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Dourson, A. J.

Publications and source records attributed to Dourson, A. J..

6 recordsLinked to original sources

Hormonal factors are poor indicators of endometriosis pain

Endometriosis is a common yet understudied condition in which sex hormones play a key role in the etiology and pathophysiology of the disease. Sex hormones are dysregulated in endometriosis and are pharmacologically targeted to reduce symptoms including pain, but the relationships between endometriosis-related pain with sex hormone levels and their receptors are not clear. In 60 women previously diagnosed or undergoing laparoscopic surgery for the diagnosis of endometriosis, we collected patient-reported endometriosis/pelvic pain intensity in the last 30 days, pain interference scale, and the Endometriosis Health Profile 30 (EHP30) pain subscale. In a sub-sample of 38 participants, biopsies from control non-lesion pelvic peritoneum and endometrial lesion tissues were collected during surgery to analyze the tissue abundance of the primary receptors for estrogen, as well as androgen, progesterone, and prolactin receptors. Serum was collected to analyze systemic sex hormone levels including estradiol, prolactin, progesterone, and testosterone. Between tissues, we found elevated transcript levels for estrogen receptor alpha (ESR1) in lesions, but no difference in estrogen receptor beta (ESR2) transcript levels between tissue samples were found. Relating tissue receptor transcript levels to clinical pain revealed that only ESR1 and PGR in lesions were negatively associated with endometriosis/pelvic pain intensity, however, following false discovery rate correction the association with ESR1 was no longer statistically significant. No other tissue or systemic factors were associated with clinical pain outcomes. Together, these data demonstrate unique alterations in receptor abundance in lesions yet select transcript levels only weakly relate to pain in endometriosis.

neuroscience↗

A multi-omic atlas of human autonomic and sensory ganglia implicates cell types in peripheral neuropathies

The human peripheral nervous system (PNS) consists of many ganglia including sympathetic ganglia (SG) and dorsal root ganglia (DRG). These ganglia house the cell bodies of diverse PNS neurons that transmit autonomic and sensory signals, as well as a much larger number of non-neuronal cells. However, the molecular and cellular diversity of these human PNS cell types and their implications in human disease remain elusive. By generating an integrated single-cell multi-omic atlas of human SG and DRG, we provide comprehensive transcriptional and epigenomic landscapes of various cell types in these peripheral ganglia. While the major cell types and their cell-type-specific transcriptional and epigenomic features are similar between human SG and DRG, we identify key differences between SG and DRG cell types. These differences highlight the distinct molecular and cellular mechanisms underlying their specific functions. We also profiled key genomic regulatory networks that govern cell-type-specific gene expression in these peripheral ganglia. Moreover, by mapping the expression and chromatin accessibility of disease-associated genes in human SG and DRG, we identify cell types that may underlie various peripheral neuropathies. This atlas serves as a valuable resource for understanding the intricate cell-type-specific molecules and interactions in the human PNS and their implications in human health and diseases.

neuroscience↗

Human sensory neurons exhibit cell-type-specific, pain-associated differences in intrinsic excitability and expression of SCN9A and SCN10A

Despite major advances in pain science, the approval of novel therapeutics has been slow. A major cause for the lack of new analgesics may be fundamental biological differences between humans and model organisms used in preclinical research. Large-scale transcriptional profiling efforts on human dorsal root ganglia (hDRG) have now identified at least 22 distinct neuronal subtypes; however, a significant knowledge gap exists in ascribing functional phenotypes to these diverse neuronal populations. In this study, we use Patch-seq recordings in hDRG to link electrical properties to transcriptionally defined cell types. First, through unbiased clustering of electrophysiological properties from 228 hDRG neurons, we identify three electrophysiological subtypes (E-types). Next, we show that E-types can be mapped onto specific transcriptional classes (T-types) of hDRG neurons. We find that donors pain history is associated with E-type-specific differences in electrical properties, some of which may be associated with higher expression of voltage-gated sodium channels, NaV1.7 and NaV1.8. These results highlight the importance of using multimodal profiling to better understand human sensory neuron biology and may help reveal novel therapeutic targets driving chronic pain. TeaserMapping electrical properties to transcriptional profiles of human sensory neurons offers new insights into pain neurobiology

neuroscience↗

The intersection of endocrine signaling and neuroimmune communication regulates neonatal nociception

Neonatal pain is a significant clinical issue but the mechanisms by which pain is produced early in life are poorly understood. Our recent work has linked the transcription factor serum response factor downstream of local growth hormone (GH) signaling to incision-related hypersensitivity in neonates. However, it remains unclear if similar mechanisms contribute to inflammatory pain in neonates. We found that local GH treatment inhibited neonatal inflammatory myalgia but appeared to do so through a unique signal transducer and activator of transcription (STAT) dependent pathway within sensory neurons. The STAT1 transcription factor appeared to regulate peripheral inflammation itself by modulation of monocyte chemoattractant protein 1 (MCP1) release from sensory neurons. Data suggests that STAT1 upregulation, downstream of GH signaling, contributes to neonatal nociception during muscle inflammation through a novel neuroimmune loop involving cytokine release from primary afferents. Results could uncover new ways to treat muscle pain and inflammation in neonates. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=132 SRC="FIGDIR/small/605393v2_ufig1.gif" ALT="Figure 1"> View larger version (28K): org.highwire.dtl.DTLVardef@18b0bdorg.highwire.dtl.DTLVardef@fb5ee9org.highwire.dtl.DTLVardef@114179aorg.highwire.dtl.DTLVardef@19979b_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗

Macrophage epigenetic memories of early life injury drive neonatal nociceptive priming

The developing peripheral nervous and immune systems are functionally distinct from adults. These systems are vulnerable to early life injury, which influences outcomes related to nociception following subsequent injury later in life (i.e., "neonatal nociceptive priming"). The underpinnings of this phenomenon are largely unknown, although previous work indicates that macrophages are epigenetically trained by inflammation and injury. We found that macrophages are both necessary and partially sufficient to drive neonatal nociceptive priming possibly due to a long-lasting epigenetic remodeling. The p75 neurotrophic factor receptor (NTR) was an important effector in regulating neonatal nociceptive priming through modulation of the inflammatory profile of rodent and human macrophages. This "pain memory" was long lasting in females and could be transferred to a naive host to alter sex-specific pain-related behaviors. This study reveals a novel mechanism by which acute, neonatal post-surgical pain drives a peripheral immune-related predisposition to persistent pain following a subsequent injury. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=134 SRC="FIGDIR/small/528015v2_ufig1.gif" ALT="Figure 1"> View larger version (34K): org.highwire.dtl.DTLVardef@117ad6eorg.highwire.dtl.DTLVardef@17b4188org.highwire.dtl.DTLVardef@10b4d9borg.highwire.dtl.DTLVardef@1142094_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗

Early life nociception is influenced by peripheral growth hormone signaling

A number of cellular systems work in concert to modulate nociceptive processing in the periphery, but the mechanisms that regulate neonatal nociception may be distinct compared to adults. Our previous work indicated a relationship between neonatal hypersensitivity and growth hormone (GH) signaling. Here, we explored the peripheral mechanisms by which GH modulated neonatal nociception under normal and injury conditions (incision). We found that GH receptor signaling in primary afferents maintains a tonic inhibition of peripheral hypersensitivity. After injury, a macrophage dependent displacement of injury-site GH was found to modulate neuronal transcription at least in part via serum response factor regulation. A single GH injection into the injured hindpaw muscle effectively restored available GH signaling to neurons and prevented acute pain-like behaviors, primary afferent sensitization, and neuronal gene expression changes. GH treatment also inhibited long-term somatosensory changes observed after repeated peripheral insult. Results may indicate a novel mechanism of neonatal nociception. Significance statementAlthough it is noted that mechanisms of pain development in early life are unique compared to adults, little research focuses on neonatal-specific peripheral mechanisms of nociception. This gap is evident in the lack of specialized care for infants following an injury including surgeries. This report evaluates how distinct cellular systems in the periphery including the endocrine, immune and nervous systems work together to modulate neonatal-specific nociception. We uncovered a novel mechanism by which muscle injury induces a macrophage-dependent sequestration of peripheral growth hormone that effectively removes its normal tonic inhibition of neonatal nociceptors to promote acute pain-like behaviors. Results indicate a possible new strategy for treatment of neonatal post-surgical pain.

neuroscience↗