Assessment of bone turnover and bone quality in type 2 diabetic bone disease： current concepts and future directions

Substantial evidence exists that in addition to the well-known complications of diabetes, increased fracture risk is an important morbidity. This risk is probably due to altered bone properties in diabetes. Circulating biochemical markers of bone turnover have been found to be decreased in type 2 diabetes （T2D） and may be predictive of fractures independently of bone mineral density （BMD）. Serum sclerostin levels have been found to be increased in T2D and appear to be predictive of fracture risk independent of BMD. Bone imaging technologies, including trabecular bone score （TBS） and quantitative CT testing have revealed differences in diabetic bone as compared to non-diabetic individuals. Specifically, high resolution peripheral quantitative CT （HRpQCT） imaging has demonstrated increased cortical porosity in diabetic postmenopausal women. Other factors such as bone marrow fat saturation and advanced glycation endproduct （AGE） accumulation might also relate to bone cell function and fracture risk in diabetes. These data have increased our understanding of how T2D adversely impacts both bone metabolism and fracture risk.

Burden of bone disease in chronic pancreatitis:A systematic review and meta-analysis

BACKGROUND Bone disease is an under-recognized cause of morbidity in chronic pancreatitis(CP).Over the past decade,publications of original studies on bone disease in CP has warranted synthesis of the evidence to ascertain the true burden of the problem.AIM To quantify the prevalence of osteopenia,osteoporosis,and fragility fractures in CP patients and investigate the associated clinical features and outcomes.METHODS A systematic search identified studies investigating bone disease in CP patients from Cochrane Library,Embase,Google Scholar,Ovid Medline,PubMed,Scopus,and Web of Science,from inception until October 2022.The outcomes included prevalence of osteopenia,osteoporosis,and fragility fractures,which were metaanalyzed using a random-effects model and underwent metaregression to delineate association with baseline clinical features.RESULTS Twenty-one studies were included for systematic review and 18 studies were included for meta-analysis.The pooled prevalence of osteopenia and osteoporosis in CP patients was 41.2%(95%CI:35.2%-47.3%)and 20.9%(95%CI:14.9%-27.6%),respectively.The pooled prevalence of fragility fractures described among CP was 5.9%(95%CI:3.9%-8.4%).Metaregression revealed significant association of pancreatic enzyme replacement therapy(PERT)use with prevalence of osteoporosis[coefficient:1.7(95%CI:0.6-2.8);P<0.0001].We observed no associations with mean age,sex distribution,body mass index,alcohol or smoking exposure,diabetes with prevalence of osteopenia,osteoporosis or fragility fractures.Paucity of data on systemic inflammation,CP severity,and bone mineralization parameters precluded a formal metaanalysis.CONCLUSION This meta-analysis confirms significant bone disease in patients with CP.Other than PERT use,we observed no patient or study-specific factor to be significantly associated with CP-related bone disease.Further studies are needed to identify confounders,at-risk population,and to understand the mechanisms of CP-related bone disease and the implications of treatment response.

Epigenetic regulation by long noncoding RNAs in osteo-/adipogenic differentiation of mesenchymal stromal cells and degenerative bone diseases

Bone is a complex tissue that undergoes constant remodeling to maintain homeostasis,which requires coordinated multilineage differentiation and proper proliferation of mesenchymal stromal cells(MSCs).Mounting evidence indicates that a disturbance of bone homeostasis can trigger degenerative bone diseases,including osteoporosis and osteoarthritis.In addition to conventional genetic modifications,epigenetic modifications(i.e.,DNA methylation,histone modifications,and the expression of noncoding RNAs)are considered to be contributing factors that affect bone homeostasis.Long noncoding RNAs(lncRNAs)were previously regarded as‘transcriptional noise’with no biological functions.However,substantial evidence suggests that lncRNAs have roles in the epigenetic regulation of biological processes in MSCs and related diseases.In this review,we summarized the interactions between lncRNAs and epigenetic modifiers associated with osteo-/adipogenic differentiation of MSCs and the pathogenesis of degenerative bone diseases and highlighted promising lncRNA-based diagnostic and therapeutic targets for bone diseases.

Surgical treatment of metastatic bone disease of the distal extremities

Metastatic bone disease of the distal extremities,also known as acrometastasis,is very rare.Thus,there is very limited information regarding the clinical manifestations and methods of surgical treatment.The current available literature shows that acrometastases are often encountered in the context of advanced disease and are thus associated with poor patient survival.As metastatic bone disease is generally uncurable,the goal of surgical treatment is to provide the patient with good function with as few complications as possible.In this article,we discuss the clinical manifestation of acrometastases,the methods of surgical intervention,and the expected clinical outcome.Non-surgically managed pathological fractures generally remain ununited;therefore,conservative treatment is reserved for patients with poor general condition or dismal prognosis.The current evidence suggests that in lesions of the lower arm and leg,osteosynthesis(plate and screw fixation or intramedullary nail)is the most common method of reconstruction,whereas local excision or amputation are more commonly used in cases of more distal lesions(such as ankle,foot and hand).Following surgery most patients receive adjuvant radiotherapy,even though its role is poorly documented.Close collaboration between orthopedic surgeons and medical oncologists is necessary to improve patient care and treatment outcome.Further studies are needed in order to provide stronger clinical evidence and improve decision-making,in an effort to optimize the patients’quality of life and avoid the need for revision surgery.

Significance of preoperative peripheral blood neutrophil-lymphocyte ratio in predicting postoperative survival in patients with multiple myeloma bone disease

BACKGROUND The neutrophil-lymphocyte ratio(NLR)is often used to predict a poor prognosis in patients with tumors.This study investigated the preoperative peripheral blood NLR in predicting postoperative survival(POS)in patients with multiple myeloma bone disease(MMBD).AIM To evaluate whether NLR can be used to predict the prognosis of MMBD patients after surgery.METHODS The clinical data of 82 MMBD patients who underwent surgical treatments in Beijing Chao-yang Hospital were collected.The NLR was obtained from the absolute number of neutrophils and lymphocytes,calculated by the number of neutrophils and divided by the number of lymphocytes.The peripheral blood lymphocyte percentage was used as the major marker to analyze the change in characteristics of the immune statuses of multiple myeloma patients.RESULTS The NLR cut-off values of NLR≥3 patients and NLR≥4 patients were significantly correlated with POS.The 3-and 5-year cumulative survival rates of the high NLR group(NLR≥3 patients)were 19.1%and 0.0%,respectively,which were lower than those of the low NLR group(NLR<3 patients)(67.2%and 48.3%)(P=0.000).In the high NLR group,POS(14.86±14.28)was significantly shorter than that in the low NLR group(32.68±21.76).Univariate analysis showed that the lymphocyte percentage 1 wk after the operation(19.33±9.08)was significantly lower than that before the operation(25.72±11.02).Survival analysis showed that postoperative chemotherapy,preoperative performance status and preoperative peripheral blood NLR≥3 were independent risk factors for POS.CONCLUSION The preoperative peripheral blood NLR can predict POS in MMBD patients.MMBD patients with a high preoperative NLR(NLR≥3)showed poor prognosis.

Long-Term Efficacy of Parathyroidectomy onHyperparathyroid Bone Disease

This is a retrospective analysis of long-term efficacy of parathyroidectomy on hyperparathyroid bone disease. The clinical manifestations, bone structure, and bone mineral density in 16 patients averaged 5.1 (1. 0-10. 5) years after parathyroidectomy were assessed. The results showed that although the bone disease could be markedly relieved after surgery, yet at terminal point of follow-up, 10/16 cases (62. 5% ) got incomplete recovery of bone disease, the ratio of incomplete recovery in Y1 group with severe bone disease was higher than that of Y2 group with mild bone disease (P <0. 05). The concentrations of serum BGP and morning void urine pyridinoline were within the refer ence ranges of young and middle aged controls. These imply that the osteoblastic and osteoclastic activities had reached a balancing state. The results suggested that hyperparathyroid patients should be operated on as early as possible, and intensively followed up after operation. subsequent therapy should be given to patients with incomplete recovery of bone disease.

Vanishing bone disease(Gorham-Stout syndrome): A review of a rare entity

Vanishing bone disease(Gorham-Stout syndrome) is a rare entity of unknown etiology, characterized by de struction of osseous matrix and proliferation of vascula structures, resulting in destruction and absorption o bone. Despite the extensive investigation of the patho genetic mechanisms of the disease, its etiology hasn'been clarified and several theories exist. The syndrome can affect one or multiple bones of the patient, includ ing the skull, the upper and lower extremities, the spine and pelvis. The clinical presentation of a patient suffer ing from vanishing bone disease includes, pain, func tional impairment and swelling of the affected region although asymptomatic cases have been reported, as well as cases in which the diagnosis was made after a pathologic fracture. In this short review we summarize the theories regarding the etiology as well as the clini cal presentation, the diagnostic approach and treat ment options of this rare disease.

Multiple myeloma mesenchymal stromal cells: Contribution to myeloma bone disease and therapeutics

Multiple myeloma is a hematological malignancy inwhich clonal plasma cells proliferate and accumulate within the bone marrow. The presence of osteolytic le-sions due to increased osteoclast(OC) activity and sup-pressed osteoblast(OB) function is characteristic of the disease. The bone marrow mesenchymal stromal cells(MSCs) play a critical role in multiple myeloma patho-physiology, greatly promoting the growth, survival, drug resistance and migration of myeloma cells. Here, we specifically discuss on the relative contribution of MSCs to the pathophysiology of osteolytic lesions in light of the current knowledge of the biology of my-eloma bone disease(MBD), together with the reported genomic, functional and gene expression differences between MSCs derived from myeloma patients(pMSCs) and their healthy counterparts(dMSCs). Being MSCs the progenitors of OBs, pMSCs primarily contribute to the pathogenesis of MBD because of their reduced osteogenic potential consequence of multiple OB inhibi-tory factors and direct interactions with myeloma cells in the bone marrow. Importantly, pMSCs also readily contribute to MBD by promoting OC formation and ac-tivity at various levels(i.e., increasing RANKL to OPG expression, augmenting secretion of activin A, uncou-pling ephrinB2-EphB4 signaling, and through augment-ed production of Wnt5a), thus further contributing to OB/OC uncoupling in osteolytic lesions. In this review, we also look over main signaling pathways involved in the osteogenic differentiation of MSCs and/or OB activity, highlighting amenable therapeutic targets; in parallel, the reported activity of bone-anabolic agents(at preclinical or clinical stage) targeting those signaling pathways is commented.

Bone disease in chronic pancreatitis

Bone disease(osteopenia or osteoporosis)is a highly prevalent condition in society and presents a tremendous,preventable public health burden.Screening procedures,such as,dual-energy X-ray absorptiometry scans,have allowed early identification and intervention to improve bone health,and reduce the risk of osteoporotic fractures,which carry significant morbidity and mortality.The association of bone disease has been recognized in several diseases of the gastrointestinal tract,resulting in established guidelines for screening in patients with malabsorptive disorders such as inflammatory bowel disease and celiac disease.Increasingly,the risk of bone disease has been recognized in patients with chronic pancreatitis(CP),who share similar risk factors as patients with other high gastrointestinal disorders.As a result,there have been a number of studies examining the prevalence and risks of bone disease and fractures in patients with CP.This review aims to summarize the recent literature and current recommendations related to bone disease in CP.

Bone disease in pediatric idiopathic hypercalciuria

Idiopathic hypercalciuria （IH） is the leading metabolic risk factor for urolithiasis and affects all age groups without gender or race predominance. IH has a high morbidity with or without lithiasis and reduced bone mineral density （BMD）, as described previously in pe-diatric patients as well as in adults. The pathogenesis of IH is complex and not completely understood, given that urinary excretion of calcium is the end result of an interplay between three organs （gut, bone and kidney）, which is further orchestrated by hormones, such as 1,25 dihydroxyvitamin D, parathyroid hormone, calcitonin and fosfatonins （i.e., fbroblast growth-factor-23）. Usu-ally, a primary defect in one organ induces compensa-tory mechanisms in the remaining two organs, such as increased absorption of calcium in the gut secondary toa primary renal loss. Thus, IH is a systemic abnormality of calcium homeostasis with changes in cellular trans-port of this ion in intestines, kidneys and bones. Re-duced BMD has been demonstrated in pediatric patients diagnosed with IH. However, the precise mechanisms of bone loss or failure of adequate bone mass gain are still unknown. The largest accumulation of bone mass occurs during childhood and adolescence, peaking atthe end of the second decade of life. This accumulation should occur without interference to achieve the peak of optimal bone mass. Any interference may be a risk factor for the reduction of bone mass with increased risk of fractures in adulthood. This review will address the pathogenesis of IH and its consequence in bone mass.

Epigenetic mechanisms involved in developmental nutritional programming

The ways in which epigenetic modifications fix the effects of early environmental events,ensuring sustained responses to transient stimuli,which result in modified gene expression patterns and phenotypes later in life,is a topic of considerable interest.This review focuses on recently discovered mechanisms and calls into question prevailing views about the dynamics,position and functions of epigenetic marks.Most epigenetic studies have addressed the long-term effects on a small number of epigenetic marks,at the global or individual gene level,of environmental stressors in humans and animal models.In parallel,increasing numbers of studies based on high-throughput technologies and focusing on humans and mice have revealed additional complexity in epigenetic processes,by highlighting the importance of crosstalk between the different epigenetic marks.A number of studies focusing on the developmental origin of health and disease and metabolic programming have identified links between early nutrition,epigenetic processes and long-term illness.The existence of a self-propagating epigenetic cycle has been demonstrated.Moreover,recent studies demonstrate an obvious sexual dimorphism both for programming trajectories and in response to the same environmental insult.Despite recent progress,we are still far from understanding how,when and where environmental stressors disturb key epigenetic mechanisms.Thus,identifying the original key marks and their changes throughout development during an individual's lifetime or over several generations remains a challenging issue.

Human embryonic stem cells as an in vitro model for studying developmental origins of type 2 diabetes

The developmental origins of health and diseases(DOHaD)is a concept stating that adverse intrauterine environments contribute to the health risks of offspring.Since the theory emerged more than 30 years ago,many epidemiological and animal studies have confirmed that in utero exposure to environmental insults,including hyperglycemia and chemicals,increased the risk of developing noncommunicable diseases(NCDs).These NCDs include metabolic syndrome,type 2 diabetes,and complications such as diabetic cardiomyopathy.Studying the effects of different environmental insults on early embryo development would aid in understanding the underlying mechanisms by which these insults promote NCD development.Embryonic stem cells(ESCs)have also been utilized by researchers to study the DOHaD.ESCs have pluripotent characteristics and can be differentiated into almost every cell lineage;therefore,they are excellent in vitro models for studying early developmental events.More importantly,human ESCs(hESCs)are the best alternative to human embryos for research because of ethical concerns.In this review,we will discuss different maternal conditions associated with DOHaD,focusing on the complications of maternal diabetes.Next,we will review the differentiation protocols developed to generate different cell lineages from hESCs.Additionally,we will review how hESCs are utilized as a model for research into the DOHaD.The effects of environmental insults on hESC differentiation and the possible involvement of epigenetic regulation will be discussed.

A Blueberry Extract Supplemented Diet Partially Restores <i>α-Synuclein</i>-Dependent Lifespan Loss and Developmental Defects in Drosophila

Oxidative stress has been strongly associated with Parkinson disease (PD) aetiology. We investigated the effects of blueberry extract (BBE) supplementation on α-synuclein induced phenotypes in a Drosophila melanogaster model of PD. Enhanced α-synuclein expression in D. melanogaster dopaminergic (DA) neurons can reduce lifespan and we have performed longevity assays to measure the effects of BBE on D. melanogaster survival. Flies expressing α-synuclein in their DA neurons fed BBE had up to an 8 day, or 15%, greater median lifespan than those fed a standard control diet. In addition, BBE improved α-synuclein-induced developmental defects in the Drosophila eye. Our biometric analyses revealed that individuals fed BBE had less atypical ommatidia as well as an increased number of mechanosensory bristle cells than those fed a control diet. We propose that BBE, rich in naturally occurring antioxidants, promotes the survival of neurons in tissues with increased levels of α-synuclein through a protective cell survival mechanism.

The essential roles of m^(6)A modification in osteogenesis and common bone diseases

N6-methyladenosine(m^(6)A)is the most prevalent modification in the eukaryotic transcriptome and has a wide range of functions in coding and noncoding RNAs.It affects the fate of the modified RNA,including its stability,splicing,and translation,and plays an important role in post-transcriptional regulation.Bones play a key role in supporting and pro-tecting muscles and other organs,facilitating the movement of the organism,ensuring blood production,etc.Bone diseases such as osteoarthritis,osteoporosis,and bone tumors are serious public health problems.The processes of bone development and osteogenic differen-tiation require the precise regulation of gene expression through epigenetic mechanisms including histone,DNA,and RNA modifications.As a reversible dynamic epigenetic mark,m^(6)A modifications affect nearly every important biological process,cellular component,and molecular function,including skeletal development and homeostasis.In recent years,studies have shown that m^(6)A modification is involved in osteogenesis and bone-related diseases.In this review,we summarized the proteins involved in RNA m^(6)A modification and the latest progress in elucidating the regulatory role of m^(6)A modification in bone formation and stem cell direc-tional differentiation.We also discussed the pathological roles and potential molecular mech-anisms of m^(6)A modification in bone-related diseases like osteoporosis and osteosarcoma and suggested potential areas for new strategies that could be used to prevent or treat bone de-fects and bone diseases.

Bone diseases in rabbits with hyperparathyroidism: computed tomography, magnetic resonance imaging and histopathology

Background Hyperparathyroidism （HPT） occurs at an early age and has a high disability rate. Unfortunately, confirmed diagnosis in most patients is done at a very late stage, when the patients have shown typical symptoms and signs, and when treatment does not produce any desirable effect. It has become urgent to find a method that would detect early bone diseases in HPT to obtain time for the ideal treatment. This study evaluated the accuracy of high field magnetic resonance imaging （MRI） combined with spiral computed tomography （SCT） scan in detecting early bone diseases in HPT, through imaging techniques and histopathological examinations on an animal model of HPT. Methods Eighty adult rabbits were randomly divided into two groups with forty in each. The control group was fed normal diet （Ca：P = 1：0.7）; the experimental group was fed high phosphate diet （Ca：P = 1：7） for 3, 4, 5, or 6-month intervals to establish the animal model of HPT. The staging and imaging findings of the early bone diseases in HPT were determined by high field MRI and SCT scan at the 3rd, 4th, 5th and 6th month. Each rabbit was sacrificed after high field MRI and SCT scan, and the parathyroid and bones were removed for pathological examination to evaluate the accuracy of imaging diagnosis. Results Parathyroid histopathological studies revealed hyperplasia, osteoporosis and early cortical bone resorption. The bone diseases in HPT displayed different levels of low signal intensity on T1WI and low to intermediate signal intensity on T2WI in bone of stage 0, Ⅰ, Ⅱ or Ⅲ, but showed correspondingly absent, probable, osteoporotic and subperiosteal cortical resorption on SCT scan. Conclusion High field MRI combined with SCT scan not only detects early bone diseases in HPT, but also indicates staging, and might be a reliable method of studying early bone diseases in HPT.

MOFs and bone: Application of MOFs in bone tissue engineering and bone diseases

Metal-organic frameworks(MOFs), a class of hybrid materials, consist of organic linkers and bridging metal ions or clusters. Their tunable pore sizes, large surface area, good biocompatibility, structural variability in combination with materials and chemicals, and osteogenic effects provide potential approaches for bone tissue engineering and bone diseases. And there are more and more research on MOFs in the field of osteogenesis in recent years. This review presents an overall summary of the application in the bone tissue engineering and bone diseases of MOFs and their composites, starting with the synthesis of MOFs, which discusses the advantages and disadvantages of different syntheses. Then, the biological functions of MOFs are discussed, which are the basics of MOFs applied in the organism. Importantly,mechanisms and abundant applications of MOFs are detailed in the bone tissue engineering and bone diseases. Finally, some prospects of MOFs are discussed, for instance, exploring whether MOFs can be used to treat other bone diseases.

Paget’s disease of bone: Report of 11 cases

BACKGROUND Paget’s disease of bone(PDB)is a rare metabolic bone disease in China and is characterized by increased bone resorption and disorganized bone formation.The main clinical symptoms of PDB are focal or multiple bone pain and deformity with high disability.The disease has high missed diagnosis and misdiagnosis rates.This report summarizes the clinical manifestations,imaging and pathological features,and treatments of 11 patients with PDB at our hospital from 1993 to 2020 in order to improve the recognition and prognosis of PDB.CASE SUMMARY There were eight male and three female patients whose average age was 48.7±11.0 years with a PDB course of 1-16 years.Nine patients had bone pain and bone deformities in different parts of the body,the majority of which involved the long bones.Laboratory examinations revealed elevated serum alkaline phosphatase(ALP)in all patients with an average of 618±460 IU/L(normal range 0-130 IU/L),and serum calcium and phosphorus levels were in the normal range.Imageology showed that osteolysis was usually combined with osteosclerosis and/or bone deformities in single or multiple bones.^(99m)Tc-methylene diphosphonate bone scintigraphy revealed increased radionuclide uptake in the bone lesions.Six patients underwent bone tissue biopsy,and the typical pathological changes were a mosaic structure of the bone trabeculae with irregularly arranged cement lines and multinuclear osteoclasts.Ten of the 11 patients were effectively treated with bisphosphonates.CONCLUSION Early diagnosis of the rare disease PDB can be made through elevated ALP levels and typical presentations on bone X-ray and from bone tissue biopsy.

Pathophysiology and therapeutic advances in myeloma bone disease

Bone disease is the most common complication in patients with multiple myeloma (MM), and it may lead to skeletal-related events (SREs) such as bone pain, pathological fractures, and spinal cord compression, which impair a patients’’ quality of life and survival. The pathogenesis of myeloma bone disease (MBD) involves disruption of bone reconstitution balance including excessive activation of osteoclasts, inhibition of osteoblasts, and participation of osteocytes and bone marrow stromal cells. Various factors, such as the receptor activator of nuclear factor-κB ligand (RANKL)/osteoprotegerin (OPG), dickkopf-1 (DKK-1), sclerostin, and activin-A, are involved in the development of MBD. Bisphosphonates and the anti-RANKL antibody denosumab are currently the main treatment options for MBD, delaying the onset of SREs. Denosumab is preferred in patients with MM and renal dysfunction. Although effective drugs have been approved, antimyeloma therapy is the most important method for controlling bone disease.

FGF23 associated bone diseases

Recently,fibroblast growth factor 23(FGF23)has sparked widespread interest because of its potential role in regulating phosphate and vitamin D metabolism.In this review,we summarized the FGF superfamily,the mechanism of FGF23 on phosphate and vitamin D metabolism,and the FGF23 related bone disease.

Sino-UK Symposium on Developmental Biology and Human Diseases Held in Tsinghua

The Sino-UK Symposium on Developmental Biology and Human Diseases opened in Tsinghua May 6, 2006. TheSymposium, which ran through May 8, 2006, was hosted by the Department of Biological Sciences and Biotechnology, Tsinghua University.