Machine learning-based prediction of in-hospital mortality for critically ill patients with sepsis-associated acute kidney injury.

OBJECTIVES: This study aims to develop and validate a prediction model in-hospital mortality in critically ill patients with sepsis-associated acute kidney injury (SA-AKI) based on machine learning algorithms. METHODS: Patients who met the criteria for inclusion were identified in the Medical Information Mart for Intensive Care-IV (MIMIC-IV) database and divided according to the validation (n = 2440) and development (n = 9756, 80%) queues. Ensemble stepwise feature selection method was used to screen for effective features. The prediction models of short-term mortality were developed by seven machine learning algorithms. Ten-fold cross-validation was used to verify the performance of the algorithm in the development queue. The area under the receiver operating characteristic curve (ROC-AUC) was used to evaluate the differentiation accuracy and performance of the prediction model in the validation queue. The best-performing model was interpreted by Shapley additive explanations (SHAP). RESULTS: A total of 12,196 patients were enrolled in this study. Eleven variables were finally chosen to develop the prediction model. The AUC of the random forest (RF) model was the highest value both in the Ten-fold cross-validation and evaluation (AUC: 0.798, 95% CI: 0.774-0.821). According to the SHAP plots, old age, low Glasgow Coma Scale (GCS) score, high AKI stage, reduced urine output, high Simplified Acute Physiology Score (SAPS II), high respiratory rate, low temperature, low absolute lymphocyte count, high creatinine level, dysnatremia, and low body mass index (BMI) increased the risk of poor prognosis. CONCLUSIONS: The RF model developed in this study is a good predictor of in-hospital mortality for patients with SA-AKI in the intensive care unit (ICU), which may have potential applications in mortality prediction.

Application of mesenchymal stem cells for anti-senescence and clinical challenges.

Senescence is a hot topic nowadays, which shows the accumulation of senescent cells and inflammatory factors, leading to the occurrence of various senescence-related diseases. Although some methods have been identified to partly delay senescence, such as strengthening exercise, restricting diet, and some drugs, these only slow down the process of senescence and cannot fundamentally delay or even reverse senescence. Stem cell-based therapy is expected to be a potential effective way to alleviate or cure senescence-related disorders in the coming future. Mesenchymal stromal cells (MSCs) are the most widely used cell type in treating various diseases due to their potentials of self-replication and multidirectional differentiation, paracrine action, and immunoregulatory effects. Some biological characteristics of MSCs can be well targeted at the pathological features of aging. Therefore, MSC-based therapy is also a promising strategy to combat senescence-related diseases. Here we review the recent progresses of MSC-based therapies in the research of age-related diseases and the challenges in clinical application, proving further insight and reference for broad application prospects of MSCs in effectively combating senesce in the future.

Engineered clinical-grade mesenchymal stromal cells combating SARS-CoV-2 omicron variants by secreting effective neutralizing antibodies.

BACKGROUND: The emergence of SARS-CoV-2 becomes life-threatening for the older and immunocompromised individuals, whereas limited treatment is available on these populations. Mesenchymal stromal cells (MSCs) have been reported to be useful in SARS-CoV-2 treatment and reduce SARS-CoV-2-related sequelae. RESULTS: In this study, we developed an autonomous cellular machine to secret neutralizing antibody in vivo constantly based on the clinical-grade MSCs, to combat SARS-CoV-2 infections. First, various modified recombinant plasmids were constructed and transfected into clinical-grade MSCs by electroporation, for assembly and expression of neutralizing anti-SARS-CoV-2 antibodies. Second, the stable antibody secreting MSCs clones were screened through pseudovirus neutralization assay. Finally, we investigated the pharmacokinetics and biodistribution of neutralizing antibody secreted by engineered MSCs in vivo. The stable clinical-grade MSCs clones, expressing XGv347-10 and LY-CoV1404-5 neutralizing antibodies, exhibited their feasibility and protective efficacy against SARS-CoV-2 infection. Transplanted engineered clinical-grade MSCs effectively delivered the SARS-CoV-2 antibodies to the lung, and the immune hyperresponsiveness caused by COVID-19 was coordinated by MSC clones through inhibiting the differentiation of CD4 + T cells into Th1 and Th17 subpopulations. CONCLUSIONS: Our data suggested that engineered clinical-grade MSCs secreting effective neutralizing antibodies as cellular production machines had the potential to combat SARS-CoV-2 infection, which provided a new avenue for effectively treating the older and immunocompromised COVID-19 patients.

The UCMSC-bFGF/Scaffold System Accelerates the Healing of the Uterine Full-Thickness Injury.

Severe uterine injury is a major cause of endometrial scar formation and female infertility. At present, the methods for accelerating injured uterine healing are still lacking. Genetic engineering modification of mesenchymal stem cells (MSCs) has been shown great promise in preclinical studies on regeneration. Here, we constructed a type of umbilical cord MSCs (UC-MSCs) with overexpressed basic fibroblast growth factor (UCMSC-bFGF) and investigated the effects of the UCMSC-bFGF/scaffold on functional regeneration of the full-thickness defect uterus of the rat model. At days 7, 14, and 30 after treatments, the rats were killed and the injured uterus was observed. The structural and functional change of uterine was assessed by hematoxylin and eosin staining, immunohistochemical staining, and fertility experiment. The UCMSC-bFGF/scaffold group exhibited anti-inflammatory effect, and the number of CD45+ cell in the UCMSC-bFGF/scaffold group was significantly less than that in UC-MSCs/scaffold group and scaffold group, but higher than sham-operated group at day 7 postmending. At day 14, the UCMSC-bFGF/scaffold group exhibited dramatically proangiogenesis efficacy compared with UC-MSCs/scaffold group and scaffold group. At day 30, the endometrial thickness, structure of myometrium, and blood vessels in the UCMSC-bFGF/scaffold were better than those of the UC-MSCs/scaffold group and scaffold group, even close to sham-operated group. Implantation rate at injury region postoperation 30 days in the UCMSC-bFGF/scaffold group (8/16) was significantly higher than that in UC-MSCs/scaffold group (1/16) and scaffold group (0/16). Taken together, the UCMSC-bFGF/scaffold system suppressed local inflammation, promoted angiogenesis, and accelerated regeneration of the defected uterine wall, and thereby greatly shortened the healing time of the injured uterus. Impact statement In this study, we used umbilical cord mesenchymal stem cells (UC-MSCs) with stably overexpressed basic fibroblast growth factor (UCMSC-bFGF) to repair the full-thickness defect uterine wall of the rat model and found that the UCMSC-bFGF/scaffold system suppressed early acute inflammation after uterus injury, promoted angiogenesis, and accelerated regeneration of the injured uterine wall.

Development and validation of short-term renal prognosis prediction model in diabetic patients with acute kidney injury.

OBJECTIVE: Diabetes is a major cause of the progression of acute kidney injury (AKI). Few prediction models have been developed to predict the renal prognosis in diabetic patients with AKI so far. The aim of this study was to develop and validate a predictive model to identify high-risk individuals with non-recovery of renal function at 90 days in diabetic patients with AKI. METHODS: Demographic data and related laboratory indicators of diabetic patients with AKI in the First Affiliated Hospital of Guangxi Medical University from January 31, 2012 to January 31, 2022 were retrospectively analysed, and patients were followed up to 90 days after AKI diagnosis. Based on the results of Logistic regression, a model predicting the risk of non-recovery of renal function at 90 days in diabetic patients with AKI was developed and internal validated. Consistency index (C-index), calibration curve, and decision curve analysis were used to evaluate the differentiation, accuracy, and clinical utility of the prediction model, respectively. RESULTS: A total of 916 diabetic patients with AKI were enrolled, with a male to female ratio of 2.14:1. The rate of non-recovery of renal function at 90 days was 66.8% (612/916). There were 641 in development cohort and 275 in validation cohort (ration of 7:3). In the development cohort, a prediction model was developed based on the results of Logistic regression analysis. The variables included in the model were: diabetes duration (OR = 1.022, 95% CI 1.012-1.032), hypertension (OR = 1.574, 95% CI 1.043-2.377), chronic kidney disease (OR = 2.241, 95% CI 1.399-3.591), platelet (OR = 0.997, 95% CI 0.995-1.000), 25-hydroxyvitamin D3 (OR = 0.966, 95% CI 0.956-0.976), postprandial blood glucose (OR = 1.104, 95% CI 1.032-1.181), discharged serum creatinine (OR = 1.003, 95% CI 1.001-1.005). The C-indices of the prediction model were 0.807 (95% CI 0.738-0.875) and 0.803 (95% CI 0.713-0.893) in the development and validation cohorts, respectively. The calibration curves were all close to the straight line with slope 1. The decision curve analysis showed that in a wide range of threshold probabilities. CONCLUSION: A prediction model was developed to help predict short-term renal prognosis of diabetic patients with AKI, which has been verified to have good differentiation, calibration degree and clinical practicability.

A long-term anti-inflammation markedly alleviated high-fat diet-induced obesity by repeated administrations of overexpressing IL10 human umbilical cord-derived mesenchymal stromal cells.

OBJECTIVES: Obesity is a chronic process and could activate various inflammatory responses, which in turn aggravates obesity and related metabolic syndrome. Here we explored whether long-term inhibition of inflammation could successfully alleviate high-fat diet (HFD)-induced obesity. METHODS: We constructed stable overexpressing interleukin 10 (IL10) human umbilical cord-derived mesenchymal stromal cells (HUCMSCs) which repeatedly were applied to obesity mice with HFD feeding to obtain a long-term anti-inflammation based on the prominent anti-inflammation effects of IL10 and immunomodulatery effects of HUCMSCs. Then we monitored the features of obesity including body weight, serum ALT, AST, and lipids. In addition, glucose homeostasis was determined by glucose tolerance and insulin sensitivity tests. The infiltrated macrophages in adipose tissues and hepatic lipid accumulation were detected, and the expressions of adipogenesis and inflammatory genes in adipose tissues were examined by real-time (RT) PCR and western blot analysis. RESULTS: Compared with HUCMSCs, IL10-HUCMSCs treatment had much better anti-obesity effects including body weight reduction, less hepatic lipids accumulation, lower amount and size of adipocyte, greater glucose tolerance, less systemic insulin resistance, and less adipose tissue inflammation in HFD feeding mice. Finally, IL10-HUCMSCs could decrease the activation of MAPK JNK of adipose tissue induced by HFD. The inhibition of MAPK JNK signal pathway by a small chemical molecule SP600125 in 3T3-L1 cells, a preadipocyte line, reduced the differentiation of adipocytes and lipid droplet accumulation. CONCLUSION: A lasting anti-inflammation based on gene modified stem cell therapy is an effective strategy in preventing diet-induced obesity and obesity-related metabolic syndrome.

Interleukin-10 genetically modified clinical-grade mesenchymal stromal cells markedly reinforced functional recovery after spinal cord injury via directing alternative activation of macrophages.

BACKGROUND: After spinal cord injury (SCI), dysregulated or nonresolving inflammatory processes can severely disturb neuronal homeostasis and drive neurodegeneration. Although mesenchymal stromal cell (MSC)-based therapies have showed certain therapeutic efficacy, no MSC therapy has reached its full clinical goal. In this study, we examine interleukin-10 (IL10) genetically modified clinical-grade MSCs (IL10-MSCs) and evaluate their clinical safety, effectiveness, and therapeutic mechanism in a completely transected SCI mouse model. METHODS: We established stable IL10-overexpressing human umbilical-cord-derived MSCs through electric transduction and screened out clinical-grade IL10-MSCs according to the criteria of cell-based therapeutic products, which were applied to mice with completely transected SCI by repeated tail intravenous injections. Then we comprehensively investigated the motor function, histological structure, and nerve regeneration in SCI mice, and further explored the potential therapeutic mechanism after IL10-MSC treatment. RESULTS: IL10-MSC treatment markedly reinforced locomotor improvement, accompanied with decreased lesion volume, regeneration of axons, and preservation of neurons, compared with naïve unmodified MSCs. Further, IL10-MSC transplantation increased the ratio of microglia to infiltrated alternatively activated macrophages (M2), and reduced the ratio of classically activated macrophages (M1) at the injured spinal cord, meanwhile increasing the percentage of Treg and Th2 cells, and reducing the percentage of Th1 cells in the peripheral circulatory system. In addition, IL10-MSC administration could prevent apoptosis and promote neuron differentiation of neural stem cells (NSCs) under inflammatory conditions in vitro. CONCLUSIONS: IL10-MSCs exhibited a reliable safety profile and demonstrated promising therapeutic efficacy in SCI compared with naïve MSCs, providing solid support for future clinical application of genetically engineered MSCs.

Engineered basic fibroblast growth factor-overexpressing human umbilical cord-derived mesenchymal stem cells improve the proliferation and neuronal differentiation of endogenous neural stem cells and functional recovery of spinal cord injury by activating the PI3K-Akt-GSK-3ß signaling pathway.

OBJECTIVES: To investigate the safety for clinic use and therapeutic effects of basic fibroblast growth factor (bFGF)-overexpressing human umbilical cord-derived mesenchymal stem cells (HUCMSCs) in mice with completely transected spinal cord injury (SCI). METHODS: Stable bFGF-overexpressing HUCMSCs clones were established by electrotransfection and then subjected to systematic safety evaluations. Then, bFGF-overexpressing and control HUCMSCs were used to treat mice with completely transected SCI by tail intravenous injection. Therapeutic outcomes were then investigated, including functional recovery of locomotion, histological structures, nerve regeneration, and recovery mechanisms. RESULTS: Stable bFGF-overexpressing HUCMSCs met the standards and safety of MSCs for clinic use. In the mouse SCI model, stable bFGF-overexpressing HUCMSCs markedly improved therapeutic outcomes such as reducing glial scar formation, improving nerve regeneration and proliferation of endogenous neural stem cells (NSCs), and increasing locomotion functional recovery of posterior limbs compared with the control HUCMSCs group. Furthermore, bFGF-overexpressing HUCMSCs promoted the proliferation and neuronal differentiation of NSCs in vitro through the PI3K-Akt-GSK-3ß pathway. CONCLUSION: bFGF-overexpressing HUCMSCs meet the requirements of clinical MSCs and improve evident therapeutic outcomes of mouse SCI treatment, which firmly supports the safety and efficacy of gene-modified MSCs for clinical application.

Analysis of Key Distinct Biological Characteristics of Human Placenta-Derived Mesenchymal Stromal Cells and Individual Heterogeneity Attributing to Donors.

For potential clinical applications in the future, we investigated the distinct biological features of mesenchymal stromal cells (MSCs) derived from different origin areas of human placenta and individual heterogeneity among different donors. Chorionic plate MSCs (CP-MSCs), amniotic membrane MSCs (AM-MSCs), and decidual plate MSCs (DP-MSCs) were isolated from 5 human placentae and were analyzed in terms of main features of MSCs including surface marker profile, growth, differentiation potential, immune regulation capability, and tubulin acetylation (Ac-tubulin). The expression profile of surface markers in the 3 types of MSCs derived from the 5 donors was relatively stable. Heterogeneity was found in growth, differentiation potential, and immune regulation among MSCs according to the different areas of isolation and different donors. CP-MSCs and AM-MSCs derived from the placentae of donors 1-3 had a higher osteogenic differentiation potential than the corresponding DP-MSCs, but those derived from the placentae of donors 4 and 5 had a markedly lower osteogenic differentiation potential than DP-MSCs. All CP-MSCs derived from donors 1-3 had the highest adipogenic differentiation potential, but CP-MSCs derived from donors 4 and 5 did not show strong capability of adipogenic differentiation. CP-MSCs markedly inhibited the proliferation of peripheral blood mononuclear cells (PBMCs) induced by phytohemagglutinin, whereas AM- and DP-MSCs did not. All MSCs decreased the proportion of CD3+/CD8-/IFN-γ+ Th1 and CD3+/CD8-/IL17+ Th17 cells, but increased the proportion of Treg cells in PBMCs, with individual differences among the 5 donors. DP-MSCs from donors 1 and 2 had higher levels of Ac-tubulin compared with CP- and AM-MSCs. However, the levels of Ac-tubulin in AM-MSCs from donors 3 and 5 were higher than those of the other 2 types of MSCs. Our results revealed that there was tissue-specific heterogeneity among the 3 types of MSCs from different origin tissues of placenta and individual heterogeneity among donors. In future, the pre-selected placenta-derived MSCs with specific biological advantages may improve the curative effect of cell therapy in different situations.

Dynamic changes in the systemic immune responses of spinal cord injury model mice.

Intraspinal inflammatory and immune responses are considered to play central roles in the pathological development of spinal cord injury. This study aimed to decipher the dynamics of systemic immune responses, initiated by spinal cord injury. The spinal cord in mice was completely transected at T8. Changes in the in vivo inflammatory response, between the acute and subacute stages, were observed. A rapid decrease in C-reactive protein levels, circulating leukocytes and lymphocytes, spleen-derived CD4+ interferon-γ+ T-helper cells, and inflammatory cytokines, and a marked increase in neutrophils, monocytes, and CD4+CD25+FOXP3+ regulatory T-cells were observed during the acute phase. These systemic immune alterations were gradually restored to basal levels during the sub-acute phase. During the acute phase of spinal cord injury, systemic immune cells and factors showed significant inhibition; however, this inhibition was transient, and the indicators of these serious disorders gradually returned to baseline levels during the subacute phase. All experiments were performed in accordance with the institutional animal care guidelines, approved by the Institutional Animal Care and Use Committee of Experimental Animal Center of Drum Tower Hospital, China (approval No. 2019AE01040) on June 25, 2019.

Efficacy of Platelet-Rich Plasma Containing Xenogenic Adipose Tissue-Derived Stromal Cells on Restoring Intervertebral Disc Degeneration: A Preclinical Study in a Rabbit Model.

Objective: Platelet-rich plasma (PRP) containing multiple growth factors is a promising strategy for disc degeneration. Thus, this study hypothesizes that the combination of PRP and adipose tissue-derived stromal cells (ADSCs) may repair degenerative disc more effectively than using each one of them alone. Methods: The model of early intervertebral disc degeneration was induced by annular puncture in the New Zealand rabbit. Autologous PRP was extracted from fresh arterial blood by using two centrifugation techniques. ADSC was offered by the Center for Clinic Stem Cell Research. Four weeks after the first experiment, PRP or ADSCs or a combination of PRP and ADSCs was injected into the punctured intervertebral disc. Four weeks later, disc height and signal intensity on T2-weighted magnetic resonance imaging (MRI) were assessed. Results: One month after puncture, we detected relatively narrow discs and lower signal intensity in MRI T2-weighted images. At four weeks after injection, the PRP-ADSC group statistically significantly restored discs, compared with PRP, ADSCs, or negative control group. Conclusions: The combination of PRP and ADSCs shows an effective potential to restore degenerated intervertebral discs in the rabbit.

Reflection and observation: cell-based screening failing to detect HBV in HUMSCs derived from HBV-infected mothers underscores the importance of more stringent donor eligibility to reduce risk of transmission of infectious diseases for stem cell-based medical products.

BACKGROUND: In cell-based therapy, the transmission of communicable diseases imposes a substantial threat to recipients. In this study, we investigated whether cell-based screening could detect hepatitis B virus (HBV) in human umbilical cord-derived mesenchymal stem cells (HUMSCs) isolated from HBV-infected donors to understand the susceptibility of HUMSCs to HBV infection. METHODS: HBV assay was performed in HUMSCs derived from healthy and HBV-infected donors with enzyme-linked immunosorbent assay (ELISA), fluorescence quantitative PCR (FQ-PCR) assay, and droplet digital PCR (ddPCR) assay. Further, HBV DNA was assayed in HUMSCs derived from healthy donors after incubation with human sera containing a high titer of HBV using FQ-PCR. RESULTS: HBV antigen/antibody and DNA failed to be detected using ELISA, FQ-PCR, and ddPCR. After incubation with HBV infection sera, HBV DNA could be detected, but below the valid titer of the assay kit. The HBV DNA levels in HBV-incubated HUMSCs gradually decreased with medium change every 2 days and then significantly decreased, not even detected after passage. CONCLUSIONS: The current cell-based screening methods could not detect HBV in HUMSCs derived from HBV-infected donors, indicating the importance of more stringent donor eligibility to reduce the risk of transmission of communicable diseases in cell-based therapy. To solve the problem of an occult HBV window period in donor eligibility determination, we recommend that the donors undergo another HBV serological test 3 months after the first serological communicable disease screening.

Homologous recombination efficiency enhanced by inhibition of MEK and GSK3ß.

Homologous recombination in embryonic stem cells (ESCs) is widely utilized in genome engineering, particularly in the generation of gene targeted mice. However, genome engineering is often plagued by the problem of low homologous recombination efficiency. In this study, we developed a novel method to increase the efficiency of homologous recombination in ESCs by changing its culture conditions. By comparing the efficiency of different ESCs in various culture conditions, we determined that chemicals that inhibit the MEK and GSK3ß pathways (2i condition) enhance homologous recombination and eliminate differences in efficiencies among cell lines. Analysis of gene expression patterns in ESCs maintained in different culture conditions has identified several homologous recombination-related candidates, including the pluripotent markers Eras and Tbx3. The results of this study suggest that homologous recombination is associated with ESC pluripotency.

The fabrication of an olfactory receptor neuron chip based on planar multi-electrode array and its odor-response analysis.

A novel olfactory neurochip based on olfactory receptor neurons (ORNs) cultivated on the surface of the 60-channel planar multi-electrode array (MEA) devices was developed in this study. In order to investigate the odor-response characteristics of ORNs, two types of odorants at different concentrations were quantitatively pumped into the neurochip by a customized gas intake system, and the extracellular electrical activities of multiple ORNs were simultaneously recorded in vitro. Accordingly, the odor-response features of ORNs such as firing amplitude, firing threshold, firing rate as well as firing channels were analyzed qualitatively and quantitatively in terms of ORN spike trains. Especially, after introducing the classification algorithm based on the spike threshold, the odor-response maps from the multiple sites could be used to identify dl-limonene (LIM) and isoamyle acetate (ISO) odorants. These preliminary studies indicate that the ORN-based biosensor developed here has a potential capability of distinguishing different odorants as a true bionic electronic nose.

[Characteristics analysis of micro-element contents in western Erdos soil and in Tetraena mongolica plant].

This paper studied why the ex-situ conservation of Tetraena mongolica isn't successful. Through measuring and analyzing the micro-element contents in the soil where Tetraena mongolica is naturally distributed and where Tetraena mongolica is introduced in western Erdos. The results showed that among the areas where Tetraena mongolica is native to and the ex situ protection area, the average contents of 9 micro-elements, except B, are not only obviously higher than the average values in China's soil, but also higher than the values in desert areas. The contents of all micro-elements, except Cu, in the ex situ protection area are higher than desert and the natural distribution areas of Tetraena mongolica. Among the contents of the micro-elements in Tetraena mongolica plant, Fe, Cu, Zn, B, Se and Co are quite higher than that in other plant species on steppes, and Mo is higher than that in other plant species but is only 50% to the desert plants. The correlation coefficient for the contents of micro-elements between soil and plants (including adults and seedlings) are not significant and the contents in Tetraena mongolica plant are much higher than available contents of the counterparts in soil. By comparing the contents of micro-elements in Tetraena mongolica, grassland plants on steppe and desert and the contents in soil, it can be seen that every micro-element was enriched by Tetraena mongolica during its growth. The results do not support the suggestion that the contents of micro-elements in soil is the factor restricting the growth of Tetraena mongolica in the ex situ protection area.