Slaves, Soldiers, Citizens: African American Artifacts of the Civil War Era

Based on the exhibit Slaves, Soldiers, Citizens: African American Artifacts of the Civil War Era, this book provides the full experience of the exhibit, which was on display in Special Collections at Musselman Library November 2012- December 2013. It also includes several student essays based on specific artifacts that were part of the exhibit. Table of Contents: Introduction Angelo Scarlato, Lauren Roedner ’13 & Scott Hancock Slave Collars & Runaways: Punishment for Rebellious Slaves Jordan Cinderich ’14 Chancery Sale Poster & Auctioneer’s Coin: The Lucrative Business of Slavery Tricia Runzel ’13 Isaac J. Winters: An African American Soldier from Pennsylvania Who Fought at Petersburg Avery Lentz ’14 Basil Biggs: A Prominent African American in Gettysburg after the Battle Lauren Roedner ’13 Linton Ingram: A Former Slave Who Became a Notable African American Educator in Georgia Brian Johnson & Lincoln Fitch ’14 Uncle Tom’s Cabin Theatre Poster: Racism in Post-Emancipation Entertainment Michelle Seabrook ’13 Essay Bibliographies Grand Army of the Republic Exhibit Inventory Acknowledgmentshttps://cupola.gettysburg.edu/libexhibits/1001/thumbnail.jp

Urokinase Plasminogen Receptor and the Fibrinolytic Complex Play a Role in Nerve Repair after Nerve Crush in Mice, and in Human Neuropathies

Remodeling of extracellular matrix (ECM) is a critical step in peripheral nerve regeneration. In fact, in human neuropathies, endoneurial ECM enriched in fibrin and vitronectin associates with poor regeneration and worse clinical prognosis. Accordingly in animal models, modification of the fibrinolytic complex activity has profound effects on nerve regeneration: high fibrinolytic activity and low levels of fibrin correlate with better nerve regeneration. The urokinase plasminogen receptor (uPAR) is a major component of the fibrinolytic complex, and binding to urokinase plasminogen activator (uPA) promotes fibrinolysis and cell movement. uPAR is expressed in peripheral nerves, however, little is known on its potential function on nerve development and regeneration. Thus, we investigated uPAR null mice and observed that uPAR is dispensable for nerve development, whereas, loss of uPAR affects nerve regeneration. uPAR null mice showed reduced nerve repair after sciatic nerve crush. This was a consequence of reduced fibrinolytic activity and increased deposition of endoneurial fibrin and vitronectin. Exogenous fibrinolysis in uPAR null mice rescued nerve repair after sciatic nerve crush. Finally, we measured the fibrinolytic activity in sural nerve biopsies from patients with peripheral neuropathies. We showed that neuropathies with defective regeneration had reduced fibrinolytic activity. On the contrary, neuropathies with signs of active regeneration displayed higher fibrinolytic activity. Overall, our results suggest that enforced fibrinolysis may facilitate regeneration and outcome of peripheral neuropathies

Characterization of human nerve biopsies and evaluation of fibrinolytic activity.

<p><b>Legend</b>: CIDP: chronic inflammatory demyelinating neuropathy; CMT: Charcot-Marie-Tooth neuropathy; UCTD: undifferentiated connective tissue disease; ax: axonal; np: neuropathy. FG: fibrin; VN: vitronectin; FN: fibronectin; m: months; y: years.</p><p>*patients already described in ⁵, respectively pt. #3, 6, 7, 8, 11, 12, 14, 17, 19, 20, 39, 41, 27, 30, 43.</p

Different expression of ECM in uPAR−/− nerves after damage.

<p>Sciatic nerve cryosections from Wt (A, C, E, G, I, K) and uPAR−/− (B, D, F, H, J, L) mice stained for fibrin (Fg), fibronectin (Fn) or vitronectin (Vn), and neurofilaments (Nf) at 15 and 45 dpc. Both at 15 and 45 dpc Fibrin expressions was higher in uPAR−/− as compared to Wt endoneurium (B versus A, and H versus G). Fibronectin expression was similarly in Wt and uPAR−/− mice at both time points (D versus C, and J versus I). Vitronectin expression was higher in uPAR−/− mice as compared to wt at 15dpc (F versus E), whereas it was similar at 45 dpc (L and K). Bar = 50 µm.</p

Sciatic nerve regeneration after injury.

<p>(A–B, D–E) semithin section and (C, F) fiber type distribution from sciatic nerve of Wt and uPAR null mice at 15 and 45 dpc. At both 15 and 45 dpc we observed reduced number of regenerating fibers. (G) g-ratio was significantly increased in uPAR−/− regenerating fibers at 45 dpc (n. 20000; p = 0.01). (H) Neurophysiological analysis showing similar values of cMAP between Wt and uPAR−/− mice, whereas NCV was significantly reduced in uPAR−/− mice (n. 8; p = 0.001). (I–J) Staining for Mac-1/CD11b (Mac1) in Wt (I) and uPAR null (J) sciatic nerve 45dpc. (K) Quantification of number of macrophages observed in sciatic nerve 15, 21 and 45dpc; differences were significant at 21 and 45 dpc (*p = 0.04; **p = 0.008). Bar = 10 µm in A, B, D, E, I and J.</p

Fibrinolytic activity in human neuropathies.

<p>In situ zymography in sural nerve biopsies of patients (#4 and #3) with regenerating (A, B) and (#15 and #18) non-regenerating (C, D) neuropathies. Fluorescent signal as a readout of fibrinolytic activity is very high in regenerating nerves, and very low in non-regenerating nerves. A^I and C^I are the same reaction depicted in A and C in which fibrinolytic reaction was blocked by amiloride (PAstop). Zym = fibrinolytic activity; Nf = neurofilaments. Bar = 50 µm.</p

Fibrinolytic molecules in myelination.

<p>(A) Time course zymography of uPA and tPA activity in Wt DRG explant homogenate (as a pool of at least 8 coverslips) and their conditioned media without ascorbic acid treatment (-) or after 5, 10, 15, 20 days of ascorbic acid (+). Note both tPA and uPA activity are induced after ascorbic acid in both cell homogenate and media, although uPA activity increases in parallel with myelination. (B–E) DRG explants from Wt and uPAR null mice stained for neurofilament (green) and MBP (red) 7 days after ascorbic acid. The number of myelinated segments were similar between Wt and uPAR null explants. Bar = 50 µm.</p

Histological characteristics of uPAR null nerve.

<p>(A–B) semithin sections from sciatic nerve of Wt (A) and uPAR null mouse (B) showing normal fiber appearance. (C) Similar fiber type distribution in Wt and uPAR null sciatic nerve. (D) Neurophysiology analysis showing similar values of cMAP and NCV between Wt and uPAR−/− mice (n. 10 mice per group). (E) g-ratio did not show differences in myelin thickness between Wt and uPAR−/− nerves (n. 20000). (F–K) sciatic nerve cryosections of Wt and uPAR null mouse stained for fibrin fibronectin and vitronectin. Fibrin and vitronectin staining was mildly increased in uPAR null endoneurium (G and K) as compared to Wt (F and J), whereas fibronectin was similarly expressed (H–I). (L) Western blot analysis of fibrin and fibronectin in Wt and uPAR null sciatic nerve homogenate. Calnexin was used to normalize loading (fibronectin and vitronectin were loaded on the same gel, hence they have the same calnexin bands). r = densitometric ratio between the band of interest and calnexin; Wt was always assigned as r = 1. Fibrin and vitronectin levels were increased in uPAR null nerves as compared to Wt, whereas levels of fibronectin were similar. Fg = fibrin; Fn = fibronectin; Vn = vitronectin; Nf = neurofilaments. Bar = 15 µm in A and B; 50 µm in F–K.</p

Impaired uPA activity and fibrin clearance in uPAR−/− nerves after damage.

<p>(A) western blot analysis of fibrin and fibronectin in Wt and uPAR null sciatic nerve homogenate at 15, 21 and 45 dpc. Calnexin was used to normalize loading. Quantification of western blot is reported as an average of 3 independent experiments, and represented as ratio fibrin/calnexin, vitronectin/calnexin and fibronectin/calnexin, assigning Wt 0dpc as 1±SEM). At each time point uPAR null homogenate showed increased levels of fibrin and vitronectin as compared to Wt, whereas fibronectin levels were higher at 15 and 21 dpc, but lower at 45 dpc. (B) Zymography of sciatic nerve homogenate from Wt and uPAR null mice measuring tPA and uPA activity 0, 7 and 15dpc. Bands were stained with Coomassie blue as loading control. Quantification of zymography is reported as an average of 3 independent experiments, and represented as ratio uPA/coomassie blue and tPA/coomassie blue, assigning Wt 0dpc as 1±SEM. Note the reduced increase of uPA in uPAR null homogenate as compared to Wt 7 and 15dpc, whereas there are no differences in the tPA activity between mutant and Wt mice. Fg = fibrin; Fn = fibronectin; Vn = vitronectin; Cln = calnexin.</p