Search Results (41)

Background/Objectives: Increasing evidence indicates that tumors interact functionally with the nervous system. Rather than being passively innervated, many cancers establish bidirectional communication with neurons, suggesting that neural activity may represent an additional regulatory layer of tumor biology. This review aims to synthesize current knowledge on the mechanisms and consequences of tumor innervation and to discuss its implications for cancer progression and therapy. Methods: We performed a narrative synthesis of recent experimental and translational studies (2015–2026), identified through PubMed and major peer-reviewed biomedical journals. The literature was analyzed to identify key mechanisms of neural influence on tumor biology, including axonogenesis, pseudo-synaptic communication, neurotransmitter signaling, and metabolic coupling. Results: Emerging evidence indicates that neural inputs can regulate multiple hallmarks of cancer, including proliferation, invasion, angiogenesis, metabolic plasticity, and immune evasion. Tumors can actively recruit nerve fibers through axonogenic signals and establish specialized neuron–cancer interfaces that enable activity-dependent oncogenic signaling. In addition, neuronal interactions can influence tumor metabolism and therapeutic resistance through mechanisms such as mitochondrial transfer and neurotransmitter-driven signaling pathways. Conclusions: Tumor innervation represents an important and increasingly recognized dimension of cancer biology. Understanding how neural circuits interact with tumor cells and the surrounding microenvironment may reveal new biomarkers and therapeutic strategies aimed at disrupting tumor–neuron communication. Full article

The authors hypothesize that idiopathic Parkinson’s disease may result from an alteration in microvascular flow at a “critical point” in the nervous system that is characterized by pigmented cells that express neuromelanin and/or lipofuscin. “Critical points” include the olfactory epithelium/bulb, the autonomic nervous system, the enteric nervous system, the prefrontal–cortico-pontine network, and the amygdala. Hypoxia–ischemia following blood flow disturbance would recruit and activate leukocytes and induce the infiltration of peripheral immune cells into neural tissue. The excess of toxic factors produced by hyperactive immune cells, such as myeloperoxidase and its derivatives, would cause the oxidation of lipids, proteins, and biogenic monoamines such as dopamine, which in turn would facilitate the accumulation and precipitation of neuromelanin, lipofuscin, and alpha-synuclein. In addition, neuromelanin and lipofuscin precipitates may accentuate the misfolding and aggregation of alpha-synuclein. This “amplification” mechanism could help explain the crucial role of pigmented neurons in the onset of Parkinson’s disease pathology, triggering abnormal neurotoxic alpha-synuclein spread throughout the nervous system from the “critical point” of origin, and enabling a self-perpetuating degenerative process. The proposed hypothesis may have implications for the identification of new therapeutic targets, early prevention strategies, and the development of vascular and/or immune biomarkers. Full article

Ovarian aging (OA) results from the senescence of different cell types present in the ovary, decreasing female fertility and quality of life and augmenting the risk of a variety of fertility-unrelated pathological conditions. The changes observed in the ovarian cells are accompanied by changes occurring in various elements of the hypothalamic–pituitary–ovarian (HPO) axis, the complex endocrine system that regulates the female reproductive cycle. Issues pertaining to the HPO axis have been addressed in animal models via hormonal treatments with preparations inhibiting ovarian follicular recruitment at the level of the receptors of gonadotropin-releasing hormone (GnRH)-secreting neurons, mainly acting on glutamate- and gamma-aminobutyric acid (GABA)-driven signaling. GnRH agonists and antagonists have also been used in women exposed to chemotherapeutics. HPO-independent OA can be delayed through the administration of different antioxidants and mitochondria-protecting agents, among which melatonin has been shown to be particularly useful. Other therapeutic approaches used with success in women include hormonal and growth factor (GF) modulators, such as growth hormone (GH), insulin-like growth factor 1 (IGF-1), vascular endothelial growth factors (VEGF), and dehydroepiandrosterone (DHEA), and the development of patient-tailored combination-based therapies (IGF-1 + VEGF + DHEA) has also been suggested. Intraovarian injection of autologous platelet-rich plasma (PRP), mitochondrial donation through pronuclear transfer, and ovarian tissue cryopreservation and autotransplantation have also yielded promising results in women, and their use can preserve not only fertility but also the ovarian endocrine function. Personalized mixtures of specific agents (desatinib, quercetin, rapamycin, metformin, resveratrol, melatonin, and coenzyme Q10) targeting different cell types in the ovary are currently under investigation. Overall, this review aims to present a global view of the subject, uniting the physiological and molecular background of this pathology with the history and development of potential treatment strategies and new perspectives in this domain. As such, this study may be helpful both to clinicians facing problems resulting from OA and to researchers pursuing further developments in this field. Full article

Cancer neuroscience is an emerging field revealing how malignancies interact with the nervous system to shape disease progression and symptom burden. In colorectal cancer (CRC), increasing evidence suggests a direct interplay between tumor cells and peripheral sensory neurons, contributing not only to cancer progression but also to chemotherapy-induced side effects such as peripheral neuropathy. Chemokines, particularly CCL3, appear to be key players in this bidirectional communication. This literature review aims to critically examine the role of CCL3 in CRC and chemotherapy-induced peripheral neuropathy (CIPN), with a focus on identifying potential mechanistic overlaps. Specifically, we evaluate whether CCL3 may serve as a molecular link between cancer progression and the development of neuropathic pain. In CRC, CCL3 is frequently upregulated, promoting tumor proliferation, invasion, and immune remodeling through CCR5- and MAPK-dependent pathways. Elevated CCL3 expression correlates with advanced stage, nerve infiltration, and worse prognosis, while select studies suggest it may also enhance antitumor immunity via dendritic cell recruitment. In parallel, CCL3 is also upregulated in the nervous system during CIPN, where it contributes to chronic pain through activation of glial cells, sensitization of nociceptive pathways (e.g., TRPV1, P2X7), and desensitization of opioid receptors. Notably, MAPK signaling is a shared downstream pathway in both contexts, suggesting a potential mechanistic bridge between tumor biology and neurotoxicity. In conclusion, CCL3 emerges as a central molecule at the intersection of CRC and CIPN. Understanding its context-dependent roles may offer new opportunities for risk prediction, biomarker development, and therapeutic intervention—contributing to the broader goals of cancer neuroscience in improving both oncologic and neurologic outcomes. Full article

Peripheral nerve injuries pose a significant clinical challenge due to the complex biological processes involved in nerve repair and their limited regenerative capacity. Despite advances in surgical techniques, conventional treatments, such as nerve autografts, are faced with limitations like donor site morbidity and inconsistent functional outcomes. As such, there is a growing interest in new, novel, and innovative strategies to enhance nerve regeneration. Tissue engineering/regenerative medicine and its use of biomaterials is an emerging example of an innovative strategy. Within the realm of tissue engineering, functionalized hydrogels have gained considerable attention due to their ability to mimic the extracellular matrix, support cell growth and differentiation, and even deliver bioactive molecules that can promote nerve repair. These hydrogels can be engineered to incorporate growth factors, bioactive peptides, and stem cells, creating a conducive microenvironment for cellular growth and axonal regeneration. Recent advancements in materials as well as cell biology have led to the development of sophisticated hydrogel systems, that not only provide structural support, but also actively modulate inflammation, promote cell recruitment, and stimulate neurogenesis. This review explores the potential of functionalized hydrogels for peripheral nerve repair, highlighting their composition, biofunctionalization, and mechanisms of action. A comprehensive analysis of preclinical studies provides insights into the efficacy of these hydrogels in promoting axonal growth, neuronal survival, nerve regeneration, and, ultimately, functional recovery. Thus, this review aims to illuminate the promise of functionalized hydrogels as a transformative tool in the field of peripheral nerve regeneration, bridging the gap between biological complexity and clinical feasibility. Full article

Trinucleotide repeat (TNR) expansion is the cause of over 40 neurodegenerative diseases, including Huntington’s disease and Friedreich’s ataxia (FRDA). There are no effective treatments for these diseases due to the poor understanding of molecular mechanisms underlying somatic TNR expansion and contraction in neural systems. We and others have found that DNA base excision repair (BER) actively modulates TNR instability, shedding light on the development of effective treatments for the diseases by contracting expanded repeats through DNA repair. In this study, temozolomide (TMZ) was employed as a model DNA base damaging agent to reveal the mechanisms of the BER pathway in modulating GAA repeat instability at the frataxin (FXN) gene in FRDA neural cells and transgenic mouse mice. We found that TMZ induced large GAA repeat contraction in FRDA mouse brain tissue, neurons, and FRDA iPSC-differentiated neural cells, increasing frataxin protein levels in FRDA mouse brain and neural cells. Surprisingly, we found that TMZ could also inhibit H3K9 methyltransferases, leading to open chromatin and increasing ssDNA breaks and recruitment of the key BER enzyme, pol β, on the repeats in FRDA neural cells. We further demonstrated that the H3K9 methyltransferase inhibitor BIX01294 also induced the contraction of the expanded repeats and increased frataxin protein in FRDA neural cells by opening the chromatin and increasing the endogenous ssDNA breaks and recruitment of pol β on the repeats. Our study provides new mechanistic insight illustrating that inhibition of H3K9 methylation can crosstalk with BER to induce GAA repeat contraction in FRDA. Our results will open a new avenue for developing novel gene therapy by targeting histone methylation and the BER pathway for repeat expansion diseases. Full article

Background: Multiple sclerosis (MS) is a chronic autoimmune and neuroinflammatory disease of the central nervous system characterized by peripheral activation of immune-inflammatory pathways which culminate in neurotoxicity causing demyelination of central neurons. Nonetheless, the pathophysiology of relapsing-remitting MS (RRMS)-related chronic fatigue, depression, anxiety, cognitive impairments, and autonomic disturbances is not well understood. Objectives: The current study aims to delineate whether the remitted phase of RRMS is accompanied by activated immune-inflammatory pathways and if the latter, coupled with erythron variables, explain the chronic fatigue and mood symptoms due to RRMS. Material and Methods: We recruited 63 MS patients, 55 in the remitted phase of RRMS and 8 with secondary progressive MS, and 30 healthy controls and assessed erythron variables, and used a bio-plex assay to measure 27 serum cytokines. Results: A significant proportion of the MS patients (46%) displayed activation of the immune-inflammatory response (IRS) and compensatory immune response (CIRS) systems, and T helper (Th)1 and Th17 cytokine profiles. Remitted RRMS patients showed increased chronic fatigue, depression, anxiety, physiosomatic, autonomic, and insomnia scores, which could partly be explained by M1 macrophage, Th1, Th-17, growth factor, and CIRS activation, as well as aberrations in the erythron including lowered hematocrit and hemoglobin levels. Conclusions: Around 50% of remitted RRMS patients show activation of immune-inflammatory pathways in association with mood and chronic-fatigue-like symptoms. IRS and CIRS activation as well as the aberrations in the erythron are new drug targets to treat chronic fatigue and affective symptoms due to MS. Full article

Brain-derived neurotrophic factor (BDNF) interacts with tropomyosin-related kinase B (TrkB) to promote neuronal growth, survival, differentiation, neurotransmitter release, and synaptic plasticity. The translocator protein (TSPO) is known to be found in arterial plaques, which are a symptom of atherosclerosis and a contributory cause of ischemic stroke. This study aims to determine the diagnostic accuracy of plasma BDNF and TSPO levels in discriminating new-onset acute ischemic stroke (AIS) patients from individuals without acute ischemic stroke. A total of 90 AIS patients (61% male, with a mean age of 67.7 ± 12.88) were recruited consecutively in a stroke unit, and each patient was paired with two age- and gender-matched controls. The sensitivity, specificity, and area of the curve between high plasma BDNF and TSPO and having AIS was determined using receiver operating characteristic curves. Furthermore, compared to the controls, AIS patients exhibited significantly higher levels of BDNF and TSPO, blood pressure, HbA1c, and white blood cells, as well as higher creatinine levels. The plasma levels of BDNF and TSPO can significantly discriminate AIS patients from healthy individuals (AUC 0.76 and 0.89, respectively). However, combining the two biomarkers provided little improvement in AUC (0.90). It may be possible to use elevated levels of TSPO as a diagnostic biomarker in patients with acute ischemic stroke upon admission. Full article

Bacterial meningitis is a devastating disease occurring worldwide, with up to half of survivors left with permanent neurological sequelae. Neonatal meningitis-causing Escherichia coli (NMEC) is the most common Gram-negative bacillary organism that causes meningitis, particularly during the neonatal period. Here, RNA-seq transcriptional profiles of microglia in response to NMEC infection show that microglia are activated to produce inflammatory factors. In addition, we found that the secretion of inflammatory factors is a double-edged sword that promotes polymorphonuclear neutrophil (PMN) recruitment to the brain to clear the pathogens but, at the same time, induces neuronal damage, which may be related to the neurological sequelae. New neuroprotective therapeutic strategies must be developed for the treatment of acute bacterial meningitis. We found that transforming growth factor-β (TGF-β) may be a strong candidate in the treatment of acute bacterial meningitis, as it shows a therapeutic effect on bacterial-meningitis-induced brain damage. Prevention of disease and early initiation of the appropriate treatment in patients with suspected or proven bacterial meningitis are the key factors in reducing morbidity and mortality. Novel antibiotic and adjuvant treatment strategies must be developed, and the main goal for new therapies will be dampening the inflammatory response. Based on this view, our findings may help develop novel strategies for bacterial meningitis treatment. Full article

Excessive inhibition of the external globus pallidus (GPe) by striatal GABAergic neurons is considered a central mechanism contributing to motor symptoms of Parkinson’s disease (PD). While electrophysiological findings support this view, behavioral studies assessing the beneficial effects of global GPe activations are scarce and the reported results are controversial. We used an optogenetic approach and the standard unilateral 6-hydroxydopamine nigrostriatal dopamine (DA) lesion model of PD to explore the effects of GPe photostimulation on motor deficits in mice. Global optogenetic GPe inhibition was used in normal mice to verify whether it reproduced the typical motor impairment induced by DA lesions. GPe activation improved ipsilateral circling, contralateral forelimb akinesia, locomotor hypoactivity, and bradykinesia in 6-OHDA-lesioned mice at ineffective photostimulation parameters (532 nm, 5 Hz, 3 mW) in normal mice. GPe photoinhibition (450 nm, 12 mW) had no effect on locomotor activity and forelimb use in normal mice. Bilateral photoinhibition (450 nm, 6 mW/side) reduced directed exploration and improved working memory performances indicating that recruitment of GPe in physiological conditions may depend on the behavioral task involved. Collectively, these findings shed new light on the functional role of GPe and suggest that it is a promising target for neuromodulatory restoration of motor deficits in PD. Full article

Objective: To evaluate if bilateral or unilateral upper limb robot-assisted rehabilitation training using a new three-dimensional end-effector robot that targets shoulder and elbow flexion and abduction is superior to conventional therapy with regard to upper extremity motor function recovery and neuromuscular improvement in stroke patients. Design: Randomized, controlled, parallel, assessor-blinded, three-arm clinical trial. Setting: Southeast University Zhongda Hospital Nanjing, Jiangsu, China. Methods: Seventy patients with hemiplegic stroke were randomly assigned to conventional training (Control, n = 23) or unilateral (URT, n = 23), or bilateral robotic training (BRT, n = 24). The conventional group received routine rehabilitation, 60 min/day, 6 days/week, for 3 weeks. For URT and BRT upper limb robot-assisted rehabilitation training was added. This was 60 min/day, 6 days/week, for 3 weeks. The primary outcome was upper limb motor function assessed with Fugl-Meyer–Upper Extremity Scale (FMA–UE). Secondary outcomes were activities of daily living (ADL) assessed with the Modified Barthel Index (MBI), Motor Evoked Potential (MEP) to assess corticospinal tract connectivity, Root Mean Square (RMS) value, and integrate Electromyography (iEMG) value recorded by surface electromyography to evaluate muscle contraction function. Results: The primary outcome indicator FMA–UE (least square mean (LSMEAN): 31.40, 95% confidence interval (95% CI): 27.74–35.07) and the secondary outcome indicator MBI (LSMEAN: 69.95, 95% CI: 66.69–73.21) were significantly improved in BRT as opposed to control (FMA–UE, LSMEAN: 24.79, 95% CI: 22.23–27.35; MBI, LSMEAN: 62.75, 95% CI: 59.42–66.09); and unilateral (FMA–UE, LSMEAN: 25.97, 95% CI: 23.57–28.36; MBI, LSMEAN: 64.34, 95% CI: 61.01–67.68). BRT also showed greater improvement in the anterior deltoid bundle with regard to muscle contraction function indicated by RMS (LSMEAN: 257.79, 95% CI: 211.45–304.12) and iEMG (LSMEAN: 202.01, 95% CI: 167.09–236.94), as compared to the controls (RMS, LSMEAN: 170.77, 95% CI: 148.97–192.58; iEMG, LSMEAN: 132.09, 95% CI: 114.51–149.68), and URT (RMS, LSMEAN: 179.05, 95% CI: 156.03–202.07; iEMG, LSMEAN: 130.38, 95% CI: 107.50–153.26). There was no statistically significant difference between URT and conventional training for any outcome. There was no significant difference in MEP extraction rate after treatment between groups (p = 0.54 for URT, p = 0.08 for BRT). Conclusions: A 60 min daily training for upper extremities using a three-dimensional end-effector targeting elbow and shoulder adding conventional rehabilitation appears to promote upper limb function and ADL in stroke patients only if delivered bilaterally. URT does not seem to result in better outcomes than conventional rehabilitation. Electrophysiological results suggest that training using a bilateral upper limb robot increases the recruitment of motor neurons rather than improving the conduction function of the corticospinal tract. Full article

Objectives: Fatigue in multiple sclerosis (MS) is a frequent and invalidating symptom, which can be relieved by non-invasive neuromodulation, which presents only negligible side effects. A 5-day transcranial direct-current stimulation, 15 min per day, anodically targeting the somatosensory representation of the whole body against a larger occipital cathode was efficacious against MS fatigue (fatigue relief in multiple sclerosis, Faremus treatment). The present proof-of-concept study tested the working hypothesis that Faremus S1 neuromodulation modifies the homology of the dominant and non-dominant corticospinal (CST) circuit recruitment. Methods: CST homology was assessed via the Fréchet distance between the morphologies of motor potentials (MEPs) evoked by transcranial magnetic stimulation in the homologous left- and right-hand muscles of 10 fatigued MS patients before and after Faremus. Results: In the absence of any change in MEP features either as differences between the two body sides or as an effect of the treatment, Faremus changed in physiological direction the CST’s homology. Faremus effects on homology were more evident than recruitment changes within the dominant and non-dominant sides. Conclusions: The Faremus-related CST changes extend the relevance of the balance between hemispheric homologs to the homology between body sides. With this work, we contribute to the development of new network-sensitive measures that can provide new insights into the mechanisms of neuronal functional patterning underlying relevant symptoms. Full article

All currently licensed medications for multiple sclerosis (MS) target the immune system. Albeit promising preclinical results demonstrated disease amelioration and remyelination enhancement via modulating oligodendrocyte lineage cells, most drug candidates showed only modest or no effects in human clinical trials. This might be due to the fact that remyelination is a sophistically orchestrated process that calls for the interplay between oligodendrocyte lineage cells, neurons, central nervous system (CNS) resident innate immune cells, and peripheral immune infiltrates and that this process may somewhat differ in humans and rodent models used in research. To ensure successful remyelination, the recruitment and activation/repression of each cell type should be regulated in a highly organized spatio–temporal manner. As a result, drug candidates targeting one single pathway or a single cell population have difficulty restoring the optimal microenvironment at lesion sites for remyelination. Therefore, when exploring new drug candidates for MS, it is instrumental to consider not only the effects on all CNS cell populations but also the optimal time of administration during disease progression. In this review, we describe the dysregulated mechanisms in each relevant cell type and the disruption of their coordination as causes of remyelination failure, providing an overview of the complex cell interplay in CNS lesion sites. Full article

Parkinson’s disease (PD) is the second most common neurodegenerative disorder in human and loss-of-functions DJ-1 mutations are associated with a familial form of early onset PD. Functionally, DJ-1 (PARK7), a neuroprotective protein, is known to support mitochondria and protect cells from oxidative stress. Mechanisms and agents by which the level of DJ-1 could be increased in the CNS are poorly described. RNS60 is a bioactive aqueous solution created by exposing normal saline to Taylor-Couette-Poiseuille flow under high oxygen pressure. Recently we have described neuroprotective, immunomodulatory and promyelinogenic properties of RNS60. Here we delineate that RNS60 is also capable of increasing the level of DJ-1 in mouse MN9D neuronal cells and primary dopaminergic neurons, highlighting another new neuroprotective effect of RNS60. While investigating the mechanism we found the presence of cAMP response element (CRE) in DJ-1 gene promoter and stimulation of CREB activation in neuronal cells by RNS60. Accordingly, RNS60 treatment increased the recruitment of CREB to the DJ-1 gene promoter in neuronal cells. Interestingly, RNS60 treatment also induced the enrollment of CREB-binding protein (CBP), but not the other histone acetyl transferase p300, to the promoter of DJ-1 gene. Moreover, knockdown of CREB by siRNA led to the inhibition of RNS60-mediated DJ-1 upregulation, indicating an important role of CREB in DJ-1 upregulation by RNS60. Together, these results indicate that RNS60 upregulates DJ-1 in neuronal cells via CREB–CBP pathway. It may be of benefit for PD and other neurodegenerative disorders. Full article

Previous work revealed an inverse correlation between tobacco smoking and Parkinson’s disease (PD) that is associated with nicotine-induced neuroprotection of dopaminergic (DA) neurons against nigrostriatal damage in PD primates and rodent models. Nicotine, a neuroactive component of tobacco, can directly alter the activity of midbrain DA neurons and induce non-DA neurons in the substantia nigra (SN) to acquire a DA phenotype. Here, we investigated the recruitment mechanism of nigrostriatal GABAergic neurons to express DA phenotypes, such as transcription factor Nurr1 and DA-synthesizing enzyme tyrosine hydroxylase (TH), and the concomitant effects on motor function. Wild-type and α-syn-overexpressing (PD) mice treated with chronic nicotine were assessed by behavioral pattern monitor (BPM) and immunohistochemistry/in situ hybridization to measure behavior and the translational/transcriptional regulation of neurotransmitter phenotype following selective Nurr1 overexpression or DREADD-mediated chemogenetic activation. We found that nicotine treatment led to a transcriptional TH and translational Nurr1 upregulation within a pool of SN GABAergic neurons in wild-type animals. In PD mice, nicotine increased Nurr1 expression, reduced the number of α-syn-expressing neurons, and simultaneously rescued motor deficits. Hyperactivation of GABA neurons alone was sufficient to elicit de novo translational upregulation of Nurr1. Retrograde labeling revealed that a fraction of these GABAergic neurons projects to the dorsal striatum. Finally, concomitant depolarization and Nurr1 overexpression within GABA neurons were sufficient to mimic nicotine-mediated dopamine plasticity. Revealing the mechanism of nicotine-induced DA plasticity protecting SN neurons against nigrostriatal damage could contribute to developing new strategies for neurotransmitter replacement in PD. Full article