Intermittent Fasting Targets Osteocyte Neuropeptide Y to Relieve Osteoarthritis.

Osteoarthritis is a highly prevalent progressive joint disease that still requires an optimal therapeutic approach. Intermittent fasting is an attractive dieting strategy for improving health. Here this study shows that intermittent fasting potently relieves medial meniscus (DMM)- or natural aging-induced osteoarthritic phenotypes. Osteocytes, the most abundant bone cells, secrete excess neuropeptide Y (NPY) during osteoarthritis, and this alteration can be altered by intermittent fasting. Both NPY and the NPY-abundant culture medium of osteocytes (OCY-CM) from osteoarthritic mice possess pro-inflammatory, pro-osteoclastic, and pro-neurite outgrowth effects, while OCY-CM from the intermittent fasting-treated osteoarthritic mice fails to induce significant stimulatory effects on inflammation, osteoclast formation, and neurite outgrowth. Depletion of osteocyte NPY significantly attenuates DMM-induced osteoarthritis and abolishes the benefits of intermittent fasting on osteoarthritis. This study suggests that osteocyte NPY is a key contributing factor in the pathogenesis of osteoarthritis and intermittent fasting represents a promising nonpharmacological antiosteoarthritis method by targeting osteocyte NPY.

Colonic epithelial cell-specific TFEB activation: a key mechanism promoting anti-bacterial defense in response to Salmonella infection.

Colitis caused by infections, especially Salmonella, has long been a common disease, underscoring the urgency to understand its intricate pathogenicity in colonic tissues for the development of effective anti-bacterial approaches. Of note, colonic epithelial cells, which form the first line of defense against bacteria, have received less attention, and the cross-talk between epithelial cells and bacteria requires further exploration. In this study, we revealed that the critical anti-bacterial effector, TFEB, was primarily located in colonic epithelial cells rather than macrophages. Salmonella-derived LPS significantly promoted the expression and nuclear translocation of TFEB in colonic epithelial cells by inactivating the mTOR signaling pathway in vitro, and this enhanced nuclear translocation of TFEB was also confirmed in a Salmonella-infected mouse model. Further investigation uncovered that the infection-activated TFEB contributed to the augmentation of anti-bacterial peptide expression without affecting the intact structure of the colonic epithelium or inflammatory cytokine expression. Our findings identify the preferential distribution of TFEB in colonic epithelial cells, where TFEB can be activated by infection to enhance anti-bacterial peptide expression, holding promising implications for the advancement of anti-bacterial therapeutics.

Young osteocyte-derived extracellular vesicles facilitate osteogenesis by transferring tropomyosin-1.

BACKGROUND: Bone marrow mesenchymal stem cells (BMSCs) can undergo inadequate osteogenesis or excessive adipogenesis as they age due to changes in the bone microenvironment, ultimately resulting in decreased bone density and elevated risk of fractures in senile osteoporosis. This study aims to investigate the effects of osteocyte senescence on the bone microenvironment and its influence on BMSCs during aging. RESULTS: Primary osteocytes were isolated from 2-month-old and 16-month-old mice to obtain young osteocyte-derived extracellular vesicles (YO-EVs) and senescent osteocyte-derived EVs (SO-EVs), respectively. YO-EVs were found to significantly increase alkaline phosphatase activity, mineralization deposition, and the expression of osteogenesis-related genes in BMSCs, while SO-EVs promoted BMSC adipogenesis. Neither YO-EVs nor SO-EVs exerted an effect on the osteoclastogenesis of primary macrophages/monocytes. Our constructed transgenic mice, designed to trace osteocyte-derived EV distribution, revealed abundant osteocyte-derived EVs embedded in the bone matrix. Moreover, mature osteoclasts were found to release osteocyte-derived EVs from bone slices, playing a pivotal role in regulating the functions of the surrounding culture medium. Following intravenous injection into young and elderly mouse models, YO-EVs demonstrated a significant enhancement of bone mass and biomechanical strength compared to SO-EVs. Immunostaining of bone sections revealed that YO-EV treatment augmented the number of osteoblasts on the bone surface, while SO-EV treatment promoted adipocyte formation in the bone marrow. Proteomics analysis of YO-EVs and SO-EVs showed that tropomyosin-1 (TPM1) was enriched in YO-EVs, which increased the matrix stiffness of BMSCs, consequently promoting osteogenesis. Specifically, the siRNA-mediated depletion of Tpm1 eliminated pro-osteogenic activity of YO-EVs both in vitro and in vivo. CONCLUSIONS: Our findings suggested that YO-EVs played a crucial role in maintaining the balance between bone resorption and formation, and their pro-osteogenic activity declining with aging. Therefore, YO-EVs and the delivered TPM1 hold potential as therapeutic targets for senile osteoporosis.

Extracellular vesicles from human urine-derived stem cells delay aging through the transfer of PLAU and TIMP1.

Aging increases the risks of various diseases and the vulnerability to death. Cellular senescence is a hallmark of aging that contributes greatly to aging and aging-related diseases. This study demonstrates that extracellular vesicles from human urine-derived stem cells (USC-EVs) efficiently inhibit cellular senescence in vitro and in vivo. The intravenous injection of USC-EVs improves cognitive function, increases physical fitness and bone quality, and alleviates aging-related structural changes in different organs of senescence-accelerated mice and natural aging mice. The anti-aging effects of USC-EVs are not obviously affected by the USC donors' ages, genders, or health status. Proteomic analysis reveals that USC-EVs are enriched with plasminogen activator urokinase (PLAU) and tissue inhibitor of metalloproteinases 1 (TIMP1). These two proteins contribute importantly to the anti-senescent effects of USC-EVs associated with the inhibition of matrix metalloproteinases, cyclin-dependent kinase inhibitor 2A (P16INK4a), and cyclin-dependent kinase inhibitor 1A (P21cip1). These findings suggest a great potential of autologous USC-EVs as a promising anti-aging agent by transferring PLAU and TIMP1 proteins.

Epigenetically upregulated NSUN2 confers ferroptosis resistance in endometrial cancer via m5C modification of SLC7A11 mRNA.

Endometrial cancer (EC) is a prevalent gynecological malignancy worldwide, and 5-methylcytosine (m5C) modification of mRNA is a crucial epigenetic modification associated with the development and occurrence of several cancers. However, the precise function of m5C modification in EC remains elusive. This study aimed to investigate the expression and clinical significance of the primary m5C modification writer, NSUN2, in EC. Our findings indicated that NSUN2 exhibited a substantial up-regulation in EC as a result of an epigenetic augmentation in H3K4me3 levels within the promoter region, which was triggered by the down-regulation of KDM5A. Moreover, gain- and loss-of-function experiments revealed the role of NSUN2 in enhancing m5C modification of mRNA, thereby promoting EC cell proliferation. RNA bisulfite sequencing and transcriptomic sequencing were employed to elucidate the involvement of NSUN2 in the regulation of ferroptosis. Subsequent in vitro experiments confirmed that the knockdown of NSUN2 significantly up-regulated the levels of lipid peroxides and lipid ROS in EC cells, thereby augmenting the susceptibility of EC to ferroptosis. Mechanistically, NSUN2 stimulated the m5C modification of SLC7A11 mRNA, and the m5C reader YBX1 exhibited direct recognition and binding to the m5C sites on SLC7A11 mRNA via its internal cold shock domain (CSD), leading to an increase in SLC7A11 mRNA stability and elevated levels of SLC7A11. Additionally, rescue experiments showed that NSUN2 functioned as a suppressor of ferroptosis, which was dependent on SLC7A11. Overall, targeting the NSUN2/SLC7A11 axis inhibited tumor growth by increasing lipid peroxidation and ferroptosis of EC cells both in vitro and in vivo. Therefore, our study provides new insight into the role of NSUN2, suggesting that NSUN2 may serve as a prognostic biomarker and therapeutic target in patients with EC.

Aptamer-functionalized hydrogels promote bone healing by selectively recruiting endogenous bone marrow mesenchymal stem cells.

Bone regeneration heavily relies on bone marrow mesenchymal stem cells (BMSCs). However, recruiting endogenous BMSCs for in situ bone regeneration remains challenging. In this study, we developed a novel BMSC-aptamer (BMSC-apt) functionalized hydrogel (BMSC-aptgel) and evaluated its functions in recruiting BMSCs and promoting bone regeneration. The functional hydrogels were synthesized between maleimide-terminated 4-arm polyethylene glycols (PEG) and thiol-flanked PEG crosslinker, allowing rapid in situ gel formation. The aldehyde group-modified BMSC-apt was covalently bonded to a thiol-flanked PEG crosslinker to produce high-density aptamer coverage on the hydrogel surface. In vitro and in vivo studies demonstrated that the BMSC-aptgel significantly increased BMSC recruitment, migration, osteogenic differentiation, and biocompatibility. In vivo fluorescence tomography imaging demonstrated that functionalized hydrogels effectively recruited DiR-labeled BMSCs at the fracture site. Consequently, a mouse femur fracture model significantly enhanced new bone formation and mineralization. The aggregated BMSCs stimulated bone regeneration by balancing osteogenic and osteoclastic activities and reduced the local inflammatory response via paracrine effects. This study's findings suggest that the BMSC-aptgel can be a promising and effective strategy for promoting in situ bone regeneration.

Ångstrom-scale silver particles ameliorate collagen-induced and K/BxN-transfer arthritis in mice via the suppression of inflammation and osteoclastogenesis.

OBJECTIVE: Nanoparticles (NPs) hold a great promise in combating rheumatoid arthritis, but are often compromised by their toxicities because the currently used NPs are usually synthesized by chemical methods. Our group has previously fabricated Ångstrom-scale silver particles (AgÅPs) and demonstrated the anti-tumor and anti-sepsis efficacy of fructose-coated AgÅPs (F-AgÅPs). This study aimed to uncover the efficacy and mechanisms of F-AgÅPs for arthritis therapy. METHODS: We evaluated the efficacy of F-AgÅPs in collagen-induced arthritis (CIA) mice. We also compared the capacities of F-AgÅPs, the commercial AgNPs, and the clinical drug methotrexate (MTX) in protecting against K/BxN serum-transfer arthritis (STA) mice. Moreover, we evaluated the effects of F-AgÅPs and AgNPs on inflammation, osteoclast formation, synoviocytes migration, and matrix metalloproteinases (MMPs) production in vitro and in vivo. Meanwhile, the toxicities of F-AgÅPs and AgNPs in vitro and in vivo were also tested. RESULTS: F-AgÅPs significantly prevented bone erosion, synovitis, and cartilage damage, attenuated rheumatic pain, and improved the impaired motor function in mouse models of CIA or STA, the anti-rheumatic effects of which were comparable or stronger than AgNPs and MTX. Further studies revealed that F-AgÅPs exhibited similar or greater inhibitory abilities than AgNPs to suppress inflammation, osteoclast formation, synoviocytes migration, and MMPs production. No obvious toxicities were observed in vitro and in vivo after F-AgÅPs treatment. CONCLUSIONS: F-AgÅPs can effectively alleviate arthritis without notable toxicities and their anti-arthritic effects are associated with the inhibition of inflammation, osteoclastogenesis, synoviocytes migration, and MMPs production. Our study suggests the prospect of F-AgÅPs as an efficient and low-toxicity agent for arthritis therapy.

Minimally invasive enucleation versus open enucleation for benign or low-grade malignant pancreatic neoplasms: Effects on clinical outcomes and quality of life.

Introduction: The efficacy and safety of minimally invasive pancreatic enucleation (PE) have rarely been investigated. This study aimed to compare the perioperative and long-term outcomes of minimally invasive enucleation (MIEn) with those of open enucleation (OEn) for benign/low-grade malignant pancreatic neoplasms. Patients and Methods: Data collected from patients who underwent PE between January 2011 and June 2020 at our centre were analysed. Results: Forty-two patients who underwent MIEn (10 - robot-assisted and 32 - laparoscopic) and 47 who underwent OEn were included in this study. Compared with the OEn group, the MIEn group showed shorter operation time (147.6 ± 71.3 min vs. 183.1 ± 64.3 min), shorter post-operative hospital stay (11.5 ± 3.9 days vs. 13.4 ± 4.2 days), shorter off-bed activity time (2.9 ± 0.9 days vs. 3.7 ± 1.0 days) and lower estimated blood loss (EBL) (118.5 ± 59.2 mL vs. 153.1 ± 85.0 mL). Overall complication rate (47.6% vs. 55.3%), overall post-operative pancreatic fistula (POPF) rate (40.5% vs. 44.7%) and Grade B + C POPF rate (11.9% vs. 19.1%) were similar in both the groups. For neoplasms located in the proximal pancreas, MIEn showed more favourable perioperative outcomes than OEn. Unlike MIEn for superficial neoplasms, MIEn for neoplasms deeply embedded in the pancreas resulted in a longer operative time and tended to increase EBL and the incidence of complications and POPF. During the follow-up period, no significant differences were observed between these two groups in terms of pancreatic function or quality of life. Conclusions: Compared to OEn, MIEn is effective and safe for patients with benign or low-grade malignant pancreatic neoplasms. However, MIEn for embedded pancreatic neoplasms is recommended only in experienced centres because of the high rates of complications and POPF.

Brain-derived extracellular vesicles promote bone-fat imbalance in Alzheimer's disease.

Inadequate osteogenesis and excessive adipogenesis of bone marrow mesenchymal stem cells (BMSCs) are key factors in the pathogenesis of osteoporosis. Patients with Alzheimer's disease (AD) have a higher incidence of osteoporosis than healthy adults, but the underlying mechanism is not clear. Here, we show that brain-derived extracellular vesicles (EVs) from adult AD or wild-type mice can cross the blood-brain barrier to reach the distal bone tissue, while only AD brain-derived EVs (AD-B-EVs) significantly promote the shift of the BMSC differentiation fate from osteogenesis to adipogenesis and induce a bone-fat imbalance. MiR-483-5p is highly enriched in AD-B-EVs, brain tissues from AD mice, and plasma-derived EVs from AD patients. This miRNA mediates the anti-osteogenic, pro-adipogenic, and pro-osteoporotic effects of AD-B-EVs by inhibiting Igf2. This study identifies the role of B-EVs as a promoter of osteoporosis in AD by transferring miR-483-5p.

The Protective Effects of Osteocyte-Derived Extracellular Vesicles Against Alzheimer's Disease Diminished with Aging.

Both Alzheimer's disease (AD) and osteoporosis (OP) are common age-associated degenerative diseases and are strongly correlated with clinical epidemiology. However, there is a lack of clear pathological relationship between the brain and bone in the current understanding. Here, it is found that young osteocyte, the most abundant cells in bone, secretes extracellular vesicles (OCYYoung -EVs) to ameliorate cognitive impairment and the pathogenesis of AD in APP/PS1 mice and model cells. These benefits of OCYYoung -EVs are diminished in aged osteocyte-derived EVs (OCYAged -EVs). Based on the self-constructed OCY-EVs tracer transgenic mouse models and the in vivo fluorescent imaging system, OCY-EVs have been observed to be transported to the brain under physiological and pathological conditions. In the hippocampal administration of Aß40 induced young AD model mice, the intramedullary injection of Rab27a-shRNA adenovirus inhibits OCYYoung -EVs secretion from bone and aggravates cognitive impairment. Proteomic quantitative analysis reveals that OCYYoung -EVs, compared to OCYAged -EVs, enrich multiple protective factors of AD pathway. The study uncovers the role of OCY-EV as a regulator of brain health, suggesting a novel mechanism in bone-brain communication.

Glucocorticoid-induced loss of beneficial gut bacterial extracellular vesicles is associated with the pathogenesis of osteonecrosis.

Osteonecrosis of the femoral head (ONFH) commonly occurs after glucocorticoid (GC) therapy. The gut microbiota (GM) participates in regulating host health, and its composition can be altered by GC. Here, this study demonstrates that cohousing with healthy mice or colonization with GM from normal mice attenuates GC-induced ONFH. 16S rRNA gene sequencing shows that cohousing with healthy mice rescues the GC-induced reduction of gut Lactobacillus animalis. Oral supplementation of L. animalis mitigates GC-induced ONFH by increasing angiogenesis, augmenting osteogenesis, and reducing cell apoptosis. Extracellular vesicles from L. animalis (L. animalis-EVs) contain abundant functional proteins and can enter the femoral head to exert proangiogenic, pro-osteogenic, and antiapoptotic effects, while its abundance is reduced after exposure to GC. Our study suggests that the GM is involved in protecting the femoral head by transferring bacterial EVs, and that loss of L. animalis and its EVs is associated with the development of GC-induced ONFH.

Aged bone matrix-derived extracellular vesicles as a messenger for calcification paradox.

Adipocyte differentiation of bone marrow mesenchymal stem/stromal cells (BMSCs) instead of osteoblast formation contributes to age- and menopause-related marrow adiposity and osteoporosis. Vascular calcification often occurs with osteoporosis, a contradictory association called "calcification paradox". Here we show that extracellular vesicles derived from aged bone matrix (AB-EVs) during bone resorption favor BMSC adipogenesis rather than osteogenesis and augment calcification of vascular smooth muscle cells. Intravenous or intramedullary injection of AB-EVs promotes bone-fat imbalance and exacerbates Vitamin D3 (VD3)-induced vascular calcification in young or old mice. Alendronate (ALE), a bone resorption inhibitor, down-regulates AB-EVs release and attenuates aging- and ovariectomy-induced bone-fat imbalance. In the VD3-treated aged mice, ALE suppresses the ovariectomy-induced aggravation of vascular calcification. MiR-483-5p and miR-2861 are enriched in AB-EVs and essential for the AB-EVs-induced bone-fat imbalance and exacerbation of vascular calcification. Our study uncovers the role of AB-EVs as a messenger for calcification paradox by transferring miR-483-5p and miR-2861.

Neuronal Induction of Bone-Fat Imbalance through Osteocyte Neuropeptide Y.

A differentiation switch of bone marrow mesenchymal stem/stromal cells (BMSCs) from osteoblasts to adipocytes contributes to age- and menopause-associated bone loss and marrow adiposity. Here it is found that osteocytes, the most abundant bone cells, promote adipogenesis and inhibit osteogenesis of BMSCs by secreting neuropeptide Y (NPY), whose expression increases with aging and osteoporosis. Deletion of NPY in osteocytes generates a high bone mass phenotype, and attenuates aging- and ovariectomy (OVX)-induced bone-fat imbalance in mice. Osteocyte NPY production is under the control of autonomic nervous system (ANS) and osteocyte NPY deletion blocks the ANS-induced regulation of BMSC fate and bone-fat balance. γ-Oryzanol, a clinically used ANS regulator, significantly increases bone formation and reverses aging- and OVX-induced osteocyte NPY overproduction and marrow adiposity in control mice, but not in mice lacking osteocyte NPY. The study suggests a new mode of neuronal control of bone metabolism through the ANS-induced regulation of osteocyte NPY.

Erratum: Inhibition of miR-331-3p and miR-9-5p ameliorates Alzheimer's disease by enhancing autophagy: Erratum.

[This corrects the article DOI: 10.7150/thno.47408.].

Fructose-coated Ångstrom silver prevents sepsis by killing bacteria and attenuating bacterial toxin-induced injuries.

Serious infection caused by multi-drug-resistant bacteria is a major threat to human health. Bacteria can invade the host tissue and produce various toxins to damage or kill host cells, which may induce life-threatening sepsis. Here, we aimed to explore whether fructose-coated Ångstrom-scale silver particles (F-AgÅPs), which were prepared by our self-developed evaporation-condensation system and optimized coating approach, could kill bacteria and sequester bacterial toxins to attenuate fatal bacterial infections. Methods: A series of in vitro assays were conducted to test the anti-bacterial efficacy of F-AgÅPs, and to investigate whether F-AgÅPs could protect against multi-drug resistant Staphylococcus aureus (S. aureus)- and Escherichia coli (E. coli)-induced cell death, and suppress their toxins (S. aureus hemolysin and E. coli lipopolysaccharide)-induced cell injury or inflammation. The mouse models of cecal ligation and puncture (CLP)- or E. coli bloodstream infection-induced lethal sepsis were established to assess whether the intravenous administration of F-AgÅPs could decrease bacterial burden, inhibit inflammation, and improve the survival rates of mice. The levels of silver in urine and feces of mice were examined to evaluate the excretion of F-AgÅPs. Results: F-AgÅPs efficiently killed various bacteria that can cause lethal infections and also competed with host cells to bind with S. aureus α-hemolysin, thus blocking its cytotoxic activity. F-AgÅPs inhibited E. coli lipopolysaccharide-induced endothelial injury and macrophage inflammation, but not by directly binding to lipopolysaccharide. F-AgÅPs potently reduced bacterial burden, reversed dysregulated inflammation, and enhanced survival in mice with CLP- or E. coli bloodstream infection-induced sepsis, either alone or combined with antibiotic therapy. After three times injections within 48 h, 79.18% of F-AgÅPs were excreted via feces at the end of the 14-day observation period. Conclusion: This study suggests the prospect of F-AgÅPs as a promising intravenous agent for treating severe bacterial infections.

Deficiency of Omentin-1 leads to delayed fracture healing through excessive inflammation and reduced CD31hiEmcnhi vessels.

Fracture healing is a complicated process affected by many factors, such as inflammatory responses and angiogenesis. Omentin-1 is an adipokine with anti-inflammatory properties, but whether omentin-1 affects the fracture healing process is still unknown. Here, by using global omentin-1 knockout (omentin-1-/-) mice, we demonstrated that omentin-1 deficiency resulted in delayed fracture healing in mice, accompanied by increased inflammation and osteoclast formation, and decreased production of platelet-derived growth factor-BB (PDGF-BB) and osteogenesis-promoting vessels that are strongly positive for CD31 and Endomucin (CD31hiEmcnhi) in the fracture area. In vitro, omentin-1 treatment suppressed the ability of the tumor necrosis factor-α (TNF-α)-activated macrophages to stimulate multi-nuclear osteoclast formation, resulting in a significant increase in the generation of mono-nuclear preosteoclasts and PDGF-BB, a pro-angiogenic protein that is abundantly secreted by preosteoclasts. PDGF-BB significantly augmented endothelial cell proliferation, tube formation and migration, whereas direct treatment with omentin-1 did not induce obvious effects on angiogenesis activities of endothelial cells. Our study suggests a positive role of omentin-1 in fracture healing, which may be associated with the inhibition of inflammation and stimulation of preosteoclast PDGF-BB-mediated promotion of CD31hiEmcnhi vessel formation.

Extracellular Vesicles from Child Gut Microbiota Enter into Bone to Preserve Bone Mass and Strength.

Recently, the gut microbiota (GM) has been shown to be a regulator of bone homeostasis and the mechanisms by which GM modulates bone mass are still being investigated. Here, it is found that colonization with GM from children (CGM) but not from the elderly (EGM) prevents decreases in bone mass and bone strength in conventionally raised, ovariectomy (OVX)-induced osteoporotic mice. 16S rRNA gene sequencing reveals that CGM reverses the OVX-induced reduction of Akkermansia muciniphila (Akk). Direct replenishment of Akk is sufficient to correct the OVX-induced imbalanced bone metabolism and protect against osteoporosis. Mechanistic studies show that the secretion of extracellular vesicles (EVs) is required for the CGM- and Akk-induced bone protective effects and these nanovesicles can enter and accumulate into bone tissues to attenuate the OVX-induced osteoporotic phenotypes by augmenting osteogenic activity and inhibiting osteoclast formation. The study identifies that gut bacterium Akk mediates the CGM-induced anti-osteoporotic effects and presents a novel mechanism underlying the exchange of signals between GM and host bone.

Extracellular Vesicles from Akkermansia muciniphila Elicit Antitumor Immunity Against Prostate Cancer via Modulation of CD8+ T Cells and Macrophages.

PURPOSE: Prostate cancer (PCa) is one of the most common malignancies in males. Despite the success of immunotherapy in many malignant cancers, strategies are still needed to improve therapeutic efficacy in PCa. This study aimed to investigate the effects of Akkermansia muciniphila-derived extracellular vesicles (Akk-EVs) on PCa and elucidate the underlying immune-related mechanism. METHODS: Akk-EVs were isolated by ultracentrifugation and intravenously injected to treat syngeneic PCa-bearing immune-competent mice. Immunophenotypic changes in immune cells, such as cytotoxic T lymphocytes and macrophages, were measured via flow cytometry analysis. Histological examination was used to detect morphological changes in major organs after Akk-EVs treatments. In vitro, flow cytometry was performed to confirm the effects of Akk-EVs on the activation of CD8+ T cells. Quantitative PCR and immunofluorescence staining were carried out to test the impact of Akk-EVs on macrophage polarization. Cell counting kit-8 (CCK-8) analysis, colony formation assays, and scratch wound healing assays were conducted to assess the effects of Akk-EVs-treated macrophages on the proliferation and invasion of PCa cells. CCK-8 assays also confirmed the impact of Akk-EVs on the viability of normal cells. RESULTS: Intravenous injection of Akk-EVs in immune-competent mice reduced the tumor burden of PCa without inducing obvious toxicity in normal tissues. This treatment elevated the proportion of granzyme B-positive (GZMB+) and interferon γ-positive (IFN-γ+) lymphocytes in CD8+ T cells and caused macrophage recruitment, with increased tumor-killing M1 macrophages and decreased immunosuppressive M2 macrophages. In vitro, Akk-EVs increased the number of GZMB+CD8+ and IFN-γ+CD8+ T cells and M1-like macrophages. In addition, conditioned medium from Akk-EVs-treated macrophages suppressed the proliferation and invasion of prostate cells. Furthermore, the effective dose of Akk-EVs was well-tolerated in normal cells. CONCLUSION: Our study revealed the promising prospects of Akk-EVs as an efficient and biocompatible immunotherapeutic agent for PCa treatment.

Inhibition of miR-331-3p and miR-9-5p ameliorates Alzheimer's disease by enhancing autophagy.

Alzheimer's disease (AD) is currently ranked as the third leading cause of death for eldly people, just behind heart disease and cancer. Autophagy is declined with aging. Our study determined the biphasic changes of miR-331-3p and miR-9-5p associated with AD progression in APPswe/PS1dE9 mouse model and demonstrated inhibiting miR-331-3p and miR-9-5p treatment prevented AD progression by promoting the autophagic clearance of amyloid beta (Aß). Methods: The biphasic changes of microRNAs were obtained from RNA-seq data and verified by qRT-PCR in early-stage (6 months) and late-stage (12 months) APPswe/PS1dE9 mice (hereinafter referred to as AD mice). The AD progression was determined by analyzing Aß levels, neuron numbers (MAP2+) and activated microglia (CD68+IBA1+) in brain tissues using immunohistological and immunofluorescent staining. MRNA and protein levels of autophagic-associated genes (Becn1, Sqstm1, LC3b) were tested to determine the autophagic activity. Morris water maze and object location test were employed to evaluate the memory and learning after antagomirs treatments in AD mice and the Aß in the brain tissues were determined. Results: MiR-331-3p and miR-9-5p are down-regulated in early-stage of AD mice, whereas up-regulated in late-stage of AD mice. We demonstrated that miR-331-3p and miR-9-5p target autophagy receptors Sequestosome 1 (Sqstm1) and Optineurin (Optn), respectively. Overexpression of miR-331-3p and miR-9-5p in SH-SY5Y cell line impaired autophagic activity and promoted amyloid plaques formation. Moreover, AD mice had enhanced Aß clearance, improved cognition and mobility when treated with miR-331-3p and miR-9-5p antagomirs at late-stage. Conclusion: Our study suggests that using miR-331-3p and miR-9-5p, along with autophagic activity and amyloid plaques may distinguish early versus late stage of AD for more accurate and timely diagnosis. Additionally, we further provide a possible new therapeutic strategy for AD patients by inhibiting miR-331-3p and miR-9-5p and enhancing autophagy.

Autophagy receptor OPTN (optineurin) regulates mesenchymal stem cell fate and bone-fat balance during aging by clearing FABP3.

Senile osteoporosis (OP) is often concomitant with decreased autophagic activity. OPTN (optineurin), a macroautophagy/autophagy (hereinafter referred to as autophagy) receptor, is found to play a pivotal role in selective autophagy, coupling autophagy with bone metabolism. However, its role in osteogenesis is still mysterious. Herein, we identified Optn as a critical molecule of cell fate decision for bone marrow mesenchymal stem cells (MSCs), whose expression decreased in aged mice. Aged mice revealed osteoporotic bone loss, elevated senescence of MSCs, decreased osteogenesis, and enhanced adipogenesis, as well as optn-/ - mice. Importantly, restoring Optn by transplanting wild-type MSCs to optn-/ - mice or infecting optn-/ - mice with Optn-containing lentivirus rescued bone loss. The introduction of a loss-of-function mutant of OptnK193R failed to reestablish a bone-fat balance. We further identified FABP3 (fatty acid binding protein 3, muscle and heart) as a novel selective autophagy substrate of OPTN. FABP3 promoted adipogenesis and inhibited osteogenesis of MSCs. Knockdown of FABP3 alleviated bone loss in optn-/ - mice and aged mice. Our study revealed that reduced OPTN expression during aging might lead to OP due to a lack of FABP3 degradation via selective autophagy. FABP3 accumulation impaired osteogenesis of MSCs, leading to the occurrence of OP. Thus, reactivating OPTN or inhibiting FABP3 would open a new avenue to treat senile OP.Abbreviations: ADIPOQ: adiponectin, C1Q and collagen domain containing; ALPL: alkaline phosphatase, liver/bone/kidney; BGLAP/OC/osteocalcin: bone gamma carboxyglutamate protein; BFR/BS: bone formation rate/bone surface; CALCOCO2/NDP52: calcium binding and coiled-coil domain 2; CDKN1A/p21: cyclin-dependent kinase inhibitor 1A; CDKN2A/p16: cyclin dependent kinase inhibitor 2A; CDKN2B/p15: cyclin dependent kinase inhibitor 2B; CEBPA: CCAAT/enhancer binding protein (C/EBP), alpha; COL1A1: collagen, type I, alpha 1; Ct. BV/TV: cortical bone volume fraction; Ct. Th: cortical thickness; Es. Pm: endocortical perimeter; FABP4/Ap2: fatty acid binding protein 4, adipocyte; H2AX: H2A.X variant histone; HE: hematoxylin and eosin; MAP1LC3B: microtubule-associated protein 1 light chain 3 beta; MAR: mineral apposition rate; MSCs: bone marrow mesenchymal stem cells; NBR1: NBR1, autophagy cargo receptor; OP: osteoporosis; OPTN: optineurin; PDB: Paget disease of bone; PPARG: peroxisome proliferator activated receptor gamma; Ps. Pm: periosteal perimeter; qRT-PCR: quantitative real-time PCR; γH2AX: Phosphorylation of the Serine residue of H2AX; ROS: reactive oxygen species; RUNX2: runt related transcription factor 2; SA-GLB1: senescence-associated (SA)-GLB1 (galactosidase, beta 1); SP7/Osx/Osterix: Sp7 transcription factor 7; SQSTM1/p62: sequestosome 1; TAX1BP1: Tax1 (human T cell leukemia virus type I) binding protein 1; Tb. BV/TV: trabecular bone volume fraction; Tb. N: trabecular number; Tb. Sp: trabecular separation; Tb. Th: trabecular thickness; µCT: micro computed tomography.