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Published in final edited form as: J Allergy Clin Immunol. 2022 May 11;150(5):1228–1231.e5. doi: 10.1016/j.jaci.2022.04.028

Dynamin Related Protein 1 Differentially Regulates FcεRI- and SP-induced Mast Cell Activation

Ying Wang 1,*, Mang Yu 1,*, Kazufumi Matsushita 1,2,*, Chen Liu 1,2, Naotada Ishihara 3, Masatoshi Nomura 4, Mindy Tsai 1,2, Stephen J Galli 1,2,5
PMCID: PMC9643595  NIHMSID: NIHMS1806861  PMID: 35561839

Abstract

Background:

The mitochondrial fission protein, dynamin related protein 1 (Drp1), has been suggested to regulate mast cell (MC) activation by certain stimuli in vitro but its functions in MCs activated by various stimuli in vivo has not been examined.

Objective:

Analyze Drp1 function in both mouse and human MCs.

Methods:

We used human peripheral blood-derived cultured MCs (PBCMCs) and two genetic mouse models in which MCs were depleted of Drp1: Drp1fl/flMcpt5cre+/− mice and Drp1fl/flCpa3cre+/− mice.

Results:

In mice, Drp1 depletion enhanced FcεRI-induced MC activation while suppressing substance P (SP)-stimulated MC activation in vitro and in vivo. This was also true in human PBCMCs in vitro after pharmacological inhibition of Drp1.

Conclusion:

Our work shows that Drp1 differentially regulates MC activation by various stimuli. These findings suggest that promoting Drp1 activation might represent a novel therapy for suppressing IgE-dependent MC activation while inhibiting Drp1 activation might mitigate other MC-dependent responses, such as those induced by substance P.

Keywords: Mast cell, FcεRI-dependent activation, Drp1, substance P

Capsule Summary:

Drp1 promotes substance P (SP)-induced but suppresses IgE-FcεRI-dependent MC activation.

Introduction:

Mast cell (MC) activation via cross-linking of the high affinity IgE receptor, FcεRI, can contribute to allergic conditions such as asthma, food allergy and atopic dermatitis (AD) (1). This process is initiated when specific antigens cross-link FcεRI-bound IgE. However, stimuli that can activate MCs via FcεRI-independent mechanisms also can contribute to inflammatory processes, including a panel of cationic substances such as the neuropeptide substance P (SP) (2).

However, factors that can regulate FcεRI-dependent and FcεRI-independent activation of MCs are not fully understood. A recent study has shown that mitochondrial fission and translocation occurs during activation of cultured MCs in vitro (3). Moreover, expression of mRNA of dynamin related protein 1 (Drp1), an essential molecule for mitochondrial fission, has been reported to increase in skin MCs from patients with AD, suggesting a positive correlation between Drp1 and MC activation in AD patients (3). Notably, however, the specific role of Drp1 in MC activation (e.g., by IgE or substance P) in vivo has not been examined.

Results and Discussion

To investigate the role of Drp1 in MC activation in vivo, we generated Drp1fl/flMcpt5cre+/− mice by crossing Drp1fl/fl mice (4) with Mcpt5cre+/− mice (5). Because Mcpt5 is dominantly expressed in connective tissue-type MCs (5), we expected to delete Drp1 in connective tissue MCs (CTMCs) with Mcpt5cre. We first confirmed that Mcpt5cre is expressed in connective MCs in the ear pinna based on the observation that the ear pinna dermis was depleted of MCs in Mcpt5cre+/−R-DTA mice, in which the diphtheria toxin A kills Mcpt5-expressing cells (Online Repository Fig 1A). Depletion of MCs in the ear pinna virtually abolished expression of the PCA reaction (Online Repository Fig 1B). These observations are in accord with the previous finding that in Mcpt5-Cre ROSA26-EYFP double transgenic mice, EYFP is specifically expressed in connective MCs (peritoneal and skin MCs) but not in other types of bone marrow-derived cells (5).

Online Repository Fig 1. Skin MC depletion eliminates PCA reactions in Mcpt5cre+/− R-DTA mice.

Online Repository Fig 1.

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(A) Ear pinna sections: R-DTA and Mcpt5cre+ R-DTA mice. Yellow arrows: MCs with toluidine-blue-stained granules. (B) PCA reaction was abolished in Mcpt5cre+/− R-DTA mice. (C) PCA reaction in WT (Mcpt5cre−) vs. Mcpt5cre+/− mice. n=3 mice/group. Error bars: SEM. *P <0.05: Mcpt5cre+/−R-DTA vs. R-DTA groups. #: Δ ear thickness significantly different (P <0.05) from zero.

Drp1fl/flMcpt5cre+/− mice were born in the expected Mendelian ratio and did not show any gross developmental defects. The MC population in the peritoneal cavity, and the total numbers of MCs in the skin, were similar in Drp1fl/flMcpt5cre+/− and Drp1fl/fl animals (Online Repository Fig 2A). However, Drp1fl/flMcpt5cre+/− mice displayed enhanced passive cutaneous anaphylaxis (PCA) reactions in the ear pinna (Fig 1A). These phenotypes were not due to the expression of Mcpt5cre alone (Online Repository Fig 1C).

Online Repository Fig 2. MCs counts and histamine in Drp1fl/fl Mcpt5cre+/− and Mcpt5cre+/−→KitW-sh/W-sh mice, Drp1 depletion, and plot of Av_488+, in BMCMCs from Drp1fl/fl Mcpt5cre+/− mice.

Online Repository Fig 2.

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(A) FcεRIα+c-Kit+ cells: % of all peritoneal cells; MCs/mm2 ear pinnae. (B) Blots of Drp1 and β-actin (loading control). (C) Relative histamine content in BMCMCs. (D) Representative dot plots and quantification (the bar graph) of Av_488+ staining in cells stimulated with vehicle and 10ng/ml NDP-HAS for 30 minutes (AVE ± SEM), n=3 technical replicates, 2 mice/group. *P <0.05: baseline vs. 30 min for each mouse group; #P <0.05: 30 min results for the 2 groups. (E) Numbers of ear pinnae MCs. N.S., not significant (P >0.05). Error Bars: SEM. 7-week-old female mice.

Figure 1. Drp1 depletion enhances FcεRI-induced MC activation in mice.

Figure 1.

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(A) PCA reactions (females). (B) IL-6 and % histamine release from IgE-sensitized, DNP-HSA stimulated BMCMCs. (C) IgE activation of BMCMCs (mean fluorescence intensity (MFI) of Alexa 488-conjugated avidin). * P<0.05 (D) PCA reactions (males). (E) Substance-P induced cutaneous inflammation. Error Bars: SEM. *P<0.05 vs. other group; #P<0.05 vs. zero DNP-HSA.

We then generated IL-3-dependent bone marrow-derived cultured mast cells (BMCMCs) by culturing BM cells in IL-3 conditioned media (6, 7). Western blot validated that the expression of Drp1 in BMCMCs derived from Drp1fl/flMcpt5cre+/− mice is substantially reduced compared to BMCMCs derived from Drp1fl/fl mice (Online Repository Fig 2B). Drp1fl/flMcpt5cre+/− BMCMCs released significantly more IL-6 and more histamine than Drp1fl/fl BMCMCs upon FcεRI activation (Fig 1B). Notably, the enhanced histamine release of Drp1fl/flMcpt5cre+/− BMCMCs was not due to an increase in total intracellular histamine content (Online Repository Fig 2C).

To further characterize MC degranulation in vitro, we used soluble fluorochrome-labeled avidin (Alex 488–coupled avidin [Av.A488]) (8, 9). During MC degranulation, secretory granule membranes fuse with the plasma membrane, and the granule matrix is externalized and rapidly bound by fluorescent avidin, allowing monitoring degranulation dynamics using flow cytometry. The level of degranulation can be quantified as the mean fluorescence intensity (MFI) of Av.488 on the cell surface and the percentage of Av.488+ cells (%AV.488+). Using this assay, we confirmed that Drp1fl/flMcpt5cre+/− BMCMCs showed enhanced degranulation upon FcεRI-induced activation (Fig 1C and Online Repository Fig 2D). Furthermore, MC-deficient KitW-sh/W-sh mice engrafted with Drp1fl/flMcpt5cre+/− MCs in the ear pinna exhibited stronger PCA reactions than did KitW-sh/W-sh animals engrafted with Drp1fl/fl MCs (Fig 1D), but the number of engrafted MCs was not significantly different between the two groups (Online Repository Fig 2E). Taken together, these findings show that suppression of Drp1 in MCs increases the intensity of PCA in vivo and also enhances FcεRI-induced MC degranulation and histamine and cytokine release in vitro.

To confirm these findings, we isolated bone marrow (BM) cells and generated BMCMCs from Drpfl/flCpa3cre+/− mice. Cpa3 is ubiquitously expressed in tissue MCs. After 6 weeks in culture, both Drpfl/fl and Drpfl/flCpa3cre+/− MCs were >95% FcεRIα and c-Kit double positive mast cells (Online Repository Fig 3A). As expected, the expression of Drp1 protein in Drpfl/flCpa3cre+/− MC was reduced by >90% in the total cell lysate (Online Repository Fig 3B). Similar to Drp1fl/flMcpt5cre+/− MCs, Drpfl/flCpa3cre+/− MCs released more IL-6 and histamine upon FcεRI stimulation than Drp1fl/fl MCs (Online Repository Fig 3C). This was not associated with increased expression of FcεRIα or c-Kit on the cell surface of Drp1fl/flCpa3cre+/− MCs (Online Repository Fig 3F). The calcium ionophore A23187 (1 uM) can elicit sustained elevations of intracellular calcium (8), mimicking intracellular calcium dynamics during FcεRI-dependent MC activation (9). We found that A23187-induced IL-6 release is increased in Drp1fl/flMcpt5cre+/− MCs compared to Drp1fl/fl MCs (Online Repository Fig 3D), suggesting that calcium functions upstream of Drp1 in the cascade of FcεRI-dependent MC activation.

Online Repository Fig 3. Enhanced FcεRI-induced activation of Drp1fl/flCpa3cre+/− MCs.

Online Repository Fig 3.

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(A) BMCMC purity. (B) Drp1 protein in BMCMC lysates (Western; protein ladder shown on left). (C) IL-6 release and % histamine release (n=3 mice/group). (D) IL-6 release from calcium ionophore A23187-stimulated BMCMC. (E) PCA reactions (male mice). (C-E) *P<0.05 between groups; #P<0.05 vs. zero DNP-HSA or A23187. (F) BMCMC surface FcεRIα and c-Kit (n=3 mice/group; technical replicates). (G) Ear pinna MCs (mixed gender). Error Bars: SEM. N.S., not significant.

Most importantly, engraftment of Drpfl/flCpa3cre+/− MCs into the ear pinnae of MC-deficient KitW-sh/W-sh mice primed them to express a stronger passive cutaneous anaphylaxis (PCA) reaction than was observed in the KitW-sh/W-sh animals engrafted with Drpfl/fl MCs (Online Repository Fig 3E). Such stronger PCA reactions were not due to increased numbers of MCs in the ear pinna after engraftment (Online Repository Fig 3G). These findings in Drpfl/flCpa3cre+/− mice thus are consistent with those from Drp1fl/flMcpt5cre+/− mice in showing that depletion of Drp1 enhances FcεRI-mediated MC activation both in vivo and in vitro.

We also investigated the potential role of Drp1 in one example of FcεRI-independent MC activation: the pseudo-allergic/neurogenic route of MC activation induced by substance P (SP). In contrast to FcεRI-induced MC activation, we found that Drp1fl/flMcpt5cre+/− mice exhibited reduced substance P (SP)-induced ear swelling compared to control Drp1fl/fl mice (Fig 1E). This finding shows that Drp1 can enhance SP-induced MC activation in vivo.

Finally, we tested the effect of Drp1 inhibition during activation of primary human peripheral blood-derived cultured MCs (PBCMCs) in vitro. Pretreatment of PBCMCs with 40 μM of the Drp1-specific inhibitor, Mdivi-1, promoted FcεRI-mediated beta-hexosaminidase (beta-hex) release (Fig 2A). Interestingly, the same dose of Mdivi-1 did not increase, but instead suppressed, substance P (SP)-mediated human MC beta-hex release (Fig 2B). This result is consistent with the report from Zhang and colleagues that Mdivi-1 suppressed SP-induced TNF-α and beta-hex release in the human mast cell line LAD2 cells (3).

Figure 2. Drp1 depletion enhances FcεRI-induced activation but inhibits substance P (SP) activation in human MCs in vitro.

Figure 2.

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Beta-hexosaminidase release from human peripheral blood-derived cultured MCs (PBCMCs) activated with anti-IgE (A) or PBCMCs activated with SP (B), with or without the incubation with Mdivi-1, a selective Drp1 inhibitor. (PBCMCs from two 2 donors and 2 experiments/donor). Error bars: SEM.

Using both human and mouse MC models, we have found that Drp1 can suppress FcεRI-mediated MC activation while enhancing SP-induced MC activation. Thus, Drp1 can differentially influence MC activation during the cells’ stimulation with distinct agonists.

Such differential effects of Drp1 in MCs activated by various stimuli (SP vs. IgE) might be explained by the diverse effects of Drp1 in signaling pathways downstream of individual stimuli (10–14). Although Drp1 directly mediates mitochondrial outer membrane fusion, more recent studies have reported the pleiotropic effects of Drp1 in regulating intracellular calcium compartmentation, organellar interactions and functions (11, 12, 14). Indeed, a recent study from our lab has shown that IgE-FcεRI-dependent cutaneous reactions are long lasting and, in contrast, a pseudoallergic reaction (i.e., MRGPRX2-dependent MC activation induced by SP) appears to be more transient (9). An apparent difference between the two activation pathways has been described: SP-induces a rapid and transient secretion of relatively small, individual and spherical granules while FcεRI-dependent activation causes a delayed secretion of larger and more heterogeneous granules, most likely due to granule fusion (9). Therefore, one plausible explanation of our observations is that Drp1 differentially regulates MC granule fusion and secretion downstream of SP stimulation vs. ligation of FcεRI.

Besides Drp1, the differential regulation of distinct stimuli-induced MC degranulation has been reported. For example, G protein-coupled receptor kinase 2 (GRK2) inhibits human MC degranulation in response to GPCR-dependent activation by C3a (15) while augmenting activation in response to IgE cross-linking (16). Such differential MC activation is associated with differential regulation of intracellular calcium dynamics. It will be interesting to determine whether the opposite effects of Drp1 in the mast cell’s response to SP stimulation vs. ligation of FcεRI is dependent on GRK2 or other GPCR associated proteins, and/or on calcium dynamics.

In conclusion, our work shows that Drp1 differentially regulates MC activation by two stimuli, IgE+antigen vs. SP. Indeed, Drp1 down-regulates FcεRI-induced MC activation but up-regulates SP-induced MC activation. These findings suggest that promoting Drp1 activation might represent a novel therapy for suppressing IgE-dependent MC activation while inhibiting Drp1 activation may mitigate other MC-dependent responses, such as those induced by substance P.

Online Repository Methods

Mice

All the mice used in this manuscript were housed and bred in specific pathogen-free animal facilities at Stanford University under a 12 hour light/12 hour dark cycle. The use of all mice for these studies was in accord with institutional guidelines with review and approval by Stanford IACUC. Drp1fl/fl mice were kindly provided by Drs. Naotada Ishihara and Masatoshi Normura from Osaka University and Kyushu University, Japan (1). Cpa3Cre+ transgenic mice were generated in the Galli lab as described (2). C57BL/6-KitW-sh/W-sh mice were originally provided by Peter Besmer (Molecular Biology Program, Memorial Sloan-Kettering Cancer Center, New York, NY, USA); we then backcrossed these mice to C57BL/6J mice for more than 11 generations (3). C57BL/6-Mcpt5Cre+ mice were provided by Axel Roers (Institute for Immunology, University of Technology Dresden, Medical Faculty Carl-Gustav Carus, Dresden, Germany). B6.129P2-Gt(ROSA)26Sortm1(DTA)Lky/J (R-DTA) mice were obtained from Jackson Laboratories.

Passive Cutaneous Anaphylaxis (PCA)

IgE-dependent PCA was induced in the ear pinna as described previously (2). Briefly, mice under isoflurane anesthesia were sensitized passively with IgE by intradermal injection of 20 ng of dinitrophenol (DNP)—specific IgE (α-DNP clone 26, using cells kindly provided by Fu-Tong Liu, University of California, Davis and D.H. Katz of LIDAK Pharmaceuticals), in 20 μL of HMEM-Pipes buffer (Sigma-Aldrich) in the left ear pinna; mice received 20 μL of vehicle intradermally in the right ear pinna as a control. The next day, mice were challenged through the retro-ortibal venus sinus with 100 μg of DNP30-40—conjugated human serum albumin (DNP-HSA; Sigma-Aldrich) in 100 μL of saline.

Immediately before or at defined intervals after antigen challenge, ear thickness was measured with a dial thickness gauge (G-1A; Ozaki). Differences between left and right ear pinna were calculated (Δ ear thickness). Mice were sacrificed 6 hours after antigen challenge and ear pinnae were collected for histological analysis.

Substance-P dependent cutaneous inflammation

Substance-P induced cutaneous inflammation was induced in the ear pinna as described previously (3, 4), with modifications. Briefly, the left ear pinna was injected i.d. with SP (1 nmol in 5 μL HMEM-PIPES solution [Hanks’ MEM containing 0.47 g/litter piperazine-N,N’ bis(2-ethane sulfonic acid)] or i.d. with 5 μL HMEM-PIPES (control). Immediately before or at defined intervals after antigen challenge, ear thickness was measured with a dial thickness gauge (G-1A; Ozaki). Differences between left and right ear pinna were calculated (Δ ear thickness).

MC culture, Degranulation and Activation

Mouse bone marrow-derived cultured mast cells (BMCMCs) were generated as previously described (5). Bone marrow cells derived from 3-week-old female or male Drp1fl/fl and Drp1fl/flCpa3cre+/− mice, or 4-week-old Drp1fl/fl and Drp1fl/flMcpt5cre+/− mice were cultured in 20% WEHI-3-conditioned media (ATCC No. TIB-68) as a source of IL-3, for 6 weeks to generate cell populations that contain >95% immature MCs. Human peripheral blood cultured MCs (PBCMCs) were generated as previously described, with modification(3). CD34+ peripheral blood cells were isolated from peripheral blood mononuclear cells using a Human CD34 Positive Selection Kit (EasySep, STEMCELL Technologies, Cat: 18086). CD34+ cells were cultured and expanded in StemSpan™ Serum-Free Expansion Media, SFEM (STEMCELL Technologies, 09650) supplemented with IL-6 (50 ng/mL, Peprotech, 200-06) and SCF (100 ng/mL, Peptrotech, 300-07). PBCMCs were tested for purity and phenotype by flow cytometry (CD117, FcεRIα) and activation (β-hexosaminidase release in response to FcεRI cross-linking) at 8–12 weeks.

FcεRIα-mediated BMCMC degranulation was performed (6) as described, with modification. Hybridoma H1-DNP-ε26, which produces IgE mAb to DNP, was used to generate ascites. Mast cells were sensitized with ascites diluted in medium at a concentration of 1 μg/mL overnight at 37 °C, washed with medium, then resuspended at 37 °C with medium containing various concentrations of 30–40 DNP conjugated to each molecule of HSA (DNP–HSA; Sigma) for 30 min or 10 ng/mL DNP-HSA for the indicated times. In some experiments, unsensitized mast cells were suspended in medium containing the indicated concentrations of calcium ionophore A23187 for 6 h. Activation was stopped by immediately placing the cells on ice. For PBCMC activation, PBCMCs were preincubated with human IgE (1 μg/mL) for 1 h, and then stimulated with 10 ng/mL anti-IgE for 30 min. For measuring histamine release, the total amount of histamine in the supernatant and cell lysate was determined by ELISA (Beckman Coulter, IM2015) after 6 h. IL-6 release was quantified using the human IL-6 ELISA kit (Thermo Fisher, EH2IL6) after 6 h. The release of beta-Hex was measured on an enzyme-linked immunosorbent assay ‘reader’ with p-nitrophenyl-N-acetyl-β-D-glucosamine (Sigma) as described (6). Briefly, 1x105 cells were resuspended in 100 μL Tyrode’s solution supplied with 1% glucose and 1% BSA and HEPES (10 mM, Gibco) in a V-shaped 96-well plate. Cells were then stimulated for 30 min at 37°C with 5% CO2. At the end of the experiment, supernatant and cell lysate (lysed in Tyrode’s solution + 0.5% triton) was collected and were analyzed by ELISA. Mdivi-1 (M0199), A23187 (C7522) and substance P (S6883) were purchased from Sigma.

Engraftment of BMCMCs into KitW-sh/W-sh mice

Engraftment of BMCMCs into KitW-sh/W-sh mice was performed as described, with modification (2). BMCMCs derived from female Drp1fl/fl and Drp1fl/flCpa3Cre+/− (C57BL/6J) mice were transferred by intradermal injection (1 x 106 cells in 20 μL DMEM in a single injection into the left ear pinna, 20 μl DMEM alone into the right pinna) into 4-week-old male KitW-sh/W-sh mice (n = 11 Drp1fl/fl→KitW-sh/W-sh and 8 Drp1fl/flCpa3cre+/−→KitW-sh/W-sh mice). In another experiment, BMCMCs derived from female Drp1fl/fl and Drp1fl/flMcpt5cre+/− (C57BL/6J) mice were transferred into 4-week-old male KitW-sh/W-sh mice (n = 8 Drp1fl/fl→KitW-sh/W-sh and 8 Drp1fl/flMcpt5cre+/−→KitW-sh/W-sh). Experiments were initiated 8 weeks after injection of the BMCMCs.

Flow Cytometry Analysis

Flow cytometry analysis was performed using BD FACSCanto II analyzer. Cells were suspended in PBS + 0.5% BSA + 0.5 mM EDTA, and stained with the following antibodies or dyes for 30 min on ice: human CD117 (Clone 104D2, 1:100), human FcεRIα (Clone AER-37, 1:100) and 1 μg/mL Alexa 488-conjugated avidin (Av.A488).

Tissue sectioning and Toluidine blue staining

Tissue specimens were fixed with 10% neutral buffered formalin and embedded in paraffin. Four-micrometer sections were stained with 0.1% Toluidine blue for histologic examination and enumeration of mast cells (2).

Statistics

All the time-course and dose-response experiments were analyzed using two-way ANOVA repeated measures in one factor (mixed-model) followed by Bonferroni post-hoc test. Comparison of multiple groups was analyzed using one-way ANOVA followed by Bonferroni post-hoc test. P values less than 0.05 were considered significant.

Key Messages.

  • Inhibition of Drp1 enhances FcεRI-dependent MC activation but reduces substance P (SP)-induced MC activation in mice.

  • Such differential regulation of MC activation also can be observed in human PBCMCs, implicating a potential context-dependent role of Drp1 in MC activation in human diseases.

Funding resources:

This study was supported by NIH T32 training award to Y.W. (T32 AI 7290-33), an award from MSD Life Science Foundation and Public Interest Incorporated Foundation (Japan) to K.M., and NIH grants (NIAID R01 AI132494, NIAID U19AI104209, NIAMS R01 AR067145) and United States-Israel Binational Science Foundation (Grant 2017182) to S.J.G.

Abbreviations:

MC

mast cell

AD

atopic dermatitis

BM

bone marrow

Drp1

dynamin related protein 1

BMCMCs

bone marrow-derived cultured mast cells

CTMC

connective tissue mast cells

PBCMC

human primary peripheral blood-derived cultured MCs

Footnotes

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References

  • 1.Galli SJ, Tsai M. IgE and mast cells in allergic disease. Nature medicine. 2012;18(5):693–704. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 2.Yano H, Wershil BK, Arizono N, Galli SJ. Substance P-induced augmentation of cutaneous vascular permeability and granulocyte infiltration in mice is mast cell dependent. J Clin Invest. 1989;84(4):1276–86. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 3.Zhang B, Alysandratos KD, Angelidou A, Asadi S, Sismanopoulos N, Delivanis DA, et al. Human mast cell degranulation and preformed TNF secretion require mitochondrial translocation to exocytosis sites: relevance to atopic dermatitis. The Journal of allergy and clinical immunology. 2011;127(6):1522–31 e8. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 4.Ishihara N, Nomura M, Jofuku A, Kato H, Suzuki SO, Masuda K, et al. Mitochondrial fission factor Drp1 is essential for embryonic development and synapse formation in mice. Nature cell biology. 2009;11(8):958–66. [DOI] [PubMed] [Google Scholar]
  • 5.Scholten J, Hartmann K, Gerbaulet A, Krieg T, Muller W, Testa G, et al. Mast cell-specific Cre/loxP-mediated recombination in vivo. Transgenic research. 2008;17(2):307–15. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 6.Tam SY, Tsai M, Snouwaert JN, Kalesnikoff J, Scherrer D, Nakae S, et al. RabGEF1 is a negative regulator of mast cell activation and skin inflammation. Nature immunology. 2004;5(8):844–52. [DOI] [PubMed] [Google Scholar]
  • 7.Yu M, Mukai K, Tsai M, Galli SJ. Thirdhand smoke component can exacerbate a mouse asthma model through mast cells. The Journal of allergy and clinical immunology. 2018;142(5):1618–27 e9. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 8.Gulledge TV, Collette NM, Mackey E, Johnstone SE, Moazami Y, Todd DA, et al. Mast cell degranulation and calcium influx are inhibited by an Echinacea purpurea extract and the alkylamide dodeca-2E,4E-dienoic acid isobutylamide. J Ethnopharmacol. 2018;212:166–74. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 9.Gaudenzio N, Sibilano R, Marichal T, Starkl P, Reber LL, Cenac N, et al. Different activation signals induce distinct mast cell degranulation strategies. J Clin Invest. 2016;126(10):3981–98. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 10.Bulfone-Paus S, Nilsson G, Draber P, Blank U, Levi-Schaffer F. Positive and Negative Signals in Mast Cell Activation. Trends in immunology. 2017;38(9):657–67. [DOI] [PubMed] [Google Scholar]
  • 11.Li X, Yang L, Mao Z, Pan X, Zhao Y, Gu X, et al. Novel role of dynamin-related-protein 1 in dynamics of ER-lipid droplets in adipose tissue. FASEB J. 2020;34(6):8265–82. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 12.Liu W, Ye C, Cheng Q, Zhang X, Yao L, Li Q, et al. Macrophage Raptor Deficiency-Induced Lysosome Dysfunction Exacerbates Nonalcoholic Steatohepatitis. Cell Mol Gastroenterol Hepatol. 2019;7(1):211–31. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 13.Kraus F, Roy K, Pucadyil TJ, Ryan MT. Function and regulation of the divisome for mitochondrial fission. Nature. 2021;590(7844):57–66. [DOI] [PubMed] [Google Scholar]
  • 14.Rogers MA, Hutcheson JD, Okui T, Goettsch C, Singh SA, Halu A, et al. Dynamin-related protein 1 inhibition reduces hepatic PCSK9 secretion. Cardiovasc Res. 2021. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 15.Guo Q, Subramanian H, Gupta K, Ali H. Regulation of C3a receptor signaling in human mast cells by G protein coupled receptor kinases. PLoS One. 2011;6(7):e22559. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 16.Subramanian H, Gupta K, Parameswaran N, Ali H. Regulation of FcεRI signaling in mast cells by G protein-coupled receptor kinase 2 and its RH domain. J Biol Chem. 2014;289(30):20917–27. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 2.Lilla JN, Chen CC, Mukai K, BenBarak MJ, Franco CB, Kalesnikoff J, et al. Reduced mast cell and basophil numbers and function in Cpa3-Cre; Mcl-1fl/fl mice. Blood. 2011;118(26):6930–8. [DOI] [PMC free article] [PubMed] [Google Scholar]

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