Hepatoerythropoietic porphyria: a missense mutation in the UROD gene is associated with mild disease and an unusual porphyrin excretion pattern

Hepatoerythropoietic porphyria (HEP) is an uncommon inherited cutaneous porphyria, related to porphyria cutanea tarda, that results from severe uroporphyrinogen decarboxylase (UROD) deficiency. It is characterized clinically by the onset in early childhood of severe lesions on sun-exposed skin. We describe a man aged 38 years with an unusually mild form of the disease that started in his early teens. Our data confirm that homozygosity for the F46L mutation in the UROD gene causes a mild form of HEP and show that this genotype may be associated with a unique urinary porphyrin excretion pattern in which pentacarboxylic porphyrin predominates.     

Antitumor effects of telomerase inhibitor TMPyP4 in osteosarcoma cell lines

Telomere studies in carcinomas have been extensively reported for prognostic utility and effective methods for targeting telomerase therapy has been described, but efficacy of telomerase inhibitor remained unknown in sarcoma cells. In this study, we investigated the effects of telomerase inhibitor cationic porphyrin TMPyP4 on telomerase activity, telomere length, cell growth, and apoptosis in osteosarcoma cell lines. TMPyP4 significantly inhibited telomerase activity in telomerase positive HOS and Saos‐2, but not in MG‐63. TMPyP4 significantly induced telomere shortening, and inhibition of the cell growth in HOS and Saos‐2 with over 17% apoptosis rates. In terms of MG‐63, TMPyP4 did not induce inhibition of both telomerase activity and cell growth, although it induced significant telomere shortening. Telomere length after treatment was 5.60 kb in HOS, 4.00 kb in Saos‐2, and 9.89 kb in MG‐63. These results may suggest that both telomerase activity loss and sufficient telomere shortening are necessary to inhibit cell growth in telomerase positive osteosarcoma cells. TMPyP4 did not induced telomere shortening but significantly inhibited the growth with 22.6% apoptosis rate in telomerase negative with extremely longer telomere‐U2OS, may indicating the antitumor effect of TMPyP4 may be related to DNA damage including telomere dysfunction through G‐quadruplex stabilization, independent on telomere length. © 2011 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 29:1707–1711, 2011     

Electrochemical characterization and electrocatalysis of high valent manganese meso-tetrakis(N-methyl-2-pyridyl)porphyrin

Electrochemical oxidation of water-soluble manganese(III) meso-tetrakis(N-methyl-2-pyridyl)porphyrin (Mn^III(2-TMPyP)) generates stable Mn^IV and Mn^V porphyrins. Speciation of various oxidation states of the porphyrin are characterized by spectroelectrochemical methods. The acid dissociation constants (pK_as) for Mn^III(2-TMPyP)(H₂O)₂ are 9.6 and 10.7, respectively. Spectroelectrochemical results of the one-electron oxidation of Mn^III(2-TMPyP) exhibit different forms of oxomanganese(IV) porphyrin, depending on the pH of the solution and the applied potential. The pK_a for OMn^IV(2-TMPyP)(H₂O) is 10.5. The axial oxygen atom ligated to the Mn(IV) center is protonated in acidic solution (pK_a 3.4). Further one-electron oxidation generates dioxomanganese(V) porphyrin, (O)₂Mn^V(2-TMPyP), which is stable in alkaline solution at room temperature. No oxidation wave is observed in the cyclic voltammograms, indicating the slow heterogeneous electron transfer rate of these oxidation reactions. The electrogenerated dioxomanganese(V) porphyrin exhibits higher reactivity toward olefin oxidation than oxomanganese(IV) porphyrin in basic solutions.     

MnTBAP对大鼠急性放射性肺损伤保护作用的实验研究

目的:观察锰四(4-苯甲酸)卟啉[MnTBAP]对大鼠急性放射性肺损伤的保护作用。方法:200～230g SD雄性大鼠分为正常对照组、照射损伤组和MnTBAP治疗组。用6 MV X射线、单次照射全肺28Gy,建立大鼠肺损伤模型。损伤组腹腔注射生理盐水(1.5mL/kg),MnTBAP组腹腔注射MnTBAP(10mg/kg)。经1、4、8和12周,采用ELISA法检测血清转化生长因子β1(TGF-β1)水平;肺组织作病理检查和生化检测超氧化物歧化酶(SOD)、脂质过氧化产物丙二醛(MDA)、羟脯氨酸(Hyp)、抗超氧阴离子自由基(ASAR)。结果:病理检查显示,MnTBAP组肺组织损伤程度较损伤组明显减轻;生化检测结果显示,经1～12周,与照射损伤组相比较,MnTBAP治疗后SOD含量显著增加(P值均<0.001),ASAR含量显著增加(P值均<0.001),MDA含量显著减少(1周,P<0.001;4～12周,P值均<0.05),TGF-β1含量显著减少(P值均<0.001),Hyp含量1～4周没有变化,8～12周明显降低(8周,P<0.05;12周,P<0.01)。结论:MnTBAP具有抗氧化清除自由基功能,对放射性肺损伤具有保护作用,可能是潜在的放射性损伤保护剂。     

An improvement to the synthesis of deuterated meso‐tetraphenylporphyrins

An improved method for the synthesis of deuterated tetraphenylporphyrins (TPPs) is reported. In this method, deuterium labelling at the pyrrole–β‐position is increased to more than 95 at%. TPP is the most widely used synthetic porphyrin and high deuterium incorporation is essential for spectroscopic studies and kinetic studies involving relaxation processes. Copyright © 2006 John Wiley & Sons, Ltd.     

Acquired sideroblastic anaemia following progesterone therapy

We report a case of acquired sideroblastic anaemia precipitated by progesterone. On two separate occasions, over 15 years apart, the patient developed sideroblastic anaemia with iron overload shortly after the administration of progesterone. No other cause for sideroblastic anaemia was found, and treatment with folic acid, pyridoxine or androgens corrected the anaemia. In both instances removal of the progestational agent led to prompt disappearance of the anaemia as well as the ringed sideroblasts. Using a two-phase liquid culture procedure in which human peripheral blood-derived progenitor cells undergo erythroid proliferation and differentiation. we demonstrated enhanced sensitivity of the patient's erythroid progenitors to progesterone. We conclude that progesterone should be added to the list of medications known to be associated with acquired sideroblastic anaemia.     

A liposome-displayed hemagglutinin vaccine platform protects mice and ferrets from heterologous influenza virus challenge

Recombinant influenza virus vaccines based on hemagglutinin (HA) hold the potential to accelerate production timelines and improve efficacy relative to traditional egg-based platforms. Here, we assess a vaccine adjuvant system comprised of immunogenic liposomes that spontaneously convert soluble antigens into a particle format, displayed on the bilayer surface. When trimeric H3 HA was presented on liposomes, antigen delivery to macrophages was improved in vitro, and strong functional antibody responses were induced following intramuscular immunization of mice. Protection was conferred against challenge with a heterologous strain of H3N2 virus, and naive mice were also protected following passive serum transfer. When admixed with the particle-forming liposomes, immunization reduced viral infection severity at vaccine doses as low as 2 ng HA, highlighting dose-sparing potential. In ferrets, immunization induced neutralizing antibodies that reduced the upper respiratory viral load upon challenge with a more modern, heterologous H3N2 viral strain. To demonstrate the flexibility and modular nature of the liposome system, 10 recombinant surface antigens representing distinct influenza virus strains were bound simultaneously to generate a highly multivalent protein particle that with 5 ng individual antigen dosing induced antibodies in mice that specifically recognized the constituent immunogens and conferred protection against heterologous H5N1 influenza virus challenge. Taken together, these results show that stable presentation of recombinant HA on immunogenic liposome surfaces in an arrayed fashion enhances functional immune responses and warrants further attention for the development of broadly protective influenza virus vaccines.

Influenza virus is a persistent global health concern, mainly because the efficacy of current vaccines is suboptimal. The narrow breadth of protection and rapid waning of vaccination-induced antibodies along with the circulation of variant viruses necessitates annual reformulation and readministration of seasonal influenza virus vaccines. Seasonal influenza epidemics result in a global total of 3 to 5 million severe infections each year, with 290,000 to 650,000 deaths (1). The viral envelope contains two major surface glycoproteins, hemagglutinin (HA) and neuraminidase (NA), of which there are many antigenically distinct subtypes (H1-18, N1-11) (2, 3). Both proteins are subject to antigenic drift; the selection of advantageous mutations that alters antigenicity and promotes escape from preexisting immunity. In addition to seasonal epidemics, novel forms of the virus have arisen throughout history to cause pandemics with high morbidity and mortality rates. These strains generally arise by antigenic shift, a process through which two different influenza virus strains reassort their genomes within host cells. This results in an influenza virus strain to which the human population is largely naive (4, 5). The influenza virus''s capacity to circumvent immune recognition through antigenic change has been a significant barrier to the development of long-lasting immunity and highly efficacious vaccines.Currently, seasonal influenza vaccination relies on a global viral surveillance system and predictive models that determine which strains will be incorporated into the seasonal vaccine each year. However, seasonal vaccine efficacy varies significantly depending upon the degree of matching between the predicted and circulating strains and does not provide significant protection when variant seasonal or pandemic strains emerge. Most seasonal influenza vaccines are still produced in embryonated chicken eggs, which necessitates a protracted vaccine production timeline and can result in egg-adapted vaccine strains that are antigenically dissimilar from circulating strains (6, 7). To address this, future vaccine strategies should be developed that can either yield a more rapid production process or protect against a more extensive repertoire of influenza virus strains, ideally including strains that are yet to arise. Both approaches favor the application of recombinant influenza virus antigens, with molecular structures that can be precisely controlled and modified. Recombinant antigens have proven safe and effective in the Flublok vaccine (8), and several studies have assessed epitope-based vaccine strategies based on conserved protein sequences in the stalk region (9, 10) and head region (11) of recombinant HA antigens. However, for many experimental recombinant vaccines to achieve a sufficient degree of immunogenicity, recombinant antigens must be administered in conjunction with an adjuvant to increase the magnitude of the immune response that they elicit. While regulatory agencies have approved several adjuvanted influenza vaccines for clinical use (12, 13), existing adjuvants may not be optimum for recombinant proteins. New adjuvants are being developed including nanoparticle-based carriers for recombinant antigens (14, 15). Liposomes, in particular, have been developed as vaccine adjuvants (16) and have been assessed with recombinant HA in preclinical studies (17–19). In this study, to enhance liposome immunogenicity, a synthetic monophosphoryl lipid A (MPLA) variant, phosphorylated hexaacyl disaccharide (PHAD), was incorporated into the lipid membrane. MPLA is used as a component of AS01, a liposomal adjuvant currently included in the Shingrix vaccine for Herpes Zoster (20, 21).We have developed an adjuvant system based on liposomes containing cobalt-porphyrin phospholipid (CoPoP). CoPoP provides a methodology that results in biostable binding due to the sequestration of His-tagged antigens directly within the bilayer (22). The CoPoP contained in the liposomal membranes results in rapid binding of His-tag modified recombinant antigens at room temperature (RT) with straightforward coincubation. When used in this way for immunization, CoPoP particles have been shown to enhance antibody responses to recombinant antigens derived from several pathogens (23–26). CoPoP has entered human clinical trials as a component of a SARS-CoV-2 vaccine (ClinicalTrials.gov Identifier: {"type":"clinical-trial","attrs":{"text":"NCT04783311","term_id":"NCT04783311"}}NCT04783311). In this study, we assess whether CoPoP can contribute to a platform for influenza virus vaccines. Recombinant HA trimers with trimerizing foldon domains from T4 bacteriophage fibritin were used to generate antigen associated with CoPoP liposome surfaces with conformation putatively replicating the trimers formed by native HA complexes (27, 28).     

补锌、钙口服液中乳酸钙和葡萄糖酸锌含量的同时测定

 目的：研究补锌、钙口服液中葡萄糖酸锌和乳酸钙含量的测定。方法：以EDTA掩蔽Zn²⁺，间接高锰酸钾法测定钙的含量；在聚山梨酯-80存在下，以抗坏血酸为辅助配位体，于pH 4.4醋酸-醋酸钠缓冲溶液中，Zn²⁺与Meso-四-(4-甲基,3-磺基苯基)卟啉进行显色反应，应用分光光度法测定Zn²⁺。结果：高锰酸钾滴定法测定Ca²⁺得到精确结果，其S=0.03，RSD%=0.4；四元络合体系在pH4.2～5.5范围内对测锌具有较高灵敏度，最大吸收波长430 nm处的表观摩尔吸光系数为5.5×105 L·mol^-1·cm^-1。Zn(Ⅱ)浓度在0～0.18 μg·ml^-1范围内遵守比耳定律。结论：应用本法直接测定口服液中葡萄糖酸锌含量，不经分离，结果满意。     

Meso-四-(3,5-二溴-4-羟基苯)卟啉光度法检测食品包装材料铅污染

研究了Ｍｅｓｏ－四－（３，５－二溴－４－羟基苯）卟啉［Ｔ（ＤＢＨＰ）Ｐ］与铅的显色反应，建立了一种测定食品包装材料铅污染的分析方法。在０．０８ｍｏｌ／ＬＮａＯＨ介质中，铅与Ｍｅｓｏ－四－（３，５－二溴－４－羟基苯）卟啉形成１２黄色配合物，最大吸收波长为４７９ｎｍ，表观摩尔吸光系数为２．２×１０５．研究表明，体系中加入８－羟基喹啉和盐酸羟胺，既加快了显色反应速度，在常温下放置５ｍｉｎ即可完成，又大大提高测定铅的选择性，能满足复杂体系中痕量铅的测定。     

Supramolecular polymer formed by reversible self-assembly of tetrakisporphyrin

S-shaped tetrakisporphyrin 2 forms supramolecular polymeric assemblies via a complementary affinity of its bisporphyrin units in solution. The self-association constant determined by applying the isodesmic model is >10⁶ L mol⁻¹, which suggests that a sizable polymer forms at millimolar concentrations at room temperature. The electron deficient aromatic guest (TNF) binds within the molecular clefts provided by the bisporphyrin units via a charge-transfer interaction. This guest complexation completely disrupts supramolecular polymeric assembly. The long, fibrous fragments of the polymeric assemblies were characterized by atomic-force microscopy imaging of a film cast on a mica surface. The polymeric assemblies have lengths of >1μm and show a coiled structure with a higher level of organization. The approach discussed in this report concerning the quick preparation of supramolecular polymeric assemblies driven by noncovalent forces sets the stage for the preparation of a previously undescribed class of macromolecular porphyrin architectures.