Antimicrobial Activity of High-Mobility-Group Box 2: a New Function to a Well-Known Protein

ABSTRACTThe human intestinal tract is highly colonized by a vast number of microorganisms. Despite this permanent challenge, infections remain rare, due to a very effective barrier defense system. Essential effectors of this system are antimicrobial peptides and proteins (AMPs), which are secreted by intestinal epithelial and lymphoid cells, balance the gut microbial community, and prevent the translocation of microorganisms. Several antimicrobial proteins have already been identified in the gut. Nonetheless, we hypothesized that additional AMPs are yet to be discovered in this setting. Using biological screening based on antimicrobial function, here we identified competent antibacterial activity of high-mobility-group box 2 (HMGB2) againstEscherichia coli. By recombinant expression, we confirmed this biologically new antimicrobial activity against different commensal and pathogenic bacteria. In addition, we demonstrated that the two DNA-binding domains (HMG boxes A and B) are crucial for the antibiotic function. We detected HMGB2 in several gastrointestinal tissues by mRNA analysis and immunohistochemical staining. In addition to the nuclei, we also observed HMGB2 in the cytoplasm of intestinal epithelial cells. Furthermore, HMGB2 was detectablein vitroin the supernatants of two different cell types, supporting an extracellular function. HMGB2 expression was not changed in inflammatory bowel disease but was detected in certain stool samples of patients, whereas it was absent from control individuals. Taken together, we characterized HMGB2 as an antimicrobial protein in intestinal tissue, complementing the diverse repertoire of gut mucosal defense molecules.

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LPS Primes Brain Responsiveness to High Mobility Group Box-1 Protein

Pharmaceuticals ◽

10.3390/ph14060558 ◽

2021 ◽

Vol 14 (6) ◽

pp. 558

Author(s):

Verena Peek ◽

Lois M. Harden ◽

Jelena Damm ◽

Ferial Aslani ◽

Stephan Leisengang ◽

...

Keyword(s):

Inflammatory Responses ◽

Area Postrema ◽

High Mobility ◽

High Mobility Group ◽

Direct Access ◽

Significant Release ◽

Factor Α ◽

Culture Supernatants

High mobility group box (HMGB)1 action contributes to late phases of sepsis, but the effects of increased endogenous plasma HMGB1 levels on brain cells during inflammation are unclear. Here, we aimed to further investigate the role of HMGB1 in the brain during septic-like lipopolysaccharide-induced inflammation in rats (LPS, 10 mg/kg, i.p.). HMGB-1 mRNA expression and release were measured in the periphery/brain by RT-PCR, immunohistochemistry and ELISA. In vitro experiments with disulfide-HMGB1 in primary neuro-glial cell cultures of the area postrema (AP), a circumventricular organ with a leaky blood–brain barrier and direct access to circulating mediators like HMGB1 and LPS, were performed to determine the direct influence of HMGB1 on this pivotal brain structure for immune-to-brain communication. Indeed, HMGB1 plasma levels stayed elevated after LPS injection. Immunohistochemistry of brains and AP cultures confirmed LPS-stimulated cytoplasmatic translocation of HMGB1 indicative of local HMGB1 release. Moreover, disulfide-HMGB1 stimulation induced nuclear factor (NF)-κB activation and a significant release of interleukin-6, but not tumor necrosis factor α, into AP culture supernatants. However, only a few AP cells directly responded to HMGB1 with increased intracellular calcium concentration. Interestingly, priming with LPS induced a seven-fold higher percentage of responsive cells to HMGB1. We conclude that, as a humoral and local mediator, HMGB1 enhances brain inflammatory responses, after LPS priming, linked to sustained sepsis symptoms.

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Phytochemical composition and in vitro screening of the antimicrobial activity of essential oils on oral pathogenic bacteria

Natural Product Research ◽

10.1080/14786419.2017.1329730 ◽

2017 ◽

Vol 32 (5) ◽

pp. 544-551 ◽

Cited By ~ 27

Author(s):

Roberta Tardugno ◽

Federica Pellati ◽

Ramona Iseppi ◽

Moreno Bondi ◽

Giacomo Bruzzesi ◽

...

Keyword(s):

Antimicrobial Activity ◽

Essential Oils ◽

Pathogenic Bacteria ◽

In Vitro Screening ◽

Phytochemical Composition

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Defective Calmodulin-Mediated Nuclear Transport of the Sex-Determining Region of the Y Chromosome (SRY) in XY Sex Reversal

Molecular Endocrinology ◽

10.1210/me.2004-0334 ◽

2005 ◽

Vol 19 (7) ◽

pp. 1884-1892 ◽

Cited By ~ 39

Author(s):

Helena Sim ◽

Kieran Rimmer ◽

Sabine Kelly ◽

Louisa M. Ludbrook ◽

Andrew H. A. Clayton ◽

...

Keyword(s):

Y Chromosome ◽

Nuclear Import ◽

High Mobility ◽

Sex Reversal ◽

High Mobility Group ◽

Missense Mutations ◽

Nuclear Localization Signals ◽

Xy Sex Reversal

Abstract The sex-determining region of the Y chromosome (SRY) plays a key role in human sex determination, as mutations in SRY can cause XY sex reversal. Although some SRY missense mutations affect DNA binding and bending activities, it is unclear how others contribute to disease. The high mobility group domain of SRY has two nuclear localization signals (NLS). Sex-reversing mutations in the NLSs affect nuclear import in some patients, associated with defective importin-β binding to the C-terminal NLS (c-NLS), whereas in others, importin-β recognition is normal, suggesting the existence of an importin-β-independent nuclear import pathway. The SRY N-terminal NLS (n-NLS) binds calmodulin (CaM) in vitro, and here we show that this protein interaction is reduced in vivo by calmidazolium, a CaM antagonist. In calmidazolium-treated cells, the dramatic reduction in nuclear entry of SRY and an SRY-c-NLS mutant was not observed for two SRY-n-NLS mutants. Fluorescence spectroscopy studies reveal an unusual conformation of SRY.CaM complexes formed by the two n-NLS mutants. Thus, CaM may be involved directly in SRY nuclear import during gonadal development, and disruption of SRY.CaM recognition could underlie XY sex reversal. Given that the CaM-binding region of SRY is well-conserved among high mobility group box proteins, CaM-dependent nuclear import may underlie additional disease states.

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Does high-mobility-group non-histone protein HMG 1 interact specifically with histone H1 subfractions?

Biochemical Journal ◽

10.1042/bj1830657 ◽

1979 ◽

Vol 183 (3) ◽

pp. 657-662 ◽

Cited By ~ 24

Author(s):

P D Cary ◽

K V Shooter ◽

G H Goodwin ◽

E W Johns ◽

J Y Olayemi ◽

...

Keyword(s):

Specific Interaction ◽

High Mobility ◽

Histone H1 ◽

High Mobility Group ◽

Chromosomal Protein ◽

Histone Protein ◽

Total Histone ◽

Equilibrium Sedimentation ◽

Histone H5

The interaction of the non-histone chromosomal protein HMG (high-mobility group) 1 with histone H1 subfractions was investigated by equilibrium sedimentation and n.m.r. sectroscopy. In contrast with a previous report [Smerdon & Isenberg (1976) Biochemistry 15, 4242–4247], it was found, by using equilibrium-sedimentation analysis, that protein HMG 1 binds to all three histone H1 subfractions CTL1, CTL2, and CTL3, arguing against there being a specific interaction between protein HMG 1 and only two of the subfractions, CTL1 and CTL2. Raising the ionic strength of the solutions prevents binding of protein HMG 1 to total histone H1 and the three subfractions, suggesting that the binding in vitro is simply a non-specific ionic interaction between acidic regions of the non-histone protein and the basic regions of the histone. Protein HMG 1 binds to histone H5 also, supporting this view. The above conclusions are supported by n.m.r. studies of protein HMG 1/histone H1 subfraction mixtures. When the two proteins were mixed, there was little perturbation of the n.m.r. spectra and there was no evidence for specific interaction of protein HMG 1 with any of the subfractions. It therefore remains an open question as to whether protein HMG 1 and histone H1 are complexed together in chromatin.

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Antimicrobial activity screening of rhizosphere soil bacteria from tomato and genome-based analysis of their antimicrobial biosynthetic potential

BMC Genomics ◽

10.1186/s12864-020-07346-8 ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Lu Zhou ◽

Chunxu Song ◽

Zhibo Li ◽

Oscar P. Kuipers

Keyword(s):

Antimicrobial Activity ◽

Plant Growth ◽

Disease Control ◽

Pseudomonas Syringae ◽

Rhizosphere Soil ◽

Erwinia Carotovora ◽

Gene Clusters ◽

Vast Number ◽

Tomato Disease

Abstract Background Tomato plant growth is frequently hampered by a high susceptibility to pests and diseases. Traditional chemical control causes a serious impact on both the environment and human health. Therefore, seeking environment-friendly and cost-effective green methods in agricultural production becomes crucial nowadays. Plant Growth Promoting Rhizobacteria (PGPR) can promote plant growth through biological activity. Their use is considered to be a promising sustainable approach for crop growth. Moreover, a vast number of biosynthetic gene clusters (BGCs) for secondary metabolite production are being revealed in PGPR, which helps to find potential anti-microbial activities for tomato disease control. Results We isolated 181 Bacillus-like strains from healthy tomato, rhizosphere soil, and tomato tissues. In vitro antagonistic assays revealed that 34 Bacillus strains have antimicrobial activity against Erwinia carotovora, Pseudomonas syringae; Rhizoctonia solani; Botrytis cinerea; Verticillium dahliae and Phytophthora infestans. The genomes of 10 Bacillus and Paenibacillus strains with good antagonistic activity were sequenced. Via genome mining approaches, we identified 120 BGCs encoding NRPs, PKs-NRPs, PKs, terpenes and bacteriocins, including known compounds such as fengycin, surfactin, bacillibactin, subtilin, etc. In addition, several novel BGCs were identified. We discovered that the NRPs and PKs-NRPs BGCs in Bacillus species are encoding highly conserved known compounds as well as various novel variants. Conclusions This study highlights the great number of varieties of BGCs in Bacillus strains. These findings pave the road for future usage of Bacillus strains as biocontrol agents for tomato disease control and are a resource arsenal for novel antimicrobial discovery.

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Biosynthesis of Silver Nanoparticles by Punica Granatum Peel Extract and their Biological Activity on different Pathogenic Bacteria

NeuroQuantology ◽

10.14704/nq.2021.19.9.nq21135 ◽

2021 ◽

Vol 19 (9) ◽

pp. 38-45

Author(s):

Hussein H. Al-Turnachy ◽

Fadhilk. alibraheemi ◽

Ahmed Abd Alreda Madhloom ◽

Zahraa Yosif Motaweq ◽

Nibras Yahya Abdulla

Keyword(s):

Antimicrobial Activity ◽

Silver Nanoparticles ◽

Biological Activity ◽

Pathogenic Bacteria ◽

Punica Granatum ◽

Gram Positive ◽

Gram Negative ◽

Inhibition Zones ◽

Peel Extract

The present study was included the assessment of the antimicrobial activity of AgNPs synthesized by Punica granatum peel extract against pathogenic bacteria by testing warm aqueous P. granatum peel extract and silver nanoparticles. Punica granatum indicated potency for AgNP extracellular nanobiosynthesis after addition of silver nitrate (AgNO3) 4mM to the extract supernatant, in both concentrations (100mg and 50mg). The biogenic AgNPs showed potency to inhibit both gram-negative and gram-positive bacterial growth. Zons of inhibition in (mm) was lesser in gram-positive than gram-negative bacteria. The resulted phytogenic AgNPs gave higher biological activity than warm aqueous Punica granatum peel extract. The inhibition zone of the phytogenic AgNPs on E. coli reached 17.53, 22.35, and 26.06 mm at (0.1, 0.5, and 1) mg/ml respectively. While inhibition zones of Punica warm aqueous extract reached 5.33, 10.63, and 16.08 mm at the same concentrations. phytogenic AgNPs gave smaller inhibition zones in gram-positive than gram- negative. Cytotoxic activity of the phytogenic AgNPs was assayed in vitro agaist human blood erythrocytes (RBCs), spectroscopic results showed absorbance at 540 nm hemolysis was observed. In general, AgNPs showed least RBCs hemolysis percentage, at 1 mg/ml concentration, hemolysis percentage was (4.50%). This study, concluded that the Punica granatum peel extract has the power of synthses of AgNPs characterized by broad spectrum antimicrobial activity with cyto-toxicity proportional to AgNPs concentration.

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Apis andreniformis associated Actinomycetes show antimicrobial activity against black rot pathogen (Xanthomonas campestris pv. campestris)

PeerJ ◽

10.7717/peerj.12097 ◽

2021 ◽

Vol 9 ◽

pp. e12097

Author(s):

Yaowanoot Promnuan ◽

Saran Promsai ◽

Wasu Pathom-aree ◽

Sujinan Meelai

Keyword(s):

Antimicrobial Activity ◽

16S Rrna ◽

16S Rrna Gene ◽

Honey Bee ◽

Pseudomonas Syringae ◽

Xanthomonas Campestris ◽

Pathogenic Bacteria ◽

Rrna Gene ◽

Apis Andreniformis

This study aimed to investigate cultivable actinomycetes associated with rare honey bee species in Thailand and their antagonistic activity against plant pathogenic bacteria. Actinomycetes were selectively isolated from the black dwarf honey bee (Apis andreniformis). A total of 64 actinomycete isolates were obtained with Streptomyces as the predominant genus (84.4%) followed by Micromonospora (7.8%), Nonomuraea (4.7%) and Actinomadura (3.1%). All isolates were screened for antimicrobial activity against Xanthomonas campestris pv. campestris, Pectobacterium carotovorum and Pseudomonas syringae pv. sesame. Three isolates inhibited the growth of X. campestris pv. campestris during in vitro screening. The crude extracts of two isolates (ASC3-2 and ASC5-7P) had a minimum inhibitory concentration (MIC) of 128 mg L−1against X. campestris pv. campestris. For isolate ACZ2-27, its crude extract showed stronger inhibitory effect with a lower MIC value of 64 mg L−1 against X. campestris pv. campestris. These three active isolates were identified as members of the genus Streptomyces based on their 16S rRNA gene sequences. Phylogenetic analysis based on the maximum likelihood algorithm showed that isolate ACZ2-27, ASC3-2 and ASC5-7P were closely related to Streptomyces misionensis NBRC 13063T (99.71%), Streptomyces cacaoi subsp. cacaoi NBRC 12748T (100%) and Streptomyces puniceus NBRC 12811T (100%), respectively. In addition, representative isolates from non-Streptomyces groups were identified by 16S rRNA gene sequence analysis. High similarities were found with members of the genera Actinomadura, Micromonospora and Nonomuraea. Our study provides evidence of actinomycetes associated with the black dwarf honey bee including members of rare genera. Antimicrobial potential of these insect associated Streptomyces was also demonstrated especially the antibacterial activity against phytopathogenic bacteria.

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Chemical characterization and in vitro antimicrobial activity of honeybee propolis and Scaptotrigona jujuyensis geopropolis against tomato pathogenic bacteria

Semina Ciências Agrárias ◽

10.5433/1679-0359.2020v41n5p1799 ◽

2020 ◽

Vol 42 (5) ◽

pp. 1799-1808

Author(s):

Irene Laura Cibanal ◽

◽

Leticia Andrea Fernández ◽

Giovanni Galietta Positano ◽

Lucía Bóffano Chebataroff ◽

...

Keyword(s):

Antimicrobial Activity ◽

Pathogenic Bacteria ◽

Chemical Characterization ◽

In Vitro Antimicrobial Activity

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Hepatocyte high-mobility group box 1 protects against steatosis and cellular stress during high fat diet feeding

Molecular Medicine ◽

10.1186/s10020-020-00227-6 ◽

2020 ◽

Vol 26 (1) ◽

Author(s):

Minjie Lin ◽

Jungke Long ◽

Wenbo Li ◽

Chenxuan Yang ◽

Patricia Loughran ◽

...

Keyword(s):

Er Stress ◽

High Fat Diet ◽

High Mobility ◽

High Mobility Group ◽

High Fat ◽

Rapid Weight Gain ◽

Nonalcoholic Fatty Liver ◽

Primary Mouse

Abstract Background Circulating high-mobility group box 1 (HMGB1) plays important roles in the pathogenesis of nonalcoholic fatty liver disease (NAFLD). Intracellular HMGB1 is critical for the biology of hepatocytes. However, the intracellular role of HMGB1 in hepatocellular steatosis is unknown. Therefore, we aimed to investigate the role of hepatocyte-specific HMGB1 (HC-HMGB1) in development of hepatic steatosis. Methods Wild type (WT) C57BL/6 and HC-HMGB1−/− mice were fed high-fat diet (HFD) or low-fat diet (LFD) for up to 16 weeks. Results As expected, HMGB1 translocated from nuclear into cytoplasm and released into circulation after HFD treatment. HC-HMGB1 deficiency significantly reduced circulating HMGB1, suggesting that hepatocyte is a major source of circulating HMGB1 during NAFLD. Unexpectedly, HC-HMGB1 deficiency promoted rapid weight gain with enhanced hepatic fat deposition compared with WT at as early as 4 weeks after HFD treatment. Furthermore, there was no difference between WT and HC-HMGB1−/− mice in glucose tolerance, energy expenditure, liver damage or systemic inflammation. Interestingly, hepatic gene expression related to free fatty acid (FFA) β-oxidation was significantly down-regulated in HC-HMGB1−/− mice compared with WT, and endoplasmic reticulum (ER) stress markers were significantly higher in livers of HC-HMGB1−/− mice. In vitro experiments using primary mouse hepatocytes showed absence of HMGB1 increased FFA-induced intracellular lipid accumulation, accompanied by increased ER-stress, significant downregulation of FFA β-oxidation, and reduced oxidative phosphorylation. Conclusions Our findings suggest that hepatocyte HMGB1 protects against dysregulated lipid metabolism via maintenance of β-oxidation and prevention of ER stress. This represents a novel mechanism for HMGB1-regulation of hepatocellular steatosis, and suggests that stabilizing HMGB1 in hepatocytes may be effective strategies for prevention and treatment of NAFLD.

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