea, vomiting, fever, and blurred vision after being administered the contrast agent iodixanol. DIAGNOSES: Multiple CT and MRI brain scans were performed. After excluding other differential diagnoses such as electrolytes imbalance, hypo/hyperglycemia and other neurological emergencies such as cerebral hemorrhage, cerebral infarction, the final diagnosis of CIE was made. INTERVENTION: Treatment consisted of adequate hydration, intravenous dexamethasone, mannitol, and anticonvulsants. OUTCOME: The patient demonstrated progressive neurological improvement, and recovered from all symptoms on the fifth day. Follow-up at 3 months shows a good prognosis for patients. CONCLUSION: Patients with CIE may have a high signal on diffusion-weighted imaging and a low signal on apparent diffusion coefficient brain MRI. This is similar to the MRI findings in acute stroke. This needs to be distinguished from acute cerebral infarction and suggests that we should closely monitor patients' neurological symptoms at the time of cerebral angiography and after the investigations.
Asunto(s)
Accidente Cerebrovascular Isquémico , Accidente Cerebrovascular , Masculino , Humanos , Persona de Mediana Edad , Angiografía Cerebral , Accidente Cerebrovascular/diagnóstico , Imagen por Resonancia Magnética/métodos , Infarto Cerebral/diagnóstico por imagen , Infarto Cerebral/etiologíaRESUMEN
Experimental autoimmune encephalomyelitis (EAE) is an induced autoimmune disease widely used as an animal model for multiple sclerosis, which is mainly characterized by demyelination, axonal loss, as well as neurodegeneration of central nervous system (CNS). T-helper (Th) 17 cell that generate interleukin-17 (IL-17) plays a key role in its pathogenesis. Their activity and differentiation are tightly regulated by some cytokines and transcription factors. Certain microRNAs (miRNAs) are involved in the pathogenesis of various autoimmune disorders, including EAE. Our research detected a novel miRNA that can regulate EAE. According to the results, during EAE, the expression of miR-485 notably lowered, and STAT3 was significantly increased. It was discovered that miR-485 knockdown in vivo upregulated Th17-associated cytokines and aggravated EAE, while the overexpressed miR-485 down-regulated Th17-associated cytokines and mitigated EAE. The up-regulation of miRNA-485 in vitro inhibited Th17-associated cytokines expression within EAE CD4+ T cells. Furthermore, as revealed by target prediction and dual-luciferase reporter assays, miR-485 directly targets STAT3, a gene that encodes a protein responsible for Th17 generation. Overall, miR-485 exert vital functions in Th17 generation and EAE pathogenesis.
Asunto(s)
Encefalomielitis Autoinmune Experimental , MicroARNs , Esclerosis Múltiple , Animales , Ratones , Diferenciación Celular , Sistema Nervioso Central/patología , Citocinas , Ratones Endogámicos C57BL , Células Th17 , Factor de Transcripción STAT3RESUMEN
OBJECTIVES: The vesicoprostatic muscle (VPM) is a longitudinal smooth muscle that originates from the trigone of the bladder or the opening of the ureter and is involved in urination as part of the detrusor apron. We explored the effect of VPM reconstruction on immediate and early recovery of urinary continence in patients undergoing robot-assisted laparoscopic radical prostatectomy (RALP). PATIENTS AND METHODS: A total of 523 patients with localized prostate cancer were enrolled from June 2018 to June 2020. All patients were diagnosed in our department based on magnetic resonance imaging and pathological findings on prostate biopsy. After 1:1 propensity score matching, 105 patient pairs were matched. The study was approved by our institutional review board and all surgeries were performed by three experienced high-volume surgeons. Demographic data, total operation time, pathological outcomes, the urinary continence rates of the two groups at different times after RALP, and factors influencing postoperative urinary continence after RALP were recorded. Student's t test was used to compare continuous variables and the Pearson χ2 test to compare categorical variables. Logistic regression analysis was used to identify factors affecting immediate and early postoperative urinary control. RESULTS: VPM reconstruction promoted immediate and early recovery of urinary continence (immediate continence, 66.67 vs. 40.00%, P = 0.000; 3-month continence, 80.95 vs. 64.76%, P = 0.008). CONCLUSIONS: VPM reconstruction improved immediate and early urinary continence in patients who underwent RALP.
Asunto(s)
Laparoscopía , Neoplasias de la Próstata , Procedimientos Quirúrgicos Robotizados , Masculino , Humanos , Procedimientos Quirúrgicos Robotizados/métodos , Micción , Próstata/patología , Neoplasias de la Próstata/cirugía , Neoplasias de la Próstata/patología , Prostatectomía/métodos , Músculos , Recuperación de la Función , Laparoscopía/métodosRESUMEN
In lieu of large bioequivalence studies and exposing healthy postmenopausal women to additional drug exposure for elagolix coadministered with hormonal add-back therapy, physiologically based pharmacokinetic (PBPK) modeling was used with in vitro dissolution data to test for virtual bioequivalence. For endometriosis, elagolix is approved at doses of 150 mg once daily and 200 mg twice daily as a tablet. As a combination therapy, two individual tablets, consisting of an elagolix tablet and an estradiol/norethindrone acetate 1/0.5 mg (E2/NETA) tablet, were utilized in Phase 3 endometriosis trials. However, the commercial combination drug products consist of a morning capsule (containing an elagolix tablet and E2/NETA tablet as a fixed-dose combination capsule, AM capsule) and an evening capsule (consisting of an elagolix tablet, PM capsule). In vitro dissolution profiles were dissimilar for the tablet and capsule formulations; thus, in vivo bioequivalence studies or a bioequivalence waiver would have been required. To simulate virtual cross-over, bioequivalence trials, in vitro dissolution data was incorporated into a previously verified PBPK model. The updated PBPK model was externally validated using relevant bioequivalence study data. Based on results of the virtual bioequivalence simulations, the commercial drug product capsules met the bioequivalence criteria of 0.80-1.25 when compared to the reference tablets. This was a novel example where PBPK modeling was utilized along with in vitro dissolution data to demonstrate virtual bioequivalence in support of a regulatory bioequivalence waiver.
Asunto(s)
Endometriosis , Humanos , Femenino , Equivalencia Terapéutica , Composición de Medicamentos , ComprimidosRESUMEN
Chronic high-altitude hypoxia induces irreversible abnormalities in various organisms. Emerging evidence indicates that hypobaric hypoxia markedly suppresses bone mass and bone strength. However, few effective means have been identified to prevent such bone deficits. Here, we assessed the potential of pulsed electromagnetic fields (PEMFs) to noninvasively resist bone deterioration induced by hypobaric hypoxia. We observed that exogenous PEMF treatment at 15 Hz and 20 Gauss (Gs) improved the cancellous and cortical bone mass, bone microstructure, and skeletal mechano-properties in rats subjected to chronic exposure of hypobaric hypoxia simulating an altitude of 4500 m for 6 weeks by primarily modulating osteoblasts and osteoblast-mediated bone-forming activity. Moreover, our results showed that whereas PEMF stimulated the functional activity of primary osteoblasts in hypoxic culture in vitro, it had negligible effects on osteoclasts and osteocytes exposed to hypoxia. Mechanistically, the primary cilium was found to function as the major electromagnetic sensor in osteoblasts exposed to hypoxia. The polycystins PC-1/PC-2 complex was identified as the primary calcium channel in the primary cilium of hypoxia-exposed osteoblastic cells responsible for the detection of external PEMF signals, and thereby translated these biophysical signals into intracellular biochemical events involving significant increase in the intracellular soluble adenylyl cyclase (sAC) expression and subsequent elevation of cyclic adenosine monophosphate (cAMP) concentration. The second messenger cAMP inhibited the transcription of oxygen homeostasis-related hypoxia-inducible factor 1-alpha (HIF-1α), and thus enhanced osteoblast differentiation and improved bone phenotype. Overall, the present study not only advances our understanding of bone physiology at high altitudes, but more importantly, proposes effective means to ameliorate high altitude-induced bone loss in a noninvasive and cost-effective manner. © 2023 American Society for Bone and Mineral Research (ASBMR).
Asunto(s)
Mal de Altura , Ratas , Animales , Mal de Altura/metabolismo , Campos Electromagnéticos , Cilios , Huesos , Hipoxia/complicaciones , Hipoxia/metabolismo , Osteoblastos/metabolismo , AMP Cíclico/metabolismoRESUMEN
Disuse osteoporosis is a metabolic bone disease resulting from skeletal unloading (e.g., during extended bed rest, limb immobilization, and spaceflight), and the slow and insufficient bone recovery during reambulation remains an unresolved medical challenge. Here, we demonstrated that loading-induced increase in bone architecture/strength was suppressed in skeletons previously exposed to unloading. This reduction in bone mechanosensitivity was directly associated with attenuated osteocytic Ca2+ oscillatory dynamics. The unloading-induced compromised osteocytic Ca2+ response to reloading resulted from the HIF-1α/PDK1 axis-mediated increase in glycolysis, and a subsequent reduction in ATP synthesis. HIF-1α also transcriptionally induced substantial glutaminase 2 expression and thereby glutamine addiction in osteocytes. Inhibition of glycolysis by blockade of PDK1 or glutamine supplementation restored the mechanosensitivity in those skeletons with previous unloading by fueling the tricarboxylic acid cycle and rescuing subsequent Ca2+ oscillations in osteocytes. Thus, we provide mechanistic insight into disuse-induced deterioration of bone mechanosensitivity and a promising therapeutic approach to accelerate bone recovery after long-duration disuse.
Asunto(s)
Calcio , Glutamina , Calcio/metabolismo , Glutamina/farmacología , Glutamina/metabolismo , Osteocitos/metabolismo , Glucosa/metabolismo , Metabolismo EnergéticoRESUMEN
BACKGROUND: Nocardia paucivorans is an infrequently found bacterium with the potential to cause severe infection, with a predilection for the central nervous system, both in immunocompromised and immunocompetent individuals. Rapid etiological diagnosis of nocardiosis can facilitate timely and rational antimicrobial treatment. Metagenomic next-generation sequencing (mNGS) can improve the rate and reduce the turnaround time for the detection of Nocardia. CASE SUMMARY: A 49-year-old man was admitted to hospital with cough and hemoptysis. Imaging revealed pulmonary consolidation as well as multiple brain lesions. Nocardia asiatica and Nocardia beijingensis were rapidly detected by mNGS of bronchoalveolar lavage fluid (BALF) while bacterial culture of BALF and pathological biopsy of lung tissue were negative. In early stages, he was treated with trimethoprim-sulfamethoxazole (TMP-SMZ) and linezolid by individual dose adjustment based on serum concentrations and the adverse effects of thrombocytopenia and leukopenia. The treatment was then replaced by TMP-SMZ and ceftriaxone or minocycline. He was treated with 8 mo of parenteral and/or oral antibiotics, and obvious clinical improvement was achieved with resolution of pulmonary and brain lesions on repeat imaging. CONCLUSION: mNGS provided fast and precise pathogen detection of Nocardia. In disseminated nocardiosis, linezolid is an important alternative that can give a better outcome with the monitoring of linezolid serum concentrations and platelet count.
RESUMEN
Background: Cardiotoxicity associated with the sequential use of anthracyclines followed by trastuzumab is common in adjuvant therapy of patients with HER2-positive early breast cancer (eBC). However, the cardiac safety of trastuzumab concurrent with pegylated liposomal doxorubicin (PLD) is relatively less studied. Method: Clinical data of patients with HER2-positive eBC treated with PLD and cyclophosphamide (PLD-C) followed by taxanes plus trastuzumab ± pertuzumab (TH or TPH) who then completed standard anti-HER2 treatment for 12 months from June 2012 to August 2021 were retrospectively collected. The primary endpoints were clinical and subclinical cardiotoxicity. Result: In total, 70 eligible patients were enrolled. Among them, 55 patients (78.6%) received PLD-C â TH and 15 patients (21.4%) received PLD-C â TPH. The median follow-up time was 41.8 months. Until August 2021, only two patients had recurrent or metastatic diseases, with 2-year and 5-year disease-free survivals of 98.6% and 96.8%, respectively. Clinical cardiotoxicity occurred in six patients (8.6%), and all of them had an absolute decline of ≥16% from baseline left ventricular ejection fraction (LVEF) but not below the lower limit of normal (LLN = 50%). Subclinical cardiotoxicity events occurred in 17 patients (24.3%), and all of them had absolute declines of ≥10% and <16% from baseline LVEF but not below the LLN. No patients were interrupted from treatment, and all patients completed anti-HER2 treatment for 12 months. The sharpest decrease in LVEF was observed at 18 months after the start of PLD treatment. The cumulative incidences of clinical and subclinical cardiotoxicity were 9.8% and 28.3%, respectively. In the univariate analysis, body mass index, age, left chest wall radiotherapy, and ongoing cardiovascular risk factors were not significantly associated with clinical or subclinical cardiotoxicity (p > 0.05). No patients had congestive heart failure or death caused by PLD or anti-HER2 treatment. Conclusion: The sequential use of PLD and trastuzumab showed a lower incidence of clinical cardiotoxicity, presented as asymptomatic decreased LVEF, compared with the results obtained in previous clinical studies using conventional anthracycline, taxanes and trastuzumab. The study regimen demonstrated good cardiac tolerance and is an alternative strategy for cardioprotection in patients with HER2-positive eBC.
RESUMEN
A reliable and efficient palladium-catalyzed cascade cyclization/alkylation of oxime ethers with unactivated alkenes is described, affording a whole variety of structurally diverse isoxazole derivatives in moderate to good yields with excellent functional group compatibility. Ionic liquid [Aeim]Br not only acts as an environmentally friendly solvent but also acts as an accelerating agent to provide excess bromine source to eliminate bromomethane from oxime ethers. More importantly, the use of "chain-walking" strategy provides a novel methodology in organic synthesis to rapid generation of molecular complexity from readily available starting materials.