Close relationship between mediators of inflammation and pancreatic cancer: Our experience.

In this editorial, we focus specifically on the mechanisms by which pancreatic inflammation affects pancreatic cancer. Cancer of the pancreas remains one of the deadliest cancer types. The highest incidence and mortality rates of pancreatic cancer are found in developed countries. Trends of pancreatic cancer incidence and mortality vary considerably worldwide. A better understanding of the etiology and identification of the risk factors is essential for the primary prevention of this disease. Pancreatic tumors are characterized by a complex microenvironment that orchestrates metabolic alterations and supports a milieu of interactions among various cell types within this niche. In this editorial, we highlight the foundational studies that have driven our understanding of these processes. In our experimental center, we have carefully studied the mechanisms of that link pancreatic inflammation and pancreatic cancer. We focused on the role of mast cells (MCs). MCs contain pro-angiogenic factors, including tryptase, that are associated with increased angiogenesis in various tumors. In this editorial, we address the role of MCs in angiogenesis in both pancreatic ductal adenocarcinoma tissue and adjacent normal tissue. The assessment includes the density of c-Kit receptor-positive MCs, the density of tryptase-positive MCs, the area of tryptase-positive MCs, and angiogenesis in terms of microvascularization density.

Loss of c-Kit in Endothelial Cells Protects against Hindlimb Ischemia.

BACKGROUND: Critical limb ischemia (CLI) is the end stage of peripheral artery disease (PAD), and around 30% of CLI patients are ineligible for current treatments. The angiogenic benefits of c-Kit have been reported in the ischemia scenario; however, the present study demonstrates the effects of specific endothelial c-Kit signaling in arteriogenesis during hindlimb ischemia. METHODS: We created conditional knockout mouse models that decrease c-Kit (c-Kit VE-Cadherin CreERT2-c-Kit) or its ligand (SCF VE-Cadherin CreERT2-SCF) specifically in endothelial cells (ECs) after tamoxifen treatment. These mice and a control group (wild-type VE-Cadherin CreERT2-WT) were subjected to hindlimb ischemia or aortic crush to evaluate perfusion/arteriogenesis and endothelial barrier permeability, respectively. RESULTS: Our data confirmed the lower gene expression of c-Kit and SCF in the ECs of c-Kit and SCF mice, respectively. In addition, we confirmed the lower percentage of ECs positive for c-Kit in c-Kit mice. Further, we found that c-Kit and SCF mice had better limb perfusion and arteriogenesis compared to WT mice. We also demonstrated that c-Kit and SCF mice had a preserved endothelial barrier after aortic crush compared to WT. CONCLUSIONS: Our data demonstrate the deleterious effects of endothelial SCF/c-Kit signaling on arteriogenesis and endothelial barrier integrity.

Qi Lang formula relieves constipation via targeting SCF/c-kit signaling pathway: An integrated study of network pharmacology and experimental validation.

Background: Constipation is one of the chronic gastrointestinal functional diseases that affects the quality of life. While Qi Lang Formula (QLF) has demonstrated effectiveness in alleviating constipation symptoms, its precise mechanism remains elusive. Methods: QLF was analyzed using UPLC-MS/MS. Targets for QLF were collected from SwissADME, Herb, ITCM databases, and constipation-related targets from scRNA-seq and Genecards databases. Overlapping targets suggested potential QLF therapy targets for constipation. Enrichment analysis used the KOBAS database. A "drug-ingredient-target" network was constructed with Cytoscape, and AutoDock verified active ingredient binding. H&E staining assessed colonic mucosa changes, TEM examined ICC structural changes. ELISA measured neurotransmitter levels, and Western blot verified QLF's effect on target proteins. ICC proliferation was observed through immunofluorescence. Results: We identified 89 targets of QLF associated with ICC-related constipation, with c-Kit emerging as the pivotal target. Molecular docking studies revealed that Atractylenolide Ⅲ, Apigenin, Formononetin, Isorhamnetin, Naringenin, and Ononin exhibited strong binding affinities for the c-Kit structural domain. QLF significantly enhanced first stool passage time, fecal frequency, fecal moisture content, and intestinal propulsion rate. Further analysis unveiled that QLF not only restored neurotransmitter levels but also mitigated colon muscular fiber ruptures. ICC ultrastructure exhibited partial recovery, while Western blot confirmed upregulated c-Kit expression and downstream targets. Immunofluorescence results indicated ICC proliferation post QLF treatment in rat colon. Conclusion: Our findings suggest that QLF may promote ICC proliferation by targeting SCF/c-Kit and its downstream signaling pathway, thereby regulating intestinal motility.

Heavy metal ions interactions with G-quadruplex-prone DNA sequences.

The industrial world exposes living organisms to a variety of metal pollutants. Here we investigated whether such elements affect G-rich sequences susceptible to fold into G-quadruplex (GQ) structures. Thermal stability and conformation of these oligoncleotides was studied at various molar ratios of a variety of heavy metal salts using thermal FRET, transition-FRET (t-FRET) and circular dichroism. Metal ions affected the thermal stability of the GQs to different extents; some metals had no effect on Tm while other metals caused small to moderate changes in Tm at 1:1 or 1:10 molar ratio. While most of the metals had no major effect, Al3+, Cd2+, Pb2+, Hg2+ and Zn2+ altered the thermal stability and structural features of the GQs. Some metals such as Pb2+ and Hg2+ exhibit differential interactions with telomere, c-myc and c-kit GQs. Overall, toxic heavy metals affect G-quadruplex stability in a sequence and topology dependent manner. This study provides new insight into how heavy metal exposure may affect gene expression and cellular responses.

SCF/C-kit drives spermatogenesis disorder induced by abscopal effects of cranial irradiation in mice.

Cranial radiotherapy is a major treatment for leukemia and brain tumors. Our previous study found abscopal effects of cranial irradiation could cause spermatogenesis disorder in mice. However, the exact mechanisms are not yet fully understood. In the study, adult male C57BL/6 mice were administrated with 20 Gy X-ray cranial irradiation (5 Gy per day for 4 days consecutively) and sacrificed at 1, 2 and 4 weeks. Tandem Mass Tag (TMT) quantitative proteomics of testis was combined with bioinformatics analysis to identify key molecules and signal pathways related to spermatogenesis at 4 weeks after cranial irradiation. GO analysis showed that spermatogenesis was closely related to oxidative stress and inflammation. Severe oxidative stress occurred in testis, serum and brain, while serious inflammation also occurred in testis and serum. Additionally, the sex hormones related to hypothalamic-pituitary-gonadal (HPG) axis were disrupted. PI3K/Akt pathway was activated in testis, which upstream molecule SCF/C-Kit was significantly elevated. Furthermore, the proliferation and differentiation ability of spermatogonial stem cells (SSCs) were altered. These findings suggest that cranial irradiation can cause spermatogenesis disorder through brain-blood-testicular cascade oxidative stress, inflammation and the secretory dysfunction of HPG axis, and SCF/C-kit drive this process through activating PI3K/Akt pathway.

Diagnostic reliability of c-KIT (CD117) in salivary gland tumours - A systematic review and meta-analysis.

c-KIT is an important diagnostic marker in salivary gland tumours and is expressed in most adenoid cystic carcinomas. Histologically similar salivary gland tumours with variable immunohistochemical expression for c-KIT pose a challenge and make diagnostic reliability ambivalent. An electronic search was performed in MEDLINE by PubMed, Google Scholar, Scopus, Trip, Cochrane Library, and EMBASE up to 31 December 2023, without period restriction. The articles that investigated CD117 or c-KIT in salivary gland tumours were included for review. Sensitivity, specificity, and positive and negative predictive values of c-KIT immunohistochemical expressions were derived and subjected to meta-analysis using Open Meta analyst for Sierra software. The risk of bias in selected studies was analysed using the QUADAS-2 tool, and RevMan 5.4 was used to output the result. Forty-three articles were reviewed, and 2285 salivary gland cases were analysed. Adenoid cystic carcinoma had an overall expression of 84.9%. A similar expression was found in epimyoepithelial carcinoma (79.1%), lymphoepithelial carcinoma (75%), myoepithelial carcinoma (60.8%), monomorphic adenoma (94.1%), and pleomorphic adenoma (74.7%). The sensitivity, specificity, and positive and negative predictive values of c-KIT/CD117 for adenoid cystic carcinoma with other salivary gland tumours were 84.99%, 69.09%, 84.79%, and 69.41%, respectively. Current evidence shows that c-KIT, despite its sensitivity, is not specific and therefore cannot be a useful diagnostic marker for distinguishing adenoid cystic carcinoma from other salivary gland tumours. Further research on other salivary gland tumours that exhibit comparable expression is necessary to validate the diagnostic accuracy of c-KIT.

Laparoscopic-Assisted Resection for an Extra-gastrointestinal Stromal Tumor Arising From the Mesentery of the Small Intestine: A Case Report.

Gastrointestinal stromal tumors (GISTs) are mesenchymal tumors that arise in the muscular or submucosal layers of the gastrointestinal tract. Extra-gastrointestinal stromal tumors (EGISTs) are rare primary entities that develop outside the digestive tract which are histologically and immunologically similar to GISTs. We present the case of a 52-year-old female diagnosed with a primary EGIST arising in the small bowel mesentery four months after undergoing hormone therapy for multiple uterine myomas. Transvaginal ultrasonography and MRI revealed a pelvic mass suspected to be a GIST. The patient was treated with laparoscopic-assisted partial resection of the small bowel. Histopathological examination of the surgical specimen confirmed the diagnosis of an EGIST. Imatinib treatment was initiated, and no clinical evidence of recurrence or metastasis was detected postoperatively. Because EGISTs are extremely rare, the differences between EGISTs and GISTs, the degree of malignancy, and prognosis have not been fully investigated. Further studies are needed to accumulate additional cases. The present case shows that laparoscopic-assisted excision can be successfully used to manage EGISTs.

FLT3 and IRAK4 Inhibitor Emavusertib in Combination with BH3-Mimetics in the Treatment of Acute Myeloid Leukemia.

Targeting the FLT3 receptor and the IL-1R associated kinase 4 as well as the anti-apoptotic proteins MCL1 and BCL2 may be a promising novel approach in the treatment of acute myeloid leukemia (AML). The FLT3 and IRAK4 inhibitor emavusertib (CA4948), the MCL1 inhibitor S63845, the BCL2 inhibitor venetoclax, and the HSP90 inhibitor PU-H71 were assessed as single agents and in combination for their ability to induce apoptosis and cell death in leukemic cells in vitro. AML cells represented all major morphologic and molecular subtypes, including FLT3-ITD and NPM1 mutant AML cell lines and a variety of patient-derived AML cells. Emavusertib in combination with MCL1 inhibitor S63845 or BCL2 inhibitor venetoclax induced cell cycle arrest and apoptosis in MOLM-13 cells. In primary AML cells, the response to emavusertib was associated with the presence of the FLT3 gene mutation with an allelic ratio >0.5 and the presence of NPM1 gene mutations. S63845 was effective in all tested AML cell lines and primary AML samples. Blast cell percentage was positively associated with the response to CA4948, S63845, and venetoclax, with elevated susceptibility of primary AML with blast cell fraction >80%. Biomarkers of the response to venetoclax included the blast cell percentage and bone marrow infiltration rate, as well as the expression levels of CD11b, CD64, and CD117. Elevated susceptibility to CA4948 combination treatments with S63845 or PU-H71 was associated with FLT3-mutated AML and CD34 < 30%. The combination of CA4948 and BH3-mimetics may be effective in the treatment in FLT3-mutated AML with differential target specificity for MCL1 and BCL2 inhibitors. Moreover, the combination of CA4948 and PU-H71 may be a candidate combination treatment in FLT3-mutated AML.

Recruitment or activation of mast cells in the liver aggravates the accumulation of fibrosis in carbon tetrachloride-induced liver injury.

Liver diseases caused by viral infections, alcoholism, drugs, or chemical poisons are a significant health problem: Liver diseases are a leading contributor to mortality, with approximately 2 million deaths per year worldwide. Liver fibrosis, as a common liver disease characterized by excessive collagen deposition, is associated with high morbidity and mortality, and there is no effective treatment. Numerous studies have shown that the accumulation of mast cells (MCs) in the liver is closely associated with liver injury caused by a variety of factors. This study investigated the relationship between MCs and carbon tetrachloride (CCl4)-induced liver fibrosis in rats and the effects of the MC stabilizers sodium cromoglycate (SGC) and ketotifen (KET) on CCl4-induced liver fibrosis. The results showed that MCs were recruited or activated during CCl4-induced liver fibrosis. Coadministration of SCG or KET alleviated the liver fibrosis by decreasing SCF/c-kit expression, inhibiting the TGF-ß1/Smad2/3 pathway, depressing the HIF-1a/VEGF pathway, activating Nrf2/HO-1 pathway, and increasing the hepatic levels of GSH, GSH-Px, and GR, thereby reducing hepatic oxidative stress. Collectively, recruitment or activation of MCs is linked to liver fibrosis and the stabilization of MCs may provide a new approach to the prevention of liver fibrosis.

Single-cell transcriptome reveals a novel mechanism of C-Kit+-liver sinusoidal endothelial cells in NASH.

AIM: To understand how liver sinusoidal endothelial cells (LSECs) respond to nonalcoholic steatohepatitis (NASH). METHODS: We profiled single-LSEC from livers of control and MCD-fed mice. The functions of C-Kit+-LSECs were determined using coculture and bone marrow transplantation (BMT) methods. RESULTS: Three special clusters of single-LSEC were differentiated. C-Kit+-LSECs of cluster 0, Msr1+-LSECs of cluster 1 and Bmp4+Selp+-VECs of cluster 2 were revealed, and these cells with diverse ectopic expressions of genes participated in regulation of endothelial, fibrosis and lipid metabolism in NASH. The number of C-Kit+-primary LSECs isolated from MCD mice was lower than control mice. Immunofluorescence co-staining of CD31 and C-KIT showed C-Kit+-LSECs located in hepatic sinusoid were also reduced in NASH patients and MCD mice, compared to AIH patients and control mice respectively. Interestingly, lipotoxic hepatocytes/HSCs cocultured with C-Kit+-LSECs or the livers of MCD mice receipting of C-Kit+-BMCs (bone marrow cells) showed less steatosis, inflammation and fibrosis, higher expression of prolipolytic FXR and PPAR-α, lower expression of TNF-α and α-SMA. Furthermore, coculturing or BMT of C-Kit+-endothelial derived cells could increase the levels of hepatic mitochondrial LC3B, decrease the degree of mitochondrial damage and ROS production through activating Pink1-mediated mitophagy pathway in NASH. CONCLUSIONS: Hence, a novel transcriptomic view of LSECs was revealed to have heterogeneity and complexity in NASH. Importantly, a cluster of C-Kit+-LSECs was confirmed to recovery Pink1-related mitophagy and NASH progression.

[MACULOPAPULAR CUTANEOUS MASTOCYTOSIS HARBORING A KIT MUTATION (ASP419DEL): A CASE REPORT].

A 2-year-old, male patient presented with an 18-month history of scattered, brown macules and nodules up to 2 cm in size on his trunk and extremities. These macules were accompanied by pruritus and were positive for Darier's sign. A skin biopsy of a brown macule on the left thigh revealed a dense accumulation of CD117-positive, round or oval cells with amphophilic cytoplasm within the upper to middle dermis. The patient was otherwise healthy and had normal laboratory and imaging test results. Sequence analysis of genomic DNA from a skin biopsy demonstrated the presence of an Asp419del mutation in exon 8 of the KIT gene. Based on these findings, maculopapular cutaneous mastocytosis (MPCM) was diagnosed. The patient received H 1-antihistamine. Although the pruritus resolved, the brown macules remained for one year after the initial treatment. To the best of our knowledge, only three cases of cutaneous mastocytosis (CM) with an Asp419del mutation, including the present case, have been reported in the Japanese literature to date; moreover, while the previous two cases were of DCM, the present case was the first instance of MPCM. Normally, the symptoms of childhood-onset MPCM are dormant until puberty. However, a recent study reported that many MPCM patients may experience persistent or exacerbated symptoms. The present study therefore evaluated 53 Japanese cases of childhood onset MPCM with a KIT gene mutation and discussed the patients' clinical outcomes.

Bone Marrow-Derived C-Kit+ Cells Improved Inflammatory IL-33/ST-2/ILC2 Axis in the Lung Tissue of Type 2 Diabetic Rats.

Inflammation is an essential factor in pulmonary complications of diabetes. Bone marrow (BM)-derived C-kit+ cells have immunomodulatory properties and their transplantation is suggested as a promising strategy for ameliorating diabetes complications. This study evaluated the effect of BM-derived C-kit+ cells on the inflammation signaling pathway in lung tissue of type 2 diabetic male rats. Ten rats were used to extract C-kit cells, and 48 male Wistar rats weighing 180 ± 20 g were randomly divided into four equal groups: (1) Control (Cont), (2) Diabetic (D), (3) Diabetic + C-kit+ cells (D + C-kit pos) intravenously injected 50-µl phosphate buffer saline (PBS) containing 300,000 C-kit+ cells, and (4) Diabetic + C-kit- cells (D + C-kit neg), intravenously injected C-kit- cells. Diabetes induction increased IL-33, ST-2, CD127, and IL-2 levels and decreased IL-10. C-kit+ cell therapy significantly decreased IL-33 and CD127 and increased IL-10. In addition, lung histopathological changes significantly improved in the C-kit+ group compared to the diabetic group. These findings suggest that C-kit+ cells may have a potential therapeutic role in mitigating diabetes-induced respiratory complications via ameliorating the inflammation and histopathological changes in lung tissue.

Screening for Synergistic Reagents With Pazopanib Against Osteosarcoma Using a Compound Library.

BACKGROUND/AIM: Osteosarcoma (OS) is the most common malignant bone tumor. As the same agents have been in use since the mid-1970s, new therapeutic approaches are needed to improve prognosis. Pazopanib (PZP) has already demonstrated marked antitumor activity clinically and can be effective in patients with metastatic OS. We investigated the combination treatment of candidate agents with PZP and examined effects on tumor growth using an in vivo model. MATERIALS AND METHODS: A library of 324 compounds was used. MG63 OS cells were treated with PZP and each compound. Cell viability was measured. The antiproliferative effects of compound combination on four OS cell lines was tested. Cell signaling was evaluated by western blot analysis. In vivo antitumor testing was performed using 143B-bearing mice. RESULTS: The screening process identified crizotinib (CRZ) as the most effective drug for combination with PZP. The combination of PZP and CRZ demonstrated effects compared to control or single therapy. Cell signal investigation showed that dual therapy down-regulated c-MYC, p-AKT, p-STAT3, p-cyclin D1 and survivin and up-regulated cleaved caspase-3 and cleaved PARP compared to control or single therapy. In vivo analysis showed dual therapy achieved synergic effects for tumor growth compared to control or single-treatment groups. No significant difference in the change in body weight was observed among groups. CONCLUSION: Combined use of PZP and CRZ offers synergic anti-tumor effects against OS, inducing apoptosis in vitro and in vivo by down-regulating AKT and STAT3. Our data suggest that these agents can be used for patients clinically.

Synthesis and Antitumor Activity Evaluation of Novel Echinatin Derivatives with a 1,3,4-Oxadiazole Moiety.

A series of novel echinatin derivatives with 1,3,4-oxadiazole moieties were designed and synthesized. Most of the newly synthesized compounds exhibited moderate antiproliferative activity against the four cancer cell lines. Notably, Compound T4 demonstrated the most potent activity, with IC50 values ranging from 1.71 µM to 8.60 µM against the four cancer cell lines. Cell colony formation and wound healing assays demonstrated that T4 significantly inhibited cell proliferation and inhibited migration. We discovered that T4 exhibited moderate binding affinity with the c-KIT protein through reverse docking. The results were effectively validated through subsequent molecular docking and c-KIT enzyme activity assays. In addition, Western blot analysis revealed that T4 inhibits the phosphorylation of downstream proteins of c-KIT. The results provide valuable inspiration for exploring novel insights into the design of echinatin-related hybrids as well as their potential application as c-KIT inhibitors to enhance the efficacy of candidates.

Clinical, pathologic, and molecular characterization of a non-metastatic multicentric cutaneous mast cell tumor in a cow.

Cutaneous mast cell tumors are rarely reported in cattle. Although mutations in the c-KIT gene have been shown to play a central role in the oncogenesis of canine mast cell tumors, few data are available in cattle. This report describes the clinical, histologic, immunohistochemical, and genetic features of a multicentric cutaneous mast cell tumor in an adult cow. An 11-year-old Prim'Holstein cow was presented for a 5-month history of multiple skin nodules. Cytologic and histologic analyses of the nodules led to a diagnosis of mast cell tumors. Immunohistochemical analysis for KIT expression showed a moderate to strong signal in neoplastic mast cells with a cytoplasmic and membranous pattern. Sequencing of the c-KIT gene coding sequence revealed no mutation. Despite partial response after corticosteroid treatment, euthanasia was elected. No metastases to the lymph nodes, spleen, and liver were identified at post-mortem and histologic examinations.

Wnt/ß-catenin-C-kit axis may play a role in adenoid cystic carcinoma prognostication.

Adenoid cystic carcinoma (ACC) is one of the most common malignant salivary gland tumors. ACC is composed of myoepithelial and epithelial neoplastic cells which grow slowly and have a tendency for neural invasion. The long term prognosis is still relatively poor. Although several gene abnormalities, such as fusions involving MYB or MYBL1 oncogenes and the transcription factor gene NFIB, and overexpression of KIT have been reported in ACC, their precise functions in the pathogenesis of ACC remain unclear. We recently demonstrated that the elevated expression of Semaphorin 3A (SEMA3A), specifically expressed in myoepithelial neoplastic cells, might function as a novel oncogene-related molecule to enhance cell proliferation through activated AKT signaling in 9/10 (90%) ACC cases. In the current study, the patient with ACC whose tumor was negative for SEMA3A in the previous study, revisited our hospital with late metastasis of ACC to the cervical lymph node eight years after surgical resection of the primary tumor. We characterized this recurrent ACC, and compared it with the primary ACC using immunohistochemical methods. In the recurrent ACC, the duct lining epithelial cells, not myoepithelial neoplastic cells, showed an elevated Ki-67 index and increased cell membrane expression of C-kit, along with the expression of phosphorylated ERK. Late metastasis ACC specimens were not positive for ß-catenin and lymphocyte enhancer binding factor 1 (LEF1), which were detected in the nuclei of perineural infiltrating cells in primary ACC cells. In addition, experiments with the GSK-3 inhibitor revealed that ß-catenin pathway suppressed not only KIT expression but also proliferation of ACC cells. Moreover, stem cell factor (SCF; also known as KIT ligand, KITL) induced ERK activation in ACC cells. These results suggest that inactivation of Wnt/ß-catenin signaling may promote C-kit-ERK signaling and cell proliferation of in metastatic ACC.

Bone marrow-derived c-kit positive stem cell administration protects against diabetes-induced nephropathy in a rat model by reversing PI3K/AKT/GSK-3ß pathway and inhibiting cell apoptosis.

Stem cell-based therapy has been proposed as a novel therapeutic strategy for diabetic nephropathy. This study was designed to evaluate the effect of systemic administration of rat bone marrow-derived c-kit positive (c-kit+) cells on diabetic nephropathy in male rats, focusing on PI3K/AKT/GSK-3ß pathway and apoptosis as a possible therapeutic mechanism. Twenty-eight animals were randomly classified into four groups: Control group (C), diabetic group (D), diabetic group, intravenously received 50 µl phosphate-buffered saline (PBS) containing 3 × 105 c-kit- cells (D + ckit-); and diabetic group, intravenously received 50 µl PBS containing 3 × 105 c-Kit positive cells (D + ckit+). Control and diabetic groups intravenously received 50 µl PBS. C-kit+ cell therapy could reduce renal fibrosis, which was associated with attenuation of inflammation as indicated by decreased TNF-α and IL-6 levels in the kidney tissue. In addition, c-kit+ cells restored the expression levels of PI3K, pAKT, and GSK-3ß proteins. Furthermore, renal apoptosis was decreased following c-kit+ cell therapy, evidenced by the lower apoptotic index in parallel with the increased Bcl-2 and decreased Bax and Caspase-3 levels. Our results showed that in contrast to c-kit- cells, the administration of c-kit+ cells ameliorate diabetic nephropathy and suggested that c-kit+ cells could be an alternative cell source for attenuating diabetic nephropathy.

Examination of age-related changes in the submandibular glands of male mice.

Salivary gland hypofunction adversely affects the oral environment and daily life by causing dry mouth (xerostomia). Senescence-related atrophy of salivary gland tissues is one cause of xerostomia, and it is particularly common among the elderly. However, the underlying mechanism is poorly understood, and no treatment has been established. Therefore, we examined age-related changes in senescence-associated secretory phenotype (SASP) factors, which regulate stemness and cellular senescence, in mouse submandibular glands. We analyzed the submandibular glands of 6-week-old (young group, n = 6) and 82-week-old mice (aged group, n = 6). We performed salivary flow rate measurements, histological analysis including immunohistochemistry, and quantitative real-time PCR. The salivary flow rate was significantly lower in the aged group than in the young group. In addition, immunostaining and quantitative real-time PCR illustrated that aquaporin-5 and α-amylase expressions were significantly decreased in aged mice, indicating salivary gland hypofunction. c-Kit and cytokeratin 5 expressions were also significantly decreased in this group, suggesting that the regenerative abilities of the submandibular glands were reduced because of decreased stem and progenitor cell counts. Furthermore, the levels of p16INK4a and p21 (the senescence markers) and TGF-ß1 and IL-6 (SASP factors) were significantly increased in mice, suggesting that senescence had been promoted. The decreased numbers of stem and progenitor cells and increased levels of SASP factors might be associated with age-related changes in mouse submandibular glands. These results might facilitate the development of treatments for senescence-related submandibular gland hypofunction.