Synucleinopathies are neurodegenerative diseases characterized by the presence of brain inclusions containing the pathologically aggregated protein α-synuclein (αSYN). The development of a positron emission tomography tracer to detect aggregates of misfolded αSYN would revolutionize disease monitoring and the evaluation of therapeutic efficacy. Here we present the development and preclinical in vitro and in vivo validation of [11C]MODAG-005. In vitro binding experiments demonstrate subnanomolar binding affinity to recombinant αSYN fibrils as well as to αSYN inclusions in human brain tissue. Specific binding in multiple system atrophy brain tissue was detected using autoradiography and microautoradiography, and was validated through immunostaining. In vivo, [11C]MODAG-005 shows good brain penetration, rapid clearance from brain tissue and low metabolite formation in rodents and non-human primates. In addition, a pronounced binding and a good signal-to-noise ratio were achieved in an αSYN fibril-injected rat model and in an αSYN(A30P) transgenic mouse model in correlation to the pathological load. To validate its value for therapy development, we show target engagement of the drug candidate anle138b in the brain tissues from αSYN(A30P) mouse and multiple system atrophy as well as in vivo in αSYN fibril-injected rats. Finally, our translational approach in a first-in-human patient with clinically established MSA, revealed a marked tracer binding in regions affected by αSYN pathology, particularly in the striatum, where the pattern corresponded with the neurodegeneration shown by dopamine transporter single-photon emission computed tomography.

Misfolded α-synuclein (αSyn) is the hallmark of α-synucleinopathies such as Parkinson's disease (PD), dementia with Lewy bodies (DLB), and multiple system atrophy (MSA). While seed amplification assays (SAA) have demonstrated ultrasensitive detection of misfolded αSyn, they have been primarily used reliably to provide binary (positive/negative) results for diagnostic purposes. We developed an SAA with enhanced specificity for Lewy-fold α-synucleinopathies and introduced a quantifiable measure correlating with clinical severity. Cerebrospinal fluid (CSF) of 170 patients with neurodegenerative diseases and controls was analyzed. Blinded measurements demonstrated 97.8% sensitivity and 100% specificity for Lewy-fold α-synucleinopathies, correctly identifying PD and DLB while excluding MSA. In addition, we validated the strain specificity of the assay by testing brain homogenates from 30 neuropathologically confirmed cases. A novel Lewy-fold pathology (LFP) score based on positive signals in a dilution series provided a quantitative measure of αSyn seeds. The LFP score significantly correlated with motor and cognitive impairment presented by Hoehn and Yahr stage, MDS-UPDRS III, and MoCA. Longitudinal tracking in seven PD cases showed progressive LFP score increases corresponding with clinical deterioration, highlighting the assay's potential for monitoring disease progression at an individual level. Our Lewy-fold-specific SAA enhances ante-mortem diagnosis and differentiates Lewy-fold α-synucleinopathies from MSA. Unlike previous assays, the LFP score offers a quantitative assessment, showing promise as a progression marker and pharmacodynamic biomarker for αSyn-targeting therapies. This represents an important step toward developing an αSyn SAA that could help to track disease progression quantitatively, with potential applications in both clinical diagnostics and therapeutic trials.

Urban planning is a complex field that requires the integration of diverse skills, knowledge, and perspectives. Engaging the public in this process promises to achieve high acceptance for resulting endeavors but poses significant challenges, particularly due to the varying levels of technical and artistic skills among participants. Moreover, discussions and collaborative efforts in urban planning often lack practical visualization tools, making it difficult to imagine and debate future urban scenarios. Generative Artificial Intelligence (GenAI) has emerged as a promising technology capable of bridging these gaps. GenAI can generate natural language output and visual content from textual descriptions, offering a novel way to facilitate more inclusive and productive participation in urban planning processes. In this paper, we explore the application of GenAI in a participatory urban planning event utilizing the novel Prompt-a-thon format. We conducted a study involving 64 participants who utilized GenAI in small groups to envision, design, and discuss the future urban landscape of the metropolitan city of Hamburg in Germany. Through this process, we examined the human-AI collaboration, assessing the technology's ability to accommodate varying skills and improve visualization in planning discussions. Our findings indicate that GenAI contributes to leveling diverse skill sets of participants, enabling more people to contribute insights into urban planning discussions. The technology also proved effective in overcoming visualization barriers, thus facilitating more engaging and fruitful discussions about future urban scenarios. These results underscore the potential of GenAI as a valuable tool in the evolving landscape of urban planning and public participation.

Tumor-induced osteomalacia (TIO) poses a significant diagnostic challenge, leading to increased disease duration and patient burden also by missing clinical suspicion. Today, diagnosis of osteomalacia relies on invasive iliac crest biopsy, if needed. Therefore, a noninvasive method would be beneficial for patients with severe osteomalacia, such as TIO, to inform their clinical management and address specific needs, like estimating the regeneration capacity at high osteoid volumes (OVs) or the potential of a hungry bone syndrome after tumor removal. Furthermore, given the lack of comprehensive histological characterization of TIO, there is a need for additional tissue characterization. Therefore, our assessment encompassed iliac crest biopsies that were examined using quantitative electron backscattered microscopy, Raman spectroscopy, micro-computed tomography, and histology to analyze the biopsy tissue. Our clinical assessment encompassed DXA and high-resolution peripheral quantitative computed tomography (HR-pQCT) alongside with biochemical analyses and clinical evaluations. Combining imaging and clinical data, we established a model to predict the OV. We compared 9 TIO patients with 10 osteoporosis (OPO) patients and 10 healthy controls. Histological analyses confirmed a pronounced OV in TIO patients (OPO: 1.20% ± 1.23% vs TIO: 23.55% ± 12.23%, P < .0005), and spectroscopy revealed lower phosphate levels in TIO biopsies. By combining HR-pQCT and laboratory diagnostics, we developed a linear regression model to noninvasively predict the OV revealing significantly higher modeled OV/BVmodel values of 24.46% ± 14.22% for TIO compared to the control group (5.952% ± 3.44%, P ≤ .001). By combining laboratory diagnostics, namely, ALP and Tt.BMDRadius measured by HR-pQCT, we achieved the calculation of the virtual osteoid volume to bone volume ratio (OV/BVmodel) with a significant correlation to histology as well as reliable identification of TIO patients compared to OPO and control. This novel approach is potentially helpful for predicting OV by noninvasive techniques in diagnostic procedures and improving the clinical management of TIO.

The high occurrence of distal fibula fractures among older women suggests a potential link to impaired bone health. Here we used a multiscale imaging approach to investigate the microarchitecture, mineralization, and biomechanics of the human distal fibula in relation to age and sex. Micro-computed tomography was performed to analyze the local volumetric bone mineral density and various microarchitectural parameters of the trabecular and the cortical compartment. Bone mineral density distribution and osteocyte lacunar parameters were quantified using quantitative backscattered electron imaging in periosteal, endocortical, and trabecular regions. Additionally, cortical hardness and Young's modulus were assessed by nanoindentation. While cortical porosity strongly increased with age independent of sex, trabecular microarchitecture remained stable. Notably, nearly half of the specimens showed non-bony hypermineralized tissue located at the periosteum, similar to that previously detected in the femoral neck, with no consistent association with advanced age. Independent of this finding, cortical and trabecular mineralization, i.e., mean calcium content, as well as endocortical tissue hardness increased with age in males but not females. Importantly, we also observed mineralized osteocyte lacunae that increased with age specifically in females. In conclusion, our results indicate that skeletal aging of the distal fibula is signified not only by pronounced cortical porosity but also by an increase in mineralized osteocyte lacunae in females. These findings may provide an explanation for the increased occurrence of ankle fractures in older women.

There is still limited understanding of the microstructural reasons for the higher susceptibility to fractures in individuals with type 2 diabetes mellitus (T2DM). In this study, we examined bone mineralization, osteocyte lacunar parameters, and microhardness of the femoral neck trabeculae in 18 individuals with T2DM who sustained low-energy fracture (T2DMFx: 78 +/- 7 years, 15 women and 3 men) and 20 controls (74 +/- 7 years, 16 women and 4 men). Femoral necks of the T2DMFx subjects were obtained at a tertiary orthopedic hospital, while those of the controls were collected at autopsy. T2DMFx individuals had lower trabecular microhardness (P = .023) and mineralization heterogeneity (P = .001), and a tendency to a lower bone area with mineralization above 95th percentile (P = .058) than the controls. There were no significant intergroup differences in the numbers of osteocyte lacunae per bone area, mineralized lacunae per bone area, and total lacunae per bone area (each P > .05). After dividing the T2DMFx group based on the presence of vascular complications (VD) to T2DMFx(VD) (VD present) and T2DMFx(NVD) (VD absent), we observed that microhardness was particularly reduced in the T2DMFx(VD) group (vs. control group, P = .02), while mineralization heterogeneity was significantly reduced in both T2DMFx subgroups (T2DMFx(NVD) vs. control, P = .002; T2DMFx(VD) vs. control, P = .038). The observed changes in mineralization and microhardness may contribute to the increased hip fracture susceptibility in individuals with T2DM.

ABSTRACT Type 2 diabetes mellitus (T2DM) is a metabolic disease affecting bone tissue and leading to increased fracture risk in men and women, independent of bone mineral density (BMD). Thus, bone material quality (i.e., properties that contribute to bone toughness but are not attributed to bone mass or quantity) is suggested to contribute to higher fracture risk in diabetic patients and has been shown to be altered. Fracture toughness properties are assumed to decline with aging and age‐related disease, while toughness of human T2DM bone is mostly determined from compression testing of trabecular bone. In this case‐control study, we determined fracture resistance in T2DM cortical bone tissue from male individuals in combination with a multiscale approach to assess bone material quality indices. All cortical bone samples stem from male nonosteoporotic individuals and show no significant differences in microstructure in both groups, control and T2DM. Bone material quality analyses reveal that both control and T2DM groups exhibit no significant differences in bone matrix composition assessed with Raman spectroscopy, in BMD distribution determined with quantitative back‐scattered electron imaging, and in nanoscale local biomechanical properties assessed via nanoindentation. Finally, notched three‐point bending tests revealed that the fracture resistance (measured from the total, elastic, and plastic J‐integral) does not significantly differ in T2DM and control group, when both groups exhibit no significant differences in bone microstructure and material quality. This supports recent studies suggesting that not all T2DM patients are affected by a higher fracture risk but that individual risk profiles contribute to fracture susceptibility, which should spur further research on improving bone material quality assessment in vivo and identifying risk factors that increase bone fragility in T2DM. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Hypophosphatasia (HPP) is characterized by severe skeletal symptoms including mineralization defects, insufficiency fractures, and delayed facture healing or non-unions. HPP is caused by mutations of the tissue nonspecific alkaline phosphatase (TNSALP). Zinc is a cofactor of TNSALP and vitamin D an important regulator of bone matrix mineralization. Data from this retrospective study indicates that deficiencies in zinc or vitamin D occur in HPP patients with a similar frequency as in the general population. While guidelines for repletion of these micronutrients have been established for the general population, the transferability of the efficacy and safety of these regiments to HPP patients still needed to be determined. We filtered for variant classification (ACMG 3-5, non-benign) and data completeness from a total cohort of 263 HPP patients. 73.5 % of this subcohort were vitamin D deficient while 27.2 % were zinc deficient. We retrospectively evaluated the effect of supplementation according to general guidelines in 10 patients with zinc-deficiency and 38 patients with vitamin D-deficiency. The treatments significantly raised serum zinc or vitamin D levels respectively. All other assessed disease markers (alkaline phosphatase, pyrodoxal-5-phosphate) or bone turnover markers (phosphate, calcium, parathyroid hormone, bone specific alkaline phosphatase, creatinine, desoxypyridinoline) remained unchanged. These results highlight that general guidelines for zinc and vitamin D repletion can be successfully applied to HPP patients in order to prevent deficiency symptoms without exacerbating the disease burden or causing adverse effects due to changes in bone and calcium homeostasis.

Bone encompasses a complex arrangement of materials at different length scales, which endows it with a range of mechanical, chemical, and biological capabilities. Changes in the microstructure and characteristics of the material, as well as the accumulation of microcracks, affect the bone fracture properties. In this study, two-dimensional finite element models of the microstructure of cortical bone were considered. The eXtended Finite Element Method (XFEM) developed by Abaqus software was used for the analysis of the microcrack propagation in the model as well as for local sensitivity analysis. The stress-strain behavior obtained for the different introduced models was substantially different, confirming the importance of bone tissue microstructure for its failure behavior. Considering the role of interfaces, the results highlighted the effect of cement lines on the crack deflection path and global fracture behavior of the bone microstructure. Furthermore, bone micromorphology and areal fraction of cortical bone tissue components such as osteons, cement lines, and pores affected the bone fracture behavior; specifically, pores altered the crack propagation path since increasing porosity reduced the maximum stress needed to start crack propagation. Therefore, cement line structure, mineralization, and areal fraction are important parameters in bone fracture. The parameter-wise sensitivity analysis demonstrated that areal fraction and strain energy release rate had the greatest and the lowest effect on ultimate strength, respectively. Furthermore, the component-wise sensitivity analysis revealed that for the areal fraction parameter, pores had the greatest effect on ultimate strength, whereas for the other parameters such as elastic modulus and strain energy release rate, cement lines had the most important effect on the ultimate strength. In conclusion, the finding of the current study can help to predict the fracture mechanisms in bone by taking the morphological and material properties of its microstructure into account.

Hypophosphatasia (HPP) is an inborn disease that causes a rare form of osteomalacia, a mineralization disorder affecting mineralized tissues. Identification of patients at high risk for fractures or other skeletal manifestations (such as insufficiency fractures or excessive bone marrow edema) by bone densitometry and laboratory tests remains clinically challenging. Therefore, we examined two cohorts of patients with variants in the ALPL gene grouped by bone manifestations. These groups were compared by means of bone microarchitecture using high-resolution peripheral quantitative computed tomography (HR-pQCT) and simulated mechanical performance utilizing finite element analysis (FEA). Whereas the incidence of skeletal manifestations among the patients could not be determined by dual energy X-ray absorptiometry (DXA) or laboratory assessment, HR-pQCT evaluation showed a distinct pattern of HPP patients with such manifestations. Specifically, these patients had a pronounced loss of trabecular bone mineral density, increased trabecular spacing, and decreased ultimate force at the distal radius. Interestingly, the derived results indicate that the non-weight-bearing radius is superior to the weight-bearing tibia in identifying deteriorated skeletal patterns. Overall, the assessment by HR-pQCT appears to be of high clinical relevance due to the improved identification of HPP patients with an increased risk for fractures or other skeletal manifestations, especially at the distal radius.

In-vivo bone microstructure measured by high-resolution peripheral quantitative computed tomography (HR-pQCT) is gaining importance in research and clinical practice. Second-generation HR-pQCT (XCT2) shows improved image quality and shorter measurement duration compared to the first generation (XCT1). Predicting and understanding the occurrence of motion artifacts is crucial for clinical practice. We retrospectively analyzed data from HR-pQCT measurements at the distal radius and tibia of 1,000 patients (aged 20 to 89) evenly distributed between both generations of HR-pQCT. Motion artifacts were graded between 1 (no motion) and 5 (severe motion), with grades greater 3 considered unusable. Additionally, baseline characteristics and patients’ muscle performance and balance were measured. Various group comparisons between the two generations of HR-pQCT and regression analyses between patient characteristics and motion grading were performed. The study groups of XCT1 and XCT2 did not differ by age (XCT1: 64.9 vs. XCT2: 63.8 years, p = 0.136), sex (both 74.5% females, p > 0.999), or BMI (both 24.2 kg/m 2 , p = 0.911) after propensity score matching. XCT2 scans exhibited significantly lower motion grading in both extremities compared to XCT1 (Radius: p < 0.001; Tibia: p = 0.002). In XCT2 motion-corrupted scans were more than halved at the radius (XCT1: 35.3% vs. XCT2: 15.5%, p < 0.001), and at the tibia the frequency of best image quality scans was increased (XCT1: 50.2% vs. XCT2: 63.7%, p < 0.001). The strongest independent predictor for motion-corrupted images is the occurrence of high motion grading at the other scanning site during the same consultation. The association between high motion grading in one scan and a corresponding high motion grading in another scan within the same session suggests a non-resting patient. Additionally, aged, female, and patients with smaller stature tend towards higher motion grading, requiring special attention to a correct extremity fixation.

Background: Several fibula-based reconstruction techniques have been introduced to address ligamentous injuries of the posterolateral corner of the knee. These techniques involve a drill tunnel with auto- or allograft placement through the proximal fibula. Purpose: To determine the skeletal microarchitecture of the proximal fibula and its association with age and to compare the microarchitecture within the regions of different drill tunnel techniques for reconstruction of the posterolateral corner. Study Design: Descriptive laboratory study. Methods: A total of 30 human fibulae were analyzed in this cadaveric imaging study. High-resolution peripheral quantitative computed tomography measurements were performed in a 4.5 cm–long volume of interest at the proximal fibula. Three-dimensional microarchitectural data sets of cortical and trabecular compartments were evaluated using customized scripts. The quadrants representing the entry and exit drill tunnel positions corresponding to anatomic techniques (LaPrade/Arciero) and the Larson technique were analyzed. Linear regression models and group comparisons were applied. Results: Trabecular microarchitecture parameters declined significantly with age in women but not men. Analysis of subregions with respect to height revealed stable cortical and decreasing trabecular values from proximal to distal in both sexes. Along with a structural variability in axial slices, superior values were found for the densitometric and microarchitectural parameters corresponding to the fibular drill tunnels in the anatomic versus Larson technique (mean ± SD; bone volume to tissue volume at the entry position, 0.273 ± 0.079 vs 0.175 ± 0.063; P < .0001; cortical thickness at the entry position, 0.501 ± 0.138 vs 0.353 ± 0.081 mm; P < .0001). Conclusion: Age represented a relevant risk factor for impaired skeletal microarchitecture in the proximal fibula in women but not men. The region of drill tunnels according to anatomic techniques showed superior bone microarchitecture versus that according to the Larson technique.

Due to the commonality of a mineralized tissue both in the case of bone (mineralized osteoid) and atherosclerosis (mineralization in the area of the endothelium during chronic inflammatory) and related biochemical mechanisms, a connection between atherosclerosis and bone structure and mineralization has been suspected for some time. Decreasing bone density has been shown to occur parallel to a occurrence of atherosclerosis. High-resolution peripheral quantitative computed tomography (HR-pQCT) offers the opportunity to detect and quantify the calcification of the lower leg arteries within the scan volume. Calcifications of the lower leg arteries (LLAC) occur in 32.6 % of patients without underlying disease. In female patients without underlying disease, in contrast to men, a concomitant decrease in specific cortical and trabecular HR- pQCT parameters was observed with an increased occurrence of LLAC. In CKD, a cortical bone loss can be observed simultaneously with the occurrence of LLAC, with CKD patients with LLAC showing significantly reduced values compared to CKD patients without LLAC. Hypoparathyroidism also shows an accumulation of LLAC in HR-pQCT compared to a control group. Therefore, the influence of a disbalance of the calcium homeostasis on the mineralization of both tissues becomes apparent. This article presents the previous findings and correlations of atherosclerosis with osteological aspects in terms of bone microstructure and other parameters.

Zusammenfassung Aufgrund der Gemeinsamkeit eines mineralisierten Gewebes sowohl im Falle des Knochens (mineralisiertes Osteoid) als auch bei Arteriosklerose (Mineralisation im Bereich des Endothels bei chronischer Entzündungsreaktion) und verwandter biochemischer Mechanismen wird seit geraumer Zeit ein Zusammenhang zwischen Arteriosklerose und der Knochenstruktur und -mineralisation vermutet. Eine abnehmende Knochendichte in der Knochendichtemessung (DXA) konnte parallel zu einem gehäuften Auftreten einer Arteriosklerose gezeigt werden, eine Kausalität konnte bis heute nicht geklärt werden. Die hochauflösende, periphere, quantitative Computertomographie (HR-pQCT) bietet die Möglichkeit die Kalzifikation der Arterien der unteren Extremität im Scanvolumen zu detektieren und quantifizieren. Hierbei treten Gefäßkalzifikationen nebenbefundlich in Abhängigkeit der Grunderkrankung bei 32,6% der Patienten ohne Grunderkrankung auf. Bei weiblichen Patient:innen ohne Grunderkrankung konnte im Gegensatz zu Männern eine gleichzeitige Abnahme einzelner kortikaler und trabekulärer HR-pQCT-Parameter bei vermehrtem Auftreten einer LLAC beobachtet werden. Bei einer CKD lässt sich parallel zum vermehrten Auftreten einer LLAC ein kortikales Knochenstrukturverlustsyndrom feststellen, wobei CKD-Patienten mit LLAC signifikant geminderte Werte im Vergleich zu CKD-Patienten ohne LLAC aufwiesen. Auch beim Hypoparathyreoidismus zeigen sich eine Häufung der LLAC im HR-pQCT im Vergleich zu einer Kontrollgruppe. Somit zeigt sich der Einfluss einer Dysbalance der Calciumhomöostase auf die Mineralisation beider Gewebe und unterstreicht die hohe Bedeutung einer Balancierung der Calciumhomöostase. Dieser Artikel stellt die bisherigen Erkenntnisse und Zusammenhänge der Arteriosklerose mit osteologischen Aspekten im Sinne der Knochenmikrostruktur und weiterer Parameter vor.

BACKGROUND:Synucleinopathies such as Parkinson ́s disease (PD), Dementia with Lewy bodies (DLB) and Multiple System Atrophy (MSA) are characterized by deposition of misfolded and aggregated α-synuclein. Small aggregates (oligomers) of α-synuclein have been shown to be the most relevant neurotoxic species and are targeted by anle138b, an orally bioavailable small molecule compound which shows strong disease-modifying effects in animal models of synucleinopathies.METHODS:Anle138b was studied in a single-centre, double-blind, randomised, placebo-controlled single ascending dose (SAD) and multiple ascending dose (MAD) study in healthy subjects. Eligible participants were randomly assigned (1:1 for sentinel subjects and 1:5 for main group) to placebo or anle138b (dose range 50 mg to 300 mg per day), respectively. In addition, the effect of food on the pharmakokinetics of anle138b in healthy subjects was examined in doses of 150 mg per day. Participants were randomized to treatment sequence (fed→fasted) or (fasted→fed). Treatment was administered orally in hard gelatine capsules containing either 10 mg or 30 mg of anle138b or excipient only. The primary endpoints were safety and tolerability, the secondary endpoint was pharmakokinetics. Data from all randomized individuals were evaluated.CLINICALTRIALS:gov-identifier: NCT04208152. EudraCT-number: 2019-004218-33.FINDINGS:Between December 17th, 2019 and June 27th, 2020 196 healthy volunteers were screened and 68 participants were enrolled. Of these, all completed the study per protocol. There were no major protocol deviations. Adverse events in this healthy volunteer trial were mostly mild and all fully recovered or resolved prior to discharge. From baseline to completion of the trial no medically significant individual changes were observed in any system organ class. Already at multiple doses of 200 mg, exposure levels above the fully effective exposure in the MI2 mouse Parkinson model were observed.INTERPRETATION:The favourable safety and PK profile of anle138b in doses resulting in exposures above the fully effective plasma level in a mouse Parkinson model warrant further clinical trials in patients with synucleinopathies.FUNDING:This study was funded by MODAG GmbH and by the Michael J. Fox foundation for Parkinson's Research.

Parkinson´s disease (PD) pathology progresses throughout the nervous system. Whereas motor symptoms are always present, there is a high variability in the prevalence of non-motor symptoms. It has been postulated that the progression of the pathology is based on a prion-like disease mechanism partly due to the seeding effect of endocytosed-alpha-synuclein (ASYN) on the endogenous ASYN. Here, we analyzed the role of endogenous ASYN in the progression of PD-like pathology in vivo and in vitro and compared the effect of endocytosed-ASYN as well as paraquat and rotenone on primary enteric, dopaminergic and cortical neurons from wild-type and ASYN-KO mice. Our results show that, in vivo, pathology progression did not occur in the absence of endogenous ASYN. Remarkably, the damage caused by endocytosed-ASYN, rotenone or paraquat was independent from endogenous ASYN and related to the alteration of the host´s mitochondrial membrane potential. Dopaminergic neurons were very sensitive to these noxae compared to other neuronal subtypes. These results suggest that ASYN-mitochondrial interactions play a major role in initiating the pathological process in the host neuron and endogenous ASYN is essential for the transsynaptical transmission of the pathology. Our results also suggest that protecting mitochondrial function is a valid primary therapeutic target.