Potential Effects of Indole-3-Lactic Acid, a Metabolite of Human Bifidobacteria, on NGF-Induced Neurite Outgrowth in PC12 Cells

Gut microbiota-derived tryptophan metabolites such as indole derivatives are an integral part of host metabolome that could mediate gut–brain communication and contribute to host homeostasis. We previously reported that infant-type Human-Residential Bifidobacteria (HRB) produced higher levels of indole-3-lactic acid (ILA), suggesting the former might play a specific role in microbiota–host crosstalk by producing ILA in human infants. Nonetheless, the biological meaning of bifidobacteria-derived ILA in infant health development remains obscure. Here, we sought to explore the potential role of ILA in neuronal differentiation. We examined the neurite outgrowth and acetylcholinesterase (AchE) activity of PC12 cells following exposure to ILA and NGF induction. We found that ILA substantially enhanced NGF-induced neurite outgrowth of PC12 cells in a dose-dependent manner, and had the most prominent effect at 100 nM. Significant increases in the expression of TrkA receptor, ERK1/2 and CREB were observed in ILA-treated PC12 cells, suggesting ILA potentiated NGF-induced neurite outgrowth through the Ras/ERK pathway. Additionally, ILA was found to act as the aryl hydrocarbon receptor (AhR) agonist and evoked NGF-induced neurite outgrowth in an AhR-mediated manner. These new findings provide clues into the potential involvement of ILA as the mediator in bifidobacterial host–microbiota crosstalk and neuronal developmental processes.

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Secretory phospholipases A2 induce neurite outgrowth in PC12 cells

Biochemical Journal ◽

10.1042/bj20030830 ◽

2003 ◽

Vol 376 (3) ◽

pp. 655-666 ◽

Cited By ~ 37

Author(s):

Satoru NAKASHIMA ◽

Yutaka IKENO ◽

Tatsuya YOKOYAMA ◽

Masakazu KUWANA ◽

Angelo BOLCHI ◽

...

Keyword(s):

Arachidonic Acid ◽

Neurite Outgrowth ◽

Pc12 Cells ◽

Streptomyces Coelicolor ◽

Dependent Manner ◽

Group V ◽

Phospholipases A2 ◽

Fatty Acid Release ◽

Activity Dependent

sPLA2s (secretory phospholipases A2) belong to a broad and structurally diverse family of enzymes that hydrolyse the sn-2 ester bond of glycerophospholipids. We previously showed that a secreted fungal 15 kDa protein, named p15, as well as its orthologue from Streptomyces coelicolor (named Scp15) induce neurite outgrowth in PC12 cells at nanomolar concentrations. We report here that both p15 and Scp15 are members of a newly identified group of fungal/bacterial sPLA2s. The phospholipid-hydrolysing activity of p15 is absolutely required for neurite outgrowth induction. Mutants with a reduced PLA2 activity exhibited a comparable reduction in neurite-inducing activity, and the ability to induce neurites closely matched the capacity of various p15 forms to promote fatty acid release from live PC12 cells. A structurally divergent member of the sPLA2 family, bee venom sPLA2, also induced neurites in a phospholipase activity-dependent manner, and the same effect was elicited by mouse group V and X sPLA2s, but not by group IB and IIA sPLA2s. Lysophosphatidylcholine, but not other lysophospholipids, nor arachidonic acid, elicited neurite outgrowth in an L-type Ca2+ channel activity-dependent manner. In addition, p15-induced neuritogenesis was unaffected by various inhibitors that block arachidonic acid conversion into bioactive eicosanoids. Altogether, these results delineate a novel, Ca2+- and lysophosphatidylcholine-dependent neurotrophin-like role of sPLA2s in the nervous system.

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Goosecoid suppresses cell growth and enhances neuronal differentiation of PC12 cells

Journal of Cell Science ◽

10.1242/jcs.113.15.2705 ◽

2000 ◽

Vol 113 (15) ◽

pp. 2705-2713

Author(s):

K. Sawada ◽

Y. Konishi ◽

M. Tominaga ◽

Y. Watanabe ◽

J. Hirano ◽

...

Keyword(s):

Transcription Factor ◽

Neurite Outgrowth ◽

Neuronal Differentiation ◽

Pc12 Cells ◽

Mammalian Cells ◽

Homeobox Gene ◽

S Phase ◽

Bhlh Transcription Factor ◽

Spemann Organizer

In all vertebrate species, the homeobox gene goosecoid serves as a marker of the Spemann organizer tissue. One function of the organizer is the induction of neural tissue. To investigate the role of goosecoid in neuronal differentiation of mammalian cells, we have introduced goosecoid into PC12 cells. Expression of goosecoid resulted in reduced cell proliferation and enhanced neurite outgrowth in response to NGF. Expression of goosecoid led to a decrease in the percentage of S-phase cells and to upregulation of the expression of the neuron-specific markers MAP-1b and neurofilament-L. Analysis of goosecoid mutants revealed that these effects were independent of either DNA binding or homodimerization of Goosecoid. Coexpression of the N-terminal portion of the ets transcription factor PU.1, a protein that can bind to Goosecoid, repressed neurite outgrowth and rescued the proliferation of PC12 cultures. In contrast, expression of the bHLH transcription factor HES-1 repressed goosecoid-mediated neurite outgrowth without changing the proportion of S-phase cells. These results suggest that goosecoid is involved in neuronal differentiation in two ways, by slowing the cell cycle and stimulating neurite outgrowth, and that these two events are separately regulated.

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Initiation and maintenance of NGF-stimulated neurite outgrowth requires activation of a phosphoinositide 3-kinase

Journal of Cell Science ◽

10.1242/jcs.109.2.289 ◽

1996 ◽

Vol 109 (2) ◽

pp. 289-300 ◽

Cited By ~ 3

Author(s):

T.R. Jackson ◽

I.J. Blader ◽

L.P. Hammonds-Odie ◽

C.R. Burga ◽

F. Cooke ◽

...

Keyword(s):

Neurite Outgrowth ◽

Pc12 Cells ◽

Specific Inhibitor ◽

Morphological Differentiation ◽

Sympathetic Neuron ◽

Neuronal Morphology ◽

Regulatory Subunit ◽

Membrane Reorganization ◽

Phosphoinositide 3 Kinase

Application of nerve growth factor (NGF) to PC12 cells stimulates a programme of physiological changes leading to the development of a sympathetic neuron like phenotype, one aspect of which is the development of a neuronal morphology characterised by the outgrowth of neuritic processes. We have investigated the role of phosphoinositide 3-kinase in NGF-stimulated morphological differentiation through two approaches: firstly, preincubation with wortmannin, a reputedly specific inhibitor of phosphoinositide kinases, completely inhibited initial morphological responses to NGF, the formation of actin filament rich microspikes and subsequent neurite outgrowth. This correlated with wortmannin inhibition of NGF-stimulated phosphatidylinositol(3,4,5)trisphosphate (PtdInsP3) and phosphatidylinositol(3,4)bisphosphate (PtdIns(3,4)P2) production and with inhibition of NGF-stimulated phosphoinositide 3-kinase activity in anti-phosphotyrosine immunoprecipitates. Secondly, the overexpression of a mutant p85 regulatory subunit of the phosphoinositide 3-kinase, which cannot interact with the catalytic p110 subunit, also substantially inhibited the initiation of NGF-stimulated neurite outgrowth. In addition, we found that wortmannin caused a rapid collapse of more mature neurites formed following several days exposure of PC12 cells to NGF. These results indicate that NGF-stimulated neurite outgrowth requires the activity of a tyrosine kinase regulated PI3-kinase and suggest that the primary product of this enzyme, PtdInsP3, is a necessary second messenger for the cytoskeletal and membrane reorganization events which occur during neuronal differentiation.

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How Ah Receptor Ligand Specificity Became Important in Understanding Its Physiological Function

International Journal of Molecular Sciences ◽

10.3390/ijms21249614 ◽

2020 ◽

Vol 21 (24) ◽

pp. 9614

Author(s):

Iain A. Murray ◽

Gary H. Perdew

Keyword(s):

Physiological Function ◽

Innate Immune ◽

Ah Receptor ◽

Ligand Specificity ◽

Aryl Hydrocarbon ◽

Innate Immune Signaling ◽

Tryptophan Metabolites ◽

Barrier Tissues ◽

Endogenous Metabolites

Increasingly, the aryl hydrocarbon receptor (AHR) is being recognized as a sensor for endogenous and pseudo-endogenous metabolites, and in particular microbiota and host generated tryptophan metabolites. One proposed explanation for this is the role of the AHR in innate immune signaling within barrier tissues in response to the presence of microorganisms. A number of cytokine/chemokine genes exhibit a combinatorial increase in transcription upon toll-like receptors and AHR activation, supporting this concept. The AHR also plays a role in the enhanced differentiation of intestinal and dermal epithelium leading to improved barrier function. Importantly, from an evolutionary perspective many of these tryptophan metabolites exhibit greater activation potential for the human AHR when compared to the rodent AHR. These observations underscore the importance of the AHR in barrier tissues and may lead to pharmacologic therapeutic intervention.

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Production of Indole-3-Lactic Acid by Bifidobacterium Strains Isolated fromHuman Infants

Microorganisms ◽

10.3390/microorganisms7090340 ◽

2019 ◽

Vol 7 (9) ◽

pp. 340 ◽

Cited By ~ 15

Author(s):

Takuma Sakurai ◽

Toshitaka Odamaki ◽

Jin-zhong Xiao

Keyword(s):

Lactic Acid ◽

Bifidobacterium Longum ◽

Bifidobacterium Bifidum ◽

Microbial Interactions ◽

Human Infants ◽

Bifidobacterium Breve ◽

Tryptophan Metabolites ◽

Tryptophan Metabolite ◽

Culture Supernatants ◽

Indole 3 Acetic Acid

Recent studies have shown that metabolites produced by microbes can be considered as mediators of host-microbial interactions. In this study, we examined the production of tryptophan metabolites by Bifidobacterium strains found in the gastrointestinal tracts of humans and other animals. Indole-3-lactic acid (ILA) was the only tryptophan metabolite produced in bifidobacteria culture supernatants. No others, including indole-3-propionic acid, indole-3-acetic acid, and indole-3-aldehyde, were produced. Strains of bifidobacterial species commonly isolated from the intestines of human infants, such as Bifidobacterium longum subsp. longum, Bifidobacterium longum subsp. infantis, Bifidobacterium breve, and Bifidobacterium bifidum, produced higher levels of ILA than did strains of other species. These results imply that infant-type bifidobacteria might play a specific role in host–microbial cross-talk by producing ILA in human infants.

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The role of cAMP in nerve growth factor-promoted neurite outgrowth in PC12 cells.

The Journal of Cell Biology ◽

10.1083/jcb.102.3.821 ◽

1986 ◽

Vol 102 (3) ◽

pp. 821-829 ◽

Cited By ~ 122

Author(s):

C Richter-Landsberg ◽

B Jastorff

Keyword(s):

Nerve Growth Factor ◽

Growth Factor ◽

Neurite Outgrowth ◽

Pc12 Cells ◽

Morphological Differentiation ◽

Intracellular Camp ◽

Nerve Growth ◽

Process Formation ◽

Dependent Protein

Nerve growth factor (NGF)-mediated neurite outgrowth in rat pheochromocytoma PC12 cells has been described to be synergistically potentiated by the simultaneous addition of dibutyryl cAMP. To elucidate further the role of cAMP in NGF-induced neurite outgrowth we have used the adenylate cyclase activator forskolin, cAMP, and a set of chemically modified cAMP analogues, including the adenosine cyclic 3',5'-phosphorothioates (cAMPS) (Rp)-cAMPS and (Sp)-cAMPS. These diastereomers have differential effects on the activation of cAMP-dependent protein kinases, i.e., (Sp)-cAMPS behaves as a cAMP agonist and (Rp)-cAMPS behaves as a cAMP antagonist. Our data show that the establishment of a neuritic network, as observed from PC12 cells treated with NGF alone, could not be induced by either forskolin, cAMP, or cAMP analogues alone. The presence of NGF in combination with forskolin or cAMP or its agonistic analogues potentiated the initiation of neurite outgrowth from PC12 cells. The (Sp)-cAMPS-induced stimulation of NGF-mediated process formation was successfully blocked by the (Rp)-cAMPS diastereomer. On the other hand, NGF-stimulated neurite outgrowth was not inhibited by the presence of the cAMP antagonist (Rp)-cAMPS. We conclude that the morphological differentiation of PC12 cells stimulated by NGF does not require cAMP as a second messenger. The constant increase of intracellular cAMP, caused by either forskolin or cAMP and the analogues, in combination with NGF, not only rapidly stimulated early neurite outgrowth but also exerted a maintaining effect on the neuronal network established by NGF.

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AhR Activation Leads to Alterations in the Gut Microbiome with Consequent Effect on Induction of Myeloid Derived Suppressor Cells in a CXCR2-Dependent Manner

International Journal of Molecular Sciences ◽

10.3390/ijms21249613 ◽

2020 ◽

Vol 21 (24) ◽

pp. 9613

Author(s):

Wurood Hantoosh Neamah ◽

Philip Brandon Busbee ◽

Hasan Alghetaa ◽

Osama A. Abdulla ◽

Mitzi Nagarkatti ◽

...

Keyword(s):

Gut Microbiome ◽

Critical Role ◽

Suppressor Cells ◽

T Cell Proliferation ◽

Dependent Manner ◽

Myeloid Derived Suppressor Cells ◽

Aryl Hydrocarbon ◽

Cxc Chemokine ◽

Consequent Effect

Aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is a potent ligand for AhR and a known carcinogen. While AhR activation by TCDD leads to significant immunosuppression, how this translates into carcinogenic signal is unclear. Recently, we demonstrated that activation of AhR by TCDD in naïve C57BL6 mice leads to massive induction of myeloid derived-suppressor cells (MDSCs). In the current study, we investigated the role of the gut microbiota in TCDD-mediated MDSC induction. TCDD caused significant alterations in the gut microbiome, such as increases in Prevotella and Lactobacillus, while decreasing Sutterella and Bacteroides. Fecal transplants from TCDD-treated donor mice into antibiotic-treated mice induced MDSCs and increased regulatory T-cells (Tregs). Injecting TCDD directly into antibiotic-treated mice also induced MDSCs, although to a lesser extent. These data suggested that TCDD-induced dysbiosis plays a critical role in MDSC induction. Interestingly, treatment with TCDD led to induction of MDSCs in the colon and undetectable levels of cysteine. MDSCs suppressed T cell proliferation while reconstitution with cysteine restored this response. Lastly, blocking CXC chemokine receptor 2 (CXCR2) impeded TCDD-mediated MDSC induction. Our data demonstrate that AhR activation by TCDD triggers dysbiosis which, in turn, regulates, at least in part, induction of MDSCs.

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The Pivotal Role of Intracellular Calcium in Oxaliplatin-Induced Inhibition of Neurite Outgrowth but Not Cell Death in Differentiated PC12 Cells

Chemical Research in Toxicology ◽

10.1021/tx200160g ◽

2011 ◽

Vol 24 (11) ◽

pp. 1845-1852 ◽

Cited By ~ 24

Author(s):

Miki Takeshita ◽

Yoshiko Banno ◽

Mitsuhiro Nakamura ◽

Mayuko Otsuka ◽

Hitomi Teramachi ◽

...

Keyword(s):

Cell Death ◽

Intracellular Calcium ◽

Neurite Outgrowth ◽

Pc12 Cells ◽

Pivotal Role ◽

Differentiated Pc12 Cells

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A Chinese Herbal Preparation, Xiao-Er-An-Shen Decoction, Exerts Neuron Protection by Modulation of Differentiation and Antioxidant Activity in Cultured PC12 Cells

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2018/8670421 ◽

2018 ◽

Vol 2018 ◽

pp. 1-9 ◽

Cited By ~ 1

Author(s):

Zhonggui Li ◽

Kelly Y. C. Lam ◽

Xiaoyan Liu ◽

Airong Qi ◽

Ping Yao ◽

...

Keyword(s):

Antioxidant Activity ◽

Neurite Outgrowth ◽

Pc12 Cells ◽

Neurological Diseases ◽

Radical Scavenging Activity ◽

Radical Scavenging ◽

Scientific Data ◽

Herbal Extract ◽

Dependent Manner ◽

Chinese Herbal

Xiao-Er-An-Shen Decoction (XEASD), a Chinese herbal formula, has been used in clinic for treating insomnia and mental excitement in children and adolescents. However, less of scientific data supports its effectiveness in clinic. Here, we aim to study the role of XEASD in regulating neuron differentiation and antioxidant activity. An HPLC-MS was used to chemically standardize herbal extract of XEASD. The standardized herbal extracts of XEASD (0.3–3.0 mg/mL) were applied onto cultured PC12 cells for 48 hours. The treatment with XEASD extract induced neurite outgrowth of PC12 cells in a dose-dependent manner, having the highest response by ~50% of differentiated cells. Application of XEASD extract dose dependently stimulated expressions of NF68, NF160, and NF200 in cultured PC12 cells. Furthermore, XEASD activated the phosphorylation of cAMP responsive element binding protein on PC12 cells, the effect of which was blocked by H89, a protein kinase A inhibitor. Moreover, XEASD showed free radical scavenging activity and stimulated the transcriptional activity of ARE. These results supported the neurobeneficial effects of XEASD in the induction of neurite outgrowth and protection against oxidative stress and could be useful for neurological diseases, in which neurotrophin deficiency and oxidation insult are involved.

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Staphylococcus aureus activates the Aryl Hydrocarbon Receptor in Human Keratinocytes

10.1101/2022.01.05.475099 ◽

2022 ◽

Author(s):

Eva-Lena Stange ◽

Franziska Rademacher ◽

Katharina Antonia Drerup ◽

Nina Heinemann ◽

Lena Möbus ◽

...

Keyword(s):

Aryl Hydrocarbon Receptor ◽

Human Keratinocytes ◽

Dependent Manner ◽

Cutaneous Infections ◽

Innate Defense ◽

Aryl Hydrocarbon ◽

Reporter Assays ◽

Ahr Gene ◽

Whole Transcriptome

Staphylococcus (S.) aureus is an important pathogen causing various infections including - as most frequently isolated bacterium - cutaneous infections. Keratinocytes as the first barrier cells of the skin respond to S. aureus by the release of defense molecules such as cytokines and antimicrobial peptides. Although several pattern recognition receptors expressed in keratinocytes such as Toll-like and NOD-like receptors have been reported to detect the presence of S. aureus, the mechanisms underlying the interplay between S. aureus and keratinocytes are still emerging. Here we report that S. aureus induced gene expression of CYP1A1 and CYP1B1, responsive genes of the aryl hydrocarbon receptor (AhR). AhR activation by S. aureus was further confirmed by AhR gene reporter assays. AhR activation was mediated by factor(s) < 2 kDa secreted by S. aureus. Whole transcriptome analyses and real-time PCR analyses identified IL-24, IL-6 and IL-1beta as cytokines induced in an AhR-dependent manner in S. aureus-treated keratinocytes. AhR inhibition in a 3D organotypic skin equivalent confirmed the crucial role of the AhR in mediating the induction of IL-24, IL-6 and IL-1beta upon stimulation with living S. aureus. Taken together, we further highlight the important role of the AhR in cutaneous innate defense and identified the AhR as a novel receptor mediating the sensing of the important skin pathogen S. aureus in keratinocytes.

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