Isotope Effect-Enabled Crystal Enlargement in Metal-Organic Frameworks.

Synthesizing large metal-organic framework (MOF) single crystals has garnered significant research interest, although it is hindered by the fast nucleation kinetics that gives rise to numerous small nuclei. Given the different chemical origins inherent in various types of MOFs, the development of a general approach to enhancing their crystal sizes presents a formidable challenge. Here, we propose a simple isotopic substitution strategy to promote size growth in MOFs by inhibiting nucleation, resulting in a substantial increase in the crystal volume ranging from 1.7- to 165-fold. Impressively, the crystals prepared under optimized conditions by normal approaches can be further enlarged by the isotope effect, yielding the largest MOF single crystal (2.9 cm × 0.48 cm × 0.23 cm) among the one-pot synthesis method. Detailed in situ characterizations reveal that the isotope effect can retard crystallization kinetics, establish a higher nucleation energy barrier, and consequently generate fewer nuclei that eventually grow larger. Compared with the smaller crystals, the isotope effect-enlarged crystal shows 33% improvement in the X-ray dose rate detection limit. This work enriches the understanding of the isotope effect on regulating the crystallization process and provides inspiration for exploring potential applications of large MOF single crystals.

SARS-CoV-2 Protein Nanoparticle Vaccines Formed In Situ From Lyophilized Lipids.

The receptor binding domain (RBD) of the SARS-CoV-2 Spike (S) glycoprotein is an appealing immunogen, but associated vaccine approaches must overcome the hapten-like nature of the compact protein and adapt to emerging variants with evolving RBD sequences. Here, a vaccine manufacturing methodology is proposed comprising a sterile-filtered freeze-dried lipid cake formulation that can be reconstituted with liquid proteins to instantaneously form liposome-displayed protein nanoparticles. Mannitol is used as a bulking agent and a small amount of Tween-80 surfactant is required to achieve reconstituted submicron particles that do not precipitate prior to usage. The lipid particles include an E. coli-derived monophosphoryl lipid A (EcML) for immunogenicity, and cobalt porphyrin-phospholipid (CoPoP) for antigen display. Reconstitution of the lipid cake with aqueous protein results in rapid conversion of the RBD into intact liposome-bound format prior to injection. Protein particles can readily be formed with sequent-divergent RBD proteins derived from the ancestral or Omicron strains. Immunization of mice elicits antibodies that neutralize respective viral strains. When K18-hACE2 transgenic mice are immunized and challenged with ancestral SARS-CoV-2 or the Omicron BA.5 variant, both liquid liposomes displaying the RBD and rapid reconstituted particles protect mice from infection, as measured by the viral load in the lungs and nasal turbinates.

A pentavalent peptide vaccine elicits Aß and tau antibodies with prophylactic activity in an Alzheimer's disease mouse model.

Amyloid-ß (Aß) and hyperphosphorylated tau protein are targets for Alzheimer's Disease (AD) immunotherapies, which are generally focused on single epitopes within Aß or tau. However, due to the complexity of both Aß and tau in AD pathogenesis, a multipronged approach simultaneously targeting multiple epitopes of both proteins could overcome limitations of monotherapies. Herein, we propose an active AD immunotherapy based on a nanoparticle vaccine comprising two Aß peptides (1-14 and pyroglutamate pE3-14) and three tau peptides (centered on phosphorylated pT181, pT217 and pS396/404). These correspond to both soluble and aggregated targets and are displayed on the surface of immunogenic liposomes in an orientation that maintains reactivity with epitope-specific monoclonal antibodies. Intramuscular immunization of mice with individual epitopes resulted in minimally cross-reactive antibody induction, while simultaneous co-display of 5 antigens ("5-plex") induced antibodies against all epitopes without immune interference. Post-immune sera recognized plaques and neurofibrillary tangles from human AD brain tissue. Vaccine administration to 3xTg-AD mice using a prophylactic dosing schedule inhibited tau and amyloid pathologies and resulted in improved cognitive function. Immunization was well tolerated and did not induce antigen-specific cellular responses or persistent inflammatory responses in the peripheral or central nervous system. Antibody levels could be reversed by halting monthly vaccinations. Altogether, these results indicate that active immune therapies based on nanoparticle formulations of multiple Aß and tau epitopes warrant further study for treating early-stage AD.

ACSL4-Mediated Ferroptosis and Its Potential Role in Central Nervous System Diseases and Injuries.

As an iron-dependent regulated form of cell death, ferroptosis is characterized by iron-dependent lipid peroxidation and has been implicated in the occurrence and development of various diseases, including nervous system diseases and injuries. Ferroptosis has become a potential target for intervention in these diseases or injuries in relevant preclinical models. As a member of the Acyl-CoA synthetase long-chain family (ACSLs) that can convert saturated and unsaturated fatty acids, Acyl-CoA synthetase long-chain familymember4 (ACSL4) is involved in the regulation of arachidonic acid and eicosapentaenoic acid, thus leading to ferroptosis. The underlying molecular mechanisms of ACSL4-mediated ferroptosis will promote additional treatment strategies for these diseases or injury conditions. Our review article provides a current view of ACSL4-mediated ferroptosis, mainly including the structure and function of ACSL4, as well as the role of ACSL4 in ferroptosis. We also summarize the latest research progress of ACSL4-mediated ferroptosis in central nervous system injuries and diseases, further proving that ACSL4-medicated ferroptosis is an important target for intervention in these diseases or injuries.

A New Surgical Technique for the Treatment of Congenital Concealed Penis Based on Anatomical Finding.

PURPOSE: Surgery is the first line treatment for congenital concealed penis but penile retraction is inevitable in some cases. We investigate the anatomical and histological characteristics of penile fasciae and describe a new technique for the correction of concealed penis. MATERIALS AND METHODS: The anatomical structures of penile fasciae were observed in 10 adult cadaveric penises. Penile tissue samples were stained with hematoxylin-eosin, Masson's trichrome and Weigert's resorcin-fuchsin, respectively. From January 2017 to May 2019, 78 patients with congenital concealed penis were treated with the new surgical technique. Median patient age was 14 years (range 8 to 18). RESULTS: Dartos fascia had sublayers. The superficial layer was a well vascularized tissue composed of nonpolar collagen fibers intermixed with nerves and vessels. The deep layer was composed of a transverse arrangement of collagen fibers and elastic fibers, and there were fewer venules and nerve fibers. Based on this finding we performed anatomical resection of the deep layer of dartos fascia to correct concealed penis. During the operation dartos fascia was separated into 2 layers and a complete circular resection of the deep layer was made at the base of the penis. Mean followup was 14 months. All patients and their parents were satisfied with the outcomes. None of the patients underwent postoperative penile retraction. CONCLUSIONS: The anatomical resection of the deep layer of dartos fascia for correcting concealed penis is technically easy, safe and effective. It provides a good cosmetic appearance and functional outcomes.

LncRNA MALAT1 Promotes Oxygen-Glucose Deprivation and Reoxygenation Induced Cardiomyocytes Injury Through Sponging miR-20b to Enhance beclin1-Mediated Autophagy.

BACKGROUND/AIMS: LncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is reported to be highly expressed in myocardial I/R injury and closely related to autophagy. However, the exact biological role of MALAT1 and its underlying mechanism in myocardial I/R injury remain to be elucidated. METHODS: We established incultured H9C2 cardiomyocytes an oxygen-glucose deprivation and reoxygenation (OGD/R) model for 6 h and then reoxygen-glucose for 4 h. We measured cell damage and autophagy levels after OGD/R by real-time quantitative PCR and Western blot. The relationships between miR-20b and MALAT1, beclin1 were confirmed by luciferase reporter assay. RESULTS: We found that the expression of MALAT1 and beclin1, cell damage levels (lactate dehydrogenase (LDH) release, 222.4 ± 29.4 vs. 577.5 ± 27.4 U/L; creatine kinase MB isoenzyme (CK-MB), 1.0 ± 0.2 vs. 4.3 ± 0.4; cardiac troponin I (cTn-I), 1.0 ± 0.3 vs. 3.0 ± 0.3; p < 0.05), and autophagy levels were significantly increased after OGD/R model, while cell viability (100.0 vs. 54.2 ± 2.2%, p < 0.05) and the expression of miR-20b and P62 were reduced; the trend of all the above data was significantly reversed by MALAT1 siRNA. In addition, the luciferase reporter assay results confirmed that MALAT1 directly binds to miR-20b-5p and functions as a ceRNA for miR-20b-5p to regulate beclin1. As a result, MALAT1 overexpression antagonized while MALAT1 knockdown enhanced the inhibitory effects of miR-20b-5p on beclin1-related cardiomyocytes autophagy in OGD/R injury. CONCLUSION: LncRNA MALAT1 promotes OGD/R-induced cardiomyocytes injury through sponging miR-20b to enhance beclin1-mediated autophagy.

[Regulatory effect of Skp2 on the expression and transactivation of the androgen receptor in the progression of castration-resistant prostate cancer].

OBJECTIVE: To determine the expression of Skp2 in different prostate cancer (PCa) cell lines and tissues, and explore its influence on the androgen receptor (AR) signaling pathway and development of castration-resistant prostate cancer (CRPC). METHODS: The expression levels of Skp2 and AR in different PCa cell lines were detected by Western blot. After knockdown of Skp2 in the C4-2 and 22RV1 cells transfected with shRNA, the expressions of AR and P27 were determined and the activity of ARR3-Luc measured by dual-luciferase reporter gene assay following treatment with dihydrotestosterone (DHT). The expressions of AR and Skp2 in human naïve PCa or CRPC specimens were detected by immunohistochemical staining followed by analysis of their differences and correlation. RESULTS: The Skp2 protein expression level was significantly higher in the C4-2 or 22RV1 cells than in the LNCaP cells. DHT treatment increased the expression of Skp2 in the C4-2 cells, but knock-down of Skp2 significantly up-regulated the expression of the well-known downstream protein P27 and down-regulated that of AR. Consistently, DHT treatment increased the activity of ARR3-Luc, while knockdown of Skp2 remarkably decreased it in the C4-2 and 22RV1 cells (P < 0.05). In addition, significantly higher expressions of Skp2 and AR were observed in the CRPC than in the naïve specimens (P < 0.05), with a positive correlation between the two proteins (r = 0.658 1, P < 0.05). CONCLUSION: Skp2 can enhance the expression and transcription activity of the AR protein in CRPC cells or tissues and is promising to be a critical molecular therapeutic target.

B-O-O-B Impurity Induces Ultralong Room-Temperature Phosphorescence of Boric Acid.

Organic materials that can emit ultralong room-temperature phosphorescence (RTP) have attracted a great deal of interest. Whether the pure boric acid (BA) solid can emit RTP and the origin of the RTP in BA caused a debate recently. Herein, our first-principles calculations and experimental measurements suggest that RTP of BA originates from the B-O-O-B group in a (H2BO3)2 species, which can be formed by polymerization of two dehydrogenated BA molecules under light irradiation. The calculated absorption, fluorescence, and phosphorescence spectra of B-O-O-B match well with the experiments. Experimental X-ray photoelectron and X-ray absorption spectra evidence the existence of B-O-O-B in BA. The O-O bond in B-O-O-B can break upon optical excitation, creating two B-O radicals. Radiative transition from localized dangling orbitals of the B-O radicals to the delocalized orbitals of the crystal bulk leads to the observed RTP. Our calculated phosphorescence lifetime is ∼1 s, which agrees well with the experiment.

The predominant Quillaja Saponaria fraction, QS-18, is safe and effective when formulated in a liposomal murine cancer peptide vaccine.

Extracts of the Chilean soapbark tree, Quillaja Saponaria (QS) are the source of potent immune-stimulatory saponin compounds. This study compared the adjuvanticity and toxicity of QS-18 and QS-21, assessing the potential to substitute QS-18 in place of QS-21 for vaccine development. QS-18, the most abundant QS saponin fraction, has been largely overlooked due to safety concerns. We found that QS-18 spontaneously inserted into liposomes, thereby neutralizing hemolytic activity, and following administration did not induce local reactogenicity in a footpad swelling test in mice. With high-dose intramuscular administration, transient weight loss was minor, and QS-18 did not induce significantly more weight loss compared to a liposome vaccine adjuvant system lacking it. Two days after administration, no elevation of inflammatory cytokines was detected in murine serum. In a formulation including cobalt-porphyrin-phospholipid (CoPoP) for short peptide sequestration, QS-18 did not impact the formation of peptide nanoparticles. With immunization, QS-18 peptide particles induced higher levels of cancer neoepitope-specific and tumor-associated antigen-specific CD8+ T cells compared to QS-21 particles, without indication of greater toxicity based on mouse body weight. T cell receptor sequencing of antigen-specific CD8+ T cells showed that QS-18 induced significantly more T cell transcripts. In two murine cancer models, vaccination with QS-18 peptide particles induced a similar therapeutic effect as QS-21 particles, without indication of increased toxicity. Antigen-specific CD8+ T cells in the tumor microenvironment were found to express the exhaustion marker PD-1, pointing to the rationale for exploring combination therapy. Taken together, these data demonstrate that QS-18, when formulated in liposomes, can be a safe and effective adjuvant to induce tumor-inhibiting cellular responses in murine models with potential to facilitate or diminish costs of production for vaccine adjuvant systems. Further studies are warranted to assess liposomal QS-18 immunogic, reactogenic and toxicological profiles in mice and other animal species.