Mesenchymal Stem Cell-Loaded Hydrogel Improves Surgical Treatment for Chronic Cerebral Ischemia.

Chronic cerebral ischemia (CCI) results in a prolonged insufficient blood supply to the brain tissue, leading to impaired neuronal function and subsequent impairment of cognitive and motor abilities. Our previous research showed that in mice with bilateral carotid artery stenosis, the collateral neovascularization post Encephalo-myo-synangiosis (EMS) treatment could be facilitated by bone marrow mesenchymal stem cells (MSCs) transplantation. Considering the advantages of biomaterials, we synthesized and modified a gelatin hydrogel for MSCs encapsulation. We then applied this hydrogel on the brain surface during EMS operation in rats with CCI, and evaluated its impact on cognitive performance and collateral circulation. Consequently, MSCs encapsulated in hydrogel significantly augment the therapeutic effects of EMS, potentially by promoting neovascularization, facilitating neuronal differentiation, and suppressing neuroinflammation. Furthermore, taking advantage of multi-RNA-sequencing and in silico analysis, we revealed that MSCs loaded in hydrogel regulate PDCD4 and CASP2 through the overexpression of miR-183-5p and miR-96-5p, thereby downregulating the expression of apoptosis-related proteins and inhibiting early apoptosis. In conclusion, a gelatin hydrogel to enhance the functionality of MSCs has been developed, and its combination with EMS treatment can improve the therapeutic effect in rats with CCI, suggesting its potential clinical benefit.

Ethylene Polymerization over Metal-Organic Framework-Supported Zirconocene Complexes.

Metallocene immobilization onto a solid support helps to overcome the drawbacks of homogeneous metallocene complexes in the catalytic olefin polymerization. In this study, valuable insights have been obtained into the effects of pore size, linker composition, and surface groups of metal-organic frameworks (MOFs) on their role as support materials for metallocene-based ethylene polymerization catalysis. Three distinct Zn-based metal-organic frameworks (MOFs), namely, MOF-5, IRMOF-3, and ZIF-8, with different linkers have been activated with methylaluminoxane (MAO) and zirconocene complexes, followed by materials characterization and testing for ethylene polymerization. Characterization has been performed by multiple analytical tools, including X-ray diffraction (XRD), scanning electron microscopy (SEM), gel permeation chromatography (GPC), differential scanning calorimetry (DSC), and CO Fourier transform infrared (FT-IR) spectroscopy. It was found that the interactions between MOFs, MAO, and the zirconocene complex not only lead to both catalyst activation and deactivation but also result in the creation of multiple active sites. By alteration of the MOF support, it is possible to obtain polyethylene with different properties. Notably, ultrahigh molecular weight polyethylene (UHMWPE, M W = 5.34 × 106) was obtained using IRMOF-3 as support. This study reveals the potential of MOF materials as tunable porous supports for metallocene catalysts active in ethylene polymerization.

Biomaterials targeting the microenvironment for spinal cord injury repair: progression and perspectives.

Spinal cord injury (SCI) disrupts nerve pathways and affects sensory, motor, and autonomic function. There is currently no effective treatment for SCI. SCI occurs within three temporal periods: acute, subacute, and chronic. In each period there are different alterations in the cells, inflammatory factors, and signaling pathways within the spinal cord. Many biomaterials have been investigated in the treatment of SCI, including hydrogels and fiber scaffolds, and some progress has been made in the treatment of SCI using multiple materials. However, there are limitations when using individual biomaterials in SCI treatment, and these limitations can be significantly improved by combining treatments with stem cells. In order to better understand SCI and to investigate new strategies for its treatment, several combination therapies that include materials combined with cells, drugs, cytokines, etc. are summarized in the current review.

Sinapic acid modulates oxidative stress and metabolic disturbances to attenuate ovarian fibrosis in letrozole-induced polycystic ovary syndrome SD rats.

Sinapic acid (SA) is renowned for its many pharmacological activities as a polyphenolic compound. The cause of polycystic ovary syndrome (PCOS), a commonly encountered array of metabolic and hormonal abnormalities in females, has yet to be determined. The present experiment was performed to evaluate the antifibrotic properties of SA in rats with letrozole-induced PCOS-related ovarian fibrosis. SA treatment successfully mitigated the changes induced by letrozole in body weight (BW) (p < .01) and relative ovary weight (p < .05). Histological observation revealed that SA reduced the number of atretic and cystic follicles (AFs) and (CFs) (p < .01), as well as ovarian fibrosis, in PCOS rats. Additionally, SA treatment impacted the serum levels of sex hormones in PCOS rats. Luteinizing hormone (LH) and testosterone (T) levels were decreased (p < .01, p < .05), and follicle-stimulating hormone (FSH) levels were increased (p < .05). SA administration also decreased triglyceride (TG) (p < .01) and total cholesterol (TC) levels (p < .05) and increased high-density lipoprotein cholesterol (HDL-C) levels (p < .01), thereby alleviating letrozole-induced metabolic dysfunction in PCOS rats. Furthermore, SA treatment targeted insulin resistance (IR) and increased the messenger RNA (mRNA) levels of antioxidant enzymes in the ovaries of PCOS rats. Finally, SA treatment enhanced the activity of peroxisome proliferator-activated receptor-γ (PPAR-γ), reduced the activation of transforming growth factor-ß1 (TGF-ß1)/Smads, and decreased collagen I, α-smooth muscle actin (α-SMA), and connective tissue growth factor (CTGF) levels in the ovaries of PCOS rats. These observations suggest that SA significantly ameliorates metabolic dysfunction and oxidative stress and ultimately reduces ovarian fibrosis in rats with letrozole-induced PCOS.

ERBB3 Overexpression is Enriched in Diverse Patient Populations with Castration-sensitive Prostate Cancer and is Associated with a Unique AR Activity Signature.

PURPOSE: Despite successful clinical management of castration-sensitive prostate cancer (CSPC), the 5-year survival rate for men with castration-resistant prostate cancer is only 32%. Combination treatment strategies to prevent disease recurrence are increasing, albeit in biomarker-unselected patients. Identifying a biomarker in CSPC to stratify patients who will progress on standard-of-care therapy could guide therapeutic strategies. EXPERIMENTAL DESIGN: Targeted deep sequencing was performed for the University of Illinois (UI) cohort (n = 30), and immunostaining was performed on a patient tissue microarray (n = 149). Bioinformatic analyses identified pathways associated with biomarker overexpression (OE) in the UI cohort, consolidated RNA sequencing samples accessed from Database of Genotypes and Phenotypes (n = 664), and GSE209954 (n = 68). Neutralizing antibody patritumab and ectopic HER3 OE were utilized for functional mechanistic experiments. RESULTS: We identified ERBB3 OE in diverse patient populations with CSPC, where it was associated with advanced disease at diagnosis. Bioinformatic analyses showed a positive correlation between ERBB3 expression and the androgen response pathway despite low dihydrotestosterone and stable expression of androgen receptor (AR) transcript in Black/African American men. At the protein level, HER3 expression was negatively correlated with intraprostatic androgen in Black/African American men. Mechanistically, HER3 promoted enzalutamide resistance in prostate cancer cell line models and HER3-targeted therapy resensitized therapy-resistant prostate cancer cell lines to enzalutamide. CONCLUSIONS: In diverse patient populations with CSPC, ERBB3 OE was associated with high AR signaling despite low intraprostatic androgen. Mechanistic studies demonstrated a direct link between HER3 and enzalutamide resistance. ERBB3 OE as a biomarker could thus stratify patients for intensification of therapy in castration-sensitive disease, including targeting HER3 directly to improve sensitivity to AR-targeted therapies.

Molecular Motor-Driven Light-Controlled Logic-Gated K+ Channel for Cancer Cell Apoptosis.

Developing artificial ion transport systems, which process complicated information and step-wise regulate properties, is essential for deeply comprehending the subtle dynamic behaviors of natural channel proteins (NCPs). Here a photo-controlled logic-gated K+ channel based on single-chain random heteropolymers containing molecular motors, exhibiting multi-core processor-like properties to step-wise control ion transport is reported. Designed with oxygen, deoxygenation, and different wavelengths of light as input signals, complicated logical circuits comprising "YES", "AND", "OR" and "NOT" gate components are established. Implementing these logical circuits with K+ transport efficiencies as output signals, multiple state transitions including "ON", "Partially OFF" and "Totally OFF" in liposomes and cancer cells are realized, further causing step-wise anticancer treatments. Dramatic K+ efflux in the "ON" state (decrease by 50% within 7 min) significantly induces cancer cell apoptosis. This integrated logic-gated strategy will be expanded toward understanding the delicate mechanism underlying NCPs and treating cancer or other diseases is expected.

Single-cell RNA sequencing of human prostate basal epithelial cells reveals zone-specific cellular populations and gene expression signatures.

Despite evidence of genetic signatures in normal tissue correlating with disease risk, prospectively identifying genetic drivers and cell types that underlie subsequent pathologies has historically been challenging. The human prostate is an ideal model to investigate this phenomenon because it is anatomically segregated into three glandular zones (central, peripheral, and transition) that develop differential pathologies: prostate cancer in the peripheral zone (PZ) and benign prostatic hyperplasia (BPH) in the transition zone (TZ), with the central zone (CZ) rarely developing disease. More specifically, prostatic basal cells have been implicated in differentiation and proliferation during prostate development and regeneration; however, the contribution of zonal variation and the critical role of basal cells in prostatic disease etiology are not well understood. Using single-cell RNA sequencing of primary prostate epithelial cultures, we elucidated organ-specific, zone-specific, and cluster-specific gene expression differences in basal cells isolated from human prostate and seminal vesicle (SV). Aggregated analysis identified ten distinct basal clusters by Uniform Manifold Approximation and Projection. Organ specificity compared gene expression in SV with the prostate. As expected, SV cells were distinct from prostate cells by clustering, gene expression, and pathway analysis. For prostate zone specificity, we identified two CZ-specific clusters, while the TZ and PZ populations clustered together. Despite these similarities, differential gene expression was identified between PZ and TZ samples that correlated with gene expression profiles in prostate cancer and BPH, respectively. Zone-specific profiles and cell type-specific markers were validated using immunostaining and bioinformatic analyses of publicly available RNA-seq datasets. Understanding the baseline differences at the organ, zonal, and cellular level provides important insight into the potential drivers of prostatic disease and guides the investigation of novel preventive or curative treatments. Importantly, this study identifies multiple prostate basal cell populations and cell type-specific gene signatures within prostate basal epithelial cells that have potential critical roles in driving prostatic diseases. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Pertinence of glioma and single nucleotide polymorphism of TERT, CCDC26, CDKN2A/B and RTEL1 genes in glioma: a meta-analysis.

Background: Previous genetic-epidemiological studies considered TERT (rs2736100), CCDC26 (rs4295627), CDKN2A/B (rs4977756) and RTEL1 (rs6010620) gene polymorphisms as the risk factors specific to glioma. However, the data samples of previous genetic-epidemiological studies are modest to determine whether they have definite association with glioma. Method: The study paid attention to systematically searching databases of PubMed, Embase, Web of Science (WoS), Scopus, Cochrane Library and Google Scholars. Meta-analysis under 5 genetic models, namely recessive model (RM), over-dominant model (O-DM), allele model (AM), co-dominant model (C-DM) and dominant model (DM) was conducted for generating odds ratios (ORs) and 95% confidence intervals (CIs). That was accompanied by subgroup analyses according to various racial groups. The software STATA 17.0 MP was implemented in the study. Result: 21 articles were collected. According to data analysis results, in four genetic models (AM, RM, DM and C-DM) TERT gene rs2736100 polymorphism, CCDC26 gene rs4295627 polymorphism, CDKN2A/B gene rs4977756 polymorphism and RTEL1 gene rs6010620 polymorphisms increased the risk of glioma in Caucasians to different degrees. In Asian populations, the CCDC26 gene rs4295627 polymorphism and CDKN2A/B gene rs4977756 polymorphism did not exhibit a relevance to the risk of glioma. It is suggested to cautiously explain these results as the sample size is small. Conclusion: The current meta-analysis suggested that the SNP of TERT (rs2736100), CCDC26 (rs4295627), CDKN2A/B (rs4977756) and RTEL1 (rs6010620) genes in glioma might increase risk of glioma, but there are ethnic differences. Further studies evaluating these polymorphisms and glioma risk are warranted.

[Research progress of natural collagen peptides and its skincare efficacy].

Natural collagen peptides are collagen hydrolysates. Because of their unique physicochemical properties and excellent biological activities, collagen peptides have been a research hotspot of cosmetic raw materials development and skincare efficacy improvement. Combined with the needs of the skincare efficacy and the development trends of cosmetics, the extraction methods and their structural characteristics of natural collagen peptides were summarized in detail. The applications and its research progress in skincare efficacy of collagen peptides, such as moisturizing and anti-wrinkle, trophism and anti-aging, filling and skin regeneration were expressed with emphasis. Finally, the development and practical applications in cosmetics of natural collagen peptides were adequately prospected.

Restoration of spinal cord injury: From endogenous repairing process to cellular therapy.

Spinal cord injury (SCI) disrupts neurological pathways and impacts sensory, motor, and autonomic nerve function. There is no effective treatment for SCI currently. Numerous endogenous cells, including astrocytes, macrophages/microglia, and oligodendrocyte, are involved in the histological healing process following SCI. By interfering with cells during the SCI repair process, some advancements in the therapy of SCI have been realized. Nevertheless, the endogenous cell types engaged in SCI repair and the current difficulties these cells confront in the therapy of SCI are poorly defined, and the mechanisms underlying them are little understood. In order to better understand SCI and create new therapeutic strategies and enhance the clinical translation of SCI repair, we have comprehensively listed the endogenous cells involved in SCI repair and summarized the six most common mechanisms involved in SCI repair, including limiting the inflammatory response, protecting the spared spinal cord, enhancing myelination, facilitating neovascularization, producing neurotrophic factors, and differentiating into neural/colloidal cell lines.

Alginate hydrogel cross-linked by Ca2+ to promote spinal cord neural stem/progenitor cell differentiation and functional recovery after a spinal cord injuryhh.

Alginate capillary hydrogels seeded with differentiated cells can fill the lesion cavity and promote axonal regeneration after grafting into the injured spinal cord. Neural stem/progenitor cells (NSPCs) can potentially repair the spinal cord; however, effects of alginate hydrogels (AHs) on NSPCs remain unknown. In this study, we fabricated AHs cross-linked by Ca2+ and seeded hydrogels with rat embryonic day 14 NSPCs. Immunocytochemistry and electron microscopy show that NSPCs survive, proliferate and differentiate into neurons in vitro within the capillaries. After transplantation into an acute T8 complete spinal cord transection site in adult rats, approximately one-third (38.3%) of grafted cells survive and differentiate into neurons (40.7%), astrocytes (26.6%) and oligodendrocytes (28.4%) at 8 weeks post-grafting. NSPCs promote the growth of host axons within the capillaries in a time-dependent manner. Host axons make synapse-like contacts with NSPC-derived neurons within the hydrogel channels, and graft-derived axons extend into the host white and gray matter making putative synapses. This is paralleled by improved electrophysiological conductivity across the lesion and partial hindlimb locomotor recovery.

HSF2 cooperates with HSF1 to drive a transcriptional program critical for the malignant state.

Heat shock factor 1 (HSF1) is well known for its role in the heat shock response (HSR), where it drives a transcriptional program comprising heat shock protein (HSP) genes, and in tumorigenesis, where it drives a program comprising HSPs and many noncanonical target genes that support malignancy. Here, we find that HSF2, an HSF1 paralog with no substantial role in the HSR, physically and functionally interacts with HSF1 across diverse types of cancer. HSF1 and HSF2 have notably similar chromatin occupancy and regulate a common set of genes that include both HSPs and noncanonical transcriptional targets with roles critical in supporting malignancy. Loss of either HSF1 or HSF2 results in a dysregulated response to nutrient stresses in vitro and reduced tumor progression in cancer cell line xenografts. Together, these findings establish HSF2 as a critical cofactor of HSF1 in driving a cancer cell transcriptional program to support the anabolic malignant state.

Near UV and Visible Light Photo-Degradation Mechanisms in Citrate Buffer: One-Electron Reduction of Peptide and Protein Disulfides promotes Oxidation and Cis/Trans Isomerization of Unsaturated Fatty Acids of Polysorbate 80.

Citrate is a common buffer for slightly acidic pH ranges of protein formulations. In the presence of iron, citrate buffer undergoes photo-degradation induced by near UV and visible light. Recent studies (Subelzu and Schöneich, Mol. Pharm. 2020, 17, 4163-4179) have documented that such photo-degradation results in the formation of carbon dioxide radical anion (•CO2-), a strong reductant which reduces Fe3+, O2, and disulfide bonds. In the present study we show that near UV and visible light photo-degradation of citrate in the presence of iron can induce reductive peptide and protein disulfide cleavage as well as free radical damage of a surfactant, polysorbate 80 (PS80). Reductive disulfide cleavage is most likely caused by efficient electron transfer from carbon dioxide radical anions to disulfides, resulting in the generation of thiol/thiolate and thiyl radicals. The latter can react with mono- and polyunsaturated fatty acids of PS80 to cause cis/trans isomerization and/or oxidation. Representative products generated by cis/trans isomerization and oxidation of oleic acid esters have been detected by HPLC-MS analysis. Further evidence for reductive disulfide cleavage was obtained through the analysis of free thiols. The oxidation of PS80 can also be the consequence of reactive oxygen species (ROS) generation through the reduction of O2 by carbon dioxide radical anions and/or intermediary Fe2+.

Fast and Selective Reaction of 2-Benzylacrylaldehyde with 1,2-Aminothiol for Stable N-Terminal Cysteine Modification and Peptide Cyclization.

N-terminal cysteine (Cys)-specific reactions have been exploited for protein and peptide modifications. However, existing reactions for N-terminal Cys suffer from low reaction rate, unavoidable side reactions, or poor stability for reagents or products. Herein we report a fast, efficient, and selective conjugation between 2-benzylacrylaldehyde (BAA) and 1,2-aminothiol, which involves multistep reactions including aldimine condensation, Michael addition, and reduction of imine by NaBH3CN. This conjugation proceeds with a rate constant of ∼2700 M-1 s-1 under neutral condition at room temperature to produce a pair of seven-membered ring diastereoisomers, which are stable under neutral and acidic conditions. This method enables the selective modifications of the N-terminal Cys residue without interference from the internal Cys and lysine residues, providing a useful alternative to existing approaches for site-specific peptide or protein modifications and synthesis of cyclic peptides.

[Expression of Versican and Its Related Molecules in Patient with Multiple Myeloma and Its Clinical Significance].

OBJECTIVE: To investigate the expression and clinical significant of VCAN and its related molecules in patients with MM. METHODS: Ficoll density gradient centrifugation method was used to speared the bone marrow mononuclear cell in 25 cases of MM before and after treatment, the relative mRNA expression of VCAN and their related molecules (FAK, FN, MK, and HAS) in bone marrow was detected by real-time quantitative PCR, and their protein expression was determined by Western bolt. RESULTS: The expression of VCAN, FK and FN in the effective group after treatment was significantly lower than that before treatment (P＜0.05), however, the expression of MK and HAS showed no statistically significantly different before and after treatment (P＜0.05). The expression of VCAN of patients in non remission group was significantly higher than that in control group (P＜0.05). The expression of FAK and FN of patients in no remission group was significant increased as compared with the patients in newly diagnosed group (P＜0.05). The relative expression of VCAN mRNA in the patients at 3rd stage was significantly higher than those at the 1st stage (P＜0.05) and control group but showed no significant difference to the patients at 2nd stage (P＜0.05). The expression of VCAN and its related proteins (FAK, MK, FN) showed positively correlation in bone marrow mononuclear cells of MM patients (P＜0.05). The correlation between VCAN and HAS was not statistically significant (r=0.259，P＞0.05). Survival analysis showed that the relative expression of VCAN mRNA was associated with OS (P=0.049) and PFS (P=0.041) in MM patients. CONCLUSION: VCAN and its related molecules are highly expressed in MM patients; VCAN may act as potential biomarker in the development of multiple myeloma.

[Clinical Significance of Platelet Closure Time in Patients with Multiple Myeloma].

OBJECTIVE: To explore the clinical significance of platelet closure time (PCT) in patients with multiple myeloma (MM). METHODS: Peripheral blood samples of 50 newly diagnosed MM patients treated in our hospital from July 2018 to November 2019 and 34 healthy persons underuent physical at the same time were collected. PCT induced by collagen/epinephrine (CEPI) and collagen/adenosinediphosphate (CADP) in peripheral blood were detected by PFA-200，and the clinical data included age, sex, leukocyte count, hemoglobin level, platelet count and level of serum creatinine, cystatin c, blood calcium, ß2-microglobulin (ß2-MG), bone marrow plasma cells, light chain protein, as well as the MM types, ISS stage of patients were collected. RESULTS: The level of PCT in MM patients was significantly higher than that in healthy persons; the level of PCT were significantly increased with the increasing of ISS stage in newly diagnosed MM patients; After chemotherapy with bortezomib/dexamethasone (BD), the level of PCT in 15 patients who were responded to the treatment was significantly lower than those before treatment. CONCLUSION: The platelet closure time is abnormal in MM patients, moreover, relates to the progress of the disease. It has an important clinical significance for the evaluation of diagnostic stage and therapeutic efficacy evaluation of MM patients.

Investigation of the Effect of Induction Heating on Asphalt Binder Aging in Steel Fibers Modified Asphalt Concrete.

Induction heating is a valuable technology to repair asphalt concrete damage inside. However, in the process of induction heating, induced particles will release a large amount of heat to act on asphalt binder in a short time. The purpose of this paper was to study the effect of induction heating on asphalt binder aging in steel fibers modified asphalt concrete. The experiments were divided into two parts: induction heating of Dramix steel fibers coated with asphalt binder (DA) and steel wool fibers modified asphalt concrete. After induction heating, the asphalt binders in the samples were extracted for testing aging indices with Fourier Transform Infrared (FTIR), Dynamic Shear Rheometer (DSR), and Four-Components Analysis (FCA) tests. The aging of asphalt binder was analyzed identifying the change of chemical structure, the diversification of rheological properties, and the difference of component. The experiments showed that the binder inside asphalt concrete began aging during induction heating due to thermal oxygen reaction and volatilization of light components. However, there was no peak value of the carbonyl index after induction heating of ten cycles, and the carbonyl index of DA was equivalent to that of binder in asphalt concrete after three induction heating cycles, which indicated the relatively closed environment inside asphalt concrete can inhibit the occurrence of the aging reaction.

Mutant RAMP2 causes primary open-angle glaucoma via the CRLR-cAMP axis.

PURPOSE: Primary open-angle glaucoma (POAG) is the leading cause of irreversible blindness worldwide and mutations in known genes can only explain 5-6% of POAG. This study was conducted to identify novel POAG-causing genes and explore the pathogenesis of this disease. METHODS: Exome sequencing was performed in a Han Chinese cohort comprising 398 sporadic cases with POAG and 2010 controls, followed by replication studies by Sanger sequencing. A heterozygous Ramp2 knockout mouse model was generated for in vivo functional study. RESULTS: Using exome sequencing analysis and replication studies, we identified pathogenic variants in receptor activity-modifying protein 2 (RAMP2) within three genetically diverse populations (Han Chinese, German, and Indian). Six heterozygous RAMP2 pathogenic variants (Glu39Asp, Glu54Lys, Phe103Ser, Asn113Lysfs*10, Glu143Lys, and Ser171Arg) were identified among 16 of 4763 POAG patients, whereas no variants were detected in any exon of RAMP2 in 10,953 control individuals. Mutant RAMP2s aggregated in transfected cells and resulted in damage to the AM-RAMP2/CRLR-cAMP signaling pathway. Ablation of one Ramp2 allele led to cAMP reduction and retinal ganglion cell death in mice. CONCLUSION: This study demonstrated that disruption of RAMP2/CRLR-cAMP axis could cause POAG and identified a potential therapeutic intervention for POAG.

Stabilizing p-Dithiobenzyl Urethane Linkers without Rate-Limiting Self-Immolation for Traceless Drug Release.

Exploiting the redox sensitivity of disulfide bonds is a prevalent strategy in targeted prodrug designs. In contrast to aliphatic disulfides, p-thiobenzyl-based disulfides have rarely been used for prodrug designs, given their intrinsic instability caused by the low pKa of aromatic thiols. Here, we examined the interplay between steric hindrance and the low-pKa effect on thiol-disulfide exchange reactions and uncovered a new thiol-disulfide exchange process for the self-immolation of p-thiobenzyl-based disulfides. We observed a central leaving group shifting effect in the α,α-dimethyl-substituted p-dithiobenzyl urethane linkers (DMTB linkers), which leads to increased disulfide stability by more than two orders of magnitude, an extent that is significantly greater than that observed with typical aliphatic disulfides. In particular, the DMTB linkers display not only high stability, but also rapid self-immolation kinetics due to the low pKa of the aromatic thiol, which can be used as a general and robust linkage between targeting reagents and cytotoxic drugs for targeted prodrug designs. The unique and promising stability characteristics of the present DMTB linker will likely inspire the development of novel targeted prodrugs to achieve traceless release of drugs into cells.

Heterologous Boost Following Mycobacterium bovis BCG Reduces the Late Persistent, Rather Than the Early Stage of Intranasal Tuberculosis Challenge Infection.

Adults are the leading population affected by tuberculosis (TB) epidemic and death. Developing an effective vaccine against adult TB is urgently needed. Mycobacterium bovis Bacillus Calmette-Guerin (BCG) prime-heterologous boost strategy has been explored extensively to protect adults against primary TB infection, but the majority of experimental regimens have not improved the protection primed by the BCG vaccine. The reason attributed to the failure remains unknown. In this study, CTT3H-based vaccines, namely DMT adjuvanted CTT3H subunit or DNA vaccine (pCTT3H-DMT), and recombinant adenovirus rAdCTT3H were constructed. Protective efficacy and immunogenicity of BCG prime-CTT3H based boosters were compared in C57BL/c mice models of primary or late persistent TB infection. Similar protective efficacy against early intranasal infection was provided by different CTT3H-based vaccines alone in vaccinated mice, and their protection was inferior to that of the BCG vaccine. In addition, CTT3H-based heterologous boosters did not enhance the protection conferred by the BCG vaccine against primary infection. However, all of these three boosters provided stronger protection against late persistent TB infection than BCG alone, regardless of vaccine types. Although BCG prime-boosters elicited Th1-biased responses to the antigen CTT3H, the number of CTT3H-sepcific IFN-γ-expressing TEM (CD62LloCD44hi) and IL-2-expressing TCM (CD62LhiCD44hi) cells in the spleen was not improved before exposure to Mycobacterium tuberculosis infection. In contrast, IFN-γ+ TEM and IL-2+ TCM cells in spleens, especially in lungs were significantly increased in BCG prime-boosters after exposure vaccination. Our results indicate that BCG prime-boost strategy might be a promising measure for the prevention against late persistent TB infection by induction of IFN-γ+ TEM and IL-2+ TCM cells in the lung, which can be used as alternative biomarkers for guiding the clinical practice and future development of TB vaccine for adults.