Illuminating the functional and structural repertoire of human TBC/RABGAPs.

The Tre2-Bub2-Cdc16 (TBC) domain-containing RAB-specific GTPase-activating proteins (TBC/RABGAPs) are characterized by the presence of highly conserved TBC domains and act as negative regulators of RABs. The importance of TBC/RABGAPs in the regulation of specific intracellular trafficking routes is now emerging, as is their role in different diseases. Importantly, TBC/RABGAPs act as key regulatory nodes, integrating signalling between RABs and other small GTPases and ensuring the appropriate retrieval, transport and delivery of different intracellular vesicles.

Long-term effectiveness and predictors of bisphosphonate treatment in type I complex regional pain syndrome.

OBJECTIVES: Complex regional pain syndrome (CRPS) is a painful disease that leads to chronic pain and disability. Bisphosphonates are largely used in the real-life for the treatment of CRPS, but data on long-term effectiveness and its predictors are lacking. METHODS: We conducted a longitudinal observational study on patients with type I CRPS treated with IV neridronate (100 mg on 4 occasions). Clinical and demographic characteristics were collected at baseline, after 3 months (M3) and after 12 months (M12). Multivariable logistic regression was employed to determine the factors associated with long-term response to treatment. RESULTS: 103 patients with type I CRPS treated with IV neridronate were included in the study. Mean VAS pain at baseline was 79.1 mm and decreased significantly at M3 (-45.9 mm, 95% CI 40.1 to 51.8) and M12 (-61.6 mm, 95% CI 55.3 to 67.9). Hyperalgesia and allodynia resolved in 84.3% and 88.1% of patients at M12. Loss of motion resolved in 53.5% of patients. The predictors of excellent response were gender (male better), predisposing event to CRPS (no event being better than any predisposing event), site of CRPS (lower limb being better), and early response at M3 on VAS pain (2.5 times the chance of being excellent responder every 10 mm decrease). CONCLUSIONS: In this real-life study neridronate was associated with rapid and progressive improvement of symptoms of CRPS which was maintained up to 3 years of follow-up. The predictors of excellent response were early response, lower limb localisation, absence of predisposing events and male gender.

Cardiomyocyte-myofibroblast contact dynamism is modulated by connexin-43.

Healthy cardiomyocytes are electrically coupled at the intercalated discs by gap junctions. In infarcted hearts, adverse gap-junctional remodeling occurs in the border zone, where cardiomyocytes are chemically and electrically influenced by myofibroblasts. The physical movement of these contacts remains unquantified. Using scanning ion conductance microscopy, we show that intercellular contacts between cardiomyocytes and myofibroblasts are highly dynamic, mainly owing to the edge dynamics (lamellipodia) of the myofibroblasts. Decreasing the amount of functional connexin-43 (Cx43) at the membrane through Cx43 silencing, suppression of Cx43 trafficking, or hypoxia-induced Cx43 internalization attenuates heterocellular contact dynamism. However, we found decreased dynamism and stabilized membrane contacts when cellular coupling was strengthened using 4-phenylbutyrate (4PB). Fluorescent-dye transfer between cells showed that the extent of functional coupling between the 2 cell types correlated with contact dynamism. Intercellular calcein transfer from myofibroblasts to cardiomyocytes is reduced after myofibroblast-specific Cx43 down-regulation. Conversely, 4PB-treated myofibroblasts increased their functional coupling to cardiomyocytes. Consistent with lamellipodia-mediated contacts, latrunculin-B decreases dynamism, lowers physical communication between heterocellular pairs, and reduces Cx43 intensity in contact regions. Our data show that heterocellular cardiomyocyte-myofibroblast contacts exhibit high dynamism. Therefore, Cx43 is a potential target for prevention of aberrant cardiomyocyte coupling and myofibroblast proliferation in the infarct border zone.-Schultz, F., Swiatlowska, P., Alvarez-Laviada, A., Sanchez-Alonso, J. L., Song, Q., de Vries, A. A. F., Pijnappels, D. A., Ongstad, E., Braga, V. M. M., Entcheva, E., Gourdie, R. G., Miragoli, M., Gorelik, J. Cardiomyocyte-myofibroblast contact dynamism is modulated by connexin-43.

Prospective comparative study of endoscopic submucosal dissection and gastrectomy for early neoplastic lesions including patients' perspectives.

BACKGROUND: There are no prospective studies comparing endoscopic submucosal dissection (ESD) and gastrectomy, especially evaluating patient-reported outcomes. Our aim was to compare the safety and impact on quality of life (QoL) of ESD and gastrectomy in patients with early gastric neoplasia. METHODS: This prospective study included consecutive patients presenting with early gastric neoplasia in a tertiary center from January 2015 to August 2016. Data collection included curative resection, adverse events (AEs), and patient-reported outcomes (questionnaires: EORTC QLQ-C30, EORTC STO-22, EQ-5D-5 L, and Assessment of Survivor Concerns) before and after interventions (after 1 month, 3 - 6 months, and 1 year). RESULTS: 254 patients with early lesions were included: 153 managed by ESD and 101 by gastrectomy, the former being significantly older and with less advanced lesions. Mean procedural time and length of stay were significantly higher in the surgery group (164 vs. 72 minutes and 16.3 vs. 3.5 days; P < 0.001). Complete resection was higher in the surgical group (99 % vs. 90 %; P = 0.02); ESD was curative in 79 % of patients. Severe AEs and surgical re-intervention were significantly more frequent in the gastrectomy group (21.8 % vs. 7.8 % and 11 % vs. 1 %, respectively). Endoscopic treatment was associated with a positive impact on global health-related QoL at 1 year (net difference + 9.9; P = 0.006), role function and symptom scales (fatigue, pain, appetite, eating restrictions, dysphagia, and body image). Concerns about recurrence did not differ between the groups. CONCLUSIONS: In patients with early gastric neoplasia, ESD is safer and is associated with a positive impact on health-related QoL when compared with gastrectomy, without increasing fear of recurrence and new lesions.

Vps34 regulates Rab7 and late endocytic trafficking through recruitment of the GTPase-activating protein Armus.

The class III phosphoinositide 3-kinase (PI3K) Vps34 (also known as PIK3C3 in mammals) produces phosphatidylinositol 3-phosphate [PI(3)P] on both early and late endosome membranes to control membrane dynamics. We used Vps34-deficient cells to delineate whether Vps34 has additional roles in endocytic trafficking. In Vps34-/- mouse embryonic fibroblasts (MEFs), transferrin recycling and EEA1 membrane localization were unaffected despite elevated Rab5-GTP levels. Strikingly, a large increase in Rab7-GTP levels, an accumulation of enlarged late endosomes, and decreased EGFR degradation were observed in Vps34-deficient cells. The hyperactivation of Rab7 in Vps34-deficient cells stemmed from the failure to recruit the Rab7 GTPase-activating protein (GAP) Armus (also known as TBC1D2), which binds to PI(3)P, to late endosomes. Protein-lipid overlay and liposome-binding assays reveal that the putative pleckstrin homology (PH) domain in Armus can directly bind to PI(3)P. Elevated Rab7-GTP led to the failure of intraluminal vesicle (ILV) formation and lysosomal maturation. Rab7 silencing and Armus overexpression alleviated the vacuolization seen in Vps34-deficient cells. Taken together, these results demonstrate that Vps34 has a previously unknown role in regulating Rab7 activity and late endosomal trafficking.

Cycling around cell-cell adhesion with Rho GTPase regulators.

The formation and stability of epithelial adhesive systems, such as adherens junctions, desmosomes and tight junctions, rely on a number of cellular processes that ensure a dynamic interaction with the cortical cytoskeleton, and appropriate delivery and turnover of receptors at the surface. Unique signalling pathways must be coordinated to allow the coexistence of distinct adhesive systems at discrete sub-domains along junctions and the specific properties they confer to epithelial cells. Rho, Rac and Cdc42 are members of the Rho small GTPase family, and are well-known regulators of cell-cell adhesion. The spatio-temporal control of small GTPase activation drives specific intracellular processes to enable the hierarchical assembly, morphology and maturation of cell-cell contacts. Here, we discuss the small GTPase regulators that control the precise amplitude and duration of the levels of active Rho at cell-cell contacts, and the mechanisms that tailor the output of Rho signalling to a particular cellular event. Interestingly, the functional interaction is reciprocal; Rho regulators drive the maturation of cell-cell contacts, whereas junctions can also modulate the localisation and activity of Rho regulators to operate in diverse processes in the epithelial differentiation programme.

miR-23b regulates cytoskeletal remodeling, motility and metastasis by directly targeting multiple transcripts.

Uncontrolled cell proliferation and cytoskeletal remodeling are responsible for tumor development and ultimately metastasis. A number of studies have implicated microRNAs in the regulation of cancer cell invasion and migration. Here, we show that miR-23b regulates focal adhesion, cell spreading, cell-cell junctions and the formation of lamellipodia in breast cancer (BC), implicating a central role for it in cytoskeletal dynamics. Inhibition of miR-23b, using a specific sponge construct, leads to an increase of cell migration and metastatic spread in vivo, indicating it as a metastatic suppressor microRNA. Clinically, low miR-23b expression correlates with the development of metastases in BC patients. Mechanistically, miR-23b is able to directly inhibit a number of genes implicated in cytoskeletal remodeling in BC cells. Through intracellular signal transduction, growth factors activate the transcription factor AP-1, and we show that this in turn reduces miR-23b levels by direct binding to its promoter, releasing the pro-invasive genes from translational inhibition. In aggregate, miR-23b expression invokes a sophisticated interaction network that co-ordinates a wide range of cellular responses required to alter the cytoskeleton during cancer cell motility.

Romosozumab added to ongoing denosumab in postmenopausal osteoporosis, a prospective observational study.

Background: Optimization of sequential and combination treatment is crucial in shaping long-term management of postmenopausal osteoporosis (OP). Methods: We conducted a 6-month prospective observational study on postmenopausal women with severe OP receiving treatment with romosozumab either alone (in patients naïve to treatment) or in combination with ongoing long-term denosumab (>2 years) or continuing ongoing denosumab alone (>2 years). We collected serum samples for bone turnover markers, bone modulators, and calcium phosphate metabolism at baseline, month 3 and month 6. BMD was assessed at baseline and after 6 months. Results: Fifty-two postmenopausal women with OP were included in the study. Nineteen received romosozumab alone, 11 received romosozumab combined to ongoing denosumab, and 22 continued denosumab alone. BMD increased significantly at all sites at 6 months of follow-up in the romosozumab alone group (femoral neck +8.1%, total hip +6.8%, and lumbar spine +7.9%). In contrast, BMD increased significantly only at lumbar spine in the combination group (+7.2%) and in the denosumab group (+1.5%). P1nP increased significantly in romosozumab groups at month 3 (+70.4% in romosozumab alone group and +99.1% in combination group). Sclerostin levels increased steeply in both romosozumab groups, and Dkk1 did not change. Conclusion: Romosozumab added to ongoing denosumab resulted in an increase in P1nP and lumbar spine BMD, but not in femoral neck BMD. For patients on denosumab, using romosozumab as an additional treatment appeared to be useful in terms of bone formation markers and spine BMD vs denosumab alone. Further randomized controlled trials, possibly powered to fracture outcomes, are needed to confirm our results.

Safe and Efficacious Near Superhydrophobic Hemostat for Reduced Blood Loss and Easy Detachment in Traumatic Wounds.

Hemorrhage is the leading cause of trauma death, and innovation in hemostatic technology is important. The strongly hydrophobic carbon nanofiber (CNF) coating has previously been shown to have excellent hemostatic properties. However, the understanding of how CNF coating guides the coagulation cascade and the biosafety of CNF as hemostatic agents has yet to be explored. Here, our thrombin generation assay investigation showed that CNF induced fast blood coagulation via factor (F) XII activation of the intrinsic pathway. We further performed studies of a rat vein injury and demonstrated that the CNF gauze enabled a substantial reduction of blood loss compared to both the plain gauze and kaolin-imbued gauze (QuikClot). Analysis of blood samples from the model revealed no acute toxicity from the CNF gauze, with no detectable CNF deposition in any organ, suggesting that the immobilization of CNF on our gauze prevented the infiltration of CNF into the bloodstream. Direct injection of CNF into the rat vein was also investigated and found not to elicit overt acute toxicity or affect animal survival or behavior. Finally, toxicity assays with primary keratinocytes revealed minimal toxicity responses to CNF. Our studies thus supported the safety and efficacy of the CNF hemostatic gauze, highlighting its potential as a promising approach in the field of hemostatic control.

RhoG is required for both FcγR- and CR3-mediated phagocytosis.

Phagocytosis is a highly ordered process orchestrated by signalling through Rho GTPases to locally organise the actin cytoskeleton and drive particle uptake. Specific Rho family members that regulate phagocytosis are not known, as the majority of studies have relied on the use of dominant-negative mutants and/or toxins, which can inactivate multiple Rho GTPases. To identify the relevant GTPases for phagocytosis through the Fcγ receptor (FcγR) and complement receptor 3 (CR3), we depleted 20 Rho proteins individually in an RNA interference (RNAi) screen. We find that distinct GTPase subsets are required for actin polymerisation and uptake by macrophages: FcγR-dependent engulfment requires Cdc42 and Rac2 (but not Rac1), whereas CR3 requires RhoA. Surprisingly, RhoG is required for particle uptake through both FcγR and CR3. RhoG has been previously linked to Rac and Cdc42 signalling in different model systems, but not to RhoA. Interestingly, we find that RhoG is also recruited and activated at phagocytic cups downstream of FcγR and CR3, irrespective of their distinct actin structures and mechanisms of internalisation. Thus, the functional links between RhoG and RhoA downstream of CR3-dependent phagocytosis are new and unexpected. Our data suggest a broad role for RhoG in consolidating signals from multiple receptors during phagocytosis.

ROCK1 and ROCK2 regulate epithelial polarisation and geometric cell shape.

BACKGROUND INFORMATION: Cell-cell adhesion and contraction play an essential role in the maintenance of geometric shape and polarisation of epithelial cells. However, the molecular regulation of contraction during cell elongation leading to epithelial polarisation and acquisition of geometric cell shape is not clear. RESULTS: Upon induction of cell-cell adhesion, we find that human keratinocytes acquire specific geometric shapes favouring hexagons, by re-modelling junction length/orientation and thus neighbour allocation. Acquisition of geometric shape correlates temporally with epithelial polarisation, as shown by an increase in lateral height. ROCK1 and ROCK2 are important regulators of myosin II contraction, but their specific role in epithelial cell shape has not been addressed. Depletion of ROCK proteins interferes with the correct proportion of hexagonal cell shapes and full elongation of lateral domain. Interestingly, ROCK proteins are not essential for maintenance of circumferential thin bundles, the main contractile epithelial F-actin pool. Instead, ROCK1 or ROCK2 regulates thin bundle contraction and positioning along the lateral domain, an important event for the stabilisation of the elongating lateral domain. Mechanistically, E-cadherin clustering specifically leads to ROCK1/ROCK2-dependent inactivation of myosin phosphatase and phosphorylation of myosin regulatory light chain. These events correlate temporally with the increase in lateral height and thin bundle compaction towards junctions. CONCLUSION: We conclude that ROCK proteins are necessary for acquisition of elongated and geometric cell shape, two key events for epithelial differentiation.

Bothrops atrox venom: Biochemical properties and cellular phenotypes of three highly toxic classes of toxins.

Snake venoms have a complex mixture of compounds that are conserved across species and act synergistically, triggering severe local and systemic effects. Identification of the toxin classes that are most damaging to cell homeostasis would be a powerful approach to focus on the main activities that underpin envenomation. Here, we focus on the venom of Bothrops atrox, snake responsible for most of the accidents in Amazon region of South America. We identified the key cytotoxic toxin fractions from B. atrox venom and mapped their biochemical properties, protein composition and cell damage. Five fractions were obtained by mass exclusion chromatography and contained either a single class of enzymatic activity (i.e., L-amino acid oxidases or Hyaluronidases) or different activities co-distributed in two or more protein fractions (e.g., Metalloproteinases, Serine Proteases, or Phospholipases A2). Only three protein fractions reduced cell viability of primary human cells. Strikingly, such activity is accompanied by disruption of cell attachment to substratum and to neighbouring cells. Such strong perturbation of morphological cell features indicates likely defects in tissue integrity in vivo. Mass spectrometry identified the main classes of toxins that contribute to these phenotypes. We provide here a strategy for the selection of key cytotoxic proteins for targeted investigation of their mechanism of action and potential synergism during snakebite envenomation. Our data highlights putative toxins (or combinations of) that may be the focus of future therapeutic interference.

The challenges of abundance: epithelial junctions and small GTPase signalling.

Small GTPases of the Ras superfamily play critical roles in epithelial biogenesis. Many key morphogenetic functions occur when small GTPases act at epithelial junctions, where they mediate an increasingly complex interplay between cell-cell adhesion molecules and fundamental cellular processes, such as cytoskeletal activity, polarity and trafficking. Important recent advances in this field include the role of additional members of the Ras superfamily in cell-cell contact stability and the capacity for polarity determinants to regulate small GTPase signalling. Interestingly, small GTPases may participate in the cross-talk between different adhesive receptors: in tissues classical cadherins can selectively regulate other junctions through cell signalling rather than through a global influence on cell-cell cohesion.

Long-term efficacy and safety of neridronate treatment in patients with complex regional pain syndrome type 1: a pre-specified, open-label, extension study.

Background: No data on the permanent and curative effect of bisphosphonate treatment in patients with complex regional pain syndrome type-1 (CRPS-1) are currently available. The aim of this pre-specified, open-label, observational study was to evaluate the long-term efficacy and safety of neridronate treatment. Design: A pre-specified, open-label, extension study. Methods: Patients treated with intramuscular (IM) placebo in the double-blind phase of the study were assigned to 100 mg intravenous (IV) neridronate treatment administered 4 times over 10 days. These patients, together with those previously treated with 400 mg IM neridronate, were followed for 1 year. Efficacy was assessed using a visual analogue scale (VAS) pain score. Changes in clinical signs and symptoms, quality of life (QoL) using the Short Form Health Survey (SF-36), and the McGill Pain Questionnaire were also assessed. Results: Benefits on pain, clinical and functional measures were maintained and further improved over 12 months in most patients treated with neridronate administered either IM or IV. In IM-treated patients, the percentage of those defined as responders (VAS score reduction ≥ 50%) progressively increased up to day 360 to 32 of 35 patients (91.4%). Among the 27 patients referred to as responders at the end of the double-blind phase, 26 reported the same result at day 360 (96.3%). In IV-treated patients, a responder rate of 88% (22 out 25) was found at day 360 (p = 0.66 between groups). Consistent improvements were also observed for all clinical signs and functional questionnaire. No drug-related adverse events were reported during the study. Conclusion: In patients with acute CRPS-1, the benefit in pain, clinical, and functional measures observed a few weeks after neridronate treatment administered either IM or IV is maintained and further improved over 12 months. Parenteral neridronate induces permanent disease remission preventing chronic pain and motor dysfunction. Trial registration: EU Clinical Trials Register (EudraCT Number): 2014-001156-28.

Intrinsic cell rheology drives junction maturation.

A fundamental property of higher eukaryotes that underpins their evolutionary success is stable cell-cell cohesion. Yet, how intrinsic cell rheology and stiffness contributes to junction stabilization and maturation is poorly understood. We demonstrate that localized modulation of cell rheology governs the transition of a slack, undulated cell-cell contact (weak adhesion) to a mature, straight junction (optimal adhesion). Cell pairs confined on different geometries have heterogeneous elasticity maps and control their own intrinsic rheology co-ordinately. More compliant cell pairs grown on circles have slack contacts, while stiffer triangular cell pairs favour straight junctions with flanking contractile thin bundles. Counter-intuitively, straighter cell-cell contacts have reduced receptor density and less dynamic junctional actin, suggesting an unusual adaptive mechano-response to stabilize cell-cell adhesion. Our modelling informs that slack junctions arise from failure of circular cell pairs to increase their own intrinsic stiffness and resist the pressures from the neighbouring cell. The inability to form a straight junction can be reversed by increasing mechanical stress artificially on stiffer substrates. Our data inform on the minimal intrinsic rheology to generate a mature junction and provide a springboard towards understanding elements governing tissue-level mechanics.

Cell-cell adhesion and signalling.

Signalling pathways activated by Rho small GTPases have recently been identified that coordinate junction assembly, stability and function, as well as interactions of adhesive complexes with the underlying cortical cytoskeleton. Particularly exciting is the interplay between adherens junctions, activation of Rho proteins and the dynamics of microtubule, actin and intermediate filaments. This interplay has important implications for functional regulation of cell-cell adhesion, and points to a more integrated view of signalling processes.

Long-term effects of neridronate and its discontinuation in patients with primary hyperparathyroidism.

In patients with primary hyperparathyroidism (PHPT) not suitable for surgical correction, a skeletal protection with bisphosphonates is considered a reasonable option, but the long-term effects after treatment discontinuation are not well known. Sixty postmenopausal women with PHPT were given 400-600 IU vitamin D(3) daily and 100 mg neridronate IV every 2 months for 2 years with 2 additional years of follow-up without antiresorptive therapies. Bone mineral density (BMD) progressively rose by 6.7 ± 7.6% (SD) and by 2.9 ± 4.5% at the spine and femoral neck, respectively. During follow-up, mean BMD progressively fell, but after 2 years it was still 3.9 ± 5.5% higher than baseline values at the spine. Bone alkaline phosphatase and serum C-telopeptide of type I collagen decreased significantly within 6 months (28 and 49% versus baseline, respectively) and rose to baseline values within 6-12 months during follow-up. Serum PTH significantly rose from baseline during treatment, but it remained significantly higher than baseline during follow-up. The PTH changes were significantly correlated with serum 25-hydroxyvitamin D (25OHD) levels. In conclusion, in this study we observed that in patients with mild PHPT treatment with bisphosphonates is associated with the expected changes in bone-turnover markers and that the significant increases of both hip and spine BMD are partially maintained for at least 2 years after treatment discontinuation at the vertebral site. The marked increases in serum PTH levels, particularly in subjects with low 25OHD levels, persist after treatment discontinuation and this raises the suspicion that this might reflect a worsening of PHPT.

Rac1-PAK1 regulation of Rab11 cycling promotes junction destabilization.

Rac1 GTPase is hyperactivated in tumors and contributes to malignancy. Rac1 disruption of junctions requires its effector PAK1, but the precise mechanisms are unknown. Here, we show that E-cadherin is internalized via micropinocytosis in a PAK1-dependent manner without catenin dissociation and degradation. In addition to internalization, PAK1 regulates E-cadherin transport by fine-tuning Rab small GTPase function. PAK1 phosphorylates a core Rab regulator, RabGDIß, but not RabGDIα. Phosphorylated RabGDIß preferentially associates with Rab5 and Rab11, which is predicted to promote Rab retrieval from membranes. Consistent with this hypothesis, Rab11 is activated by Rac1, and inhibition of Rab11 function partially rescues E-cadherin destabilization. Thus, Rac1 activation reduces surface cadherin levels as a net result of higher bulk flow of membrane uptake that counteracts Rab11-dependent E-cadherin delivery to junctions (recycling and/or exocytosis). This unique small GTPase crosstalk has an impact on Rac1 and PAK1 regulation of membrane remodeling during epithelial dedifferentiation, adhesion, and motility.

Intramuscular neridronate for the treatment of complex regional pain syndrome type 1: a randomized, double-blind, placebo-controlled study.

BACKGROUND: Complex regional pain syndrome type-1 (CRPS-1) is a severely disabling painful disease challenging to treat. This multicenter, randomized, double-blind placebo-controlled trial examined the efficacy of intramuscular (i.m.) neridronate in CRPS-1 patients. METHODS: A total of 78 patients diagnosed with CRPS-1 (aged 59.5 ± 10.3, 66.7% female) were randomly assigned to 25 mg (i.m.) neridronate (N = 41) given once daily for 16 consecutive days or placebo control (N = 37). Efficacy was assessed after 30 days using a visual analogue scale (VAS) pain score and the number of patients achieving ⩾50% reduction in VAS score. Change in clinical signs and symptoms, quality of life (QoL) using Short Form Health Survey (SF-36) and the McGill Pain Questionnaire were also assessed. RESULTS: After 30 days, VAS score decreased significantly to a greater extent in neridronate-treated patients versus placebo (31.9 ± 23.3 mm versus 52.3 ± 27.8 mm, p = 0.0003). Furthermore, the proportion of patients achieving a VAS reduction of ⩾50% was greater in the neridronate group (65.9% versus 29.7%, p = 0.0017). Clinical signs and symptoms were improved significantly in the neridronate group versus placebo for edema (72.5% versus 79.9%, p = 0.03), pain during motion (70% versus 83.3%, p = 0.0009), allodynia (20% versus 63.3%, p = 0.0004), and hyperalgesia (20% versus 56.7%, p = 0.0023). Whereas no difference was observed for QoL measures using the SF-36 questionnaire, three of the four pain variables using the McGill Pain Questionnaire improved significantly in the neridronate group. No serious drug-related adverse events were reported during the study. CONCLUSION: In patients with acute CRPS-1, i.m. injections of 25 mg neridronate were associated with clinically relevant benefit compared with placebo controls. TRIAL REGISTRATION: EU Clinical Trials Register: https://www.clinicaltrialsregister.eu/ctr-search/search?query=2014-001156-28.

Effect of neridronate in osteopenic patients after heart, liver or lung transplant: a multicenter, randomized, double-blind, placebo-controlled study.

BACKGROUND: Transplantation (Tx) is an effective therapeutic option in patients with end-stage organ failure and osteoporosis and related fractures are a recognized complication in these patients. Aim of this study was to evaluate the efficacy of neridronate in patients with reduced bone mass after Tx of the heart, liver or lung. METHODS: In this multicenter randomized double-blind controlled trial (RCT), 22 patients were treated with neridronate (25 mg i.m./month) and 17 received placebo. All patients received daily oral calcium (500 mg) and vitamin D (400 IU). Dual-energy X-ray absorptiometry (DXA) was evaluated at 0, 6 and 12 months and markers of bone turnover at 0, 3, 6, 9 and 12 months. RESULTS: Thirty-nine patients (11 heart Tx, 21 liver Tx, 7 lung Tx), aged 49.3±9.1 years, with a T-score <-2.0 SD at lumbar spine or femoral level were included. In neridronate-treated patients, a significant increase in lumbar bone mineral density (BMD) was observed after 12 months vs. placebo control (0.92±0.13 g/cm2 vs. 0.84±0.08 g/cm2; P=0.005). Femur and hip BMD remained unchanged between groups. Total alkaline phosphatase, bone alkaline phosphatase and beta-cross-laps significantly decreased over the 12 months in neridronate-treated patients vs. placebo, respectively (107.4±74 U/L vs. 157.6±107.1 U/L, P=0.002; 5.7±3.3 µg/L vs. 11.7±4.3 µg/L, P<0.001 and 0.25±0.13 ng/mL vs. 0.73±0.57 ng/mL, P<0.001). No difference was observed between neridronate and placebo groups regarding safety profile. CONCLUSIONS: This is the first RCT that demonstrates the efficacy of neridronate in increasing bone density and reducing bone turnover in organ Tx recipients with significant skeletal morbidity.