Development of regional specificity of spinal and medullary dorsal horn neurons

Extensive studies have focused on the development and regionalization of neurons in the central nervous system(CNS). Many genes, which play crucial roles in the development of CNS neurons, have been identified. By using the technique "direct reprogramming", neurons can be produced from multiple cell sources such as fibroblasts. However, understanding the region-specific regulation of neurons in the CNS is still one of the biggest challenges in the research field of neuroscience. Neurons located in the trigeminal subnucleus caudalis(Vc) and in the spinal dorsal horn(SDH) play crucial roles in pain and sensorimotor functions in the orofacial and other somatic body regions, respectively. Anatomically, Vc represents the most caudal component of the trigeminal system, and is contiguous with SDH. This review is focused on recent data dealing with the regional specificity involved in the development of neurons in Vc and SDH.

IN VIVO NEAR-INFRAREDFLUORESCENCEIMAGING OF HUMANCOLONADENOCARCINOMABY SPECIFIC IMMUNOTARGETINGOFA TUMOR-ASSOCIATEDMUCIN

Background and Aims: Accurate endoscopic detection of premalignant lesions and earlycancers in the colon is essential for cure, since prognosis is closely related to lesion size andstage. Although it has great clinical potential, autofluorescence endoscopy has limited tumorto-normal tissue image contrast for detecting small preneoplastic lesions. We have developed amolecularly specific, near-infrared fluorescent monoclonal antibody (CC49) bioconjugate whichtargets tumor-associated glycoprotein 72 (TAG72), as a contrast agent to improve fluorescencebased endoscopy of colon cancer. Methods: The fluorescent anti-TAG72 conjugate was evaluated in vitro and in vivo in athymic nude mice bearing human colon adenocarcinoma (LS174T)subcutaneous tumors. Autofluorescence, a fluorescent but irrelevant antibody and the free fluorescent dye served as controls. Fluorescent agents were injected intravenously, and in vivowhole body fluorescence imaging was performed at various time points to determine pharmacokinetics, followed by ex vivo tissue analysis by confocal fluorescence microscopy and histology Results: Fluorescence microscopy and histology confirmed specific LS174T cell membrane targeting of labeled CC49 in vitro and ex vivo. In vivo fluorescence imaging demonstrated significant tumor-to-normal tissue contrast enhancement with labeled-CC49 at three hours postinjection, with maximum contrast after 48 h. Accumulation of tumor fluorescence demonstratedthat modification of CC49 antibodies did not alter their specific tumor-localizing properties, andwas antibody-dependent since controls did not produce detectable tumor fluorescence. Conclusions: These results show proof-of-principle that our near-infrared fluorescent-antibody probetargeting a tumor-associated mucin detects colonic tumors at the molecular level in real time,and offer a basis for future improvement of image contrast during clinical fluorescence endoscopy.

An emerging terpolymeric nanoparticle pore former as an internal recrystallization inhibitor of celecoxib in controlled release amorphous solid dispersion beads:Experimental studies and molecular dynamics analysis

Solid oral controlled release formulations feature numerous clinical advantages for drug candidates with adequate solubility and dissolution rate.However,most new chemical entities exhibit poor water solubility,and hence are exempt from such benefits.Although combining drug amorphization with controlled release formulation is promising to elevate drug solubility,like other supersaturating systems,the problem of drug recrystallization has yet to be resolved,particularly within the dosage form.Here,we explored the potential of an emerging,non-leachable terpolymer nanoparticle(TPN)pore former as an internal recrystallization inhibitor within controlled release amorphous solid dispersion(CRASD)beads comprising a poorly soluble drug(celecoxib)reservoir and insoluble polymer(ethylcellulose)membrane.Compared to conventional pore former,polyvinylpyrrolidone(PVP),TPN-containing membranes exhibited superior structural integrity,less crystal formation at the CRASD bead surface,and greater extent of celecoxib release.All-atom molecular dynamics analyses revealed that in the presence of TPN,intra-molecular bonding,crystal formation tendency,diffusion coefficient,and molecular flexibility of celecoxib were reduced,while intermolecular H-bonding was increased as compared to PVP.This work suggests that selection of a pore former that promotes prolonged molecular separation within a nanoporous controlled release membrane structure may serve as an effective strategy to enhance amorphicity preservation inside CRASD.

Remodeling Tumor Immune Microenvironment by Using Polymer-Lipid-Manganese Dioxide Nanoparticles with Radiation Therapy to Boost Immune Response of Castration-Resistant Prostate Cancer

Despite substantial progress in the treatment of castration-resistant prostate cancer (CRPC), including radiation therapy and immunotherapy alone or in combination, the response to treatment remains poor due to the hypoxic and immunosuppressive nature of the tumor microenvironment. Herein, we exploited the bioreactivity of novel polymer–lipid manganese dioxide nanoparticles (PLMDs) to remodel the tumor immune microenvironment (TIME) by increasing the local oxygen levels and extracellular pH and enhancing radiation-induced immunogenic cell death. This study demonstrated that PLMD treatment sensitized hypoxic human and murine CRPC cells to radiation, significantly increasing radiation-induced DNA double-strand breaks and ultimately cell death, which enhanced the secretion of damage-associated molecular patterns, attributable to the induction of autophagy and endoplasmic reticulum stress. Reoxygenation via PLMDs also polarized hypoxic murine RAW264.7 macrophages toward the M1 phenotype, enhancing tumor necrosis factor alpha release, and thus reducing the viability of murine CRPC TRAMP-C2 cells. In a syngeneic TRAMP-C2 tumor model, intravenous injection of PLMDs suppressed, while radiation alone enhanced recruitment of regulatory T cells and myeloid-derived suppressor cells. Pretreatment with PLMDs followed by radiation down-regulated programmed death-ligand 1 and promoted the infiltration of antitumor CD8+ T cells and M1 macrophages to tumor sites. Taken together, TIME modulation by PLMDs plus radiation profoundly delayed tumor growth and prolonged median survival compared with radiation alone. These results suggest that PLMDs plus radiation is a promising treatment modality for improving therapeutic efficacy in radioresistant and immunosuppressive solid tumors.

SARS-CoV-2 RBD and Its Variants Can Induce Platelet Activation and Clearance:Implications for Antibody Therapy and Vaccinations against COVID-19

The COVID-19 pandemic caused by SARS-CoV-2 virus is an ongoing global health burden.Severe cases of COVID-19 and the rare cases of COVID-19 vaccine-induced-thrombotic-thrombocytopenia(VITT)are both associated with thrombosis and thrombocytopenia;however,the underlying mechanisms remain inadequately understood.Both infection and vaccination utilize the spike protein receptor-binding domain(RBD)of SARS-CoV-2.We found that intravenous injection of recombinant RBD caused significant platelet clearance in mice.Further investigation revealed the RBD could bind platelets,cause platelet activation,and potentiate platelet aggregation,which was exacerbated in the Delta and Kappa variants.The RBD–platelet interaction was partially dependent on theβ3 integrin as binding was significantly reduced inβ3−/−mice.Furthermore,RBD binding to human and mouse platelets was significantly reduced with relatedαIIbβ3 antagonists and mutation of the RGD(arginine-glycine-aspartate)integrin binding motif to RGE(arginine-glycine-glutamate).We developed anti-RBD polyclonal and several monoclonal antibodies(mAbs)and identified 4F2 and 4H12 for their potent dual inhibition of RBD-induced platelet activation,aggregation,and clearance in vivo,and SARS-CoV-2 infection and replication in Vero E6 cells.Our data show that the RBD can bind platelets partially thoughαIIbβ3 and induce platelet activation and clearance,which may contribute to thrombosis and thrombocytopenia observed in COVID-19 and VITT.Our newly developed mAbs 4F2 and 4H12 have potential not only for diagnosis of SARS-CoV-2 virus antigen but also importantly for therapy against COVID-19.

Crosslinked hydrogels--a promising class of insoluble solid molecular dispersion carriers for enhancing the delivery of poorly soluble drugs

Water-insoluble materials containing amorphous solid dispersions(ASD)are an emerging category of drug carriers which can effectively improve dissolution kinetics and kinetic solubility of poorly soluble drugs.ASDs based on water-insoluble crosslinked hydrogels have unique features in contrast to those based on conventional water-soluble and water-insoluble carriers.For example,solid molecular dispersions of poorly soluble drugs in poly(2-hydroxyethyl methacrylate)(PHEMA)can maintain a high level of supersaturation over a prolonged period of time via a feedback-controlled diffusion mechanism thus avoiding the initial surge of supersaturation followed by a sharp decline in drug concentration typically encountered with ASDs based on water-soluble polymers.The creation of both immediate-and controlled-release ASD dosage forms is also achievable with the PHEMA based hydrogels.So far,ASD systems based on glassy PHEMA have been shown to be very effective in retarding precipitation of amorphous drugs in the solid state to achieve a robust physical stability.This review summarizes recent research efforts in investigating the potential of developing crosslinked PHEMA hydrogels as a promising alternative to conventional water-soluble ASD carriers,and a related finding that the rate of supersaturation generation does affect the kinetic solubility profiles implications to hydrogel based ASDs.

建议将非药物治疗作为慢性失眠的一线治疗

指南推荐将非药物治疗(包括认知行为治疗)作为成人慢性失眠的一线治疗(框图1)1-5。然而治疗失眠通常会处方镇静剂。根据2017年的一项初级保健调查估计,英国有超过25万人使用镇静剂持续一年以上6。英国的一项药物调查报告称,2017至2018年间,有240万成人收到并使用了医生开具的一份或多份镇静剂处方7。

Orotidine Monophosphate Decarboxylase——A Fascinating Workhorse Enzyme with Therapeutic Potential

Orotidine 5＇-monophosphate decarboxylase （ODCase） is known as one of the most proficient enzymes. The enzyme catalyzes the last reaction step of the de novo pyrimidine biosynthesis, the conversion from orotidine 5＇-monophosphate （OMP） to uridine 5＇-mono- phosphate. The enzyme is found in all three domains of life, Bacteria, Eukarya and Archaea. Multiple sequence alignment of 750 putative ODCase sequences resulted in five distinct groups. While the universally conserved DxKxxDx motif is present in all the groups, depending on the groups, several characteristic motifs and residues can be identified. Over 200 crystal structures of ODCases have been determined so far. The structures, together with biochemical assays and computational studies, elucidated that ODCase utilized both transition state stabilization and substrate distortion to accelerate the decarboxylation of its natural substrate. Stabilization of the vinyl anion intermediate by a conserved lysine residue at the catalytic site is considered the largest contributing factor to catalysis, while bending of the carboxyl group from the plane of the aromatic pyrimidine ring of OMP accounts for substrate distortion. A number of crystal structures of ODCases complexed with potential drug candidate molecules have also been determined, including with 6-iodo- uridine, a potential antimalarial agent.

AD-16 Protects Against Hypoxic-Ischemic Brain Injury by Inhibiting Neuroinflammation

Neuroinflammation is a key contributor to the pathogenic cascades induced by hypoxic-ischemic(HI)insult in the neonatal brain.AD-16 is a novel anti-inflammatory compound,recently found to exert potent inhibition of the lipopolysaccharide-induced production of pro-inflammatory and neurotoxic mediators.In this study,we evaluated the effect of AD-16 on primary astrocytes and neurons under oxygen-glucose deprivation(OGD)in vitro and in mice with neonatal HI brain injury in vivo.We demonstrated that AD-16 protected against OGD-induced astrocytic and neuronal cell injury.Single dose post-treatment with AD-16(1 mg/kg)improved the neurobehavioral outcome and reduced the infarct volume with a therapeutic window of up to 6 h.Chronic administration reduced the mortality rate and preserved whole-brain morphology following neonatal HI.The in vitro and in vivo effects suggest that AD-16 offers promising therapeutic efficacy in attenuating the progression of HI brain injury and protecting against the associated mortality and morbidity.