Researcher, philosopher, traveler.My background is in the field of Biochemistry, but my current research deals with the computer-aided molecular design and modeling.
Background Immune checkpoint blockade (ICB) therapy targeting the programmed death 1 (PD-1)/progr... more Background Immune checkpoint blockade (ICB) therapy targeting the programmed death 1 (PD-1)/programmed death-ligand 1 (PD-L1) axis has achieved considerable success in treating a wide range of cancers. However, most patients are still resistant to ICB and lack of optimal biomarkers to predict response. Thus, uncovering the underlying cellular and molecular determinants of ICB resistance is needed to improve the efficacy of anti-PD-1/L1 therapy. Palmitoylation is mediated by a family of 23 S-acyltransferases, Asp-His‐His‐Cys type (ZDHHC) palmitoyltransferases, that precisely control various cancer-related protein functions, representing promising drug targets for cancer therapy. However, how specific ZDHHC palmitoyltransferases affect the tumour microenvironment (TME) and augment the therapeutic efficacy of ICB remains elusive. Methods Five syngeneic subcutaneous tumour models were used to demonstrate the anti-tumour activity of ZDHHC9 deficiency. Multispectral flow cytometry was use...
Background Multiple sclerosis (MS) is one of the most common autoimmune disorders characterized b... more Background Multiple sclerosis (MS) is one of the most common autoimmune disorders characterized by the infiltration of immune cells into the brain and demyelination. The unwanted immunosuppressive side effect of therapeutically successful natalizumab led us to focus on the choroid plexus (CP), a key site for the first wave of immune cell infiltration in experimental autoimmune encephalomyelitis (EAE), for the control of immune cells trafficking. Adenosine A2A receptor (A2AR) is emerging as a potential pharmacological target to control EAE pathogenesis. However, the cellular basis for the A2AR-mediated protection remains undetermined. Methods In the EAE model, we assessed A2AR expression and leukocyte trafficking determinants in the CP by immunohistochemistry and qPCR analyses. We determined the effect of the A2AR antagonist KW6002 treatment at days 8–12 or 8–14 post-immunization on T cell infiltration across the CP and EAE pathology. We determined the critical role of the CP-A2AR on...
Peptidoglycan is a cross-linked polymer responsible for maintaining the bacterial cell wall integ... more Peptidoglycan is a cross-linked polymer responsible for maintaining the bacterial cell wall integrity and morphology in Gram-negative and Gram-positive bacteria. The peptidoglycan pathway consists of the enzymatic reactions held in three steps: cytoplasmic, membrane-associated, and periplasmic. The Mur enzymes (MurA-MurF) are involved in a cytoplasmic stage. The UDP-N-acetylglucosamine enolpyruvyl transferase (MurA) enzyme is responsible for transferring the enolpyruvate group from phosphoenolpyruvate (PEP) to UDP-N-acetylglucosamine (UNAG) to form UDP-N-acetylglucosamine enolpyruvate (EP-UNAG). Fosfomycin is a natural product analogous to PEP that acts on the MurA target enzyme via binding covalently to the key cysteine residue in the active site. Similar to fosfomycin, other MurA covalent inhibitors have been described with a warhead in their structure that forms a covalent bond with the molecular target. In MurA, the nucleophilic thiolate of Cys115 is pointed as the main group in...
Computer methods can now be used on almost every stage of drug development, but the most common a... more Computer methods can now be used on almost every stage of drug development, but the most common areas of computers application are virtual screening and lead generation/optimization stages. Accurate prediction of the protein-ligand binding affinities is a crucial step in the structure-based drug design approach. Current algorithms and tools for binding energy calculation that are used upon the development of new drug candidates with an emphasize on underlying principles, advantages and limitations, software and general considerations in the selection of specific methods are discussed in the paper. Four main classes of currently available physics-based computer methods (molecular docking, end point / approximate free energy, relative binding free energy, and absolute binding free energy) are reviewed in details. Molecular docking approaches are the method of choice to filter out compounds-nonbinders, but they are not accurate enough to predict binding affinity. The end point methods ...
Perinatal inflammatory insult in preterm babies is associated with vision impairment, but the und... more Perinatal inflammatory insult in preterm babies is associated with vision impairment, but the underlying cellular mechanism is still unknown. In this study, we set out to explore whether systemic inflammatory stress affects the development of retinal ganglion cells (RGCs). Neonatal inflammation was induced by single and systemic injection of lipopolysaccharide (LPS, 1 mg/kg) at postnatal day 4 (P4). Morphological changes of RGCs were investigated by using 3D neuron reconstruction technique in Thy-1 YFPH transgenic mice at P21, of which a fraction of RGCs selectively expresses the yellow fluorescent protein (YFP). Three types (Type I, II, III) of RGCs were distinguished and classified according to the characteristic features in their dendritic field area and dendrite density. Neonatal exposure to LPS did not alter the composition of the three RGC types but induced a reorganization of dendritic architecture in the RGC Type I and II (but not Type III). The average diameter, surface are...
Identifying new potential herbicides from natural products and describing their interactions with... more Identifying new potential herbicides from natural products and describing their interactions with a double EPSP synthase mutant.
Chromatin interactions functionally affect genome architecture and gene regulation, but to date, ... more Chromatin interactions functionally affect genome architecture and gene regulation, but to date, only fresh samples must be used in Hi-C (High-through chromosome conformation capture) to keep natural chromatin conformation intact. This requirement has impeded the advancement of 3D genome research by limiting sample collection and storage options for researchers and severely limiting the number of samples that can be processed in a short time. Here, we developed a freeze substitution Hi-C (FS-Hi-C) technique that overcomes the need for fresh samples. FS-Hi-C can be used with samples stored in liquid nitrogen (LN2): the water in a vitreous form in the sample cells is replaced with ethanol via automated freeze substitution. After confirming that the FS step preserves the natural chromosome conformation during sample thawing, we tested the performance of FS-Hi-C with Drosophila melanogaster and Gossypium hirsutum. Beyond allowing the use of frozen samples and confirming that FS-Hi-C delivers robust data for generating contact heat maps and delineating A/B compartments and topologically associating domains, we found that FS-Hi-C outperforms the in situ Hi-C in terms of library quality, reproducibility, and valid interactions. Thus, FS-Hi-C will probably extend the application of 3D genome structure analysis to the vast number of experimental contexts in biological and medical research for which Hi-C methods have been unfeasible to date.
The choroid plexus (CP) is one of the key gateways regulating the entry of peripheral immune cell... more The choroid plexus (CP) is one of the key gateways regulating the entry of peripheral immune cells into the CNS. However, the neuromodulatory mechanisms of maintaining its gateway activity are not fully understood. Here, we identified adenosine A2A receptor (A2AR) activity as a regulatory signal for the activity of CP gateway under physiological conditions. In association with a tightly closed CP gateway, we found that A2AR was present at low density in the CP. The RNA-seq analysis revealed that the A2AR antagonist KW6002 affected the expression of the cell adhesion molecules' (CAMs) pathway and cell response to IFN-γ in the CP. Furthermore, blocking or activating A2AR signaling in the CP resulted in a decreased and an increased, respectively, expression of lymphocyte trafficking determinants and disruption of the tight junctions (TJs). Furthermore, A2AR signaling regulates the CP permeability. Thus, A2AR activity in the CP may serve as a therapeutic target for remodeling the immune homeostasis in the CNS with implications for the treatment of neuroimmunological disorders.
Noninfectious (autoimmune and immune-mediated) uveitis is one of the primary diseases leading to ... more Noninfectious (autoimmune and immune-mediated) uveitis is one of the primary diseases leading to blindness in the world. Due to the limitation of current first-line drugs for clinical uveitis, novel drugs and targets against uveitis are urgently needed. Ganciclovir (GCV), an FDA-approved antiviral drug, is often used to treat cytomegalovirus-induced retinitis in clinical patients. Recently, GCV was found to suppress neuroinflammation via targeting STING signaling because the STING pathway plays a pivotal role in autoimmune diseases. However, until now, the effect of GCV on non-infectious uveitis has never been explored. In this work, using the rat experimental autoimmune uveitis (EAU) model, we first found STING to be highly expressed in infiltrating cells (CD68+, CD45+, and CD4+) and retinal glial cells (Iba1+ and GFAP+) of the immunized retina. More importantly, GCV treatment can significantly suppress the initiation and progression of EAU by inhibiting infiltration of Th17 and inflammatory cells into the retina. Mechanistically, we found that GCV could reverse the levels of pro-inflammatory factors (such as IL-1β) and chemokine-related factors (such as Cxcr3), possibly via targeting the STING pathway. The present results suggest that GCV may be considered as a novel therapeutic strategy against human uveitis.
Рассмотрены основные международные индексы цитирования и наукометрические базы публикаций: Web of... more Рассмотрены основные международные индексы цитирования и наукометрические базы публикаций: Web of Knowledge, Scopus, Index Copernicus, GoogleScholar, Российский индекс научного цитирования. Объяснены принципы расчета и различия между наиболее распространенными наукометрическими показателями, такими как импакт-фактор, эйгенфактор, h-индекс, SJR, SNIP, ICV и др. Кратко описаны методы поиска списков журналов, включенных в международные индексы цитирования, а также значений вышеуказанных метрических показателей. Приведен современный список украинских биологических журналов, которые индексируются международными наукометрическими базами, и показано динамику их цитирования и индексации за период 1996-2013 гг. В конце рассмотрена новая проблема т.н. "хищных журналов" и приведены соображения относительно стратегии улучшения отображения украинской биологической периодики в международном информационном пространстве. Ключевые слова: наукометрические базы, периодика, индекс цитирования...
Fungal keratitis (FK) remains a serious clinical problem worldwide, so the ultimate goal of the t... more Fungal keratitis (FK) remains a serious clinical problem worldwide, so the ultimate goal of the treatment is to develop a minimally invasive, safe, and effective method for ocular drug delivery. Here, a minimally invasive delivery system is reported for treating FK by using a dissolving microneedle (MN)-array patch based on Poly(D,L-lactide) (PLA) and hyaluronic acid (HA). By altering the concentration of PLA, MN patches with excellent properties are modified and optimized. The 30% PLA-HA MN patches penetrate the corneal epithelial layer reversibly with no apparent ocular irritation as well as a short recovery time of less than 12 h, and increase the residence time by 2.5 h in the conjunctival sac, thereby offering higher drug bioavailability. Remarkably, the rabbit model of FK shows that the topical MN(+) patch medication exerts superior therapeutic effects compared with the conventional eye drop formulation, and also presents comparable therapeutic efficacy with that of the clinical mainstay strategy (i.e., intrastromal injection). Therefore, the MN patch, acting as an ocular drug delivery system with high efficacy and ability of rapid corneal healing, promises a cost-effective household solution for the treatment of FK, which may also lead to a new approach for treating FK in clinics.
Noninfectious (autoimmune and immune-mediated) uveitis is an ocular inflammatory disease which ca... more Noninfectious (autoimmune and immune-mediated) uveitis is an ocular inflammatory disease which can lead to blindness in severe cases. Due to the potential side effects of first-line drugs for clinical uveitis, novel drugs and targets against uveitis are still urgently needed. In the present study, using rat experimental autoimmune uveitis (EAU) model, we first found that minocycline treatment can substantially inhibit the development of EAU and improve the retinal function by suppressing the retinal microglial activation, and block the infiltration of inflammatory cells, including Th17, into the retina by decreasing the major histocompatibility complex class II (MHC II) expression in resident and infiltrating cells. Moreover, we demonstrated that minocycline treatment can remodel the gut microenvironment of EAU rats by restoring the relative abundance of Ruminococcusbromii, Streptococcushyointestinalis, and Desulfovibriosp.ABHU2SB and promoting a functional shift in the gut via reversing the levels of L-proline, allicin, aceturic acid, xanthine, and leukotriene B4, and especially increasing the production of propionic acid, histamine, and pantothenic acid. At last, we revealed that minocycline treatment can significantly attenuate the progression of EAU after inflammation onset, which may be explained by the role of minocycline in the remodeling of the gut microenvironment since selective elimination of retinal microglia on the later stages of EAU was shown to have little effect. These data clearly demonstrated that inhibition of microglial activation and remodeling of the gut microenvironment can suppress the development and progression of experimental autoimmune uveitis. Considering the excellent safety profile of minocycline in multiple clinical experiments, we suggest that minocycline may have therapeutic implications for clinical uveitis.
Human diamine oxidase (hDAO) rapidly inactivates histamine by deamination. No pharmacokinetic dat... more Human diamine oxidase (hDAO) rapidly inactivates histamine by deamination. No pharmacokinetic data are available to better understand its potential as a new therapeutic modality for diseases with excess local and systemic histamine, like anaphylaxis, urticaria or mastocytosis. After intravenous administration of recombinant hDAO to rats and mice, more than 90% of the dose disappeared from the plasma pool within 10 min. Human DAO did not only bind to various endothelial and epithelial cell lines in vitro, but was also unexpectedly internalized and visible in granule-like structures. The uptake of rhDAO into cells was dependent on neither the asialoglycoprotein-receptor (ASGP-R) nor the mannose receptor (MR) recognizing terminal galactose or mannose residues, respectively. Competition experiments with ASGP-R and MR ligands did not block internalization in vitro or rapid clearance in vivo. The lack of involvement of N-glycans was confirmed by testing various glycosylation mutants. High...
Despite the progress in deorphanization of G Protein-Coupled Receptors (GPCRs), ≈100 GPCRs are st... more Despite the progress in deorphanization of G Protein-Coupled Receptors (GPCRs), ≈100 GPCRs are still classified as orphan receptors without identified endogenous ligands and with unknown physiological functions. The lack of endogenous ligands triggering GPCR signaling has hampered the study of orphan GPCR functions. Using GPR37 as an example, we provide here the first demonstration of the channelrhodopsin 2 (ChR2)-GPCR approach to bypass the endogenous ligand and selectively activate the orphan GPCR signal by optogenetics. Inspired by the opto-XR approach, we designed the ChR2-GPR37 chimera, in which the corresponding parts of GPR37 replaced the intracellular portions of ChR2. We showed that optogenetic activation of ChR2/opto-GPR37 elicited specific GPR37 signaling, as evidenced by reduced cAMP level, enhanced ERK phosphorylation and increased motor activity, confirming the specificity of opto-GPR37 signaling. Besides, optogenetic activation of opto-GPR37 uncovered novel aspects of...
Background Immune checkpoint blockade (ICB) therapy targeting the programmed death 1 (PD-1)/progr... more Background Immune checkpoint blockade (ICB) therapy targeting the programmed death 1 (PD-1)/programmed death-ligand 1 (PD-L1) axis has achieved considerable success in treating a wide range of cancers. However, most patients are still resistant to ICB and lack of optimal biomarkers to predict response. Thus, uncovering the underlying cellular and molecular determinants of ICB resistance is needed to improve the efficacy of anti-PD-1/L1 therapy. Palmitoylation is mediated by a family of 23 S-acyltransferases, Asp-His‐His‐Cys type (ZDHHC) palmitoyltransferases, that precisely control various cancer-related protein functions, representing promising drug targets for cancer therapy. However, how specific ZDHHC palmitoyltransferases affect the tumour microenvironment (TME) and augment the therapeutic efficacy of ICB remains elusive. Methods Five syngeneic subcutaneous tumour models were used to demonstrate the anti-tumour activity of ZDHHC9 deficiency. Multispectral flow cytometry was use...
Background Multiple sclerosis (MS) is one of the most common autoimmune disorders characterized b... more Background Multiple sclerosis (MS) is one of the most common autoimmune disorders characterized by the infiltration of immune cells into the brain and demyelination. The unwanted immunosuppressive side effect of therapeutically successful natalizumab led us to focus on the choroid plexus (CP), a key site for the first wave of immune cell infiltration in experimental autoimmune encephalomyelitis (EAE), for the control of immune cells trafficking. Adenosine A2A receptor (A2AR) is emerging as a potential pharmacological target to control EAE pathogenesis. However, the cellular basis for the A2AR-mediated protection remains undetermined. Methods In the EAE model, we assessed A2AR expression and leukocyte trafficking determinants in the CP by immunohistochemistry and qPCR analyses. We determined the effect of the A2AR antagonist KW6002 treatment at days 8–12 or 8–14 post-immunization on T cell infiltration across the CP and EAE pathology. We determined the critical role of the CP-A2AR on...
Peptidoglycan is a cross-linked polymer responsible for maintaining the bacterial cell wall integ... more Peptidoglycan is a cross-linked polymer responsible for maintaining the bacterial cell wall integrity and morphology in Gram-negative and Gram-positive bacteria. The peptidoglycan pathway consists of the enzymatic reactions held in three steps: cytoplasmic, membrane-associated, and periplasmic. The Mur enzymes (MurA-MurF) are involved in a cytoplasmic stage. The UDP-N-acetylglucosamine enolpyruvyl transferase (MurA) enzyme is responsible for transferring the enolpyruvate group from phosphoenolpyruvate (PEP) to UDP-N-acetylglucosamine (UNAG) to form UDP-N-acetylglucosamine enolpyruvate (EP-UNAG). Fosfomycin is a natural product analogous to PEP that acts on the MurA target enzyme via binding covalently to the key cysteine residue in the active site. Similar to fosfomycin, other MurA covalent inhibitors have been described with a warhead in their structure that forms a covalent bond with the molecular target. In MurA, the nucleophilic thiolate of Cys115 is pointed as the main group in...
Computer methods can now be used on almost every stage of drug development, but the most common a... more Computer methods can now be used on almost every stage of drug development, but the most common areas of computers application are virtual screening and lead generation/optimization stages. Accurate prediction of the protein-ligand binding affinities is a crucial step in the structure-based drug design approach. Current algorithms and tools for binding energy calculation that are used upon the development of new drug candidates with an emphasize on underlying principles, advantages and limitations, software and general considerations in the selection of specific methods are discussed in the paper. Four main classes of currently available physics-based computer methods (molecular docking, end point / approximate free energy, relative binding free energy, and absolute binding free energy) are reviewed in details. Molecular docking approaches are the method of choice to filter out compounds-nonbinders, but they are not accurate enough to predict binding affinity. The end point methods ...
Perinatal inflammatory insult in preterm babies is associated with vision impairment, but the und... more Perinatal inflammatory insult in preterm babies is associated with vision impairment, but the underlying cellular mechanism is still unknown. In this study, we set out to explore whether systemic inflammatory stress affects the development of retinal ganglion cells (RGCs). Neonatal inflammation was induced by single and systemic injection of lipopolysaccharide (LPS, 1 mg/kg) at postnatal day 4 (P4). Morphological changes of RGCs were investigated by using 3D neuron reconstruction technique in Thy-1 YFPH transgenic mice at P21, of which a fraction of RGCs selectively expresses the yellow fluorescent protein (YFP). Three types (Type I, II, III) of RGCs were distinguished and classified according to the characteristic features in their dendritic field area and dendrite density. Neonatal exposure to LPS did not alter the composition of the three RGC types but induced a reorganization of dendritic architecture in the RGC Type I and II (but not Type III). The average diameter, surface are...
Identifying new potential herbicides from natural products and describing their interactions with... more Identifying new potential herbicides from natural products and describing their interactions with a double EPSP synthase mutant.
Chromatin interactions functionally affect genome architecture and gene regulation, but to date, ... more Chromatin interactions functionally affect genome architecture and gene regulation, but to date, only fresh samples must be used in Hi-C (High-through chromosome conformation capture) to keep natural chromatin conformation intact. This requirement has impeded the advancement of 3D genome research by limiting sample collection and storage options for researchers and severely limiting the number of samples that can be processed in a short time. Here, we developed a freeze substitution Hi-C (FS-Hi-C) technique that overcomes the need for fresh samples. FS-Hi-C can be used with samples stored in liquid nitrogen (LN2): the water in a vitreous form in the sample cells is replaced with ethanol via automated freeze substitution. After confirming that the FS step preserves the natural chromosome conformation during sample thawing, we tested the performance of FS-Hi-C with Drosophila melanogaster and Gossypium hirsutum. Beyond allowing the use of frozen samples and confirming that FS-Hi-C delivers robust data for generating contact heat maps and delineating A/B compartments and topologically associating domains, we found that FS-Hi-C outperforms the in situ Hi-C in terms of library quality, reproducibility, and valid interactions. Thus, FS-Hi-C will probably extend the application of 3D genome structure analysis to the vast number of experimental contexts in biological and medical research for which Hi-C methods have been unfeasible to date.
The choroid plexus (CP) is one of the key gateways regulating the entry of peripheral immune cell... more The choroid plexus (CP) is one of the key gateways regulating the entry of peripheral immune cells into the CNS. However, the neuromodulatory mechanisms of maintaining its gateway activity are not fully understood. Here, we identified adenosine A2A receptor (A2AR) activity as a regulatory signal for the activity of CP gateway under physiological conditions. In association with a tightly closed CP gateway, we found that A2AR was present at low density in the CP. The RNA-seq analysis revealed that the A2AR antagonist KW6002 affected the expression of the cell adhesion molecules' (CAMs) pathway and cell response to IFN-γ in the CP. Furthermore, blocking or activating A2AR signaling in the CP resulted in a decreased and an increased, respectively, expression of lymphocyte trafficking determinants and disruption of the tight junctions (TJs). Furthermore, A2AR signaling regulates the CP permeability. Thus, A2AR activity in the CP may serve as a therapeutic target for remodeling the immune homeostasis in the CNS with implications for the treatment of neuroimmunological disorders.
Noninfectious (autoimmune and immune-mediated) uveitis is one of the primary diseases leading to ... more Noninfectious (autoimmune and immune-mediated) uveitis is one of the primary diseases leading to blindness in the world. Due to the limitation of current first-line drugs for clinical uveitis, novel drugs and targets against uveitis are urgently needed. Ganciclovir (GCV), an FDA-approved antiviral drug, is often used to treat cytomegalovirus-induced retinitis in clinical patients. Recently, GCV was found to suppress neuroinflammation via targeting STING signaling because the STING pathway plays a pivotal role in autoimmune diseases. However, until now, the effect of GCV on non-infectious uveitis has never been explored. In this work, using the rat experimental autoimmune uveitis (EAU) model, we first found STING to be highly expressed in infiltrating cells (CD68+, CD45+, and CD4+) and retinal glial cells (Iba1+ and GFAP+) of the immunized retina. More importantly, GCV treatment can significantly suppress the initiation and progression of EAU by inhibiting infiltration of Th17 and inflammatory cells into the retina. Mechanistically, we found that GCV could reverse the levels of pro-inflammatory factors (such as IL-1β) and chemokine-related factors (such as Cxcr3), possibly via targeting the STING pathway. The present results suggest that GCV may be considered as a novel therapeutic strategy against human uveitis.
Рассмотрены основные международные индексы цитирования и наукометрические базы публикаций: Web of... more Рассмотрены основные международные индексы цитирования и наукометрические базы публикаций: Web of Knowledge, Scopus, Index Copernicus, GoogleScholar, Российский индекс научного цитирования. Объяснены принципы расчета и различия между наиболее распространенными наукометрическими показателями, такими как импакт-фактор, эйгенфактор, h-индекс, SJR, SNIP, ICV и др. Кратко описаны методы поиска списков журналов, включенных в международные индексы цитирования, а также значений вышеуказанных метрических показателей. Приведен современный список украинских биологических журналов, которые индексируются международными наукометрическими базами, и показано динамику их цитирования и индексации за период 1996-2013 гг. В конце рассмотрена новая проблема т.н. "хищных журналов" и приведены соображения относительно стратегии улучшения отображения украинской биологической периодики в международном информационном пространстве. Ключевые слова: наукометрические базы, периодика, индекс цитирования...
Fungal keratitis (FK) remains a serious clinical problem worldwide, so the ultimate goal of the t... more Fungal keratitis (FK) remains a serious clinical problem worldwide, so the ultimate goal of the treatment is to develop a minimally invasive, safe, and effective method for ocular drug delivery. Here, a minimally invasive delivery system is reported for treating FK by using a dissolving microneedle (MN)-array patch based on Poly(D,L-lactide) (PLA) and hyaluronic acid (HA). By altering the concentration of PLA, MN patches with excellent properties are modified and optimized. The 30% PLA-HA MN patches penetrate the corneal epithelial layer reversibly with no apparent ocular irritation as well as a short recovery time of less than 12 h, and increase the residence time by 2.5 h in the conjunctival sac, thereby offering higher drug bioavailability. Remarkably, the rabbit model of FK shows that the topical MN(+) patch medication exerts superior therapeutic effects compared with the conventional eye drop formulation, and also presents comparable therapeutic efficacy with that of the clinical mainstay strategy (i.e., intrastromal injection). Therefore, the MN patch, acting as an ocular drug delivery system with high efficacy and ability of rapid corneal healing, promises a cost-effective household solution for the treatment of FK, which may also lead to a new approach for treating FK in clinics.
Noninfectious (autoimmune and immune-mediated) uveitis is an ocular inflammatory disease which ca... more Noninfectious (autoimmune and immune-mediated) uveitis is an ocular inflammatory disease which can lead to blindness in severe cases. Due to the potential side effects of first-line drugs for clinical uveitis, novel drugs and targets against uveitis are still urgently needed. In the present study, using rat experimental autoimmune uveitis (EAU) model, we first found that minocycline treatment can substantially inhibit the development of EAU and improve the retinal function by suppressing the retinal microglial activation, and block the infiltration of inflammatory cells, including Th17, into the retina by decreasing the major histocompatibility complex class II (MHC II) expression in resident and infiltrating cells. Moreover, we demonstrated that minocycline treatment can remodel the gut microenvironment of EAU rats by restoring the relative abundance of Ruminococcusbromii, Streptococcushyointestinalis, and Desulfovibriosp.ABHU2SB and promoting a functional shift in the gut via reversing the levels of L-proline, allicin, aceturic acid, xanthine, and leukotriene B4, and especially increasing the production of propionic acid, histamine, and pantothenic acid. At last, we revealed that minocycline treatment can significantly attenuate the progression of EAU after inflammation onset, which may be explained by the role of minocycline in the remodeling of the gut microenvironment since selective elimination of retinal microglia on the later stages of EAU was shown to have little effect. These data clearly demonstrated that inhibition of microglial activation and remodeling of the gut microenvironment can suppress the development and progression of experimental autoimmune uveitis. Considering the excellent safety profile of minocycline in multiple clinical experiments, we suggest that minocycline may have therapeutic implications for clinical uveitis.
Human diamine oxidase (hDAO) rapidly inactivates histamine by deamination. No pharmacokinetic dat... more Human diamine oxidase (hDAO) rapidly inactivates histamine by deamination. No pharmacokinetic data are available to better understand its potential as a new therapeutic modality for diseases with excess local and systemic histamine, like anaphylaxis, urticaria or mastocytosis. After intravenous administration of recombinant hDAO to rats and mice, more than 90% of the dose disappeared from the plasma pool within 10 min. Human DAO did not only bind to various endothelial and epithelial cell lines in vitro, but was also unexpectedly internalized and visible in granule-like structures. The uptake of rhDAO into cells was dependent on neither the asialoglycoprotein-receptor (ASGP-R) nor the mannose receptor (MR) recognizing terminal galactose or mannose residues, respectively. Competition experiments with ASGP-R and MR ligands did not block internalization in vitro or rapid clearance in vivo. The lack of involvement of N-glycans was confirmed by testing various glycosylation mutants. High...
Despite the progress in deorphanization of G Protein-Coupled Receptors (GPCRs), ≈100 GPCRs are st... more Despite the progress in deorphanization of G Protein-Coupled Receptors (GPCRs), ≈100 GPCRs are still classified as orphan receptors without identified endogenous ligands and with unknown physiological functions. The lack of endogenous ligands triggering GPCR signaling has hampered the study of orphan GPCR functions. Using GPR37 as an example, we provide here the first demonstration of the channelrhodopsin 2 (ChR2)-GPCR approach to bypass the endogenous ligand and selectively activate the orphan GPCR signal by optogenetics. Inspired by the opto-XR approach, we designed the ChR2-GPR37 chimera, in which the corresponding parts of GPR37 replaced the intracellular portions of ChR2. We showed that optogenetic activation of ChR2/opto-GPR37 elicited specific GPR37 signaling, as evidenced by reduced cAMP level, enhanced ERK phosphorylation and increased motor activity, confirming the specificity of opto-GPR37 signaling. Besides, optogenetic activation of opto-GPR37 uncovered novel aspects of...
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Papers by Serhii Vakal