The Effect of Low Intensity Pulsed Ultrasound on Endometrial Receptivity in Infertile Patients with Adenomyosis

Objective: Adenomyosis (AM) is an important cause of female infertility, and its disease mechanism remains unclear. This study preliminarily investigated the expression of endometrial receptivity markers homeobox A10 (HOXA10) and leukemia inhibitory factor (LIF) in infertile patients with AM and described the effects of low intensity pulsed ultrasound (LIPUS) on it. Methods: In vivo, tissues were obtained from the infertile female AM patient group (AG group, n=10) and healthy control group (CG group, n=11). The expression of HOXA10 and LIF in the two groups was detected by immunohistochemistry (IHC) and western blotting. In vitro, primary cells were extracted and cultured from the two groups, and the expression of HOXA10 and LIF protein was detected by western blotting. Then the AG cells were treated with 15, 30, and 60 mW/cm2 of LIPUS for 7 days (20 min/day), and detected the cell adhesion rate. Finally, treat the AG cells with 30mW/cm2 LIPUS for 7 days (20 min/day), and detect the expression level of ICAM-1 in the cell supernatant by ELISA. The AG cells was treated with 30 mW/cm2 LIPUS for 4 days (20 min/day), and the expression levels of HOXA10 and LIF were detected by western blotting, RT-PCR, and agarose gel electrophoresis. Results: In vivo, IHC staining showed that HOXA10 and LIF proteins were mainly localized in endometrial epithelial cells. Both IHC and western blot showed that the levels of HOXA10 and LIF in the AG group were significantly lower than those in the CG group (P<0.01, P<0.05). In vitro, the expression levels of HOXA10 and LIF protein in the AG cell was significantly lower than those in the CG cell (P<0.001). Then, the cell adhesion ability of the 30 and 60 mW/cm2 groups was higher than that of the 15 mW/cm2 group after LIPUS treatment. Finally, The concentration of ICAM-1 in the supernatant of AG cells treated with LIPUS was significantly higher than that of the control group (P<0.01), and the AG cells were treated with 30 mW/cm2 LIPUS for 4 days (20 min/day), the protein and mRNA expression levels of HOXA10 and LIF were higher than those of the control group (P<0.001). Conclusion: The reduction of HOXA10 and LIF may be one of the reasons for the decreased endometrial receptivity in AM. The LIPUS promoted the adhesion and the expression of HOXA10 and LIF of EEECs from the AM group, thereby increasing endometrial receptivity.

Potential Application of Low-Intensity Pulsed Ultrasound in Delaying Aging for Mice

<b><i>Introduction:</i></b> The low-intensity pulsed ultrasound (LIPUS) is one of the popular treatment modalities allowing to boost the proliferation, differentiation, and migratory activity of cells, which might be a powerful strategy for anti-aging. Seeking a novel setup for LIPUS would benefit the development of ultrasound therapeutics. <b><i>Methods:</i></b> Here, we proposed a novel underwater exposure setup of LIPUS. C57BL/6 mice were reared in the designated age-groups, which consisted of a middle-aged group (12–14 months) and an old-age group (20–23 months). The age-related changes of body composition, imbalance of energy supply and demand, imbalance of signal network maintaining internal stability, and representative phenotypes of neurodegeneration and neuroplasticity with the presence and absence of underwater LIPUS in middle-aged and aged groups were evaluated. <b><i>Results:</i></b> The results showed that there were obvious aging changes, imbalance of energy supply and demand, imbalance of signal network maintaining homeostasis, neurodegeneration, and damage of neural plasticity in the middle-aged and aged group with or without the LIPUS. Although middle-aged group and aged group responded differently to LIPUS, they mostly generated positive results in relieving bone loss, improving ovarian structure, regulated immune system, and enhanced endurance ability, which should have declined over age. <b><i>Discussion:</i></b> These findings indicate that underwater extracorporeal LIPUS exposure could be employed as single or combined anti-aging strategies that generated positive outcomes against the process of aging.

The Attenuating Effect of Low-Intensity Pulsed Ultrasound on Hypoxia-Induced Rat Chondrocyte Damage in TMJ Osteoarthritis Based on TMT Labeling Quantitative Proteomic Analysis

Temporomandibular joint osteoarthritis (TMJOA) is a degenerative disease with a complex and multifactorial etiology. An increased intrajoint pressure or weakened penetration can exacerbate the hypoxic state of the condylar cartilage microenvironment. Our group previously simulated the hypoxic environment of TMJOA in vitro. Low-intensity pulsed ultrasound (LIPUS) stimulation attenuates chondrocyte matrix degradation via a hypoxia-inducible factor (HIF) pathway-associated mechanism, but the mode of action of LIPUS is currently poorly understood. Moreover, most recent studies investigated the pathological mechanisms of osteoarthritis, but no biomarkers have been established for assessing the therapeutic effect of LIPUS on TMJOA with high specificity, which results in a lack of guidance regarding clinical application. Here, tandem mass tag (TMT)-based quantitative proteomic technology was used to comprehensively screen the molecular targets and pathways affected by the action of LIPUS on chondrocytes under hypoxic conditions. A bioinformatic analysis identified 902 and 131 differentially expressed proteins (DEPs) in the &lt;1% oxygen treatment group compared with the control group and in the &lt;1% oxygen + LIPUS stimulation group compared with the &lt;1% oxygen treatment group, respectively. The DEPs were analyzed by gene ontology (GO), KEGG pathway and protein-protein interaction (PPI) network analyses. By acting on extracellular matrix (ECM)-associated proteins, LIPUS increases energy production and activates the FAK signaling pathway to regulate cell biological behaviors. DEPs of interest were selected to verify the reliability of the proteomic results. In addition, this experiment demonstrated that LIPUS could upregulate chondrogenic factors (such as Sox9, Collagen Ⅱ and Aggrecan) and increase the mucin sulfate content. Moreover, LIPUS reduced the hydrolytic degradation of the ECM by decreasing the MMP3/TIMP1 ratio and vascularization by downregulating VEGF. Interestingly, LIPUS improved the migration ability of chondrocytes. In summary, LIPUS can regulate complex biological processes in chondrocytes under hypoxic conditions and alter the expression of many functional proteins, which results in reductions in hypoxia-induced chondrocyte damage. ECM proteins such as thrombospondin4, thrombospondin1, IL1RL1, and tissue inhibitors of metalloproteinase 1 play a central role and can be used as specific biomarkers determining the efficacy of LIPUS and viable clinical therapeutic targets of TMJOA.

Low Intensity Pulsed Ultrasound for Bone Tissue Engineering

As explained by Wolff’s law and the mechanostat hypothesis, mechanical stimulation can be used to promote bone formation. Low intensity pulsed ultrasound (LIPUS) is a source of mechanical stimulation that can activate the integrin/phosphatidylinositol 3-OH kinase/Akt pathway and upregulate osteogenic proteins through the production of cyclooxygenase-2 (COX-2) and prostaglandin E2 (PGE2). This paper analyzes the results of in vitro and in vivo studies that have evaluated the effects of LIPUS on cell behavior within three-dimensional (3D) titanium, ceramic, and hydrogel scaffolds. We focus specifically on cell morphology and attachment, cell proliferation and viability, osteogenic differentiation, mineralization, bone volume, and osseointegration. As shown by upregulated levels of alkaline phosphatase and osteocalcin, increased mineral deposition, improved cell ingrowth, greater scaffold pore occupancy by bone tissue, and superior vascularization, LIPUS generally has a positive effect and promotes bone formation within engineered scaffolds. Additionally, LIPUS can have synergistic effects by producing the piezoelectric effect and enhancing the benefits of 3D hydrogel encapsulation, growth factor delivery, and scaffold modification. Additional research should be conducted to optimize the ultrasound parameters and evaluate the effects of LIPUS with other types of scaffold materials and cell types.

Molecular and Metabolic Mechanism of Low-Intensity Pulsed Ultrasound Improving Muscle Atrophy in Hindlimb Unloading Rats

Low-intensity pulsed ultrasound (LIPUS) has been proved to promote the proliferation of myoblast C2C12. However, whether LIPUS can effectively prevent muscle atrophy has not been clarified, and if so, what is the possible mechanism. The aim of this study is to evaluate the effects of LIPUS on muscle atrophy in hindlimb unloading rats, and explore the mechanisms. The rats were randomly divided into four groups: normal control group (NC), hindlimb unloading group (UL), hindlimb unloading plus 30 mW/cm2 LIPUS irradiation group (UL + 30 mW/cm2), hindlimb unloading plus 80 mW/cm2 LIPUS irradiation group (UL + 80 mW/cm2). The tails of rats in hindlimb unloading group were suspended for 28 days. The rats in the LIPUS treated group were simultaneously irradiated with LIPUS on gastrocnemius muscle in both lower legs at the sound intensity of 30 mW/cm2 or 80 mW/cm2 for 20 min/d for 28 days. C2C12 cells were exposed to LIPUS at 30 or 80 mW/cm2 for 5 days. The results showed that LIPUS significantly promoted the proliferation and differentiation of myoblast C2C12, and prevented the decrease of cross-sectional area of muscle fiber and gastrocnemius mass in hindlimb unloading rats. LIPUS also significantly down regulated the expression of MSTN and its receptors ActRIIB, and up-regulated the expression of Akt and mTOR in gastrocnemius muscle of hindlimb unloading rats. In addition, three metabolic pathways (phenylalanine, tyrosine and tryptophan biosynthesis; alanine, aspartate and glutamate metabolism; glycine, serine and threonine metabolism) were selected as important metabolic pathways for hindlimb unloading effect. However, LIPUS promoted the stability of alanine, aspartate and glutamate metabolism pathway. These results suggest that the key mechanism of LIPUS in preventing muscle atrophy induced by hindlimb unloading may be related to promoting protein synthesis through MSTN/Akt/mTOR signaling pathway and stabilizing alanine, aspartate and glutamate metabolism.