Adventures with Cyanobacteria: A Personal Perspective

Cyanobacteria, or the blue-green algae as they used to be called until 1974, are the oldest oxygenic photosynthesizers. We summarize here adventures with them since the early 1960s. This includes studies on light absorption by cyanobacteria, excitation energy transfer at room temperature down to liquid helium temperature, fluorescence (kinetics as well as spectra) and its relationship to photosynthesis, and afterglow (or thermoluminescence) from them. Further, we summarize experiments on their two-light reaction – two-pigment system, as well as the unique role of bicarbonate (hydrogen carbonate) on the electron-acceptor side of their photosystem II, PSII. This review, in addition, includes a discussion on the regulation of changes in phycobilins (mostly in PSII) and chlorophyll a (Chl a; mostly in photosystem I, PSI) under oscillating light, on the relationship of the slow fluorescence increase (the so-called S to M rise, especially in the presence of diuron) in minute time scale with the so-called state-changes, and on the possibility of limited oxygen evolution in mixotrophic PSI (minus) mutants, up to 30 min, in the presence of glucose. We end this review with a brief discussion on the position of cyanobacteria in the evolution of photosynthetic systems

The interaction of polyhydroxyalkanoate polymer group with cells and tissues

In the recent literature devoted to the results of the study, formulation and application of polyhydroxyalkanoates (PHA), contains a wealth of experimental and clinical data on efficacy and safety of using these polymers with biomedical goals. However, the application of PHA, both independently and in combination with other drugs and substances that must surely have its advantages and disadvantages. It should be noted the complete absence, information on contraindications and complications of the PHA, and insufficient data on the patterns of degradation of PHA in vivo, and morphological processes connected with it of scientific literature.У літературі останніх років, присвяченій результатам вивчення, отримання і застосування полігідроксиалканоатів (ПГА), міститься безліч експериментальних і клінічних даних щодо ефективності і безпеки використання цих полімерів для медико-біологічних потреб. Проте застосування ПГА як самостійно, так і в комбінації з іншими препаратами і речовинами, поза сумнівом, повинно мати свої переваги і свої недоліки. Варто відмітити повну відсутність у науковій літературі відомостей про протипоказання і ускладнення за використання ПГА, а також недостатню кількість даних стосовно закономірностей деградації ПГА у живому організмі і морфологічних процесах, з цим пов’язаних.В литературе последних лет, посвященной результатам изучения, получения и применения полигидроксиалканоатов (ПГА), содержится множество экспериментальных и клинических данных об эффективности и безопасности использования этих полимеров в медико-биологических целях. Однако применение ПГА как самостоятельно, так и в комбинации с другими препаратами и веществами, несомненно, должно иметь свои преимущества и свои недостатки. Следует отметить полное отсутствие в научной литературе сведений о противопоказаниях и осложнениях при использовании ПГА, а также недостаточное количество данных о закономерностях деградации ПГА в живом организме и морфологических процессах, с этим связанных

EFFECT OF M2 MACROPHAGE-DERIVED SOLUBLE FACTORS ON DIFFERENTIATION OF SH-SY5Y CELLS

Macrophages play a key role in triggering and regulation of neuroregeneration. The characteristic feature of macrophages is pronounced plasticity, which manifests itself in the ability of macrophages to change their functional phenotype depending on the micromilieu. Apoptotic cell clearance (efferocytosis) is an important inducer of a macrophage polarization to M2 phenotype under pathological settings. Previously, we have developed an original protocol for the generation of M2-like macrophages, polarized by efferocytosis under serum-deprived conditions (M2 (LS), Low Serum). The present study was aimed to assess a neuroregenerative potential of M2 (LS) macrophages. We studied their effect on the differentiation of SH-SY5Y cells in comparison with retinoic acid (RA). As the morphological criteria of differentiation we have assessed the relative content of differentiated cells, i.e., cells with a neurite length exceeding the cell body length, and the average neurite length on days 3, 7, and 13. The ratio of neuron-like (N-type) and epithelial-like (S-type) cells in cultures was also assessed. SH-SY5Y cells were characterized by a low level of spontaneous differentiation, both under standard conditions (10% FBS) and serum deprivation (1% FBS). Upon RA treatment, SH-SY5Y cells stopped proliferating and underwent neuronal differentiation. Cultivation of SH-SY5Y cells in the presence of M2 (LS) conditioned medium also led to a significant increase in the relative content of differentiated cells, the average length of neurite-like processes, as well as a change in the balance of S- and N-type cells towards a pronounced predominance of the latter. The morphological features of differentiation were significantly less pronounced at early stage (day 3) of differentiation as compared with the RA-induced changes and reached the level of positive control only at later stages (day 13) (p < 0.05). In contrast to retinoic acid, M2 (LS) conditioned medium induced neuronal differentiation of SH-SY5Y cells without suppressing their proliferative activity. The data obtained may indicate a high neuroregenerative potential of M2 macrophages in vitro, which is realized through soluble factors and manifests itself in promoting SH-SY5Y differentiation

EVALUATION OF THE EFFICIENCY OF COMBINATION THERAPY WITH HYALURONATES IN PATIENTS WITH HIP OSTEOARTHROSIS

Objective: to make the results of treatment for coxarthrosis better via prosthetic synovial fluid replacement, by improving drug delivery into the joint cavity. Subjects and methods. The clinical trial enrolled 359 outpatients treated for coxarthrosis. A control group comprised 50 patients receiving the intraarticular combination drug Alflutop under ultrasound (US) guidance. A study group included 309 patients treated using a new three-stage procedure. At stage 1, the patients were given periarticular injections of the current enzyme preparation longidase with a hyaluronidase activity of 3000 IU. At stage 2, postisometric relaxation sessions were performed. At stage 3, after defining the optimal access, synovial fluid prosthetic devices were inserted into the joint cavity under US guidance (a total of 2-3 injections) once weekly. To evaluate the efficiency of the developed treatment option, the authors used a number of standard tests, WOMAC index, Leken's index, integral index of lower limb dysfunction, needs for nonsteroidal anti-inflammatory drugs; total treatment scores given by a physician and a patient; quality of life estimation using the SF-36 questionnaire. Results. The developed treatment option could significantly reduce the clinical and functional WOMAC index and Leken's index, and inadequate joint function in the immediate period and a year after the treatment performed. It also considerably improved quality of life in patients with hip osteoarthrosis, which appeared as a significant increase of its rating according to eight SF-36 scales during more than a year

Влияние мультипотентных стромальных клеток, адсорбированных на полимере молочной кислоты, на воспалительную реакцию после его экспериментальной имплантации

Цель. Изучить влияние аутологичных мезенхимальных мультипотентных стромальных клеток (ММСК) костномозгового происхождения, адсорбированных на полимере молочной кислоты - полилактиде (ПЛ), на воспалительный процесс после экспериментальной имплантации этого полимера. Материалы и методы. С помощью световой микроскопии с применением люминесценции изучали изменения подкожно-жировой клетчатки крыс после имплантации ПЛ с пассивно адсорбированными на поверхности ММСК с трансфицированным геном GFP и дополнительно окрашенными Vybrant® CM-Dil клеточными мембранами. Результаты. Спустя 1 нед рядом с имплантированным ПЛ с адсорбированными ММСК методами флуоресцентной микроскопии были найдены фибробластоподобные клетки с ярким и равномерным свечением цитоплазмы при использовании родаминового фильтра. На 2-й неделе возле ПЛ присутствовали макрофаги разных размеров и форм, с интенсивной флуоресценцией множества включений в условиях применения родаминового фильтра. Далее яркость люминесценции и количество светящихся объектов прогрессивно снижались вплоть до почти полного исчезновения к 4-й неделе. В результате адсорбции на ПЛ ММСК уменьшается объем склерозированной клетчатки с увеличением в ней числа сосудов на 1 - 2-й неделях после имплантации. В этой клетчатке в течение 1-й недели численная плотность всех лейкоцитов и лимфоцитов ниже. Типичная капсула вокруг имплантированного ПЛ у крыс формируется только к 3-й неделе. Объем капсулы, ее васкуляризация и цитограмма лейкоцитов не зависели от адсорбции ММСК. Выводы. При имплантации ПЛ с адсорбированными ММСК уже к 2-й неделе эти клеточные элементы из тканей фагоцитируются макрофагами, ММСК и их детрит полностью элиминируются из места введения к 4-й неделе. Адсорбция ММСК на ПЛ способствует уменьшению выраженности склероза и воспалительных изменений подкожно-жировой клетчатки при увеличении ее васкуляризации на 1 - 2-й неделях после имплантации. Сроки формирования капсулы вокруг ПЛ, а также ее структура не связаны с использованием клеточных технологий

Water oxidation by photosystem II is the primary source of electrons for sustained H2 photoproduction in nutrient-replete green algae

The unicellular green alga Chlamydomonas reinhardtii is capable of photosynthetic H2 production. H2 evolution occurs under anaerobic conditions and is difficult to sustain due to 1) competition between [FeFe]-hydrogenase (H2ase), the key enzyme responsible for H2 metabolism in algae, and the Calvin–Benson–Bassham (CBB) cycle for photosynthetic reductants and 2) inactivation of H2ase by O2 coevolved in photosynthesis. Recently, we achieved sustainable H2 photoproduction by shifting algae from continuous illumination to a train of short (1 s) light pulses, interrupted by longer (9 s) dark periods. This illumination regime prevents activation of the CBB cycle and redirects photosynthetic electrons to H2ase. Employing membrane-inlet mass spectrometry and H18O2, we now present clear evidence that efficient H2 photoproduction in pulse-illuminated algae depends primarily on direct water biophotolysis, where water oxidation at the donor side of photosystem II (PSII) provides electrons for the reduction of protons by H2ase downstream of photosystem I. This occurs exclusively in the absence of CO2 fixation, while with the activation of the CBB cycle by longer (8 s) light pulses the H2 photoproduction ceases and instead a slow overall H2 uptake is observed. We also demonstrate that the loss of PSII activity in DCMU-treated algae or in PSII-deficient mutant cells can be partly compensated for by the indirect (PSII-independent) H2 photoproduction pathway, but only for a short (2 yield.<br /

Localisation and interactions of the Vipp1 protein in cyanobacteria

Biotechnology and Biological Sciences Research Council. Grant Number: BB/G021856. Deutsche Forschungsgemeinschaft. Grant Number: FOR 929, SCHN 690/3-1. European Commission. Grant Number: FP7-PEOPLE-2009-IEF 254575. NFR. Grant Numbers: 192436, 197119. OCISB. Royal Society and Engineering and Physical Sciences Research Council. Grant Number: EP/G0061009/

Effect of soluble factors of macrophages polarized by efferocytosis on neuronal density in the frontal cortex and hippocampus of mice in a model of stress-induced depression

Recently, there has been a steady increase in depressive disorders, which occupy an important place in the structure of the causes of disability. In the pathogenesis of depression, an important role is played by neuroinflammation, which is associated with impaired adult neurogenesis. Notably, neuroinflammation is partially reversible, and the leading role in the initiation and regulation of neuroregeneration is given to macrophages. Opposite states of macrophage activation are classically activated M1 and alternatively activated M2 macrophages, characterized, respectively, by pro- and anti-inflammatory activity. A balance shift towards M2 macrophages has been considered as a new therapeutic strategy of psycho-neurological disorders. One of the inducers of the M2 phenotype is the efferocytosis. We have previously developed an original protocol for the generation of human macrophages under conditions of deficiency of growth / serum factors, in which M2 phenotype is formed through efferocytosis. Macrophages (M2(LS), LS – Low Serum) obtained according to this protocol express M2-associated markers, and are characterized by high production of growth and pro- angiogenic factors (IGF-1, VEGF, BDNF, EGF, FGF-basic, etc.), which can suppress inflammation and stimulate neuroregeneration / neuroplasticity. In the model of stress-induced depression, the antidepressant effect of soluble factors of M2(LS) macrophages was shown, accompanied by a decrease in the level of pro- inflammatory cytokines in certain brain structures. However, the effect of M2(LS) factors on neurogenesis remained unexplored. In the present work, which is a continuation of the aforementioned study, we analyzed the effect of intranasal administration of M2(LS) soluble factors on neuronal density in different brain areas – the frontal cortex and hippocampus – of depression-like mice. The results obtained showed that neuronal density in the frontal cortex, CA1 and CA3 zones of the hippocampus, was significantly higher in mice with intranasal administration of M2(LS) conditioned medium than in depression-like mice, and reached the level of neuronal density in intact animals. These results may indicate the neuroregenerative activity of M2(LS) macrophages in the model of stress-induced depression, which is mediated through soluble factors and manifests itself in an increase in the density of neurons in the brain