Estimation of Periodontal Inflamed Surface Area by Salivary Lactate Dehydrogenase Level Using a Test Kit.

Background: Salivary lactate dehydrogenase (LD) levels are a feasible and useful parameter for screening periodontal diseases. The periodontal inflamed surface area (PISA) is useful to clinically assess periodontal diseases. However, PISA is difficult to calculate and PISA-compatible screening kits are required. We aimed to investigate the association between salivary LD levels, using a test kit, and PISA and PISA-Japanese and determine the feasibility and reliability of the salivary LD test kit for evaluation of periodontal status. Methods: This study included 110 patients (66.4% female, median and 25-75 percentiles of age were 66.5 and 53.0-75.0 years, respectively) who visited the Dental University Clinic in Japan. Resting saliva samples were collected from each participant and LD levels were evaluated in real time using a kit featuring an integer scale ranging from 1 to 10. PISA and PISA-Japanese were calculated using periodontal parameters. Results: The median salivary LD level was 4.0. The medians of PISA and PISA-Japanese were 46.9 and 61.0, respectively. Salivary LD levels were positively correlated with the bleeding on probing rate (r = 0.626, p < 0.001), PISA (r = 0.560, p < 0.001), and PISA-Japanese (r = 0.581, p < 0.001). Conclusions: Our results suggest that salivary LD levels assessed using the salivary LD kit showed a significantly positive correlation with PISA and PISA-Japanese. In addition, we developed the PISA estimation formula using salivary LD levels measured with a test kit, sex, and age.

Combined Autophagy Inhibition and Dendritic Cell Recruitment Induces Antitumor Immunity and Enhances Immune Checkpoint Blockade Sensitivity in Pancreatic Cancer.

The effect of immune checkpoint inhibitors is extremely limited in patients with pancreatic ductal adenocarcinoma (PDAC) due to the suppressive tumor immune microenvironment (TIME). Autophagy, which has been shown to play a role in anti-tumor immunity, has been proposed as a therapeutic target for PDAC. Here, single-cell RNA-sequencing of autophagy-deficient murine PDAC tumors revealed that autophagy inhibition in cancer cells induced dendritic cell (DC) activation. Analysis of human PDAC tumors substantiated a negative correlation between autophagy and DC activation signatures. Mechanistically, autophagy inhibition increased intracellular accumulation of tumor antigens, which could activate DCs. Administration of chloroquine (CQ), an autophagy inhibitor, in combination with Flt3 ligand (Flt3L)-induced DC infiltration inhibited tumor growth and increased tumor-infiltrating T lymphocytes. However, autophagy inhibition in cancer cells also induced CD8+ T cell exhaustion with high expression of immune checkpoint LAG3. A triple therapy comprising CQ, Flt3L, and an anti-LAG3 antibody markedly reduced tumor growth in orthotopic syngeneic PDAC mouse models. Thus, targeting autophagy in cancer cells and activating DCs sensitizes PDAC tumors to immune checkpoint inhibitor therapy, warranting further development of this treatment approach to overcome immunosuppression in pancreatic cancer.

Dynamic glycolytic reprogramming effects on dendritic cells in pancreatic ductal adenocarcinoma.

BACKGROUND: Pancreatic ductal adenocarcinoma tumors exhibit resistance to chemotherapy, targeted therapies, and even immunotherapy. Dendritic cells use glucose to support their effector functions and play a key role in anti-tumor immunity by promoting cytotoxic CD8+ T cell activity. However, the effects of glucose and lactate levels on dendritic cells in pancreatic ductal adenocarcinoma are unclear. In this study, we aimed to clarify how glucose and lactate can impact the dendritic cell antigen-presenting function and elucidate the relevant mechanisms. METHODS: Glycolytic activity and immune cell infiltration in pancreatic ductal adenocarcinoma were evaluated using patient-derived organoids and resected specimens. Cell lines with increased or decreased glycolysis were established from KPC mice. Flow cytometry and single-cell RNA sequencing were used to evaluate the impacts on the tumor microenvironment. The effects of glucose and lactate on the bone marrow-derived dendritic cell antigen-presenting function were detected by flow cytometry. RESULTS: The pancreatic ductal adenocarcinoma tumor microenvironment exhibited low glucose and high lactate concentrations from varying levels of glycolytic activity in cancer cells. In mouse transplantation models, tumors with increased glycolysis showed enhanced myeloid-derived suppressor cell infiltration and reduced dendritic cell and CD8+ T cell infiltration, whereas tumors with decreased glycolysis displayed the opposite trends. In three-dimensional co-culture, increased glycolysis in cancer cells suppressed the antigen-presenting function of bone marrow-derived dendritic cells. In addition, low-glucose and high-lactate media inhibited the antigen-presenting and mitochondrial functions of bone marrow-derived dendritic cells. CONCLUSIONS: Our study demonstrates the impact of dynamic glycolytic reprogramming on the composition of immune cells in the tumor microenvironment of pancreatic ductal adenocarcinoma, especially on the antigen-presenting function of dendritic cells.

Size-Dependent Glioblastoma Targeting by Polymeric Nanoruler with Prolonged Blood Circulation.

Currently, there is no effective treatment for glioblastoma multiforme (GBM), the most frequent and malignant type of brain tumor. The blood-brain (tumor) barrier (BB(T)B), which is composed of tightly connected endothelial cells and pericytes (with partial vasculature collapse), hampers nanomedicine accumulation in tumor tissues. We aimed to explore the effect of nanomedicine size on passive targeting of GBM. A series of size-tunable poly(ethylene glycol) (PEG)-grafted copolymers (gPEGs) were constructed with hydrodynamic diameters of 8-30 nm. Biodistribution studies using orthotopic brain tumor-bearing mice revealed that gPEG brain tumor accumulation was maximized at 10 nm with ∼14 dose %/g of tumor, which was 19 times higher than that in the normal brain region and 4.2 times higher than that of 30-nm gPEG. Notably, 10-nm gPEG exhibited substantially higher brain tumor accumulation than 11-nm linear PEG owing to the prolonged blood circulation property of gPEGs, which is derived from a densely PEG-packed structure. 10 nm gPEG exhibited deeper penetration into the brain tumor tissue than the larger gPEGs did (>10 nm). This study demonstrates, for the first time, the great potential of a nanomedicine downsizing strategy for passive GBM targeting.

Carrier-free mRNA vaccine induces robust immunity against SARS-CoV-2 in mice and non-human primates without systemic reactogenicity.

Carrier-free naked mRNA vaccines may reduce the reactogenicity associated with delivery carriers; however, their effectiveness against infectious diseases has been suboptimal. To boost efficacy, we targeted the skin layer rich in antigen-presenting cells (APCs) and utilized a jet injector. The jet injection efficiently introduced naked mRNA into skin cells, including APCs in mice. Further analyses indicated that APCs, after taking up antigen mRNA in the skin, migrated to the lymph nodes (LNs) for antigen presentation. Additionally, the jet injection provoked localized lymphocyte infiltration in the skin, serving as a physical adjuvant for vaccination. Without a delivery carrier, our approach confined mRNA distribution to the injection site, preventing systemic mRNA leakage and associated systemic proinflammatory reactions. In mouse vaccination, the naked mRNA jet injection elicited robust antigen-specific antibody production over 6 months, along with germinal center formation in LNs and the induction of both CD4- and CD8-positive T cells. By targeting the SARS-CoV-2 spike protein, this approach provided protection against viral challenge. Furthermore, our approach generated neutralizing antibodies against SARS-CoV-2 in non-human primates at levels comparable to those observed in mice. In conclusion, our approach offers a safe and effective option for mRNA vaccines targeting infectious diseases.

mRNA vaccine designs for optimal adjuvanticity and delivery.

Adjuvanticity and delivery are crucial facets of mRNA vaccine design. In modern mRNA vaccines, adjuvant functions are integrated into mRNA vaccine nanoparticles, allowing the co-delivery of antigen mRNA and adjuvants in a unified, all-in-one formulation. In this formulation, many mRNA vaccines utilize the immunostimulating properties of mRNA and vaccine carrier components, including lipids and polymers, as adjuvants. However, careful design is necessary, as excessive adjuvanticity and activation of improper innate immune signalling can conversely hinder vaccination efficacy and trigger adverse effects. mRNA vaccines also require delivery systems to achieve antigen expression in antigen-presenting cells (APCs) within lymphoid organs. Some vaccines directly target APCs in the lymphoid organs, while others rely on APCs migration to the draining lymph nodes after taking up mRNA vaccines. This review explores the current mechanistic understanding of these processes and the ongoing efforts to improve vaccine safety and efficacy based on this understanding.

Selective Intracellular Delivery of Antibodies in Cancer Cells with Nanocarriers Sensing Endo/Lysosomal Enzymatic Activity.

The differential enzymatic activity in the endo/lysosomes of particular cells could trigger targeted endosomal escape functions, enabling selective intracellular protein delivery. However, this strategy may be jeopardized due to protein degradation during endosomal trafficking. Herein, using custom made fluorescent probes to assess the endosomal activity of cathepsin B (CTSB) and protein degradation, we found that certain cancer cells with hyperacidified endosomes grant a spatiotemporal window where CTSB activity surpass protein digestion. This inspired the engineering of antibody-loaded polymeric nanocarriers having CTSB-activatable endosomal escape ability. The nanocarriers selectively escaped from the endo/lysosomes in the cells with high endosomal CTSB activity and delivered active antibodies to intracellular targets. This study provides a viable strategy for cell-specific protein delivery using stimuli-responsive nanocarriers with controlled endosomal escape.

Relationship between risk of oral frailty and awareness of oral frailty among community-dwelling adults: a cross-sectional study.

We aimed to investigate the relationship between the risk of oral frailty and awareness of oral frailty among Japanese adults in an adult dental health field study conducted in Kanagawa Prefecture. Questionnaire data from a total of 5051 individuals (1907 males, 3144 females; mean age; 59.9 years) were used. The risk of oral frailty was assessed using the Oral Frailty Index-8. Of the participants, 1418 (28.1%) had a high risk of oral frailty and 1495 (29.6%) had knowledge of oral frailty. Logistic regression analysis indicated that the risk of oral frailty was significantly associated with awareness of oral frailty. We further found that awareness of oral frailty was significantly related to gender (female), age (20-39 compared to 70-79, ≥ 80), residential areas (Yokohama compared to Kawasaki, Sagamihara), exercise habits (yes), eating a balanced diet (yes), consciousness of oral health (yes), risk of oral frailty (low) and outpatient category (hospital visit). For groups with low levels of awareness obtained from the results of this study, it is necessary to consider the means of accessibility and increase awareness further.

Terbium-Rose Bengal Coordination Nanocrystals-Induced ROS Production under Low-Dose X-rays in Cultured Cancer Cells for Photodynamic Therapy.

X-ray-triggered scintillators (Sc) and photosensitizers (Ps) have been developed for X-ray-induced photodynamic therapy (X-PDT) to selectively destruct deep tissue tumors with a low X-ray dose. This study designed terbium (Tb)-rose bengal (RB) coordination nanocrystals (T-RBNs) by a solvothermal treatment, aiming to reduce photon energy dissipation between Tb3+ and RB and thus increase the reactive oxygen species (ROS) production efficiency. T-RBNs synthesized at a molar ratio of [RB]/[Tb] = 3 exhibited a size of 6.8 ± 1.2 nm with a crystalline property. Fourier transform infrared analyses of T-RBNs indicated successful coordination between RB and Tb3+. T-RBNs generated singlet oxygen (1O2) and hydroxyl radicals (•OH) under low-dose X-ray irradiation (0.5 Gy) via scintillating and radiosensitizing pathways. T-RBNs produced ∼8-fold higher ROS amounts than bare RB and ∼3.6-fold higher ROS amounts than inorganic nanoparticle-based controls. T-RBNs did not exhibit severe cytotoxicity up to 2 mg/mL concentration in cultured luciferase-expressing murine epithelial breast cancer (4T1-luc) cells. Furthermore, T-RBNs were efficiently internalized into cultured 4T1-luc cells and induced DNA double strand damage, as evidenced by an immunofluorescence staining assay with phosphorylated γ-H2AX. Ultimately, under 0.5 Gy X-ray irradiation, T-RBNs induced >70% 4T1-luc cell death via simultaneous apoptosis/necrosis pathways. Overall, T-RBNs provided a promising Sc/Ps platform under low-dose X-PDT for advanced cancer therapy.

Neoadjuvant chemotherapy enhances anti-tumor immune response of tumor microenvironment in human esophageal squamous cell carcinoma.

Although chemotherapy has been an essential treatment for cancer, the development of immune checkpoint blockade therapy was revolutionary, and a comprehensive understanding of the immunological tumor microenvironment (TME) has become crucial. Here, we investigated the impact of neoadjuvant chemotherapy (NAC) on immune cells in the TME of human esophageal squamous cell carcinoma using single cell RNA-sequencing. Analysis of 30 fresh samples revealed that CD8+/CD4+ T cells, dendritic cells (DCs), and macrophages in the TME of human esophageal squamous cell carcinoma showed higher levels of an anti-tumor immune response in the NAC(+) group than in the NAC(-) group. Furthermore, the immune cells of the NAC(+) group interacted with each other resulting in enhanced anti-tumor immune response via various cytokines, including IFNG in CD8+/CD4+ T cells, EBI3 in DCs, and NAMPT in macrophages. Our results suggest that NAC potentially enhances the anti-tumor immune response of immune cells in the TME.

Upregulation of Piezo2 in the mesangial, renin, and perivascular mesenchymal cells of the kidney of Dahl salt-sensitive hypertensive rats and its reversal by esaxerenone.

The recent discovery of mechanosensitive ion channels has promoted mechanobiological research in the field of hypertension and nephrology. We previously reported Piezo2 expression in mouse mesangial and juxtaglomerular renin-producing cells, and its modulation by dehydration. This study aimed to investigate how Piezo2 expression is altered in hypertensive nephropathy. The effects of the nonsteroidal mineralocorticoid receptor blocker, esaxerenone, were also analyzed. Four-week-old Dahl salt-sensitive rats were randomly assigned to three groups: rats fed a 0.3% NaCl diet (DSN), rats fed a high 8% NaCl diet (DSH), and rats fed a high salt diet supplemented with esaxerenone (DSH + E). After six weeks, DSH rats developed hypertension, albuminuria, glomerular and vascular injuries, and perivascular fibrosis. Esaxerenone effectively decreased blood pressure and ameliorated renal damage. In DSN rats, Piezo2 was expressed in Pdgfrb-positive mesangial and Ren1-positive cells. Piezo2 expression in these cells was enhanced in DSH rats. Moreover, Piezo2-positive cells accumulated in the adventitial layer of intrarenal small arteries and arterioles in DSH rats. These cells were positive for Pdgfrb, Col1a1, and Col3a1, but negative for Acta2 (αSMA), indicating that they were perivascular mesenchymal cells different from myofibroblasts. Piezo2 upregulation was reversed by esaxerenone treatment. Furthermore, Piezo2 inhibition by siRNA in the cultured mesangial cells resulted in upregulation of Tgfb1 expression. Cyclic stretch also upregulated Tgfb1 in both transfections of control siRNA and Piezo2 siRNA. Our findings suggest that Piezo2 may have a contributory role in modulating the pathogenesis of hypertensive nephrosclerosis and have also highlighted the therapeutic effects of esaxerenone on salt-induced hypertensive nephropathy. Mechanochannel Piezo2 is known to be expressed in the mouse mesangial cells and juxtaglomerular renin-producing cells, and this was confirmed in normotensive Dahl-S rats. In salt-induced hypertensive Dahl-S rats, Piezo2 upregulation was observed in the mesangial cells, renin cells, and notably, perivascular mesenchymal cells, suggesting its involvement in kidney fibrosis.

Single-cell transcriptome analysis reveals functional changes in tumour-infiltrating B lymphocytes after chemotherapy in oesophageal squamous cell carcinoma.

BACKGROUND: Tumour immune microenvironment is related with carcinogenesis and efficacy of immunotherapy. B cells play major roles in humoral immunity, but detailed functions of tumour-infiltrating B lymphocytes (TIL-Bs) are unknown. Therefore, our aim was to investigate the functional heterogeneity of TIL-Bs in oesophageal squamous cell carcinoma (ESCC) and lymph nodes (LNs) during chemotherapy. METHODS: Single-cell transcriptome analysis was performed on 23 specimens. We also performed immunohistochemical analysis of immunoglobulin κ C (IGKC), an antibody-secreting cell (ASC) marker, in 166 ESCC samples and evaluated the implication of IGKC in 2-year recurrence free survival (RFS) and 3-year overall survival (OS). RESULTS: A total of 81,246 cells were grouped into 24 clusters. We extracted B cell clusters based on canonical markers and identified 12 TIL-B subtypes in ESCC. We found that several functions, such as co-stimulation and CD40 signalling, were enhanced in TIL-Bs after chemotherapy. The proportion of naive B cells (NBCs) decreased and B cell activation genes were up-regulated in NBCs after chemotherapy. The proportion of ASCs in tumours increased with the loss of migratory abilities and antibody production in ASCs was promoted after chemotherapy. Differentially expressed genes up-regulated with chemotherapy in ASCs correlated with prolonged survival with oesophageal cancer (p = .028). In a metastatic LN, the ASC proportion increased and B cell differentiation was enhanced. In immunohistochemical analysis, RFS and OS of high IGKC expression cases were significantly better than those of low IGKC expression cases (RFS: p < .0001, OS: p < .0001). And in multivariable analysis, the expression of IGKC was an independent favourable prognostic factor for RFS (hazard ratio (HR): 0.23, 95% confidence interval (CI): 0.12-0.45, p < .0001) and OS (HR: 0.20, 95% CI: 0.086-0.47, p = .0002) in ESCC. CONCLUSIONS: Our findings provide novel insights for the heterogeneity of TIL-Bs during chemotherapy and will be useful to understand the clinical importance of TIL-Bs.

Model to Predict Oral Frailty Based on a Questionnaire: A Cross-Sectional Study.

A statistical model to predict oral frailty based on information obtained from questionnaires might help to estimate its prevalence and clarify its determinants. In this study, we aimed to develop and validate a predictive model to assess oral frailty thorough a secondary data analysis of a previous cross-sectional study on oral frailty conducted on 843 patients aged ≥ 65 years. The data were split into training and testing sets (a 70/30 split) using random sampling. The training set was used to develop a multivariate stepwise logistic regression model. The model was evaluated on the testing set and its performance was assessed using a receiver operating characteristic (ROC) curve. The final model in the training set consisted of age, number of teeth present, difficulty eating tough foods compared with six months ago, and recent history of choking on tea or soup. The model showed good accuracy in the testing set, with an area of 0.860 (95% confidence interval: 0.806-0.915) under the ROC curve. These results suggested that the prediction model was useful in estimating the prevalence of oral frailty and identifying the associated factors.

Development of a Japanese Version of the Formula for Calculating Periodontal Inflamed Surface Area: A Simulation Study.

The periodontal inflamed surface area (PISA) is a useful indicator of periodontal status. However, its formula was based on a meta-analysis involving five countries, and racial differences in tooth root morphology could have affected the calculations. This study aimed to develop a Japanese version of the PISA and compare it with the original version. The formulas reported by a previous Japanese study calculating the amount of remaining periodontal ligament from clinical attachment measurements were used to calculate the PISA. A simulation was performed to compare the Japanese version with the original version by inputting probing pocket depth (PPD) from 1 to10 mm and by using clinical data. The PISA values in the Japanese version were larger and smaller than those in the original version for PPDs of 1-5 mm and 6-10 mm, respectively. The PISA values for the clinical data from the Japanese version were significantly higher than those from the original version. Both versions of the PISA values correlated equally well with body mass index. The Japanese version of the PISA can be used to assess the amount of inflamed periodontal tissue resulting from periodontitis in Japanese populations, taking into account racial heterogeneity in root morphologies.

Delayed tension gastrothorax caused necrosis of stomach and re-expansion pulmonary edema: a case report.

BACKGROUND: Traumatic tension gastrothorax is a rare and potentially fatal condition occurring in patients with congenital or acquired diaphragmatic defects. Traumatic tension gastrothorax leads to acute and severe respiratory distress. Delayed tension gastrothorax that develops late during injury can be more severe. CASE PRESENTATION: An 84-year-old woman was brought to our facility with cardiac arrest and returned to spontaneous circulation after 2 min of cardiopulmonary resuscitation. Computed tomography showed diaphragmatic injury and tension gastrothorax due to trauma because of a fall episode few days earlier. Emergency thoracotomy and laparotomy was performed, because nasogastric tube insertion failed. There was a partially necrotic stomach in the chest cavity. The stomach was retracted from the thoracic cavity into the abdominal cavity and placed in its proper position. There was a 5 cm tear of the diaphragm. The tear was sutured and closed and then the necrotic area of the stomach was resected. Although the surgery relieved the intrathoracic compression, it resulted in re-expansion pulmonary edema immediately after surgery and hypoxemia. The patient was unable to overcome the hypoxemic state and eventually died. CONCLUSIONS: Delayed tension gastrothorax can lead not only to obstructive shock due to intrathoracic compression but also to more severe organ ischemia and re-expansion pulmonary edema due to insufflation.

Changeable net charge on nanoparticles facilitates intratumor accumulation and penetration.

The Enhanced Permeability and Retention (EPR) effect is a golden strategy for the nanoparticle (NP)-based targeting of solid tumors, and the surface property of NPs might be a determinant on their targeting efficiency. Poly(ethylene glycol) (PEG) is commonly used as a shell material; however, it has been pointed out that PEG-coated NPs may exhibit accumulation near tumor vasculature rather than having homogenous intratumor distribution. The PEG shell plays a pivotal role on prolonged blood circulation of NPs but potentially impairs the intratumor retention of NPs. In this study, we report on a shell material to enhance tumor-targeted delivery of NPs by maximizing the EPR effect: polyzwitterion based on ethylenediamine-based carboxybetaine [PGlu(DET-Car)], which shows the changeable net charge responding to surrounding pH. The net charge of PGlu(DET-Car), is neutral at physiological pH 7.4, allowing it to exhibit a stealth property during the blood circulation; however, it becomes cationic for tissue-interactive performance under tumorous acidic conditions owing to the stepwise protonation behavior of ethylenediamine. Indeed, the PGlu(DET-Car)-coated NPs (i.e., gold NPs in the present study) exhibited prolonged blood circulation and remarkably enhanced tumor accumulation and retention than PEG-coated NPs, achieving 32.1% of injected dose/g of tissue, which was 4.2 times larger relative to PEG-coated NPs. Interestingly, a considerable portion of PGlu(DET-Car)-coated NPs clearly penetrated into deeper tumor sites and realized the effective accumulation in hypoxic regions, probably because the cationic net charge of PGlu(DET-Car) is augmented in more acidic hypoxic regions. This study suggests that the changeable net charge on the NP surface in response to tumorous acidic conditions is a promising strategy for tumor-targeted delivery based on the EPR effect.

Subtypes in pancreatic ductal adenocarcinoma based on niche factor dependency show distinct drug treatment responses.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is characterized by abundant stroma in which microenvironmental (niche) factors promote PDAC progression. In mouse models, reduction of the stroma increased the proportion of poorly differentiated PDAC with a worse prognosis. Here, we aimed to clarify the effects of stroma on PDAC that may define the PDAC phenotype and induce distinct therapeutic responses. METHODS: The molecular features of PDAC based on differentiation grade were clarified by genome and transcriptome analysis using PDAC organoids (PDOs). We identified the dependency on niche factors that might regulate the differentiation grade. A three-dimensional co-culture model with cancer-associated fibroblasts (CAFs) was generated to determine whether CAFs provide niche factors essential for differentiated PDAC. PDOs were subtyped based on niche factor dependency, and the therapeutic responses for each subtype were compared. RESULTS: The expression profiles of PDOs differed depending on the differentiation grade. Consistent with the distinct profiles, well differentiated types showed high niche dependency, while poorly differentiated types showed low niche dependency. The three-dimensional co-culture model revealed that well differentiated PDOs were strongly dependent on CAFs for growth, and moderately differentiated PDOs showed plasticity to change morphology depending on CAFs. Differentiated PDOs upregulated the expression of mevalonate pathway-related genes correlated with the niche dependency and were more sensitive to simvastatin than poorly differentiated PDOs. CONCLUSIONS: Our findings suggest that CAFs maintain the differentiated PDAC phenotype through secreting niche factors and induce distinct drug responses. These results may lead to the development of novel subtype-based therapeutic strategies.

Piezo2 expression and its alteration by mechanical forces in mouse mesangial cells and renin-producing cells.

The kidney plays a central role in body fluid homeostasis. Cells in the glomeruli and juxtaglomerular apparatus sense mechanical forces and modulate glomerular filtration and renin release. However, details of mechanosensory systems in these cells are unclear. Piezo2 is a recently identified mechanically activated ion channel found in various tissues, especially sensory neurons. Herein, we examined Piezo2 expression and regulation in mouse kidneys. RNAscope in situ hybridization revealed that Piezo2 expression was highly localized in mesangial cells and juxtaglomerular renin-producing cells. Immunofluorescence assays detected GFP signals in mesangial cells and juxtaglomerular renin-producing cells of Piezo2GFP reporter mice. Piezo2 transcripts were observed in the Foxd1-positive stromal progenitor cells of the metanephric mesenchyme in the developing mouse kidney, which are precursors of mesangial cells and renin-producing cells. In a mouse model of dehydration, Piezo2 expression was downregulated in mesangial cells and upregulated in juxtaglomerular renin-producing cells, along with the overproduction of renin and enlargement of the area of renin-producing cells. Furthermore, the expression of the renin coding gene Ren1 was reduced by Piezo2 knockdown in cultured juxtaglomerular As4.1 cells under static and stretched conditions. These data suggest pivotal roles for Piezo2 in the regulation of glomerular filtration and body fluid balance.

Effective mRNA Protection by Poly(l-ornithine) Synergizes with Endosomal Escape Functionality of a Charge-Conversion Polymer toward Maximizing mRNA Introduction Efficiency.

For efficient delivery of messenger (m)RNA, delivery carriers need two major functions: protecting mRNA from nucleases and translocating mRNA from endolysosomes to the cytoplasm. Herein, these two complementary functionalities are integrated into a single polyplex by fine-tuning the catiomer chemical structure and incorporating the endosomal escape modality. The effect of the methylene spacer length on the catiomer side chain is evaluated by comparing poly(l-lysine) (PLL) with a tetramethylene spacer and poly(L-ornithine) (PLO) with a trimethylene spacer. Noteworthily, the nuclease stability of the mRNA/catiomer polyplexes is largely affected by the difference in one methylene group, with PLO/mRNA polyplex showing enhanced stability compared to PLL/mRNA polyplex. To introduce the endosomal escape function, the PLO/mRNA polyplex is wrapped with a charge-conversion polymer (CCP), which is negatively charged at extracellular pH but turns positive at endosomal acidic pH to disrupt the endosomal membrane. Compared to the parent PLO/mRNA polyplex, CCP facilitated the endosomal escape of the polyplex in cultured cells to improve the protein expression efficiency from mRNA by approximately 80-fold. Collectively, this system synergizes the protective effect of PLO against nucleases and the endosomal escape capability of CCP in mRNA delivery.