Cervical HPV infection and related diseases among 149,559 women in Fujian: an epidemiological study from 2018 to 2023.

Objectives: To comprehensively analyze the epidemiological features of human papillomavirus (HPV) and HPV-related cervical diseases in females aged 35-64 years. Methods: A total of 149,559 samples of exfoliated cervical cells screened for HPV and related cervical lesions from January 2018 to December 2023 were enrolled. The prevalence of 15 high-risk and 6 low-risk HPV genotypes were detected, and the cervical cytology were analyzed. The impact of single and multiple HPV infections was characterized, and the effect of age was studied. Results: The cervix cytology was normal in 86.60% of the females, while 7.13% of the females were diagnosed with cervix inflammation, 0.60% with ASC-US, 0.22% with ASC-H, 0.72% with LSIL, 0.49% with HSIL, 0.03% with ICC. The highest median age was observed in ASC-H group with 54 years old. Females with primary school education or lower have the highest positive rates. The overall HPV prevalence was 8.60%. The relatively prevalent HPV types were HPV52, 58, 16, 39, 51. HPV16, HPV18, HPV58, HPV33 and HPV52 were the top5 predominant types in ICC patients. 17.41% females suffered from multiple HPV infection with the most frequently co-infection subtypes being HPV52, HPV58 and HPV16. The prevalence of all HPV subtypes increased with age. Multiple HPV infections accounted for a larger proportion in those aged above 55 years. The peak HPV16 prevalence was observed in ICC group in cases aged 45-49 and 55-59. The peak HPV33 prevalence was observed in younger individuals aged 40-44 who developed ICC. Conclusion: More action should be taken against HPV33 infection.

Clinical and epidemiological features of imported loiasis in Beijing: a report from patients returned from Africa.

BACKGROUND: Loiasis is one of the significant filarial diseases for people living in West and Central Africa with wide endemic area but is not seen in China. As economy booms and international traveling increase, China faces more and more imported parasitic diseases that are not endemic locally. Loiasis is one of the parasitic diseases that enter China by travelers infected in Africa. The better understanding of the clinical and laboratory features of loa loa infection will facilitate the diagnosis and treatment of loiasis in China. METHODS: The study targeted travelers who were infected with L. loa in endemic Africa regions and returned to Beijing between 2014 and 2023. Epidemiological, clinical, and biological data as well as treatment of these patients were collected. RESULTS: Total 21 cases were identified as L. loa infection based on their typical clinical manifestations and parasite finding. All cases had a history of travel to Africa for more than 6 months, most of them are the construction workers dispatched to West Africa with outdoor activities. Calabar swelling (n = 19; 90.5%) and pruritus (n = 11; 52.4%) were among the most common clinical symptoms followed by muscle pain (n = 7; 33.3%) and skin rash (n = 2; 9.5%). The adult worms were observed in the eyelid or subconjunctiva (n = 2; 9.5%) and subcutaneous tissues (n = 2; 9.5%). Although all patients presented with a high eosinophil count (> 0.52 × 109/L), only two cases displayed microfilariae in fresh venous blood and positive for filarial antigen. A cut section of adult worm was observed through biopsy on a skin nodule surrounded by lymphocytes, plasma cells and eosinophils. All subjects were positive in PCR targeting L. loa ITS-1. The constructed phylogenetic tree based on the amplified ITS-1 sequences identified their genetical relation to the L. Loa from Africa. All patients treated with albendazole and diethylcarbamazine were recovered without relapse. CONCLUSION: This study provides useful information and guideline for physicians and researchers in non-endemic countries to diagnose and treat loiasis and L. loa infections acquired from endemic regions.

RanGAP1 maintains chromosome stability in limb bud mesenchymal cells during bone development.

BACKGROUND: Bone development involves the rapid proliferation and differentiation of osteogenic lineage cells, which makes accurate chromosomal segregation crucial for ensuring cell proliferation and maintaining chromosomal stability. However, the mechanism underlying the maintenance of chromosome stability during the rapid proliferation and differentiation of Prx1-expressing limb bud mesenchymal cells into osteoblastic precursor cells remains unexplored. METHODS: A transgenic mouse model of RanGAP1 knockout of limb and head mesenchymal progenitor cells was constructed to explore the impact of RanGAP1 deletion on bone development by histomorphology and immunostaining. Subsequently, G-banding karyotyping analysis and immunofluorescence staining were used to examine the effects of RanGAP1 deficiency on chromosome instability. Finally, the effects of RanGAP1 deficiency on chromothripsis and bone development signaling pathways were elucidated by whole-genome sequencing, RNA-sequencing, and qPCR. RESULTS: The ablation of RanGAP1 in limb and head mesenchymal progenitor cells expressing Prx1 in mice resulted in embryonic lethality, severe cartilage and bone dysplasia, and complete loss of cranial vault formation. Moreover, RanGAP1 loss inhibited chondrogenic or osteogenic differentiation of mesenchymal stem cells (MSCs). Most importantly, we found that RanGAP1 loss in limb bud mesenchymal cells triggered missegregation of chromosomes, resulting in chromothripsis of chromosomes 1q and 14q, further inhibiting the expression of key genes involved in multiple bone development signaling pathways such as WNT, Hedgehog, TGF-ß/BMP, and PI3K/AKT in the chromothripsis regions, ultimately disrupting skeletal development. CONCLUSIONS: Our results establish RanGAP1 as a critical regulator of bone development, as it supports this process by preserving chromosome stability in Prx1-expressing limb bud mesenchymal cells.

Partially knocking out NtPDK1a/1b/1c/1d simultaneously in Nicotiana tabacum using CRISPR/CAS9 technology results in auxin-related developmental defects.

The eukaryotic AGC protein kinase subfamily (protein kinase A/ protein kinase G/ protein kinase C-family) is involved in regulating numerous biological processes across kingdoms, including growth and development, and apoptosis. PDK1(3-phosphoinositide-dependent protein kinase 1) is a conserved serine/threonine kinase in eukaryotes, which is both a member of AGC kinase and a major regulator of many other downstream AGC protein kinase family members. Although extensively investigated in model plant Arabidopsis, detailed reports for tobacco PDK1s have been limited. To better understand the functions of PDK1s in tobacco, CRISPR/CAS9 transgenic lines were generated in tetraploid N. tabacum, cv. Samsun (NN) with 5-7 of the 8 copies of 4 homologous PDK1 genes in tobacco genome (NtPDK1a/1b/1c/1d homologs) simultaneously knocked out. Numerous developmental defects were observed in these NtPDK1a/1b/1c/1d CRISPR/CAS9 lines, including cotyledon fusion leaf shrinkage, uneven distribution of leaf veins, convex veins, root growth retardation, and reduced fertility, all of which reminiscence of impaired polar auxin transport. The severity of these defects was correlated with the number of knocked out alleles of NtPDK1a/1b/1c/1d. Consistent with the observation in Arabidopsis, it was found that the polar auxin transport, and not auxin biosynthesis, was significantly compromised in these knockout lines compared with the wild type tobacco plants. The fact that no homozygous plant with all 8 NtPDK1a/1b/1c/1d alleles being knocked out suggested that knocking out 8 alleles of NtPDK1a/1b/1c/1d could be lethal. In conclusion, our results indicated that NtPDK1s are versatile AGC kinases that participate in regulation of tobacco growth and development via modulating polar auxin transport. Our results also indicated that CRISPR/CAS9 technology is a powerful tool in resolving gene redundancy in polyploidy plants.

n-3 polyunsaturated fatty acids delay intervertebral disc degeneration by inhibiting nuclear receptor coactivator 4-mediated iron overload.

n-3 polyunsaturated fatty acids (PUFAs) are closely related to the progression of numerous chronic inflammatory diseases, but the role of n-3 PUFAs in the intervertebral disc degeneration (IVDD) remains unclear. In this study, male C57BL/6 wildtype mice (WT group, n = 30) and fat-1 transgenic mice (TG group, n = 30) were randomly selected to construct the IVDD model. The results demonstrated that the optimized composition of PUFAs in the TG mice had a significant impact on delaying IVDD and cellular senescence of intervertebral disc (IVD). Mechanismly, n-3 PUFAs inhibited IVD senescence by alleviating NCOA4-mediated iron overload. NCOA4 overexpression promoted iron overload and weakened the pro-proliferation and anti-senescence effect of DHA on the IVD cells. Furthermore, this study futher revealed n-3 PUFAs downregulated NCOA4 expression by inactiviting the LGR5/ß-catenin signaling pathway. This study provides an important theoretical basis for preventing and treating IVDD and low back pain.

Staphylococcus aureus ß-hemolysin causes skin inflammation by acting as an agonist of epidermal growth factor receptor.

IMPORTANCE: Staphylococcus aureus is a Gram-positive opportunistic bacterium that is responsible for the majority of skin infections in humans. Our study provides important molecular insights into the pathogenesis of S. aureus skin infections and identifies a potential therapeutic target for the treatment of these infections. Our findings also indicate that ß-hemolysin (Hlb) secreted by colonized S. aureus is a risk factor for epidermal growth factor receptor (EGFR)-related diseases by acting as an agonist of EGFR. The neutralized monoclonal antibody we have developed for the first time will provide a functional inhibitor of Hlb. This study provides important insights to better understand the relationship between the skin colonization of S. aureus and inflammatory skin diseases.

Angiopoietin-2 Promotes Mechanical Stress-induced Extracellular Matrix Degradation in Annulus Fibrosus Via the HIF-1α/NF-κB Signaling Pathway.

OBJECTIVE: Mechanical stress is an important risk factor for intervertebral disc degeneration (IVDD). Angiopoietin-2 (ANG-2) is regulated by mechanical stress and is widely involved in the regulation of extracellular matrix metabolism. In addition, the signaling cascade between HIF-1α and NF-κB is critical in matrix degradation. This study aims to investigate the role and molecular mechanism of ANG-2 in regulating the degeneration of annulus fibrosus (AF) through the HIF-1α/NF-κB signaling pathway. METHODS: The bipedal standing mice IVDD model was constructed, and histological experiments were used to evaluate the degree of IVDD and the expression of ANG-2 in the AF. Mouse primary AF cells were extracted in vitro and subjected to mechanical stretching experiments. Western blot assay was used to detect the effect of mechanical stress on ANG-2, and the role of the ANG-2-mediated HIF-1α/NF-κB pathway in matrix degradation. In addition, the effect of inhibiting ANG-2 expression by siRNA or monoclonal antibody on delaying IVDD was investigated at in vitro and in vivo levels. One-way ANOVA with the least significant difference method was used for pairwise comparison of the groups with homogeneous variance, and Dunnett's method was used to compare the groups with heterogeneous variance. RESULTS: In IVDD, the expressions of catabolic biomarkers (mmp-13, ADAMTS-4) and ANG-2 were significantly increased in AF. In addition, p65 expression was increased while HIF-1α expression was significantly decreased. The results of western blot assay showed mechanical stress significantly up-regulated the expression of ANG-2 in AF cells, and promoted matrix degradation by regulating the activity of HIF-1α/NF-κB pathway. Exogenous addition of Bay117082 and CoCl2 inhibited matrix degradation caused by mechanical stress. Moreover, injection of neutralizing antibody or treatment with siRNA to inhibit the expression of ANG-2 improved the matrix metabolism of AF and inhibited IVDD progression by regulating the HIF-1α/NF-κB signaling pathway. CONCLUSION: In IVDD, mechanical stress could regulate the HIF-1α/NF-κB signaling pathway and matrix degradation by mediating ANG-2 expression in AF degeneration.

PD-L2 Blockade Exacerbates Liver Lesion in Mice Infected with Capillaria hepatica through Reducing Alternatively Activated Macrophages.

Capillaria hepatica is a seriously neglected zoonotic parasite, which infects the liver of mammalian hosts, causing fibrosis or even hepatic failure. At present, the immune responses elicited by C. hepatica are not fully understood, and the role(s) of the programmed death 1 (PD-1) signaling pathway in the context of C. hepatica-induced pathology are not known. In this study, we identify that the late stage of infection with C. hepatica-especially the egg-derived antigens-modulates the host immune responses to promote alternatively activated macrophage (M2) polarization and programmed death ligand 2 (PD-L2) expression. The PD-L2-expressing alternatively activated M2 macrophages play an important role in maintaining Th2-biased regulatory immune responses, which may facilitate the survival of parasitic worms or eggs within the infected liver and reduce the liver pathology caused by the egg granulomas. Treatment with anti-PD-L2 antibody had no effect on the survival of parasitic eggs but deteriorated the pathology of egg granulomas. The obtained results suggest that PD-1/PD-L2 signaling, which is involved in alternative macrophage polarization, determines the immune response pattern and the immunopathology, consequently determining the outcome of the parasitic infection.

[Retracted] Isopsoralen­mediated suppression of bone marrow adiposity and attenuation of the adipogenic commitment of bone marrow­derived mesenchymal stem cells.

Following the publication of the above article, an interested reader drew to the authors' attention that Figs. 1C and 2 in the paper appeared to contain instances of duplicated data. The authors were able to consult their original data files, and realized that these figures had indeed been assembled incorrectly. Moreover, they identified further errors with a number of the other figures in their published formats (specifically, Figs. 3, 4, 6 and 7), and requested that a corrigendum be published to take account of all the errors that were made during the compilation of these figures. The Editor of International Journal of Molecular Medicine has considered the authors' request to publish a corrigendum, but has declined this request on account of the large number of errors that have been identified, and subsequently determined that this article should be retracted from the Journal on the basis of an overall lack of confidence in the presented data. Upon receiving this decision from the Editor, the authors were in agreement that the article should be retracted. The Editor apologizes to the readership of the Journal for any inconvenience caused. [International Journal of Molecular Medicine 39: 527­538, 2017; DOI: 10.3892/ijmm.2017.2880].

A Rare Case of Cysticercosis Involving the Whole Spinal Canal.

BACKGROUND: Cysticercosis is the commonest parasitic disease to affect the central nervous system (CNS). However, cysticercosis affecting the spine is extremely rare. We reported a rare case of cysticercosis involving the whole spinal canal in China. CASE PRESENTATION: A rare case of cysticercosis involving the entire spinal cord, in a 52-year-old Chinese man, was detected in 2021. Epidemiological investigation, clinical and etiological examination was performed. CONCLUSION: Since spinal cysticercosis is a rare but potentially life-threatening disease, clinicians should always consider the differential diagnosis of space-occupying lesions.

Clinical and laboratory characteristics of hemophagocytic lymphohistiocytosis induced by Leishmania infantum infection.

BACKGROUND: Visceral leishmaniasis (VL) could progress to secondary hemophagocytic lymphohistiocytosis (HLH), which is a rare but life-threatening condition with poor prognosis. So far, the clinical and laboratory characteristics of VL associated HLH have not been well elucidated. METHOD AND FINDINGS: In this study, we retrospectively analyzed the clinical and laboratory profiles between 17 patients with VL associated HLH and 27 patients with VL alone admitted at the Beijing Friendship Hospital, Capital Medical University from May 2016 to March 2021. In addition to the identification of Leishmania infection, hemophagocytosis was identified in bone marrow in the most cases of VL associated HLH (15/17). The patients with VL associated HLH had higher chances of bleeding, hepatomegaly, thrombocytopenia, hypertriglyceridemia, hyperferritinemia, hypofibrinogenemia, elevated secretion of soluble IL-2 receptor or lower NK cell activity compared to patients with VL only. Furthermore, patients with VL associated HLH had higher inflammation status associated with higher levels of Th1 (TNF-α, IFN-γ, IL-1beta, IL-6, IL-8, IL-12p70), Th2 (IL-4) and Th17 cytokines (IL-17, IL-23) in the peripheral blood, and higher parasite load (qPCR and parasite culture). All 27 VL cases were totally recovered after being treated with Sodium Stibogluconate, five of the 17 patients with VL associated HLH died even after timely treatment with anti-parasite and immunosuppressive chemotherapy. CONCLUSION: Without appropriate treatment, visceral leishmaniosis could develop to secondary HLH. The parasite culturing and qPCR detection of bone marrow samples facilitates the diagnosis of VL associated HLH in addition to other findings of HLH. Prompt treatment with anti-Leishmania and immunosuppressive chemotherapy is critical to reduce the mortality of VL associated HLH.

Macrophage-derived neurotrophin-3 promotes heterotopic ossification in rats.

Heterotopic ossification (HO) is a debilitating condition that results from traumatic injuries or genetic diseases, for which the underlying mechanisms remain unclear. Recently, we have demonstrated the expression of neurotrophin-3 (NT-3) and its role in promoting HO formation via mediating endothelial-mesenchymal transition (EndMT) of vascular endothelial cells. The current study investigated the role of NT-3 on the surrounding mesenchymal cells and its potential origin throughout HO formation at injured Achilles tendons in rats. We used an Achilles tenotomy to induce HO formation in vivo and cultured primary tendon-derived stem cells (TDSCs) to investigate the underlying mechanisms mediating the osteogenesis in vitro. Furthermore, RAW264.7 cells were employed to identify the origin of NT-3. The mRNA levels of NGF, BDNF, NT-3, and NT-4 and their tyrosine protein kinase (Trk) receptors as well as p75 receptor were elevated at injury sites. NT-3 and TrkC showed the highest induction. Neutralization of the NT-3-induced effects by the pan-Trk inhibitor GNF5837 reduced the expression of bone/cartilage-related genes while injection of NT-3 promoted HO formation with elevated mRNA of bone/cartilage-related markers at injured sites. In vitro, NT-3 accelerated osteogenic differentiation and mineralization of TDSCs through activation of the ERK1/2 and PI3K/Akt signaling pathways. Moreover, the colocalization of NT-3 and macrophages, including M1 and M2 macrophages, was observed in injured sites throughout HO formation, and in vitro studies demonstrated that activated macrophages mediated the secretion of NT-3. In addition, an increasing concentration of serum or supernatant NT-3 was observed both in vivo and in vitro. Depletion of macrophages with clodronate-loaded liposomes reduced HO formation as well as secretion and mRNA expression of NT-3. Our study suggests that macrophage-derived NT-3 may promote HO formation and osteogenesis of TDSCs via the ERK1/2 and PI3K/Akt signaling pathways, which may provide new insights for the therapeutic directions of HO in the future.

Disseminated cysticercosis in China with complex and variable clinical manifestations: a case series.

BACKGROUND: Cysticercosis is an emerging and neglected tropical disease (NTD) that poses a serious public health concern worldwide. Disseminated cysticercosis (DCC) is an uncommon manifestation of cysticercosis, also found in China. CASE PRESENTATION: We report three cases of DCC in patients living in China, with different clinical and radiological presentations. All three patients had DCC with active ocular cysticercosis, including one patient with widespread DCC caused by direct ingestion of Taenia solium eggs. The intravitreal cysticercus cyst in this patient was completely extracted entirely by 23-gauge pars plana vitrectomy, and the cyst was oval in shape on the flat mount preparation. CONCLUSION: The clinical presentation of DCC is highly sophisticated. The diagnosis depended on the typical radiological presentations, biopsy and flat mount preparations of the cyst.

Neurotrophin-3 acts on the endothelial-mesenchymal transition of heterotopic ossification in rats.

Despite the fact that extensive studies have focused on heterotopic ossification (HO), its molecular mechanism remains unclear. The endothelial-mesenchymal transition (EndMT), which may be partially modulated by neuroendocrine cytokines is thought to play a major role in HO. Neurotrophin-3 (NT-3), which has neuroendocrine characteristics is believed to promote skeletal remodeling. Herein, we suggest that that NT-3 may promote HO formation through regulation of EndMT. Here, we used an in vivo model of HO and an in vitro model of EndMT induction to elucidate the effect and underlying mechanism of NT-3 on EndMT in HO. Our results showed that heterotopic bone and cartilage arose from EndMT and NT-3 promoted HO formation in vivo. Our in vitro results showed that NT-3 up-regulated mesenchymal markers (FSP-1, α-SMA and N-cadherin) and mesenchymal stem cell (MSC) markers (STRO-1, CD44 and CD90) and down-regulated endothelial markers (Tie-1, VE-cadherin and CD31). Moreover, NT-3 enhanced a chondrogenesis marker (Sox9) and osteogenesis markers (OCN and Runx2) via activation of EndMT. However, both EndMT specific inhibitor and tropomyosin-related kinase C (TrkC) specific inhibitor rescued NT-3-induced HO formation and EndMT induction in vivo and in vitro. In conclusion, our findings demonstrate that NT-3 promotes HO formation via modulation of EndMT both in vivo and in vitro, which offers a new potential target for the prevention and therapy of HO.

Characterization of a Novel Calcific Achilles Tendinopathy Model in Mice: Contralateral Tendinopathy Induced by Unilateral Tenotomy.

Achilles tendinopathy is a significant clinical disease characterized by activity-related pain, focal movement limitation, and intratendinous imaging changes. However, treatment of Achilles tendinopathy has been based mainly on theoretical rationale and clinical experience because of its unclear underlying pathogenesis and mechanism. The purpose of the study was to develop a simple but reproducible overuse-induced animal model of Achilles tendinopathy in mice to better understand the underlying mechanism and prevent calcific Achilles tendinopathy. A total of 80 C57/B6 mice (8 or 9 weeks old) were employed and randomly divided into control and experimental groups. Unilateral Achilles tenotomy was performed on the right hind limbs in the experiment group. 12 weeks after unilateral Achilles tenotomy, the onset of Achilles tendinopathy in the contralateral Achilles tendon was determined by radiological assessment, histologic analysis, electron microscopy observation, and biomechanical test. The onset of calcific Achilles tendinopathy in contralateral Achilles tendon was confirmed after 12 weeks of unilateral tenotomy. The contralateral Achilles tendon in the experimental group was characterized as hypercellularity, neovascularization, and fused collagen fiber disarrangement, compared with the control group. Importantly, intra-tendon endochondral ossification and calcaneus deformity were featured in contralateral Achilles tendon. In addition, poor biomechanical properties in the contralateral Achilles tendon revealed the incidence of Achilles tendinopathy. We hereby introduce a novel, simple, but reproducible spontaneous contralateral calcific Achilles tendinopathy model in mice, which represents overuse conditions during tendinopathy development in humans. It should be a useful tool to further study the underlying pathogenesis of calcific Achilles tendinopathy.

Locally Produced IGF-1 Promotes Hypertrophy of the Ligamentum Flavum via the mTORC1 Signaling Pathway.

BACKGROUND/AIMS: Narrowing of the lumbar spinal canal is a condition called lumbar spinal stenosis (LSS) and is a high-morbidity problem in the elderly. LSS is commonly caused by hypertrophy of the ligamentum flavum (HLF). Previous studies showed that fibrosis of the ligamentum flavum (LF) largely contributed to HLF. However, the underlying pathomechanism remains unclear. Insulin-like growth factor-1 (IGF-1) is known to have an intimate relationship with fibrosis in various tissues. Nevertheless, currently, there are few studies regarding IGF-1 in HLF. In this study, we investigated the role of IGF-1 in HLF and its potential molecular mechanism of action. METHODS: First, the IGF-1, phosphorylation of IGF-1 receptor (pIGF-1R), phosphorylation of AKT (pAKT), phosphorylation of S6(pS6), collagen I and collagen III expression levels were examined via immunohistochemistry and Western blotting in LF tissues from patients with LSS or Non-LSS. Second, primary LF cells were isolated from adults with a normal LF thickness and were cultured with different concentrations of IGF-1 with or without NVP-AEW541/rapamycin. RESULTS: The results showed that IGF-1, pIGF-1R, pAKT, pS6, collagen I and collagen III protein expression in the LSS group was significantly higher than that in the Non-LSS group. Meanwhile, pIGF-1R, pAKT, pS6, collagen I and collagen III protein expression was significantly enhanced in LF cells after IGF-1 exposure, which can be notably blocked by NVP-AEW541. In addition, pS6, collagen I and collagen III protein expression was blocked by rapamycin. CONCLUSIONS: Enhanced IGF-1 promotes the synthesis of collagen I and collagen III via the mTORC1 signaling pathway, which eventually contributes to hypertrophy of the ligamentum flavum.

Leptin accelerates the pathogenesis of heterotopic ossification in rat tendon tissues via mTORC1 signaling.

Leptin, an adipocyte-derived cytokine associated with bone metabolism, is believed to play a critical role in the pathogenesis of heterotopic ossification (HO). The effect and underlying action mechanism of leptin were investigated on osteogenic differentiation of tendon-derived stem cells (TDSCs) in vitro and the HO formation in rat tendons. Isolated rat TDSCs were treated with various concentrations of leptin in the presence or absence of mTORC1 signaling specific inhibitor rapamycin in vitro. A rat model with Achilles tenotomy was employed to evaluate the effect of leptin on HO formation together with or without rapamycin treatment. In vitro studies with TDSCs showed that leptin increased the expression of osteogenic biomarkers (alkaline phosphatase, runt-related transcription factor 2, osterix, osteocalcin) and enhanced mineralization of TDSCs via activating the mTORC1 signal pathway (as indicated by phosphorylation of p70 ribosomal S6 kinase 1 and p70 ribosomal S6). However, mTORC1 signaling blockade with rapamycin treatment suppressed leptin-induced osteogenic differentiation and mineralization. In vivo studies showed that leptin promoted HO formation in the Achilles tendon after tenotomy, and rapamycin treatment blocked leptin-induced HO formation. In conclusion, leptin can promote TDSC osteogenic differentiation and heterotopic bone formation via mTORC1 signaling in both vitro and vivo model, which provides a new potential therapeutic target for HO prevention.

Isopsoralen-mediated suppression of bone marrow adiposity and attenuation of the adipogenic commitment of bone marrow-derived mesenchymal stem cells.

Osteoporosis (OP) increases the risk of bone fractures and other complications, and is thus a major clinical problem. In this study, we examined the effect of isopsoralen on the differentiation of bone-derived marrow mesenchymal stem cells (BMSCs) into osteoblasts and adipocytes, as well as bone formation under osteoporotic conditions. Primary femoral BMSCs isolated from C57BL/6 mice were used to evaluate the isopsoralen-mediated regulation of the expression of alkaline phosphatase (ALP), osteocalcin (OCN) and runt-related transcription factor 2 (RUNX2) during osteogenesis 2 weeks. We also examined the expression of peroxisome proliferator-activated receptor Î³ (PPARγ) and CCAAT/enhancer binding protein ß (C/EBPß) under adipogenic conditions for 1 and 2 weeks. In addition, ovariectomized (OVX) mice were used to examine the effects of isopsoralen on bone formation for 2 months. Finally, mammalian target of rapamycin complex 1 (mTORC1) signaling was examined under osteogenic and adipogenic conditions. We found that following treatment with isopsoralen, the expression levels of ALP, OCN and RUNX2 were upregulated, whereas those of PPARγ and C/EBPß were downregulated. mTORC1 signaling was also inhibited in vitro and in vivo. In the OVX mice that were intragastrically administered isopsoralen, bone parameters (trabecular thickness, bone volume/total volume and trabecular number) in the distal femoral metaphysis were significantly increased and the adipocyte number was decreased. On the whole, our findings demonstrate that isopsoralen promoted BMSC differentiation into osteoblasts and suppressed differentiation into adipocytes.

Tenuigenin promotes the osteogenic differentiation of bone mesenchymal stem cells in vitro and in vivo.

Osteoporosis, which is a systemic skeletal disease characterized by low bone mineral density and microarchitectural deterioration of bone quality, is a global and increasing public health problem. Recent studies have suggested that Tenuigenin (TEN), a class of native compounds with numerous biological activities such as anti-resorptive properties, exerts protective effects against postmenopausal bone loss. The present study aims to investigate the osteogenic effects of TEN on bone mesenchymal stem cells (BMSCs) in vitro and in vivo. Alkaline phosphatase (ALP) activity/staining, Alizarin red staining and the expression of osteogenic markers, including runt-related transcription factor 2, osterix, osteocalcin, collagen Iα1, ß-catenin and glycogen synthase kinase-3ß were investigated in primary femoral BMSCs from C57/BL6 mice cultured under osteogenic conditions for 2 weeks to examine the effects of TEN. An ovariectomized (OVX) mouse model was used to investigate the effect of TEN treatment for 3 months in vivo. We found that ALP activity, mineralized nodules and the expression of osteogenic markers were increased and WNT/ß-catenin signaling was enhanced in vitro and in vivo. Bone parameters, including trabecular thickness, trabecular number and bone mineral density were higher in the OVX+TEN group than in control OVX mice. Our results suggest the therapeutic potential of TEN for the treatment of patients with postmenopausal osteoporosis.

Osteoblasts secrete Cxcl9 to regulate angiogenesis in bone.

Communication between osteoblasts and endothelial cells (ECs) is essential for bone turnover, but the molecular mechanisms of such communication are not well defined. Here we identify Cxcl9 as an angiostatic factor secreted by osteoblasts in the bone marrow microenvironment. We show that Cxcl9 produced by osteoblasts interacts with vascular endothelial growth factor and prevents its binding to ECs and osteoblasts, thus abrogating angiogenesis and osteogenesis both in mouse bone and in vitro. The mechanistic target of rapamycin complex 1 activates Cxcl9 expression by transcriptional upregulation of STAT1 and increases binding of STAT1 to the Cxcl9 promoter in osteoblasts. These findings reveal the essential role of osteoblast-produced Cxcl9 in angiogenesis and osteogenesis in bone, and Cxcl9 can be targeted to elevate bone angiogenesis and prevent bone loss-related diseases.