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Chung CJ, Hermes BM, Gupta Y, Ibrahim S, Belheouane M, Baines JF. Genome-wide mapping of gene-microbe interactions in the murine lung microbiota based on quantitative microbial profiling. Anim Microbiome 2023; 5:31. [PMID: 37264412 DOI: 10.1186/s42523-023-00250-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Accepted: 05/10/2023] [Indexed: 06/03/2023] Open
Abstract
BACKGROUND Mammalian lungs comprise a complex microbial ecosystem that interacts with host physiology. Previous research demonstrates that the environment significantly contributes to bacterial community structure in the upper and lower respiratory tract. However, the influence of host genetics on the makeup of lung microbiota remains ambiguous, largely due to technical difficulties related to sampling, as well as challenges inherent to investigating low biomass communities. Thus, innovative approaches are warranted to clarify host-microbe interactions in the mammalian lung. RESULTS Here, we aimed to characterize host genomic regions associated with lung bacterial traits in an advanced intercross mouse line (AIL). By performing quantitative microbial profiling (QMP) using the highly precise method of droplet digital PCR (ddPCR), we refined 16S rRNA gene amplicon-based traits to identify and map candidate lung-resident taxa using a QTL mapping approach. In addition, the two abundant core taxa Lactobacillus and Pelomonas were chosen for independent microbial phenotyping using genus-specific primers. In total, this revealed seven significant loci involving eight bacterial traits. The narrow confidence intervals afforded by the AIL population allowed us to identify several promising candidate genes related to immune and inflammatory responses, cell apoptosis, DNA repair, and lung functioning and disease susceptibility. Interestingly, one genomic region associated with Lactobacillus abundance contains the well-known anti-inflammatory cytokine Il10, which we confirmed through the analysis of Il10 knockout mice. CONCLUSIONS Our study provides the first evidence for a role of host genetic variation contributing to variation in the lung microbiota. This was in large part made possible through the careful curation of 16S rRNA gene amplicon data and the incorporation of a QMP-based methods. This approach to evaluating the low biomass lung environment opens new avenues for advancing lung microbiome research using animal models.
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Affiliation(s)
- C J Chung
- Max Planck Institute for Evolutionary Biology, August-Thienemann-Str. 2, 24306, Plön, Germany
- Section of Evolutionary Medicine, Institute for Experimental Medicine, Kiel University, Arnold-Heller-Str. 3, 24105, Kiel, Germany
| | - B M Hermes
- Max Planck Institute for Evolutionary Biology, August-Thienemann-Str. 2, 24306, Plön, Germany
- Section of Evolutionary Medicine, Institute for Experimental Medicine, Kiel University, Arnold-Heller-Str. 3, 24105, Kiel, Germany
| | - Y Gupta
- Division of Nephrology, Department of Medicine, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - S Ibrahim
- College of Medicine and Health Sciences, Khalifa University, Abu Dhabi, UAE
| | - Meriem Belheouane
- Max Planck Institute for Evolutionary Biology, August-Thienemann-Str. 2, 24306, Plön, Germany.
- Section of Evolutionary Medicine, Institute for Experimental Medicine, Kiel University, Arnold-Heller-Str. 3, 24105, Kiel, Germany.
- Research Center Borstel, Evolution of the Resistome, Leibniz Lung Center, Parkallee 1-40, 23845, Borstel, Germany.
| | - John F Baines
- Max Planck Institute for Evolutionary Biology, August-Thienemann-Str. 2, 24306, Plön, Germany.
- Section of Evolutionary Medicine, Institute for Experimental Medicine, Kiel University, Arnold-Heller-Str. 3, 24105, Kiel, Germany.
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Activation of 5-HT1A Receptors Promotes Retinal Ganglion Cell Function by Inhibiting the cAMP-PKA Pathway to Modulate Presynaptic GABA Release in Chronic Glaucoma. J Neurosci 2018; 39:1484-1504. [PMID: 30541912 DOI: 10.1523/jneurosci.1685-18.2018] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 11/30/2018] [Accepted: 12/03/2018] [Indexed: 12/12/2022] Open
Abstract
Serotonin (5-hydroxytryptamine, 5-HT) receptor agonists are neuroprotective in CNS injury models. However, the neuroprotective functional implications and synaptic mechanism of 8-hydroxy-2- (di-n-propylamino) tetralin (8-OH-DPAT), a serotonin receptor (5-HT1A) agonist, in an adult male Wistar rat model of chronic glaucoma model remain unknown. We found that ocular hypertension decreased 5-HT1A receptor expression in rat retinas because the number of retinal ganglion cells (RGCs) was significantly reduced in rats with induced ocular hypertension relative to that in control retinas and 8-OH-DPAT enhanced the RGC viability. The protective effects of 8-OH-DPAT were blocked by intravitreal administration of the selective 5-HT1A antagonist WAY-100635 or the selective GABAA receptor antagonist SR95531. Using patch-clamp techniques, spontaneous and miniature GABAergic IPSCs (sIPSCs and mIPSCs, respectively) of RGCs in rat retinal slices were recorded. 8-OH-DPAT significantly increased the frequency and amplitude of GABAergic sIPSCs and mIPSCs in ON- and OFF-type RGCs. Among the signaling cascades mediated by the 5-HT1A receptor, the role of cAMP-protein kinase A (PKA) signaling was investigated. The 8-OH-DPAT-induced changes at the synaptic level were enhanced by PKA inhibition by H-89 and blocked by PKA activation with bucladesine. Furthermore, the density of phosphorylated PKA (p-PKA)/PKA was significantly increased in glaucomatous retinas and 8-OH-DPAT significantly decreased p-PKA/PKA expression, which led to the inhibition of PKA phosphorylation upon relieving neurotransmitter GABA release. These results showed that the activation of 5-HT1A receptors in retinas facilitated presynaptic GABA release functions by suppressing cAMP-PKA signaling and decreasing PKA phosphorylation, which could lead to the de-excitation of RGC circuits and suppress excitotoxic processes in glaucoma.SIGNIFICANCE STATEMENT We found that serotonin (5-HT) receptors in the retina (5-HT1A receptors) were downregulated after intraocular pressure elevation. Patch-clamp recordings demonstrated differences in the frequencies of miniature GABAergic IPSCs (mIPSCs) in ON- and OFF-type retinal ganglion cells (RGCs) and RGCs in normal and glaucomatous retinal slices. Therefore, phosphorylated protein kinase A (PKA) inhibition upon release of the neurotransmitter GABA was eliminated by 8-hydroxy-2- (di-n-propylamino) tetralin (8-OH-DPAT), which led to increased levels of GABAergic mIPSCs in ON- and OFF-type RGCs, thus enhancing RGC viability and function. These protective effects were blocked by the GABAA receptor antagonist SR95531 or the 5-HT1A antagonist WAY-100635. This study identified a novel mechanism by which activation of 5-HT1A receptors protects damaged RGCs via the cAMP-PKA signaling pathway that modulates GABAergic presynaptic activity.
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Robichaux WG, Cheng X. Intracellular cAMP Sensor EPAC: Physiology, Pathophysiology, and Therapeutics Development. Physiol Rev 2018; 98:919-1053. [PMID: 29537337 PMCID: PMC6050347 DOI: 10.1152/physrev.00025.2017] [Citation(s) in RCA: 138] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 09/05/2017] [Accepted: 09/06/2017] [Indexed: 12/13/2022] Open
Abstract
This review focuses on one family of the known cAMP receptors, the exchange proteins directly activated by cAMP (EPACs), also known as the cAMP-regulated guanine nucleotide exchange factors (cAMP-GEFs). Although EPAC proteins are fairly new additions to the growing list of cAMP effectors, and relatively "young" in the cAMP discovery timeline, the significance of an EPAC presence in different cell systems is extraordinary. The study of EPACs has considerably expanded the diversity and adaptive nature of cAMP signaling associated with numerous physiological and pathophysiological responses. This review comprehensively covers EPAC protein functions at the molecular, cellular, physiological, and pathophysiological levels; and in turn, the applications of employing EPAC-based biosensors as detection tools for dissecting cAMP signaling and the implications for targeting EPAC proteins for therapeutic development are also discussed.
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Affiliation(s)
- William G Robichaux
- Department of Integrative Biology and Pharmacology, Texas Therapeutics Institute, The Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center , Houston, Texas
| | - Xiaodong Cheng
- Department of Integrative Biology and Pharmacology, Texas Therapeutics Institute, The Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center , Houston, Texas
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Afify EA, Andijani NM. Potentiation of Morphine-Induced Antinociception by Propranolol: The Involvement of Dopamine and GABA Systems. Front Pharmacol 2017; 8:794. [PMID: 29209205 PMCID: PMC5701645 DOI: 10.3389/fphar.2017.00794] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 10/20/2017] [Indexed: 12/26/2022] Open
Abstract
Tolerance to the analgesic effect of morphine is a major clinical problem which can be managed by co-administration of another drug. This study investigated the ability of propranolol to potentiate the antinociceptive action of morphine and the possible mechanisms underlying this effect. Antinociception was assessed in three nociceptive tests (thermal, hot plate), (visceral, acetic acid), and (inflammatory, formalin test) in mice and quantified by measuring the percent maximum possible effect, the percent inhibition of acetic acid-evoked writhing response, and the area under the curve values of number of flinches for treated mice, respectively. The study revealed that propranolol (0.25-20 mg/Kg, IP) administration did not produce analgesia in mice. However, 10 mg/Kg propranolol, enhanced the antinociceptive effect of sub-analgesic doses of morphine (0.2, 1, and 2 mg/Kg, IP) in the three nociceptive tests. It also shifted the dose response curve of morphine to the left. The combined effect of propranolol and morphine was attenuated by haloperidol (D2 receptor antagonist, 1.5 mg/Kg, IP), and bicuculline (GABAA receptor antagonist, 2 mg/Kg, IP). Repeated daily administration of propranolol (10 mg/Kg, IP) did not alter the nociceptive responses in the three pain tests, but it significantly potentiated morphine-induced antinociception in the hot plate, acetic acid-evoked writhing, and in the second phase of formalin tests. Together, the data suggest that a cross-talk exists between the opioidergic and adrenergic systems and implicate dopamine and GABA systems in this synergistic effect of morphine-propranolol combination. Propranolol may serve as an adjuvant therapy to potentiate the effect of opioid analgesics.
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Affiliation(s)
- Elham A Afify
- Department of Pharmacology, Faculty of Pharmacy, King Abdulaziz University, Jeddah, Saudi Arabia.,Department of Pharmacology and Toxicology, Faculty of Pharmacy, Alexandria University, Alexandria, Egypt
| | - Najlaa M Andijani
- Department of Pharmacology, Faculty of Pharmacy, King Abdulaziz University, Jeddah, Saudi Arabia
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Prakash YS. Emerging concepts in smooth muscle contributions to airway structure and function: implications for health and disease. Am J Physiol Lung Cell Mol Physiol 2016; 311:L1113-L1140. [PMID: 27742732 DOI: 10.1152/ajplung.00370.2016] [Citation(s) in RCA: 99] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Accepted: 10/06/2016] [Indexed: 12/15/2022] Open
Abstract
Airway structure and function are key aspects of normal lung development, growth, and aging, as well as of lung responses to the environment and the pathophysiology of important diseases such as asthma, chronic obstructive pulmonary disease, and fibrosis. In this regard, the contributions of airway smooth muscle (ASM) are both functional, in the context of airway contractility and relaxation, as well as synthetic, involving production and modulation of extracellular components, modulation of the local immune environment, cellular contribution to airway structure, and, finally, interactions with other airway cell types such as epithelium, fibroblasts, and nerves. These ASM contributions are now found to be critical in airway hyperresponsiveness and remodeling that occur in lung diseases. This review emphasizes established and recent discoveries that underline the central role of ASM and sets the stage for future research toward understanding how ASM plays a central role by being both upstream and downstream in the many interactive processes that determine airway structure and function in health and disease.
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Affiliation(s)
- Y S Prakash
- Departments of Anesthesiology, and Physiology & Biomedical Engineering, Mayo Clinic, Rochester, Minnesota
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