Parvalbumin gates chronic pain through the modulation of firing patterns in inhibitory neurons.

Spinal cord dorsal horn inhibition is critical to the processing of sensory inputs, and its impairment leads to mechanical allodynia. How this decreased inhibition occurs and whether its restoration alleviates allodynic pain are poorly understood. Here, we show that a critical step in the loss of inhibitory tone is the change in the firing pattern of inhibitory parvalbumin (PV)-expressing neurons (PVNs). Our results show that PV, a calcium-binding protein, controls the firing activity of PVNs by enabling them to sustain high-frequency tonic firing patterns. Upon nerve injury, PVNs transition to adaptive firing and decrease their PV expression. Interestingly, decreased PV is necessary and sufficient for the development of mechanical allodynia and the transition of PVNs to adaptive firing. This transition of the firing pattern is due to the recruitment of calcium-activated potassium (SK) channels, and blocking them during chronic pain restores normal tonic firing and alleviates chronic pain. Our findings indicate that PV is essential for controlling the firing pattern of PVNs and for preventing allodynia. Developing approaches to manipulate these mechanisms may lead to different strategies for chronic pain relief.

Enabling population protein dynamics through Bayesian modeling.

MOTIVATION: The knowledge of protein dynamics, or turnover, in patients provides invaluable information related to certain diseases, drug efficacy, or biological processes. A great corpus of experimental and computational methods has been developed, including by us, in the case of human patients followed in vivo. Moving one step further, we propose a novel modeling approach to capture population protein dynamics using Bayesian methods. RESULTS: Using two datasets, we demonstrate that models inspired by population pharmacokinetics can accurately capture protein turnover within a cohort and account for inter-individual variability. Such models pave the way for comparative studies searching for altered dynamics or biomarkers in diseases. AVAILABILITY AND IMPLEMENTATION: R code and preprocessed data are available from zenodo.org. Raw data are available from panoramaweb.org.

Modeling the Simultaneous Dynamics of Proteins in Blood Plasma and the Cerebrospinal Fluid in Human In Vivo.

The analysis of protein dynamics or turnover in patients has the potential to reveal altered protein recycling, such as in Alzheimer's disease, and to provide informative data regarding drug efficacy or certain biological processes. The observed protein dynamics in a solid tissue or a fluid is the net result of not only protein synthesis and degradation but also transport across biological compartments. We report an accurate 3-biological compartment model able to simultaneously account for the protein dynamics observed in blood plasma and the cerebrospinal fluid (CSF) including a hidden central nervous system (CNS) compartment. We successfully applied this model to 69 proteins of a single individual displaying similar or very different dynamics in plasma and CSF. This study puts a strong emphasis on the methods and tools needed to develop this type of model. We believe that it will be useful to any researcher dealing with protein dynamics data modeling.

Descriptive epidemiology of 30,223 histopathologically confirmed meningiomas in France: 2006-2015.

BACKGROUND AND OBJECTIVES: Meningioma is one of the most common neoplasm of the central nervous system. To describe the epidemiology of meningioma operated in France and, to assess grading and histopathological variability among the different neurosurgical centres. METHODS: We processed the French Brain Tumour Database (FBTDB) to conduct a nationwide population-based study of all histopathologically confirmed meningiomas between 2006 and 2015. RESULTS: 30,223 meningiomas cases were operated on 28,424 patients, in 61 centres. The average number of meningioma operated per year in France was 3,022 (SD ± 122). Meningioma was 3 times more common in women (74.1% vs. 25.9%). The incidence of meningioma increased with age and, mean age at surgery was 58.5 ± 13.9 years. Grade 1, 2, and 3 meningiomas accounted for 83.9%, 13.91% and, 2.19% respectively. There was a significant variability of meningioma grading by institutions, especially for grade 2 which spanned from 5.1% up to 22.4% (p < 0.001). Moreover, the proportion of grade 2 significantly grew over the study period (p < 0.001). There was also a significant variation in grade 1 subtypes diagnosis among the institutions (p < 0.001). 89.05% of the patients had solely one meningioma surgery, 8.52% two and, 2.43% three or more. The number of surgeries was associated to the grade of malignancy (p < 0.001). CONCLUSION: The incidence of meningioma surgery increased with age and, peaked at 58.5 years. They were predominantly benign with meningothelial subtype being the most common. However, there was a significant variation of grade 1 subtypes diagnosis among the centres involved. The proportion of grade 2 meningioma significantly grew over the study time, on contrary to malignant meningioma proportion, which remained rare and, stable over time around 2%. Likewise, there was a significant variability of grade 2 meningioma rate among the institutions.

Descriptive epidemiology of 399 histologically confirmed newly diagnosed meningeal solitary fibrous tumours and haemangiopericytomas in France: 2006-2015.

PURPOSE: Meningeal solitary fibrous tumour (SFT) and haemangiopericytoma (HPC) are uncommon tumours that have been merged into a single entity in the last 2021 WHO Classification of Tumors of the Central Nervous System. To describe the epidemiology of SFT/HPC operated in France and, to assess their incidence. METHODS: We processed the French Brain Tumour Database (FBTDB) to conduct a nationwide population-based study of all histopathologically confirmed SFT/HPC between 2006 and 2015. RESULTS: Our study included 399 SFT/HPC patients, operated in France between 2006 and 2015, in one of the 46 participating neurosurgical centres. The incidence reached 0.062, 95%CI[0.056-0.068] for 100,000 person-years. SFT accounted for 35.8% and, HPC for 64.2%. The ratio of SFT/HPC over meningioma operated during the same period was 0.013. SFT/HPC are about equally distributed in women and men (55.9% vs. 44.1%). For the whole population, mean age at surgery was 53.9 (SD ± 15.8) years. The incidence of SFT/HPC surgery increases with the age and, is maximal for the 50-55 years category. Benign SFT/HPC accounted for 65.16%, SFT/HPC of uncertain behaviour for 11.53% and malignant ones for 23.31%. The number of resection progresses as the histopathological behaviour became more aggressive. 6.7% of the patients with a benign SFT/HPC had a second surgery vs.16.6% in case of uncertain behaviour and, 28.4% for malignant SFT/HPC patients. CONCLUSION: Meningeal SFT and HPC are rare CNS mesenchymal tumours which both share common epidemiological characteristics, asserting their merging under a common entity. SFT/HPC incidence is less that one case for 1 billion per year and, for around 100 meningiomas-like tumours removed, one SFT/HPC may be diagnosed. SFT/HPC are equally distributed in women and men and, are mainly diagnosed around 50-55 years. The more aggressive the tumour, the higher the probability of recurrence.

Cauda equina myxopapillary ependymoma in von Hippel-Lindau disease: A case report.

Background: Patients affected by Von Hippel-Lindau (VHL) are prone to develop central nervous system neoplasms such as hemangioblastomas (HBs). Myxopapillary ependymoma (MPE) is not commonly associated with VHL disease. Case Description: We present the first case of a VHL patient affected by simultaneous silent cauda equina MPE and a symptomatic conus medullaris HB. The patient was first operated for systemic tumors and followed for asymptomatic HBs. Simple surveillance was maintained until neurological symptoms appeared. Regular follow-up demonstrated objective growth of the cystic conus medullaris tumor while the cauda equina lesion remained stable. Surgery was performed to avoid further neurological worsening. Histopathological examination showed conus medullaris HB and a nearby cauda equina MPE. Conclusion: Simultaneous spinal HBs and isolated MPE may exceptionally occur in VHL patients.

Survival After Newly-Diagnosed High-Grade Glioma Surgery: What Can We Learn From the French National Healthcare Database?

BACKGROUND: This study aimed to assess the overall survival (OS) of patients after high-grade glioma (HGG) resection and to search for associated prognostic factors. METHODS: A random sample of ad hoc cases was extracted from the French medico-administrative national database, Système National des Données de Santé (SNDS). We solely considered the patients who received chemoradiotherapy with temozolomide (TMZ/RT) after HGG surgery. Statistical survival methods were implemented. RESULTS: A total of 1,438 patients who had HGG resection at 58 different institutions between 2008 and 2019 were identified. Of these, 34.8% were female, and the median age at HGG resection was 63.2 years (interquartile range [IQR], 55.6-69.4 years). Median OS was 1.69 years (95% confidence interval [CI], 1.63-1.76), i.e., 20.4 months. Median age at death was 65.5 years (IQR, 58.5-71.8). OS at 1, 2, and 5 years was 78.5% (95% CI, 76.4-80.7), 40.3% (95% CI, 37.9-43), and 11.8% (95% CI, 10.2-13.6), respectively. In the adjusted Cox regression, female gender (HR=0.71; 95% CI, 0.63-0.79; p<0.001), age at HGG surgery (HR=1.02; 95% CI, 1.02-1.03; p<0.001), TMZ treatment over 6 months after HGG surgery (HR=0.36; 95% CI, 0.32-0.4; p<0.001), bevacizumab (HR=1.22; 95% CI, 1.09-1.37; p<0.001), and redo surgery (HR=0.79; 95% CI, 0.67-0.93; p=0.005) remained significantly associated with the outcome. CONCLUSION: The SNDS is a reliable source for studying the outcome of HGG patients. OS is better in younger patient, female gender, and those who complete concomitant chemoradiotherapy. Redo surgery for HGG recurrence was also associated with prolonged survival.

Prognostic impact of the number and total tumor burden of secondary cerebral lesions in patients with resected brain metastases of non-small cell lung cancers.

OBJECTIVE: Systemic therapeutic advancements have improved the prognosis of cancer patients, leading to surgery more frequently being carried out for patients with multiple brain metastases (BM). The underlying evidence for the strategy is currently lacking. This study aimed to evaluate the prognostic significance of the number of BM and total tumor burden (TTB) on the overall survival (OS) of patients with resected BM of non-small cell lung cancer (NSCLC) in a modern series. METHODS: In this monocentric retrospective series, patients who underwent resection of BM of NSCLC between 2015 and 2021 were included. Demographic, clinical, and histological parameters were collected, and formal radiological volumetric analyses were performed. Prognostic biomarkers for cerebral progression-free survival (C-PFS) and OS were analyzed with univariate and multivariate Cox proportional hazards analysis. RESULTS: One hundred eighty-four patients were included in the study. Among these, 108 patients (58.7%) presented with a single brain metastasis, 36 patients (19.6%) with 2 BM, 22 patients (11.9%) with 3 BM, and 18 patients (9.8%) with more than 3 BM (maximum 15 BM). The mean ± SD (range) preoperative tumor burden was 23.1 ± 25.3 (1.1-145.3) cm3. The mean residual tumor burden after surgery was 0.3 ± 0.8 (0.0-6.3) cm3. By the time of the analysis, 128 patients (69.6%) had died. The median follow-up duration was 49.0 months (95% CI 39.6-63.6). The median OS was 19.2 months (95% CI 13.2-24.0), and the survival rates at 6 months, 1 year, and 2 years were 76% (95% CI 69%-82%), 61% (95% CI 53%-67%), and 43% (95% CI 35%-50%), respectively. The median C-PFS was 8.4 months (95% CI 7.2-12.0). In the Cox multivariate regression model, younger age (< 65 years), single brain metastasis, adjuvant brain radiation therapy, adjuvant use of targeted therapy, and TTB < 7 cm3 were all independent predictors of longer OS. CONCLUSIONS: In this era of modern systemic treatments for cancer, the number of BM and total cerebral tumor burden remain significant prognostic factors of OS. However, resection should be considered as an option even in those patients with multiple BM in order to enhance patient clinical status, enable further local and systemic treatment delivery, and improve their survival and quality of life.

Radiotherapy for central neurocytoma: A multicentric retrospective study in France.

PURPOSE: Neurocytomas represent 0.25 to 0.5% of primary brain tumours and are mainly found in young adults. These tumours have neuronal differentiation. The cornerstone treatment is neurosurgery. The efficacy of other therapies, including radiotherapy, is still unclear. The objective of this study was to evaluate the management of central neurocytomas and the role of radiotherapy. MATERIALS AND METHODS: All adult patients (age 18 years or older) newly diagnosed with a histologically confirmed neurocytoma between 2006 and 2015 in France were included. RESULTS: One hundred and sixteen patients were diagnosed with a central neurocytoma during the study period. All patients underwent surgical resection, and six received adjuvant radiotherapy. Eleven patients received radiotherapy due to progression. After a median follow-up of 68.7 months, local failure occurred in 29 patients. The 5-year local control rate was 73.4%. According to univariate analysis, marker of proliferation Ki67 index greater than 2% (hazard ratio [HR]: 1.48; confidence interval [CI]: 1.40-1.57; P=0.027) and subtotal resection (HR: 8.48; CI: 8.01-8.99; P<0.001) were associated with an increase in local failure. Gross total resection was associated with a higher risk of sequelae epilepsy (HR: 3.62; CI: 3.42-3.83; P<0.01) and memory disorders (HR: 1.35; CI: 1.07-1.20; P<0.01). Ten patients (8.6%) died during the follow-up. The 10-year overall survival rate was 89.0%. No prognostic factors for overall survival were found. CONCLUSION: The analysis showed that patients who underwent subtotal surgical resection, particularly when the tumour had a Ki67 index greater than 2%, had an increased risk of local recurrence. These patients could benefit from adjuvant radiotherapy.

Induction of antiviral interferon-stimulated genes by neuronal STING promotes the resolution of pain in mice.

Inflammation and pain are intertwined responses to injury, infection, or chronic diseases. While acute inflammation is essential in determining pain resolution and opioid analgesia, maladaptive processes occurring during resolution can lead to the transition to chronic pain. Here we found that inflammation activates the cytosolic DNA-sensing protein stimulator of IFN genes (STING) in dorsal root ganglion nociceptors. Neuronal activation of STING promotes signaling through TANK-binding kinase 1 (TBK1) and triggers an IFN-ß response that mediates pain resolution. Notably, we found that mice expressing a nociceptor-specific gain-of-function mutation in STING exhibited an IFN gene signature that reduced nociceptor excitability and inflammatory hyperalgesia through a KChIP1-Kv4.3 regulation. Our findings reveal a role of IFN-regulated genes and KChIP1 downstream of STING in the resolution of inflammatory pain.

A Cohort Study of CNS Tumors in Multiple Endocrine Neoplasia Type 1.

PURPOSE: Multiple endocrine neoplasia type 1 (MEN1) is thought to increase the risk of meningioma and ependymoma. Thus, we aimed to describe the frequency, incidence, and specific clinical and histological features of central nervous system (CNS) tumors in the MEN1 population (except pituitary tumors). EXPERIMENTAL DESIGN: The study population included patients harboring CNS tumors diagnosed with MEN1 syndrome after 1990 and followed up in the French MEN1 national cohort. The standardized incidence ratio (SIR) was calculated based on the French Gironde CNS Tumor Registry. Genomic analyses were performed on somatic DNA from seven CNS tumors, including meningiomas and ependymomas from patients with MEN1, and then on 50 sporadic meningiomas and ependymomas. RESULTS: A total of 29 CNS tumors were found among the 1,498 symptomatic patients (2%; incidence = 47.4/100,000 person-years; SIR = 4.5), including 12 meningiomas (0.8%; incidence = 16.2/100,000; SIR = 2.5), 8 ependymomas (0.5%; incidence = 10.8/100,000; SIR = 17.6), 5 astrocytomas (0.3%; incidence = 6.7/100,000; SIR = 5.8), and 4 schwannomas (0.3%; incidence = 5.4/100,000; SIR = 12.7). Meningiomas in patients with MEN1 were benign, mostly meningothelial, with 11 years earlier onset compared with the sporadic population and an F/M ratio of 1/1. Spinal and cranial ependymomas were mostly classified as World Health Organization grade 2. A biallelic MEN1 inactivation was observed in 4/5 ependymomas and 1/2 meningiomas from patients with MEN1, whereas MEN1 deletion in one allele was present in 3/41 and 0/9 sporadic meningiomas and ependymomas, respectively. CONCLUSIONS: The incidence of each CNS tumor was higher in the MEN1 population than in the French general population. Meningiomas and ependymomas should be considered part of the MEN1 syndrome, but somatic molecular data are missing to conclude for astrocytomas and schwannomas.