Abstract
Painful diabetic neuropathy (PDN) is a challenging complication of diabetes with patients experiencing a painful and burning sensation in their extremities. Existing treatments provide limited relief without addressing the underlying mechanisms of the disease. PDN involves the gradual degeneration of nerve fibers in the skin. Keratinocytes, the most abundant epidermal cell type, are closely positioned to cutaneous nerve terminals, suggesting the possibility of bi-directional communication. Extracellular vesicles are lipid-bilayer encapsulated nanovesicles released from many cell types that mediate cell to cell communication. The role of keratinocyte-derived extracellular vesicles (KDEVs) in influencing signaling between the skin and cutaneous nerve terminals and their contribution to the genesis of PDN has not been explored. In this study, we characterized KDEVs in a well-established high-fat diet mouse model of PDN using primary adult mouse keratinocyte cultures. We obtained highly enriched KDEVs through size-exclusion chromatography and then analyzed their molecular cargo using proteomic analysis and small RNA sequencing. We found significant differences in the protein and microRNA content of high-fat diet KDEVs compared to KDEVs obtained from control mice on a regular diet, including pathways involved in axon guidance and synaptic transmission. Additionally, using an in vivo conditional extracellular vesicle reporter mouse model, we demonstrated that epidermal-originating GFP-tagged KDEVs are retrogradely trafficked into the dorsal root ganglion (DRG) neuron cell bodies. This study presents the first comprehensive isolation and molecular characterization of the KDEV protein and microRNA cargo in RD and HFD mice. Our findings suggest a potential novel communication pathway between keratinocytes and DRG neurons in the skin, which could have implications for PDN.
Original language | English (US) |
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Article number | 100176 |
Journal | Neurobiology of Pain |
Volume | 17 |
DOIs | |
State | Published - Jan 1 2025 |
Funding
Zetasizer Nano ZSP (DLS), Nanosight (NTA), and IZON Exoid (TRPS) experiments were performed in the Analytical bioNanoTechnology Equipment Core Facility of the Simpson Querrey Institute for BioNanotechnology at Northwestern University. ANTEC receives partial support from the Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource (NSF ECCS-2025633) and Feinberg School of Medicine, Northwestern University. Electron microscopy imaging work was performed at the Northwestern University Center for Advanced Microscopy (RRID: SCR_020996) generously supported by NCI CCSG P30 CA060553 awarded to the Robert H Lurie Comprehensive Cancer Center. This work made use of the EPIC facility of Northwestern University's NUANCE Center, which has received support from the SHyNE Resource (NSF ECCS-2025633), the IIN, and Northwestern's MRSEC program (NSF DMR-2308691). And this work was supported by the Northwestern University NUSeq Core Facility. This work was supported by the NIH and NIH HEAL initiative supplement R01 NS104295-01 (DMM), NIH R01 AR077691-01 (DMM, RJM, AP), and NIH/Rush University Medical Center 1R01AR 064251-01 (RJM). We would like to thank Dr. Rajeshwar Awatramani for his helpful discussions. Statement of data and materials, We will make the raw MS data publicly available in an accessible database upon acceptance. Zetasizer Nano ZSP (DLS), Nanosight (NTA), and IZON Exoid (TRPS) experiments were performed in the Analytical bioNanoTechnology Equipment Core Facility of the Simpson Querrey Institute for BioNanotechnology at Northwestern University. ANTEC receives partial support from the Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource (NSF ECCS-2025633) and Feinberg School of Medicine, Northwestern University. Electron microscopy imaging work was performed at the Northwestern University Center for Advanced Microscopy (RRID: SCR_020996) generously supported by NCI CCSG P30 CA060553 awarded to the Robert H Lurie Comprehensive Cancer Center. This work made use of the EPIC facility of Northwestern University\u2019s NUANCE Center, which has received support from the SHyNE Resource (NSF ECCS-2025633), the IIN, and Northwestern's MRSEC program (NSF DMR-2308691). And this work was supported by the Northwestern University NUSeq Core Facility.
Keywords
- Alix
- DRG neuron
- Extracellular vesicle
- Keratinocyte
- Painful diabetic neuropathy
- Peripheral pain
- Retrograde transport
- Size exclusion chromatography
- Skin
- Small-fiber neuropathy
- Tunable resistive pulse sensing (TRPS)
ASJC Scopus subject areas
- Neuroscience (miscellaneous)
- Clinical Neurology
- Anesthesiology and Pain Medicine