Schwann cells acquire a repair phenotype after assembling into spheroids and show enhanced in vivo therapeutic potential for promoting peripheral nerve repair.

The prognosis for postinjury peripheral nerve regeneration remains suboptimal. Although transplantation of exogenous Schwann cells (SCs) has been considered a promising treatment to promote nerve repair, this strategy has been hampered in practice by the limited availability of SC sources and an insufficient postengraftment cell retention rate. In this study, to address these challenges, SCs were aggregated into spheroids before being delivered to an injured rat sciatic nerve. We found that the three-dimensional aggregation of SCs induced their acquisition of a repair phenotype, as indicated by enhanced levels of c-Jun expression/activation and decreased expression of myelin sheath protein. Furthermore, our in vitro results demonstrated the superior potential of the SC spheroid-derived secretome in promoting neurite outgrowth of dorsal root ganglion neurons, enhancing the proliferation and migration of endogenous SCs, and recruiting macrophages. Moreover, transplantation of SC spheroids into rats after sciatic nerve transection effectively increased the postinjury nerve structure restoration and motor functional recovery rates, demonstrating the therapeutic potential of SC spheroids. In summary, transplantation of preassembled SC spheroids may hold great potential for enhancing the cell delivery efficiency and the resultant therapeutic outcome, thereby improving SC-based transplantation approaches for promoting peripheral nerve regeneration.

The Transplantation of 3-Dimensional Spheroids of Adipose-Derived Stem Cells Promotes Achilles Tendon Healing in Rabbits by Enhancing the Proliferation of Tenocytes and Suppressing M1 Macrophages.

BACKGROUND: Tendons have limited regenerative potential, so healing of ruptured tendon tissue requires a prolonged period, and the prognosis is suboptimal. Although stem cell transplantation-based approaches show promise for accelerating tendon repair, the resultant therapeutic efficacy remains unsatisfactory. HYPOTHESIS: The transplantation of stem cells preassembled as 3-dimensional spheroids achieves a superior therapeutic outcome compared with the transplantation of single-cell suspensions. STUDY DESIGN: Controlled laboratory study. METHODS: Adipose-derived stem cells (ADSCs) were assembled as spheroids using a methylcellulose hydrogel system. The secretome of ADSC suspensions or spheroids was collected and utilized to treat tenocytes and macrophages to evaluate their therapeutic potential and investigate the mechanisms underlying their effects. RNA sequencing was performed to investigate the global difference in gene expression between ADSC suspensions and spheroids in an in vitro inflammatory microenvironment. For the in vivo experiment, rabbits that underwent Achilles tendon transection, followed by stump suturing, were randomly assigned to 1 of 3 groups: intratendinous injection of saline, rabbit ADSCs as conventional single-cell suspensions, or preassembled ADSC spheroids. The tendons were harvested for biomechanical testing and histological analysis at 4 weeks postoperatively. RESULTS: Our in vitro results demonstrated that the secretome of ADSCs assembled as spheroids exhibited enhanced modulatory activity in (1) tenocyte proliferation (P = .015) and migration (P = .001) by activating extracellular signal-regulated kinase (ERK) signaling and (2) the suppression of the secretion of interleukin-6 (P = .005) and interleukin-1α (P = .042) by M1 macrophages via the COX-2/PGE2/EP4 signaling axis. Gene expression profiling of cells exposed to an inflammatory milieu revealed significantly enriched terms that were associated with the immune response, cytokines, and tissue remodeling in preassembled ADSC spheroids. Ex vivo fluorescence imaging revealed that the engraftment efficiency of ADSCs in the form of spheroids was higher than that of ADSCs in single-cell suspensions (P = .003). Furthermore, the transplantation of ADSC spheroids showed superior therapeutic effects in promoting the healing of sutured stumps, as evidenced by improvements in the tensile strength (P = .019) and fiber alignment (P < .001) of the repaired tendons. CONCLUSION: The assembly of ADSCs as spheroids significantly advanced their potential to harness tenocytes and macrophages. As a proof of concept, this study clearly demonstrates the effectiveness of using ADSC spheroids to promote tendon regeneration. CLINICAL RELEVANCE: The present study lays a foundation for future clinical applications of stem cell spheroid-based therapy for the management of tendon injuries.

Predicting Negative Emotions Based on Mobile Phone Usage Patterns: An Exploratory Study.

BACKGROUND: Prompt recognition and intervention of negative emotions is crucial for patients with depression. Mobile phones and mobile apps are suitable technologies that can be used to recognize negative emotions and intervene if necessary. OBJECTIVE: Mobile phone usage patterns can be associated with concurrent emotional states. The objective of this study is to adapt machine-learning methods to analyze such patterns for the prediction of negative emotion. METHODS: We developed an Android-based app to capture emotional states and mobile phone usage patterns, which included call logs (and use of apps). Visual analog scales (VASs) were used to report negative emotions in dimensions of depression, anxiety, and stress. In the system-training phase, participants were requested to tag their emotions for 14 consecutive days. Five feature-selection methods were used to determine individual usage patterns and four machine-learning methods were tested. Finally, rank product scoring was used to select the best combination to construct the prediction model. In the system evaluation phase, participants were then requested to verify the predicted negative emotions for at least 5 days. RESULTS: Out of 40 enrolled healthy participants, we analyzed data from 28 participants, including 30% (9/28) women with a mean (SD) age of 29.2 (5.1) years with sufficient emotion tags. The combination of time slots of 2 hours, greedy forward selection, and Naïve Bayes method was chosen for the prediction model. We further validated the personalized models in 18 participants who performed at least 5 days of model evaluation. Overall, the predictive accuracy for negative emotions was 86.17%. CONCLUSION: We developed a system capable of predicting negative emotions based on mobile phone usage patterns. This system has potential for ecological momentary intervention (EMI) for depressive disorders by automatically recognizing negative emotions and providing people with preventive treatments before it escalates to clinical depression.

GALNT14 genotype effectively predicts the therapeutic response in unresectable hepatocellular carcinoma treated with transcatheter arterial chemoembolization.

AIM: Transcatheter arterial chemoembolization is currently the standard treatment in hepatocellular carcinoma patients with Barcelona Clinic Liver Cancer stage B. Genomic variants of GALNT14 were recently identified as effective predictors for chemotherapy responses in Barcelona Clinic Liver Cancer stage C patients. METHODS: We investigated the prognosis predictive value of GALNT14 genotypes in 327 hepatocelluar carcinoma patients treated by transcatheter arterial chemoembolization. RESULT: Cox proportional hazards model analysis showed that the genotype 'TT' was associated with shorter time-to-response (multivariate p < 0.001), time-to-complete-response (p = 0.004) and longer time-to-tumor progression (p < 0.001), compared with the genotype 'non-TT'. In patients with albumin <3.5 g/dl, genotype 'TT' was associated with longer overall survival (p = 0.027). Finally, genotype 'TT' correlated with higher cancer-to-noncancer ratios of GALNT14 protein levels, lower cancer-to-noncancer ratios of antiapoptotic cFLIP-S, and a clustered glycosylation pattern in the extracellular domain of death receptor 5. CONCLUSION: GALNT14 genotypes were significantly associated with clinical outcomes of transcatheter arterial chemoembolization. The differential status of extrinsic apoptotic signaling between cancerous and non-cancerous tissues might underlie the clinical association.

Genotyping the GALNT14 gene by joint analysis of two linked single nucleotide polymorphisms using liver tissues for clinical and geographical comparisons.

A GALNT14 single nucleotide polymorphism, rs9679162, has recently been found to be capable of predicting chemotherapy responses in patients with far-advanced hepatocellular carcinoma (HCC). In the present study, a novel assay was designed and genotyping was performed on 244 surgically removed liver tissues. This assay employed two polymerase chain reaction (PCR)-generated restriction enzyme sites to simultaneously determine the genotypes of two adjacent single nucleotide polymorphisms (SNPs), rs9679162 and rs6752303, on the GALNT14 gene. Genotypes determined by this assay reached 100% concordance with those detected by the direct sequencing method. Clinical analysis showed that the TT genotype of rs9679162 was lower in percentage among patients with virus-originated HCC compared with those with non-viral HCC (22.57 vs. 47.06%, respectively; P=0.023). The proportion of the TT genotype in the 244 HCC patients (24.18%) did not deviate significantly from those of two public-domain (HapMap) Chinese cohorts from Denver, Colorado, USA (28.44%) and Beijing, China (30.15%) (P>0.05). The proportion of the TT genotype was significantly higher in Japanese and African populations (42.11-54.55%; P<0.0001) but significantly lower in an Italian cohort (7.84%; P=0.0004). In conclusion, the novel PCR-generated double restriction enzyme sites method could correctly determine the genotypes of two target SNPs in GALNT14 in liver tissues. The TT genotype was associated with the non-viral etiology of HCC. A marked variation in ethnicity was found for the distribution of this genotype.

Targeted delivery of tissue plasminogen activator by binding to silica-coated magnetic nanoparticle.

BACKGROUND AND METHODS: Silica-coated magnetic nanoparticle (SiO(2)-MNP) prepared by the sol-gel method was studied as a nanocarrier for targeted delivery of tissue plasminogen activator (tPA). The nanocarrier consists of a superparamagnetic iron oxide core and an SiO(2) shell and is characterized by transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, superconducting quantum interference device, and thermogravimetric analysis. An amine-terminated surface silanizing agent (3-aminopropyltrimethoxysilane) was used to functionalize the SiO(2) surface, which provides abundant -NH(2) functional groups for conjugating with tPA. RESULTS: The optimum drug loading is reached when 0.5 mg/mL tPA is conjugated with 5 mg SiO(2)-MNP where 94% tPA is attached to the carrier with 86% retention of amidolytic activity and full retention of fibrinolytic activity. In vitro biocompatibility determined by lactate dehydrogenase release and cell proliferation indicated that SiO(2)-MNP does not elicit cytotoxicity. Hematological analysis of blood samples withdrawn from mice after venous administration indicates that tPA-conjugated SiO(2)-MNP (SiO(2)-MNP-tPA) did not alter blood component concentrations. After conjugating to SiO(2)-MNP, tPA showed enhanced storage stability in buffer and operation stability in whole blood up to 9.5 and 2.8-fold, respectively. Effective thrombolysis with SiO(2)-MNP-tPA under magnetic guidance is demonstrated in an ex vivo thrombolysis model where 34% and 40% reductions in blood clot lysis time were observed compared with runs without magnetic targeting and with free tPA, respectively, using the same drug dosage. Enhanced penetration of SiO(2)-MNP-tPA into blood clots under magnetic guidance was confirmed from microcomputed tomography analysis. CONCLUSION: Biocompatible SiO(2)-MNP developed in this study will be useful as a magnetic targeting drug carrier to improve clinical thrombolytic therapy.