Metastatic Infiltration of Nervous Tissue and Periosteal Nerve Sprouting in Multiple Myeloma-Induced Bone Pain in Mice and Human.

Multiple myeloma (MM) is a neoplasia of B plasma cells that often induces bone pain. However, the mechanisms underlying myeloma-induced bone pain (MIBP) are mostly unknown. Using a syngeneic MM mouse model, we show that periosteal nerve sprouting of calcitonin gene-related peptide (CGRP+) and growth associated protein 43 (GAP43+) fibers occurs concurrent to the onset of nociception and its blockade provides transient pain relief. MM patient samples also showed increased periosteal innervation. Mechanistically, we investigated MM induced gene expression changes in the dorsal root ganglia (DRG) innervating the MM-bearing bone of male mice and found alterations in pathways associated with cell cycle, immune response and neuronal signaling. The MM transcriptional signature was consistent with metastatic MM infiltration to the DRG, a never-before described feature of the disease that we further demonstrated histologically. In the DRG, MM cells caused loss of vascularization and neuronal injury, which may contribute to late-stage MIBP. Interestingly, the transcriptional signature of a MM patient was consistent with MM cell infiltration to the DRG. Overall, our results suggest that MM induces a plethora of peripheral nervous system alterations that may contribute to the failure of current analgesics and suggest neuroprotective drugs as appropriate strategies to treat early onset MIBP.SIGNIFICANCE STATEMENT Multiple myeloma (MM) is a painful bone marrow cancer that significantly impairs the quality of life of the patients. Analgesic therapies for myeloma-induced bone pain (MIBP) are limited and often ineffective, and the mechanisms of MIBP remain unknown. In this manuscript, we describe cancer-induced periosteal nerve sprouting in a mouse model of MIBP, where we also encounter metastasis to the dorsal root ganglia (DRG), a never-before described feature of the disease. Concomitant to myeloma infiltration, the lumbar DRGs presented blood vessel damage and transcriptional alterations, which may mediate MIBP. Explorative studies on human tissue support our preclinical findings. Understanding the mechanisms of MIBP is crucial to develop targeted analgesic with better efficacy and fewer side effects for this patient population.

Controlling axonal regeneration with acellular nerve allograft limits neuroma formation in peripheral nerve transection: An experimental study in a swine model.

BACKGROUND: Symptomatic neuromata are a common indication for revision surgery following amputation. Previously described treatments, including traction neurectomy, nerve transposition, targeted muscle re-innervation, and nerve capping, have provided inconsistent results or are technically challenging. Prior research using acellular nerve allografts (ANA) has shown controlled termination of axonal regrowth in long grafts. The purpose of this study was to determine the ability of a long ANA to prevent neuroma formation following transection of a peripheral nerve in a swine model. MATERIALS AND METHODS: Twenty-two adult female Yucatan miniature swine (Sus scrofa; 4-6 months, 15-25 kg) were assigned to control (ulnar nerve transection only, n = 10), treatment (ulnar transection and coaptation of 50 mm ANA, n = 10), or donor (n = 2) groups. Nerves harvested from donor group animals were treated to create the ANA. After 20 weeks, the transected nerves including any neuroma or graft were harvested. Both qualitative (nerve architecture, axonal sprouting) and quantitative histologic analyses (myelinated axon number, cross sectional area of nerve tissue) were performed. RESULTS: Qualitative histologic analysis of control specimens revealed robust axon growth into dense scar tissue. In contrast, the treatment group revealed dwindling axons in the terminal tissue, consistent with attenuated neuroma formation. Quantitative analysis revealed a significantly decreased number of myelinated axons in the treatment group (1232 ± 540) compared to the control group (44,380 ± 7204) (p < .0001). Cross sectional area of nerve tissue was significantly smaller in treatment group (2.83 ± 1.53 mm2 ) compared to the control group (9.14 ± 1.19 mm2 ) (p = .0012). CONCLUSIONS: Aberrant axonal growth is controlled to termination with coaptation of a 50 mm ANA in a swine model of nerve injury. These early results suggest further investigation of this technique to prevent and/or treat neuroma formation.

Tumoral Neuroligin 1 Promotes Cancer-Nerve Interactions and Synergizes with the Glial Cell Line-Derived Neurotrophic Factor.

Many nervous proteins are expressed in cancer cells. In this report, we asked whether the synaptic protein neuroligin 1 (NLGN1) was expressed by prostatic and pancreatic carcinomas; in addition, given the tendency of these tumors to interact with nerves, we asked whether NLGN1 played a role in this process. Through immunohistochemistry on human tissue microarrays, we showed that NLGN1 is expressed by prostatic and pancreatic cancer tissues in discrete stages and tumor districts. Next, we performed in vitro and in vivo assays, demonstrating that NLGN1 promotes cancer cell invasion and migration along nerves. Because of the established role of the neurotrophic factor glial cell line-derived neurotrophic factor (GDNF) in tumor-nerve interactions, we assessed a potential NLGN1-GDNF cooperation. We found that blocking GDNF activity with a specific antibody completely inhibited NLGN1-induced in vitro cancer cell invasion of nerves. Finally, we demonstrated that, in the presence of NLGN1, GDNF markedly activates cofilin, a cytoskeletal regulatory protein, altering filopodia dynamics. In conclusion, our data further prove the existence of a molecular and functional cross-talk between the nervous system and cancer cells. NLGN1 was shown here to function along one of the most represented neurotrophic factors in the nerve microenvironment, possibly opening new therapeutic avenues.

Intra-Tumoral Nerve-Tracing in a Novel Syngeneic Model of High-Grade Serous Ovarian Carcinoma.

Dense tumor innervation is associated with enhanced cancer progression and poor prognosis. We observed innervation in breast, prostate, pancreatic, lung, liver, ovarian, and colon cancers. Defining innervation in high-grade serous ovarian carcinoma (HGSOC) was a focus since sensory innervation was observed whereas the normal tissue contains predominantly sympathetic input. The origin, specific nerve type, and the mechanisms promoting innervation and driving nerve-cancer cell communications in ovarian cancer remain largely unknown. The technique of neuro-tracing enhances the study of tumor innervation by offering a means for identification and mapping of nerve sources that may directly and indirectly affect the tumor microenvironment. Here, we establish a murine model of HGSOC and utilize image-guided microinjections of retrograde neuro-tracer to label tumor-infiltrating peripheral neurons, mapping their source and circuitry. We show that regional sensory neurons innervate HGSOC tumors. Interestingly, the axons within the tumor trace back to local dorsal root ganglia as well as jugular-nodose ganglia. Further manipulations of these tumor projecting neurons may define the neuronal contributions in tumor growth, invasion, metastasis, and responses to therapeutics.

Fipronil induced oxidative stress in neural tissue of albino rat with subsequent apoptosis and tissue reactivity.

Fipronil (FIP) insecticide is extensively used in agriculture, public health and veterinary medicine. Although it is considered as a neurotoxin to insects (target organisms) and exhibits neurological signs upon vertebrates (non-target organisms) exposure, slight is known about its potential neurotoxic effects and its molecular mechanisms on vertebrates. The current study is designed to assess oxidative stress as a molecular mechanism of FIP neurotoxicity subordinated with apoptosis and neural tissue reactivity. Ten adult male albino rats received 10 mg/kg body weight fipronil technical grade by oral gavage daily for 45 days (subacute exposure). Brain neural tissue regions (hippocampus, cerebellum and caudate putamen) were processed to examine oxidative stress induced cellular macromolecular alterations as MDA, PCC and DNA fragmentation. Besides, TNF-α and Bcl-2 gene expression and immunoreactivity for caspase-3 (active form), iNOS and GFAP were evaluated. Also, histopathological assessment was conducted. We found that FIP significantly raised MDA, PCC and DNA fragmentation (p ≤ 0.05). Also, it significantly upregulated TNF-α and non-significantly down-regulated Bcl-2 gene expression (p ≤ 0.05). Further, significant increased immunoreactivity to GFAP, iNOS and caspase-3 (active form) in these brain neural tissue regions in FIP treated group was noticed (p ≤ 0.05). Histopathological findings, including alterations in the histological architecture and neuronal degeneration, were also observed in these brain regions of FIP treated group. In conclusion, we suggest the ability of FIP to induce oxidative stress mediated macromolecular alterations, leading to apoptosis and tissue reaction in these brain regions which showed variable susceptibility to FIP toxic effects.

Silencing of O-linked N-acetylglucosamine transferase ameliorates hypercalcemia-induced neurotoxicity in renal failure by regulating EZH2/KLF2/CXCL1 axis.

Hypocalcemia, associated with Calcium neurotoxicity, has been reported to induce nerve dysfunction, which is a significant problem of renal failure. This study identifies a molecular mechanism of the O-linked N-acetylglucosamine transferase (OGT)-mediated enhancer of zeste homolog 2 (EZH2)/krüppel-like factor 2 (KLF2)/chemokine (C-X-C motif) ligand 1 (CXCL1) axis underlying the hypercalcemia-induced nerve injury in renal failure. Bioinformatics analyses were used to screen out the key factors in hypercalcemia-induced nerve injury in renal failure. Chronic kidney disease (CKD) was induced by an adenine diet in mice, followed by injection of adenovirus vector carrying short hairpin RNA targeting OGT, followed by behavioral tests and collection of the cerebral cortex for primary neurons. Calcium level in neurons was measured by Fluo-4-am and Perkin Elmer+ Operetta. Neuronal apoptosis and viability were detected by flow cytometry and the MTS method. The binding of EZH2 to KLF2 promoter was verified by chromatin immunoprecipitation assay. The concentration of Ca2+ in brain tissues of CKD model mice was increased, and nerve functions were obviously damaged. High expression of OGT occurred in kidney tissue of CKD model mice. Silencing OGT reduced the hypercalcemia-induced toxicity of neurons by inhibiting the expression of EZH2, which elevated the expression of CXCL1 in primary neurons by diminishing KLF2. Silencing OGT attenuated hypercalcemia-induced neurotoxicity by regulating the EZH2/KLF2/CXCL1 axis. In vivo experiments further confirmed that silencing OGT could reduce hypercalcemia-induced nerve injury in CKD mice. Taken together, silencing OGT downregulates EZH2, which increases the expression of KLF2 and then decreases the expression of CXCL1, thus alleviating hypercalcemia-induced nerve injury in renal failure.

Determination of bupivacaine tissue concentration in human biopsy samples using high-performance liquid chromatography with mass spectrometry.

In the present study, we developed a simple and rapid analytical method for the quantification of bupivacaine hydrochloride in human biopsy samples of adipose, muscle, neural, connective and cartilage tissue using liquid chromatography-mass spectrometry. Anesthetics were extracted from the tissue samples using 0.1% formic acid in acetonitrile for protein denaturation and hexane for removal of lipophilic impurities. Analytes were separated adequately on Phenomenex Luna Omega polar C18 column using a gradient mobile phase 0.1% formic acid in water and 0.1% formic acid in acetonitrile. The lower limits of quantification were ≤ 97 ng g-1 tissue for all studied tissues. Intra-day recoveries were between 48.2% and 82.1% with relative standard deviations (RSDs) between 1.47% and 14.28%, whereas inter-day recoveries were between 52.2% and 77.6% with RSDs between 2.98% and 14.79%. The calibration curve showed a linear fit with R2 higher than 0.99 in the concentration range from 0.16 to 100 µg g-1 . Lidocaine hydrochloride was tested as internal standard because its recoveries and matrix effects were comparable to bupivacaine hydrochloride. Post-analytical corrections of measured bupivacaine tissue concentrations can accordingly be made based on recovery of lidocaine as internal standard, with recoveries between 51.2% and 86.9% and RSDs between 1.99% and 16.88%. The developed method could be used to study time-dependent spread of bupivacaine locally or to more distant locations across tissue barriers.

Pan-cancer Transcriptomic Predictors of Perineural Invasion Improve Occult Histopathologic Detection.

PURPOSE: Perineural invasion (PNI) is associated with aggressive tumor behavior, recurrence, and metastasis, and can influence the administration of adjuvant treatment. However, standard histopathologic examination has limited sensitivity in detecting PNI and does not provide insights into its mechanistic underpinnings. EXPERIMENTAL DESIGN: A multivariate Cox regression was performed to validate associations between PNI and survival in 2,029 patients across 12 cancer types. Differential expression and gene set enrichment analysis were used to learn PNI-associated programs. Machine learning models were applied to build a PNI gene expression classifier. A blinded re-review of hematoxylin and eosin (H&E) slides by a board-certified pathologist helped determine whether the classifier could improve occult histopathologic detection of PNI. RESULTS: PNI associated with both poor overall survival [HR, 1.73; 95% confidence interval (CI), 1.27-2.36; P < 0.001] and disease-free survival (HR, 1.79; 95% CI, 1.38-2.32; P < 0.001). Neural-like, prosurvival, and invasive programs were enriched in PNI-positive tumors (P adj < 0.001). Although PNI-associated features likely reflect in part the increased presence of nerves, many differentially expressed genes mapped specifically to malignant cells from single-cell atlases. A PNI gene expression classifier was derived using random forest and evaluated as a tool for occult histopathologic detection. On a blinded H&E re-review of sections initially described as PNI negative, more specimens were reannotated as PNI positive in the high classifier score cohort compared with the low-scoring cohort (P = 0.03, Fisher exact test). CONCLUSIONS: This study provides salient biological insights regarding PNI and demonstrates a role for gene expression classifiers to augment detection of histopathologic features.

Nerve biopsy: Current indications and decision tools.

After initial investigation of patients presenting with symptoms suggestive of neuropathy, a clinical decision is made for a minority of patients to undergo further assessment with nerve biopsy. Many nerve biopsies do not demonstrate a definitive pathological diagnosis and there is considerable cost and morbidity associated with the procedure. This highlights the need for appropriate selection of patients, nerves and neuropathology techniques. Additionally, concomitant muscle and skin biopsies may improve the diagnostic yield in some cases. Several advances have been made in diagnostics in recent years, particularly in genomics. The indications for nerve biopsy have consequently changed over time. This review explores the current indications for nerve biopsies and some of the issues surrounding its use. Also included are comments on alternative diagnostic modalities that may help to supplant or reduce the use of nerve biopsy as a diagnostic test. These primarily include extraneural biopsy and neuroimaging techniques such as magnetic resonance neurography and nerve ultrasound. Finally, we propose an algorithm to assist in deciding when to perform nerve biopsies.

Genomic Action of Sigma-1 Receptor Chaperone Relates to Neuropathic Pain.

Sigma-1 receptors (Sig-1Rs) are endoplasmic reticulum (ER) chaperones implicated in neuropathic pain. Here we examine if the Sig-1R may relate to neuropathic pain at the level of dorsal root ganglia (DRG). We focus on the neuronal excitability of DRG in a "spare nerve injury" (SNI) model of neuropathic pain in rats and find that Sig-1Rs likely contribute to the genesis of DRG neuronal excitability by decreasing the protein level of voltage-gated Cav2.2 as a translational inhibitor of mRNA. Specifically, during SNI, Sig-1Rs translocate from ER to the nuclear envelope via a trafficking protein Sec61ß. At the nucleus, the Sig-1R interacts with cFos and binds to the promoter of 4E-BP1, leading to an upregulation of 4E-BP1 that binds and prevents eIF4E from initiating the mRNA translation for Cav2.2. Interestingly, in Sig-1R knockout HEK cells, Cav2.2 is upregulated. In accordance with those findings, we find that intra-DRG injection of Sig-1R agonist (+)pentazocine increases frequency of action potentials via regulation of voltage-gated Ca2+ channels. Conversely, intra-DRG injection of Sig-1R antagonist BD1047 attenuates neuropathic pain. Hence, we discover that the Sig-1R chaperone causes neuropathic pain indirectly as a translational inhibitor.

Nerve-sparing in Gynecologic Surgery: A Perspective.

OBJECTIVE: To provide a perspective on nerve-sparing (NS) surgery in gynecology. DATA SOURCES: Literature review, English language. METHODS OF STUDY SELECTION: Systematic reviews and meta-analyses studies were selected for review for oncology; comparative studies were selected for endometriosis, and 1 comparative and 1 prospective study were chosen for sacrocolpopexy. TABULATION, INTEGRATION, AND RESULTS: Two tables summarize the results of systematic reviews and meta-analyses in oncology. Oncology, endometriosis, and urogynecology sections. Primary benefit of NS technique is decreased bladder dysfunction, and, to a lesser degree, vaginal and rectal dysfunc. CONCLUSION: NS is preferable to conventional surgery for benign and malignant conditions to reduce postoperative bladder, rectal, and vaginal dysfunction.

Cutaneous Cephalic Neurocristic Hamartoma on the Head With Melanocytic, Cartilage, Blood Vessel, Neural, and Bony Tissue.

ABSTRACT: We report on a congenital tumor of the face and scalp in a male newborn, histologically proven to contain melanocytes, cartilage, and bone, vascular, and neural tissue as part of a pigmented congenital tumor. Thus, this tumor was classified as a cutaneous cephalic neurocristic hamartoma.

Ablation of TRPV1-positive nerves exacerbates salt-induced hypertension and tissue injury in rats after renal ischemia-reperfusion via infiltration of macrophages.

Background: High-salt intake after renal ischemia/reperfusion (I/R) injury leads to hypertension and further renal injury, but the mechanisms are largely unknown. This study tested the hypothesis that degeneration of transient receptor potential vanilloid 1 (TRPV1)-positive nerves exacerbates salt-induced hypertension and renal injury after I/R via enhancing renal macrophage infiltration.Methods: Large dose of capsaicin (CAP, 100 mg/kg, subcutaneously) was used to degenerate rat TRPV1-positive nerves. Then, rats were subjected to renal I/R injury and fed with a low-salt (0.4% NaCl) diet for 5 weeks after I/R, followed by a high-salt (4% NaCl) diet for 4 weeks during which macrophages were depleted using liposome-encapsulated clodronate (LC, 1.3 ml/kg/week, intravenously).Results: The protein level of TRPV1 in the kidney was downregulated by renal I/R injury and was further decreased by CAP treatment. LC treatment did not affect the protein levels of renal TRPV1. After renal I/R injury, high-salt diet significantly increased renal macrophage infiltration, inflammatory cytokines (tumor necrosis factor-alpha and interleukin 1 beta), systolic blood pressure, the urine/water intake ratio, plasma creatine and urea levels, urinary 8-isoprostane, and renal collagen deposition. Interestingly, CAP treatment further increased these parameters. These increases were abolished by depleting macrophages with LC treatment.Conclusions: These data suggest that degenerating TRPV1-positive nerves exacerbates salt-induced hypertension and tissue injury in rats after renal I/R injury via macrophages-mediated renal inflammation.

Neurons Release Serine to Support mRNA Translation in Pancreatic Cancer.

Pancreatic ductal adenocarcinoma (PDAC) tumors have a nutrient-poor, desmoplastic, and highly innervated tumor microenvironment. Although neurons can release stimulatory factors to accelerate PDAC tumorigenesis, the metabolic contribution of peripheral axons has not been explored. We found that peripheral axons release serine (Ser) to support the growth of exogenous Ser (exSer)-dependent PDAC cells during Ser/Gly (glycine) deprivation. Ser deprivation resulted in ribosomal stalling on two of the six Ser codons, TCC and TCT, and allowed the selective translation and secretion of nerve growth factor (NGF) by PDAC cells to promote tumor innervation. Consistent with this, exSer-dependent PDAC tumors grew slower and displayed enhanced innervation in mice on a Ser/Gly-free diet. Blockade of compensatory neuronal innervation using LOXO-101, a Trk-NGF inhibitor, further decreased PDAC tumor growth. Our data indicate that axonal-cancer metabolic crosstalk is a critical adaptation to support PDAC growth in nutrient poor environments.

The Lipid Receptor G2A (GPR132) Mediates Macrophage Migration in Nerve Injury-Induced Neuropathic Pain.

Nerve injury-induced neuropathic pain is difficult to treat and mechanistically characterized by strong neuroimmune interactions, involving signaling lipids that act via specific G-protein coupled receptors. Here, we investigated the role of the signaling lipid receptor G2A (GPR132) in nerve injury-induced neuropathic pain using the robust spared nerve injury (SNI) mouse model. We found that the concentrations of the G2A agonist 9-HODE (9-Hydroxyoctadecadienoic acid) are strongly increased at the site of nerve injury during neuropathic pain. Moreover, G2A-deficient mice show a strong reduction of mechanical hypersensitivity after nerve injury. This phenotype is accompanied by a massive reduction of invading macrophages and neutrophils in G2A-deficient mice and a strongly reduced release of the proalgesic mediators TNFα, IL-6 and VEGF at the site of injury. Using a global proteome analysis to identify the underlying signaling pathways, we found that G2A activation in macrophages initiates MyD88-PI3K-AKT signaling and transient MMP9 release to trigger cytoskeleton remodeling and migration. We conclude that G2A-deficiency reduces inflammatory responses by decreasing the number of immune cells and the release of proinflammatory cytokines and growth factors at the site of nerve injury. Inhibiting the G2A receptor after nerve injury may reduce immune cell-mediated peripheral sensitization and may thus ameliorate neuropathic pain.

c-Abl-p38α signaling pathway mediates dopamine neuron loss in trigeminal neuralgia.

Trigeminal neuralgia is a common neuropathic pain in the head and face. The pathogenesis of trigeminal neuralgia is complex, and so far, the pathogenesis of trigeminal neuralgia involving peripheral and central nervous inflammation theory has not been explained clearly. The loss of dopamine neurons in striatum may play an important role in the development of trigeminal nerve, but the reason is not clear. C-Abl is a nonreceptor tyrosine kinase, which can be activated abnormally in the environment of neuroinflammation and cause neuron death. We found that in the rat model of infraorbital nerve ligation trigeminal neuralgia, the pain threshold decreased, the expression of c-Abl increased significantly, the downstream activation product p38 was also activated abnormally and the loss of dopamine neurons in striatum increased. When treated with imatinib mesylate (STI571), a specific c-Abl family kinase inhibitor, the p38 expression was decreased and the loss of dopaminergic neurons was reduced. The mechanical pain threshold of rats was also improved. In conclusion, c-abl-p38 signaling pathway may play an important role in the pathogenesis of trigeminal neuralgia, and it is one of the potential targets for the treatment of trigeminal neuralgia.

Role of the superior ovarian nerve in the regulation of follicular development and steroidogenesis in the morning of diestrus 1.

PURPOSE: Little is known about the role of the superior ovarian nerve (SON) in follicular development during the estrus cycle. The aim of the present study was to analyze the role of neural signals arriving through the SON at the ovaries in the regulation of follicular development and ovarian steroid secretion in diestrus 1 of cyclic rats. METHODS: Cyclic rats were subjected to left, right, or bilateral SON sectioning or to unilateral or bilateral laparotomy at diestrus 1 at 11:00 h. Animals were sacrificed 24 h after surgery. RESULTS: Compared to laparotomized animals, unilateral SON sectioning decreased the number of preovulatory follicles, while bilateral SON sectioning resulted in a decreased number of atretic preantral follicles. An important observation was the presence of invaginations in the follicular wall of large antral and preovulatory follicles in animals with denervation. Furthermore, left SON sectioning increased progesterone levels but decreased testosterone levels, which are effects that were not observed in animals that were subjected to right denervation. CONCLUSIONS: At 11:00 h of diestrus 1, the SON was found to stimulate follicle development, possibly via neural signals, such as noradrenaline and/or vasoactive intestinal peptide, and this stimulation induced the formation of follicle-stimulating hormone receptors. The role of the SON in the regulation of ovarian steroid secretion is asymmetric: the left SON inhibits the regulation of progesterone and stimulates testosterone secretion, and the right nerve does not participate in these processes.

3D bioprinting applications in neural tissue engineering for spinal cord injury repair.

Spinal cord injury (SCI) is a disease of the central nervous system (CNS) that has not yet been treated successfully. In the United States, almost 450,000 people suffer from SCI. Despite the development of many clinical treatments, therapeutics are still at an early stage for a successful bridging of damaged nerve spaces and complete recovery of nerve functions. Biomimetic 3D scaffolds have been an effective option in repairing the damaged nervous system. 3D scaffolds allow improved host tissue engraftment and new tissue development by supplying physical support to ease cell function. Recently, 3D bioprinting techniques that may easily regulate the dimension and shape of the 3D tissue scaffold and are capable of producing scaffolds with cells have attracted attention. Production of biologically more complex microstructures can be achieved by using 3D bioprinting technology. Particularly in vitro modeling of CNS tissues for in vivo transplantation is critical in the treatment of SCI. Considering the potential impact of 3D bioprinting technology on neural studies, this review focus on 3D bioprinting methods, bio-inks, and cells widely used in neural tissue engineering and the latest technological applications of bioprinting of nerve tissues for the repair of SCI are discussed.

Sight and switch off: Nerve density visualization for interventions targeting nerves in prostate cancer.

Nerve density is associated with prostate cancer (PCa) aggressiveness and prognosis. Thus far, no visualization methods have been developed to assess nerve density of PCa in vivo. We compounded propranolol-conjugated superparamagnetic iron oxide nerve peptide nanoparticles (PSN NPs), which achieved the nerve density visualization of PCa with high sensitivity and high specificity, and facilitated assessment of nerve density and aggressiveness of PCa using magnetic resonance imaging and magnetic particle imaging. Moreover, PSN NPs facilitated targeted therapy for PCa. PSN NPs increased the survival rate of mice with orthotopic PCa to 83.3% and decreased nerve densities and proliferation indexes by more than twofold compared with the control groups. The present study, thus, developed a technology to visualize the nerve density of PCa and facilitate targeted neural drug delivery to tumors to efficiently inhibit PCa progression. Our study provides a potential basis for clinical imaging and therapeutic interventions targeting nerves in PCa.

Histological and functional outcomes in a rat model of hemisected spinal cord with sustained VEGF/NT-3 release from tissue-engineered grafts.

Microvascular disturbance, excessive inflammation and gliosis are key pathophysiologic changes in relation to functional status following the traumatic spinal cord injury (SCI). Continuous release of vascular endothelial growth factor (VEGF) to the lesion site was proved be able to promote the vascular remodelling, whereas the effects on reduction of inflammation and gliosis remain unclear. Currently, aiming at exploring the synergistic roles of VEGF and neurotrophin-3 (NT-3) on angiogenesis, anti-inflammation and neural repair, we developed a technique to co-deliver VEGF165 and NT-3 locally with a homotopic graft of tissue-engineered acellular spinal cord scaffold (ASCS) in a hemisected (3 mm in length) SCI model. As the potential in secretion of growth factors (GFs), bone mesenchymal stem cells (BMSCs) were introduced with the aim to enhance the VEGF/NT-3 release. Our data demonstrate that sustained VEGF/NT-3 release from ASCS significantly increases the local levels of VEGF/NT-3 and angiogenesis, regardless of whether it is in combination with BMSCs transplantation that exhibits positive effects on anti-inflammation, axonal outgrowth and locomotor recovery. This study verifies that co-delivery of VEGF/NT-3 reduces inflammation and gliosis in the hemisected spinal cord, promotes axonal outgrowth and results in better locomotor recovery, while the BMSCs transplantation facilitates these functions limitedly.