Microglial replacement in the aged brain restricts neuroinflammation following intracerebral hemorrhage

Aged microglia display augmented inflammatory activity after neural injury. Although aging is a risk factor for poor outcome after brain insults, the precise impact of aging-related alterations in microglia on neural injury remains poorly understood. Microglia can be eliminated via pharmacological inhibition of the colony–stimulating factor 1 receptor (CSF1R). Upon withdrawal of CSF1R inhibitors, microglia rapidly repopulate the entire brain, leading to replacement of the microglial compartment. In this study, we investigated the impact of microglial replacement in the aged brain on neural injury using a mouse model of intracerebral hemorrhage (ICH) induced by collagenase injection. We found that replacement of microglia in the aged brain reduced neurological deficits and brain edema after ICH. Microglial replacement-induced attenuation of ICH injury was accompanied with alleviated blood-brain barrier disruption and leukocyte infiltration. Notably, newly repopulated microglia had reduced expression of IL-1β, TNF-α and CD86, and upregulation of CD206 in response to ICH. Our findings suggest that replacement of microglia in the aged brain restricts neuroinflammation and brain injury following ICH.

Surgical Treatment for Recurrent Dupuytren Disease

Background: Revision procedures for recurrent Dupuytren disease (DD) can be difficult and carry a high risk of complications. Our goal was to describe surgical strategies used for cases of recurrence and report on their outcomes. Methods: We reviewed 1 surgeon’s operative cases for recurrent DD performed at 1 institution. Prior procedures included collagenase injection, percutaneous needle fasciotomy, or open surgical fasciectomy in the same digit or area of the hand. Results: From January 1981 to December 2020, 54 procedures were performed on 33 patients for recurrent DD. Most patients were men (82%), had bilateral involvement (64%) and family history (52%), and some had ectopic disease in their feet (24%). The small finger was involved in 76% of the cases, and the proximal interphalangeal (PIP) joint was involved in 83% of these digits. The procedures included 38 partial fasciectomies (72%), 12 dermofasciectomies (23%), 3 radical fasciectomies (6%), 1 of each needle fasciotomy, ray amputation, and PIP joint arthrodesis (2%). Twenty-three patients (43%) required full thickness skin grafts with an average area of 7.1 cm2 (range: 1-20 cm2). Conclusions: This study highlights the complexity of recurrent DD case management and found the treatment required for 95% of patients in this series was open partial fasciectomy with or without demofasciectomy. Full thickness skin grafting was necessary in nearly half of the cases.

Collagenase-Induced Patellar Tendinopathy with Neovascularization: First Results towards a Piglet Model of Musculoskeletal Embolization

Background: Therapeutic strategies targeting neovessels responsible for musculoskeletal chronic pain have emerged, including neovessels embolization. Our study aimed to develop a large animal model of patellar tendinopathy with neovascularization. Methods: Nine 3-month-old male piglets (18 patellar tendons) received percutaneous injections of increasing doses of collagenase (0 to 50 mg) at day 0 (D0). Tendinopathy was evaluated by ultrasound (D7 and D14). Neovascularization was evaluated visually and on angiographies. Bonar score was used for histological analysis (D14). Correlations were evaluated using Spearman’s rank (Rs) test. Results: Research protocol was well tolerated. All tendons were enlarged with a median increase of 31.58% [25–40.28] at D7 (p = 0.244) at D7 and 57.52% [48.41–91.45] at D14 (p = 0.065). Tendons with collagenase injection had more hypoechoic changes, with one tendon rupture (p = 0.012). Neovascularization was reported above 5 mg collagenase (p < 0.01) at D7 and D14 with dose-related neovessels induction (Rs = 0.8, p < 0.001). The Bonar score increased above 5 mg collagenase, correlated with the dose (Rs = 0.666, p = 0.003). Conclusions: The study shows the feasibility, safety and reproducibility of this new large animal model of patellar tendinopathy with neovascularization after collagenase injection. It will allow studying new treatments on direct embolization of neovessels by endovascular approach.

Dupuytren’s interventions surgery versus collagenase (DISC) trial: study protocol for a pragmatic, two-arm parallel-group, non-inferiority randomised controlled trial

Background Dupuytren’s contracture is a fibro-proliferative disease of the hands affecting over 2 million UK adults, particularly the white, male population. Surgery is the traditional treatment; however, recent studies have indicated that an alternative to surgery—collagenase clostridium histolyticum (collagenase)—is better than a placebo in the treatment of Dupuytren’s contracture. There is however no robust randomised controlled trial that provides a definitive answer on the clinical effectiveness of collagenase compared with limited fasciectomy surgery. Dupuytren’s intervention surgery vs collagenase trial (DISC) trial was therefore designed to fill this evidence gap. Methods/design The DISC trial is a multi-centre pragmatic two-arm parallel-group, randomised controlled trial. Participants will be assigned 1:1 to receive either collagenase injection or surgery (limited fasciectomy). We aim to recruit 710 adult participants with Dupuytren’s contracture. Potential participants will be identified in primary and secondary care, screened by a delegated clinician and if eligible and consenting, baseline data will be collected and randomisation completed. The primary outcome will be the self-reported patient evaluation measure assessed 1 year after treatment. Secondary outcome measures include the Unité Rhumatologique des Affections de la Main Scale, the Michigan Hand Questionnaire, EQ-5D-5L, resource use, further procedures, complications, recurrence, total active movement and extension deficit, and time to return to function. Given the limited evidence comparing recurrence rates following collagenase injection and limited fasciectomy, and the importance of a return to function as soon as possible for patients, the associated measures for each will be prioritised to allow treatment effectiveness in the context of these key elements to be assessed. An economic evaluation will assess the cost-effectiveness of treatments, and a qualitative sub-study will assess participants’ experiences and preferences of the treatments. Discussion The DISC trial is the first randomised controlled trial, to our knowledge, to investigate the clinical and cost-effectiveness of collagenase compared to limited fasciectomy surgery for patients with Dupuytren’s contracture. Trial registration Clinical.Trials.gov ISRCTN18254597. Registered on April 11, 2017.

Profiling of Blood-Brain Barrier Disruption in Mouse Intracerebral Hemorrhage Models: Collagenase Injection vs. Autologous Arterial Whole Blood Infusion

Disruption of the blood-brain barrier (BBB) and the subsequent formation of brain edema is the most severe consequence of intracerebral hemorrhage (ICH), leading to drastic neuroinflammatory responses and neuronal cell death. A better understanding of ICH pathophysiology to develop effective therapy relies on selecting appropriate animal models. The collagenase injection ICH model and the autologous arterial whole blood infusion ICH model have been developed to investigate the pathophysiology of ICH. However, it remains unclear whether the temporal progression and the underlying mechanism of BBB breakdown are similar between these two ICH models. In this study, we aimed to determine the progression and the mechanism of BBB disruption via the two commonly used murine ICH models: the collagenase-induced ICH model (c-ICH) and the double autologous whole blood ICH model (b-ICH). Intrastriatal injection of 0.05 U collagenase or 20 μL autologous blood was used for a comparable hematoma volume in these two ICH models. Then we analyzed BBB permeability using Evan’s blue and IgG extravasation, evaluated tight junction (TJ) damage by transmission electron microscope (TEM) and Western blotting, and assessed matrix metalloproteinase-9 (MMP-9) activity and aquaporin 4 (AQP4) mRNA expression by Gelatin gel zymography and RT-PCR, respectively. The results showed that the BBB leakage was associated with a decrease in TJ protein expression and an increase in MMP-9 activity and AQP4 expression on day 3 in the c-ICH model compared with that on day 5 in the b-ICH model. Additionally, using TEM, we found that the TJ was markedly damaged on day 3 in the c-ICH model compared with that on day 5 in the b-ICH model. In conclusion, the BBB was disrupted in the two ICH models; compared to the b-ICH model, the c-ICH model presented with a more pronounced disruption of BBB at earlier time points, suggesting that the c-ICH model might be a more suitable model for studying early BBB damage and protection after ICH.

Dupuytren’s disease

Dupuytren’s disease is benign fibromatosis affecting primarily the fascia of the hand and fingers. The epidemiology, pathology, and clinical presentation are described in this chapter. Non-surgical treatments, including clostridial collagenase injection, and a variety of surgical techniques are discussed. Expected outcomes are also described together with the author’s preferred treatment algorithm.

Radial extracorporeal shock wave therapy for Dupuytren’scontracture: a case report

Dupuytren’s contracture (DC) is a fibro-proliferative disorder of palmar and digital fascia, which leads to contracture deformity of hand and consequent disability. There is not a satisfying method for management of the disease and standard invasive treatments such as collagenase injection and fasciectomy have high rates of failure and recurrence. Recently, focused extracorporeal shock wave therapy (ESWT) has been used successfully for reduction of pain and dysfunction in DC. We hypothesized that radial ESWT would benefit this condition and used it in a chronic case. The patient was a 64-year-old farmer with the history of DC in both hands for eight years. He experienced exacerbation in the flexion contracture of the fourth metacarpophalangeal (MCP) joint of his right hand in the past month. We treated the patient with six weekly sessions of radial shock wave. Extension restriction in the fourth MCP joint reached from 30° to normal at the end of treatment and function of hand was also improved. Thus, radial ESWT should be considered and investigated for management of the DC in future studies.

Glycerol Improves Intracerebral Hemorrhagic Brain Injury and Associated Kidney Dysfunction in Rats

In stroke patients, the development of acute kidney injury (AKI) is closely linked with worse outcomes and increased mortality. In this study, the interplay between post-stroke and AKI and treatment options was investigated in a rodent model of hemorrhagic stroke. Intrastriatal collagenase injection for 24 h caused neurological deficits, hematoma formation, brain edema, apoptosis, blood–brain barrier disruption, oxidative stress, and neuroinflammation in Sprague Dawley rats. Elevation of serum blood urea nitrogen, serum creatinine, urine cytokine-induced neutrophil chemoattractant-1, and urine Malondialdehyde, as well as moderate histological abnormality in the kidney near the glomerulus, indicated evidence of kidney dysfunction. The accumulation of podocalyxin DNA in urine further suggested a detachment of podocytes and structural deterioration of the glomerulus. Circulating levels of stress hormones, such as epinephrine, norepinephrine, corticosterone, and angiotensin II were elevated in rats with intracerebral hemorrhage. Osmotic agent glycerol held promising effects in alleviating post-stroke brain injury and kidney dysfunction. Although the detailed protective mechanisms of glycerol have yet to be determined, the intrastriatal collagenase injection hemorrhagic stroke model in rats allowed us to demonstrate the functional and structural integrity of glomerulus are targets that are vulnerable to post-stroke injury and stress hormones could be surrogates of remote communications.

Deletion of MicroRNA-144/451 Cluster Aggravated Brain Injury in Intracerebral Hemorrhage Mice by Targeting 14-3-3ζ

This study aims at evaluating the importance and its underlying mechanism of the cluster of microRNA-144/451 (miR-144/451) in the models with intracerebral hemorrhage (ICH). A model of collagenase-induced mice with ICH and a model of mice with simple miR-144/451 gene knockout (KO) were used in this study. Neurodeficits and the water content of the brain of the mice in each group were detected 3 days after collagenase injection. The secretion of proinflammatory cytokines, such as tumor necrosis factor α (TNF-α) and interleukin 1β (IL-1β), as well as certain biomarkers of oxidative stress, was determined in this study. The results revealed that the expression of miR-451 significantly decreased in the mice with ICH, whereas miR-144 showed no significant changes. KO of the cluster of miR-144/451 exacerbated the neurological deficits and brain edema in the mice with ICH. Further analyses demonstrated that the KO of the cluster of miR-144/451 significantly promoted the secretion of TNF-α and IL-1β and the oxidative stress in the perihematomal region of the mice with ICH. In addition, the miR-144/451's depletion inhibited the regulatory axis' activities of miR-451-14-3-3ζ-FoxO3 in the mice with ICH. In conclusion, these data demonstrated that miR-144/451 might protect the mice with ICH against neuroinflammation and oxidative stress by targeting the pathway of miR-451-14-3-3ζ-FoxO3.