scholarly journals Digging into the lesser-known aspects of CRISPR biology

Author(s):  
Noemí M. Guzmán ◽  
Belén Esquerra-Ruvira ◽  
Francisco J. M. Mojica

Abstract A long time has passed since regularly interspaced DNA repeats were discovered in prokaryotes. Today, those enigmatic repetitive elements termed clustered regularly interspaced short palindromic repeats (CRISPR) are acknowledged as an emblematic part of multicomponent CRISPR-Cas (CRISPR associated) systems. These systems are involved in a variety of roles in bacteria and archaea, notably, that of conferring protection against transmissible genetic elements through an adaptive immune-like response. This review summarises the present knowledge on the diversity, molecular mechanisms and biology of CRISPR-Cas. We pay special attention to the most recent findings related to the determinants and consequences of CRISPR-Cas activity. Research on the basic features of these systems illustrates how instrumental the study of prokaryotes is for understanding biology in general, ultimately providing valuable tools for diverse fields and fuelling research beyond the mainstream.

2020 ◽  
Vol 10 (5) ◽  
pp. 535-542
Author(s):  
Mohaddese Mahboubi

Background:: Benign Prostatic hyperplasia (BPH) is known as a disease prevalent in men after the age of 50 years old. Ninety percent of men with the age of 80 years and over have BPH. BPH is associated with functional problems like dysuria, nocturia, polyuria, urinary incontinence and recurrent urinary tract infections. Urtica dioica or nettle is a popular medicinal plant for management of BPH in men. Objective:: This article evaluates the efficacy and safety of nettle and its related possible mechanisms in the management of BPH. Methods:: For the preparation of this manuscript, all the information was gathered from accessible and inaccessible resources (Web, Books, Thesis, etc.). Results:: The results of preclinical and clinical studies confirmed the efficacy of nettle roots extracts (methanol, ethanol, and petroleum ether) in the improvement of BPH in term of IPSS score, and patient's life quality. An increase in mean and maximum urinary flow rates and a reduction in prostate volume and residual urine level were observed after treatment with nettle extract. Nettle roots should be used for 6-12 months as its use is possible for a long time without any serious adverse effects. Conclusion:: Designing the clinical trials to compare the efficacy of different extracts from roots or leaves and investigation of molecular mechanisms of action could be the approaches for future.


2020 ◽  
Vol 21 (21) ◽  
pp. 8151
Author(s):  
Sharda Kumari ◽  
Shibani Mukherjee ◽  
Debapriya Sinha ◽  
Salim Abdisalaam ◽  
Sunil Krishnan ◽  
...  

Radiation therapy (RT), an integral component of curative treatment for many malignancies, can be administered via an increasing array of techniques. In this review, we summarize the properties and application of different types of RT, specifically, conventional therapy with x-rays, stereotactic body RT, and proton and carbon particle therapies. We highlight how low-linear energy transfer (LET) radiation induces simple DNA lesions that are efficiently repaired by cells, whereas high-LET radiation causes complex DNA lesions that are difficult to repair and that ultimately enhance cancer cell killing. Additionally, we discuss the immunogenicity of radiation-induced tumor death, elucidate the molecular mechanisms by which radiation mounts innate and adaptive immune responses and explore strategies by which we can increase the efficacy of these mechanisms. Understanding the mechanisms by which RT modulates immune signaling and the key players involved in modulating the RT-mediated immune response will help to improve therapeutic efficacy and to identify novel immunomodulatory drugs that will benefit cancer patients undergoing targeted RT.


Author(s):  
Cesar A. López ◽  
Animesh Agarwal ◽  
Que N. Van ◽  
Andrew G. Stephen ◽  
S. Gnanakaran

AbstractSmall GTPase proteins are ubiquitous and responsible for regulating several processes related to cell growth and differentiation. Mutations that stabilize their active state can lead to uncontrolled cell proliferation and cancer. Although these proteins are well characterized at the cellular scale, the molecular mechanisms governing their functions are still poorly understood. In addition, there is limited information about the regulatory function of the cell membrane which supports their activity. Thus, we have studied the dynamics and conformations of the farnesylated KRAS4b in various membrane model systems, ranging from binary fluid mixtures to heterogeneous raft mimics. Our approach combines long time-scale coarse-grained (CG) simulations and Markov state models to dissect the membrane-supported dynamics of KRAS4b. Our simulations reveal that protein dynamics is mainly modulated by the presence of anionic lipids and to some extent by the nucleotide state (activation) of the protein. In addition, our results suggest that both the farnesyl and the polybasic hypervariable region (HVR) are responsible for its preferential partitioning within the liquid-disordered (Ld) domains in membranes, potentially enhancing the formation of membrane-driven signaling platforms. Graphic Abstract


Biomolecules ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 79
Author(s):  
Svetlana N. Morozkina ◽  
Thi Hong Nhung Vu ◽  
Yuliya E. Generalova ◽  
Petr P. Snetkov ◽  
Mayya V. Uspenskaya

For a long time, the pharmaceutical industry focused on natural biologically active molecules due to their unique properties, availability and significantly less side-effects. Mangiferin is a naturally occurring C-glucosylxantone that has substantial potential for the treatment of various diseases thanks to its numerous biological activities. Many research studies have proven that mangiferin possesses antioxidant, anti-infection, anti-cancer, anti-diabetic, cardiovascular, neuroprotective properties and it also increases immunity. It is especially important that it has no toxicity. However, mangiferin is not being currently applied to clinical use because its oral bioavailability as well as its absorption in the body are too low. To improve the solubility, enhance the biological action and bioavailability, mangiferin integrated polymer systems have been developed. In this paper, we review molecular mechanisms of anti-cancer action as well as a number of designed polymer-mangiferin systems. Taking together, mangiferin is a very promising anti-cancer molecule with excellent properties and the absence of toxicity.


2021 ◽  
Vol 9 (4) ◽  
pp. 683
Author(s):  
Julio Villena ◽  
Chang Li ◽  
Maria Guadalupe Vizoso-Pinto ◽  
Jacinto Sacur ◽  
Linzhu Ren ◽  
...  

The most important characteristics regarding the mucosal infection and immune responses against the Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) as well as the current vaccines against coronavirus disease 2019 (COVID-19) in development or use are revised to emphasize the opportunity for lactic acid bacteria (LAB)-based vaccines to offer a valid alternative in the fight against this disease. In addition, this article revises the knowledge on: (a) the cellular and molecular mechanisms involved in the improvement of mucosal antiviral defenses by beneficial Lactiplantibacillus plantarum strains, (b) the systems for the expression of heterologous proteins in L. plantarum and (c) the successful expressions of viral antigens in L. plantarum that were capable of inducing protective immune responses in the gut and the respiratory tract after their oral administration. The ability of L. plantarum to express viral antigens, including the spike protein of SARS-CoV-2 and its capacity to differentially modulate the innate and adaptive immune responses in both the intestinal and respiratory mucosa after its oral administration, indicates the potential of this LAB to be used in the development of a mucosal COVID-19 vaccine.


2017 ◽  
Vol 7 (4) ◽  
pp. 214-230 ◽  
Author(s):  
A. N. Irkitova ◽  
A. V. Matsyura

<p>Lactobacillus acidophilus - homofermentative lactobacillus, specializing in living in the gastrointestinal and urogenital tracts of mammals and birds. It accompanies a person from birth and throughout his life, providing a whole range of useful services, the main one of which is active participation in the body's defense system against the harmful action of undesirable microorganisms (preventing the growth of pathogenic bacteria and restraining populations of opportunistic microbes at a safe level) . It is this property of the acidophilus rod that explains its wide practical use in various probiotic products and preparations of dietary, medical and agricultural purposes.<br />Although the acidophilus rod is known and purposefully used for a long time, it still ha the great potential for the research. The use of gene-molecular approaches has made it possible to clarify the systematic position of L. acidophilus in the family of lactobacilli and to identify a group of closely related species, often indistinguishable by traditional physiological and biochemical identification methods. Today, the efforts of researchers are focused on elucidating the molecular mechanisms by which antagonistically active strains of L. acidophilus carry out a bactericidal and bacteriolytic effect on harmful microbes. Disclosure of these mechanisms will not only allow more efficient selection and use of strains of L. acidophilus, but also create a new class of antibiotics that are more effective and have less side effects than existing ones.<br />This review is devoted to the description of the probiotic microorganism Lactobacillus acidophilus. In the article the biological and ecological properties of the acidophilus rod are described in detail, examples of practical use of this microorganism in various branches of the national economy are given.</p>


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6697 ◽  
Author(s):  
Lian Yih Pong ◽  
Sinikka Parkkinen ◽  
Amreeta Dhanoa ◽  
Han Ming Gan ◽  
Indeevari Abisheka Chiharu Wickremesinghe ◽  
...  

BackgroundDengue caused by dengue virus (DENV) serotypes −1 to −4 is the most important mosquito-borne viral disease in the tropical and sub-tropical countries worldwide. Yet many of the pathophysiological mechanisms of host responses during DENV infection remain largely unknown and incompletely understood.MethodsUsing a mouse model, the miRNA expressions in liver during DENV-1 infection was investigated using high throughput miRNA sequencing. The differential expressions of miRNAs were then validated by qPCR, followed by target genes prediction. The identified miRNA targets were subjected to gene ontology (GO) annotation and pathway enrichment analysis to elucidate the potential biological pathways and molecular mechanisms associated with DENV-1 infection.ResultsA total of 224 and 372 miRNAs out of 433 known mouse miRNAs were detected in the livers of DENV-1-infected and uninfected mice, respectively; of these, 207 miRNAs were present in both libraries. The miR-148a-3p and miR-122-5p were the two most abundant miRNAs in both groups. Thirty-one miRNAs were found to have at least 2-fold change in upregulation or downregulation, in which seven miRNAs were upregulated and 24 miRNAs were downregulated in the DENV-1-infected mouse livers. The miR-1a-3p was found to be the most downregulated miRNA in the DENV-1-infected mouse livers, with a significant fold change of 0.10. To validate the miRNA sequencing result, the expression pattern of 12 miRNAs, which were highly differentially expressed or most abundant, were assessed by qPCR and nine of them correlated positively with the one observed in deep sequencing.In silicofunctional analysis revealed that the adaptive immune responses involving TGF-beta, MAPK, PI3K-Akt, Rap1, Wnt and Ras signalling pathways were modulated collectively by 23 highly differentially expressed miRNAs during DENV-1 infection.ConclusionThis study provides the first insight into the global miRNA expressions of mouse livers in response to DENV-1 infectionin vivoand the possible roles of miRNAs in modulating the adaptive immune responses during DENV-1 infection.


Author(s):  
Jorge A. Moura de Sousa ◽  
Eduardo P. C. Rocha

Bacteriophages (phages) are bacterial parasites that can themselves be parasitized by phage satellites. The molecular mechanisms used by satellites to hijack phages are sometimes understood in great detail, but the origins, abundance, distribution and composition of these elements are poorly known. Here, we show that P4-like elements are present in more than 30% of the genomes of Enterobacterales, and in almost half of those of Escherichia coli , sometimes in multiple distinct copies. We identified over 1000 P4-like elements with very conserved genetic organization of the core genome and a few hotspots with highly variable genes. These elements are never found in plasmids and have very little homology to known phages, suggesting an independent evolutionary origin. Instead, they are scattered across chromosomes, possibly because their integrases are often exchanged with other elements. The rooted phylogenies of hijacking functions are correlated and suggest longstanding coevolution. They also reveal broad host ranges in P4-like elements, as almost identical elements can be found in distinct bacterial genera. Our results show that P4-like phage satellites constitute a very distinct, widespread and ancient family of mobile genetic elements. They pave the way for studying the molecular evolution of antagonistic interactions between phages and their satellites. This article is part of the theme issue ‘The secret lives of microbial mobile genetic elements’.


Vaccines ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 530
Author(s):  
Rosa C. Coldbeck-Shackley ◽  
Nicholas S. Eyre ◽  
Michael R. Beard

Zika Virus (ZIKV) and Dengue Virus (DENV) are related viruses of the Flavivirus genus that cause significant disease in humans. Existing control measures have been ineffective at curbing the increasing global incidence of infection for both viruses and they are therefore prime targets for new vaccination strategies. Type-I interferon (IFN) responses are important in clearing viral infection and for generating efficient adaptive immune responses towards infection and vaccination. However, ZIKV and DENV have evolved multiple molecular mechanisms to evade type-I IFN production. This review covers the molecular interactions, from detection to evasion, of these viruses with the type-I IFN response. Additionally, we discuss how this knowledge can be exploited to improve the design of new vaccine strategies.


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