scholarly journals Screening of Compounds for Anti-tuberculosis Activity, and in vitro and in vivo Evaluation of Potential Candidates

2021 ◽  
Vol 12 ◽  
Author(s):  
Wei Zhou ◽  
Bing Yang ◽  
Yanyan Zou ◽  
Khaista Rahman ◽  
Xiaojian Cao ◽  
...  
Keyword(s):  
Small Molecules ◽  
Point Mutation ◽  
First Line ◽  
In Vivo Evaluation ◽  
Computational Docking ◽  
Strong Inflammatory Response ◽  
Tuberculosis Activity

Tuberculosis (TB) is a debilitating infectious disease responsible for more than one million deaths per year. The emergence of drug-resistant TB poses an urgent need for the development of new anti-TB drugs. In this study, we screened a library of over 4,000 small molecules and found that orbifloxacin and the peptide AK15 possess significant bactericidal activity against Mycobacterium tuberculosis (Mtb) in vitro. Orbifloxacin also showed an effective ability on the clearance of intracellular Mtb and protect mice from a strong inflammatory response but not AK15. Moreover, we identified 17 nucleotide mutations responsible for orbifloxacin resistance by whole-genome sequencing. A critical point mutation (D94G) of the DNA gyrase (gyrA) gene was found to be the key role of resistance to orbifloxacin. The computational docking revealed that GyrA D94G point mutation can disrupt the orbifloxacin–protein gyrase interactions mediated by magnesium ion bridge. Overall, this study indicated the potential ability of orbifloxacin as an anti-tuberculosis drug, which can be used either alone or in combination with first-line antibiotics to achieve more effective therapy on TB.

Double Lumen Needle in Unipuncture Dialysis Type Double Headpump

1981 ◽  
Vol 4 (2) ◽  
pp. 72-74 ◽  
Author(s):  
R. Vanholder ◽  
M. De Paepe ◽  
N.A. Hoenich ◽  
S. Ringoir ◽  
A. De Cubber ◽  
...  
Keyword(s):  
Small Molecules ◽  
Vascular Access ◽  
In Vitro Studies ◽  
Double Lumen ◽  
Single Lumen

Single needle dialysis is used as a method of vascular access in many European dialysis centres. However, recirculation has been incriminated as a disadvantage of this procedure. According to in vitro studies, recirculation should be limited to a minimum when using double lumen needles. The present study makes an in vivo comparison between single and double lumen needles in unipuncture (single needle) dialysis of the type double headpump (Bellco, BL 760) and studies the role of recirculation in dialysis performance. Although recirculation is significantly reduced with the double lumen needle, compared to the single lumen needle, the clearance of small molecules is not significantly different for both needle types.

scholarly journals The Role of Small Molecules and Their Effect on the Molecular Mechanisms of Early Retinal Organoid Development

2021 ◽  
Vol 22 (13) ◽  
pp. 7081
Author(s):  
Philip E. Wagstaff ◽  
Andrea Heredero Berzal ◽  
Camiel J. F. Boon ◽  
Peter M. J. Quinn ◽  
Anneloor L. M. A. ten Asbroek ◽  
...  
Keyword(s):  
Small Molecules ◽  
Signaling Pathways ◽  
Hedgehog Signaling ◽  
Molecular Mechanisms ◽  
Retinal Development ◽  
Comprehensive Overview ◽  
Or Efficiency

Early in vivo embryonic retinal development is a well-documented and evolutionary conserved process. The specification towards eye development is temporally controlled by consecutive activation or inhibition of multiple key signaling pathways, such as the Wnt and hedgehog signaling pathways. Recently, with the use of retinal organoids, researchers aim to manipulate these pathways to achieve better human representative models for retinal development and disease. To achieve this, a plethora of different small molecules and signaling factors have been used at various time points and concentrations in retinal organoid differentiations, with varying success. Additions differ from protocol to protocol, but their usefulness or efficiency has not yet been systematically reviewed. Interestingly, many of these small molecules affect the same and/or multiple pathways, leading to reduced reproducibility and high variability between studies. In this review, we make an inventory of the key signaling pathways involved in early retinogenesis and their effect on the development of the early retina in vitro. Further, we provide a comprehensive overview of the small molecules and signaling factors that are added to retinal organoid differentiation protocols, documenting the molecular and functional effects of these additions. Lastly, we comparatively evaluate several of these factors using our established retinal organoid methodology.

scholarly journals Eosinophils and Neutrophils Eliminate Migrating Strongyloides ratti Larvae at the Site of Infection in the Context of Extracellular DNA Trap Formation

2021 ◽  
Vol 12 ◽  
Author(s):  
Alexandra Ehrens ◽  
Nikolas Rüdiger ◽  
Lennart Heepmann ◽  
Lara Linnemann ◽  
Wiebke Hartmann ◽  
...  
Keyword(s):  
Extracellular Dna ◽  
Parasitic Nematodes ◽  
Intestinal Helminth ◽  
Dependent Manner ◽  
Helminth Parasites ◽  
First Line ◽  
Innate And Adaptive Immunity

Parasitic nematodes such as hookworms actively penetrate the skin of their hosts, encountering skin-resident innate immune cells that represent the host´s first line of defense. Here we use Strongyloides ratti as a model for an intestinal helminth parasite with tissue migrating stages. We show that interception and killing of migrating larvae in mice during a 1st infection occurred predominantly in skin and muscle tissue before larvae migrated via lung and head tissue to the intestine. Inhibition of larval migration was even more efficient in immune mice during a 2nd infection where larvae barely left the site of entry i.e. the foot. Using cell-deficient mice we show that interception in the tissue was predominantly mediated by neutrophils and eosinophils while basophils and mast cells were dispensable in vivo. Likewise, neutrophils and eosinophils inhibited S. ratti L3 motility in vitro in the context of ETosis. Thereby eosinophils were strictly dependent on the presence of anti-S. ratti antibodies while neutrophils inhibited L3 motility as such. Also, MPO and MMP-9 were released by neutrophils in response to L3 alone, but immune plasma further stimulated MPO release in an antibody-dependent manner. In summary, our findings highlight the central role of the skin as first line of defense against helminth parasites in both, innate and adaptive immunity.

Antibacterial and Antibiofilm Activity of Cationic Small Molecules with Spatial Positioning of Hydrophobicity: An in Vitro and in Vivo Evaluation

2016 ◽  
Vol 59 (23) ◽  
pp. 10750-10762 ◽  
Author(s):  
Jiaul Hoque ◽  
Mohini M. Konai ◽  
Shanola S. Sequeira ◽  
Sandip Samaddar ◽  
Jayanta Haldar
Keyword(s):  
Small Molecules ◽  
Antibiofilm Activity ◽  
In Vivo Evaluation ◽  
Spatial Positioning

scholarly journals Correction: In vitro–in vivo evaluation of hyaluronic acid-based amphiphilic copolymers for tumour targeted delivery: the role of hydrophobic groups

RSC Advances ◽  
2017 ◽  
Vol 7 (48) ◽  
pp. 30049-30050
Author(s):  
Zhihong Zhu ◽  
Dongyang Li ◽  
Yuenan Li ◽  
Xinggang Yang ◽  
Weisan Pan
Keyword(s):  
Hyaluronic Acid ◽  
Targeted Delivery ◽  
Amphiphilic Copolymers ◽  
In Vivo Evaluation

Correction for ‘In vitro–in vivo evaluation of hyaluronic acid-based amphiphilic copolymers for tumour targeted delivery: the role of hydrophobic groups’ by Zhihong Zhu et al., RSC Adv., 2017, 7, 23942–23953.

Techniques for Research in Deer Antlers, the Sole Mammalian Organ which undergoes Epimorphic Regeneration

2020 ◽  
Author(s):  
Chunyi Li
Keyword(s):  
Opportunity To Learn ◽  
Research Field ◽  
In Vivo Evaluation ◽  
Epimorphic Regeneration ◽  
Organ Regeneration ◽  
Transplantation Technique ◽  
Antler Development

The annual renewal of deer antlers offers the only opportunity to learn how nature has solved the problem of mammalian organ regeneration. Promotion of the antler model to the field of regenerative biology and medicine, however, requires understanding the mechanism underlying the generation and regeneration of this unique organ. During the course of nearly four decades of antler research, we developed a number of techniques specifically for carrying out the investigation of deer antler biology. In this paper, I summarized six of them including 1) Mechanical disintegration of antler stem cell (AnSC) tissue; 2) In vivo investigation of the interactions between antlerogenic tissue and overlying skin; 3) In vivo identification of skin tissue components required for establishing interactions with AP; 4) Alternative transplantation technique to reduce AP quantity required for antler induction; 5) In vivo evaluation of the role of interposing tissue layers in antler generation; 6) In vitro identification of the interactive molecules between AnSCs and niche cell populations. I believe if these techniques are adopted in the antler research field, it would greatly facilitate the progress for revealing the mechanisms of antler development and ultimately benefit regenerative medicine in general.

scholarly journals Role of HTRA1 in bone formation and regeneration: In vitro and in vivo evaluation

PLoS ONE ◽  
2017 ◽  
Vol 12 (7) ◽  
pp. e0181600 ◽  
Author(s):  
Gladys Filliat ◽  
Ali Mirsaidi ◽  
André N. Tiaden ◽  
Gisela A. Kuhn ◽  
Franz E. Weber ◽  
...  
Keyword(s):  
Bone Formation ◽  
In Vivo Evaluation ◽  
Regeneration In Vitro

scholarly journals Inhibition of the Methyltransferase G9a with Small Molecules As a New Therapeutic Strategy for Treatment of Hematological Malignancies

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 3532-3532 ◽  
Author(s):  
Edurne San José-Enériz ◽  
Xabier Agirre ◽  
Obdulia Rabal ◽  
Sergio Roa ◽  
Amaia Vilas-Zornoza ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Western Blot ◽  
Small Molecules ◽  
Cell Lines ◽  
Hematological Malignancies ◽  
Epigenetic Drugs ◽  
Inhibitory Molecules

Abstract The indisputable role of epigenetics in hematological malignancies, along with the fact that unfavorable epigenetic alterations might be reversible, has favored the development of novel epigenetic drugs. Although according to the Structural Genomics Consortium there are 377 known epigenetic proteins, currently most epigenetic drugs are inhibitors of DNA methyltransferases (DNMTS) and histone deacetylases (HDACS). Therefore, many epigenetic targets remain to be discovered and exploited within the vast field of epigenetics. With the aim of identify novel epigenetic targets we carried out a screening using small interfering RNAs (siRNAS): we interfered the expression of 134 genes belonging to the main protein families implicated in the epigenetic mechanism regulation (methyltransferases, demethylases, bromodomain proteins and MBT proteins) in several cell lines of Acute Lymphoblastic Leukemia (ALL), Multiple Myeloma (MM) and Lymphoma and determined the effect of the interference in cell proliferation. Those candidates with a decrease in cell proliferation greater than 40% in all cell lines analyzed were selected. In this way, we identified the histone H3 Lysine 9 (K9H3) methyltransferase G9a as a potential target in hematological malignancies. In parallel, ChIP on chip assays was performed, and a considerable number of genes showed an increase in K9H3me2 and K9H3me3 marks in ALL cell lines in comparison with healthy donor samples, suggesting an important role of G9a in this disease. In order to corroborate the results obtained, we nucleofected a greater number of cell lines with two different siRNAs against G9a. As expected, inhibition of G9a expression induced a significant decrease in cell proliferation. We verified that G9a was overexpressed at mRNA and protein level in ALL, AML and MM cell lines and ALL primary samples by Q-RT-PCR and western blot, respectively. Besides, treatment of ALL, AML, MM and Lymphoma cell lines with the G9a inhibitors BIX01294 and UNC0638 induced a decreased in cell proliferation and an increased in apoptosis. All these data suggest that G9a is an ideal epigenetic target for the treatment of hematological malignancies, so we designed and synthesized small molecules against G9a. The design was based on the mechanisms of action of G9a, taking into account the available structural and biochemical information. We selected those compounds that presented an optimal affinity with G9a (biochemical assay) and a good in vitro G9a activity inhibition, decreasing H3K9me2 mark by western blot and flow cytometry. These compounds showed an important in vitro antitumoral effect with GI50 values lying in the nanomolar concentration range. In fact, our compounds are much better than reference compounds BIX01294 and UNC0638, both in cellular and H3K9me2 inhibition level. Moreover, the small molecules against G9a induced apoptosis in addition to decrease cell proliferation. Once the lead compounds were selected, we performed ADME, toxicity and pharmacokinetic studies in order to carry out the in vivo analysis in human CEMO-1 ALL mouse model. Treatment of mice engrafted with CEMO-1 cells with G9a small inhibitory molecules induced an in vivo decrease of the H3K9me2 mark, which was accompanied with a significant prolonged survival of G9a inhibitors-treated mice (57.3 days) in comparison with control group (90.8 days). This is the first evidence of in vivo efficacy of G9a inhibitors. Further studies using RNA-sequencing will be performed in the presence of G9a inhibitors to determine mechanism of action. In conclusion, we have identified and validated G9a as an epigenetic target for the treatment of hematological malignancies and we have developed small inhibitory molecules against this target. Finally, our results show the therapeutic activity of G9a small inhibitory molecules in models of ALL and suggest that these compounds may be of clinical value in the treatment of patients with ALL and other hematological malignancies. Disclosures No relevant conflicts of interest to declare.

scholarly journals In vitro–in vivo evaluation of hyaluronic acid-based amphiphilic copolymers for tumour targeted delivery: the role of hydrophobic groups

RSC Advances ◽  
2017 ◽  
Vol 7 (39) ◽  
pp. 23942-23953 ◽  
Author(s):  
Zhihong Zhu ◽  
Dongyang Li ◽  
Yuenan Li ◽  
Xinggang Yang ◽  
Weisan Pan
Keyword(s):  
Hyaluronic Acid ◽  
Targeted Delivery ◽  
Polymeric Micelles ◽  
Amphiphilic Copolymers ◽  
In Vivo Evaluation ◽  
Therapeutic Applications

Polymeric micelles are widely used as suitable nano-carriers for a variety of therapeutic applications.

scholarly journals Male infertility-linked point mutation reveals a vital binding role for the C2 domain of sperm PLCζ

2017 ◽  
Vol 474 (6) ◽  
pp. 1003-1016 ◽  
Author(s):  
Michail Nomikos ◽  
Panagiotis Stamatiadis ◽  
Jessica R. Sanders ◽  
Konrad Beck ◽  
Brian L. Calver ◽  
...  
Keyword(s):  
Male Infertility ◽  
Point Mutation ◽  
Biochemical Properties ◽  
Vital Role ◽  
Egg Activation ◽  
C2 Domain ◽  
Binding Characteristics

Sperm-specific phospholipase C zeta (PLCζ) is widely considered to be the physiological stimulus that evokes intracellular calcium (Ca2+) oscillations that are essential for the initiation of egg activation during mammalian fertilisation. A recent genetic study reported a male infertility case that was directly associated with a point mutation in the PLCζ C2 domain, where an isoleucine residue had been substituted with a phenylalanine (I489F). Here, we have analysed the effect of this mutation on the in vivo Ca2+ oscillation-inducing activity and the in vitro biochemical properties of human PLCζ. Microinjection of cRNA or recombinant protein corresponding to PLCζI489F mutant at physiological concentrations completely failed to cause Ca2+ oscillations and trigger development. However, this infertile phenotype could be effectively rescued by microinjection of relatively high (non-physiological) amounts of recombinant mutant PLCζI489F protein, leading to Ca2+ oscillations and egg activation. Our in vitro biochemical analysis suggested that the PLCζI489F mutant displayed similar enzymatic properties, but dramatically reduced binding to PI(3)P and PI(5)P-containing liposomes compared with wild-type PLCζ. Our findings highlight the importance of PLCζ at fertilisation and the vital role of the C2 domain in PLCζ function, possibly due to its novel binding characteristics.

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