Analysis of the relationship between age-related erythrocyte dysfunction and fatigue.

With the declining birth rates and aging societies in developed countries, the average age of the working population is increasing. Older people tend to get tired more easily, so prevention of fatigue is important to improve the quality of life for older workers. This study aimed to assess the mechanism of fatigue in older people, especially focused on relation between dysfunction of erythrocyte and fatigue. Total power (TP), which is the value of autonomic nerve activity, was measured as a value of fatigue and significantly decreased in workers with aging. As properties of senescent erythrocytes, the erythrocyte sedimentation rate and damaged erythrocytes population increased with aging and correlated with TP. These results suggested that the accumulation of damaged erythrocytes contributes to fatigue. Recent studies revealed that senescence-associated secretory phenotype (SASP), a phenomenon in which senescent cells secrete a variety of cytokines, affected hematopoiesis in bone marrow. We analyzed the effects of SASP factors on erythropoiesis and found that Interleukin -1α (IL-1α) suppressed erythrocyte differentiation of hematopoietic stem cells in vitro. We also showed that IL-1α levels in human blood and saliva increase with aging, suggesting the possibility that IL-1α level in saliva can be used to predict the decline in hematopoietic function.

True significance of the number of retrieved lymph nodes in stage II colon cancer resected by minimally invasive surgery: Influence of tumor sidedness.

BACKGROUND: In patients with stage II colon cancer (CC) undergoing minimally invasive surgery, the association between the clinical significance of lymph node yield and tumor localization remains unknown. We aimed to determine the optimal number of lymph nodes to be retrieved based on tumor localization in patients with stage II CC undergoing minimally invasive surgery. METHODS: This was a multicenter retrospective study. Overall, 263 patients with stage II CC who underwent laparoscopic surgery between January 1, 2008 and December 31 were enrolled. The primary outcome was the optimal number of lymph nodes retrieved based on tumor localization. RESULTS: The median number of retrieved lymph nodes was 30 and 26 in the right-(n = 125) and left-sided (n = 138) CC groups, respectively (p = .0007). Inadequate dissection (<12 nodes) occurred in 4.2% of patients: 1.6% in the right-sided CC group and 6.5% in the left-sided CC group. Multivariate Cox regression analysis showed a decreasing trend in adjusted hazard ratios with increasing nodes, with an optimal cutoff of 15 lymph nodes in the left-sided CC group (adjusted hazard ratio, 5.868; 95% confidence interval, 1.247-27.62; p = .02). Lymph node yield was not independently associated with survival in the right-sided CC group. CONCLUSIONS: For patients with left-sided stage II CC undergoing laparoscopic surgery, aiming for at least 15 retrieved lymph nodes may be optimal for accurate staging and prognostic assessment. The optimal lymph node yield likely varies based on tumor location, requiring further investigation in right-sided CC.

Multicenter randomized phase II study on S-1 and oxaliplatin therapy as an adjuvant after hepatectomy for colorectal liver metastases (YCOG1001).

PURPOSE: The high recurrence rate of colorectal cancer liver metastasis (CRCLM) after surgery remains a crucial problem. However, adjuvant chemotherapy after hepatectomy for CRCLM has not yet been established. This study evaluated the efficacy of adjuvant therapy with S-1 and oxaliplatin (SOX). METHODS: In a multicenter, randomized, phase II study, patients undergoing curative resection of CRCLM were randomly enrolled in a 1:1 ratio to either the low- or high-dose group. S-1 and oxaliplatin were administered from days 1 to 14 of a 3-week cycle as a 2-h infusion every 3 weeks. The dose of S-1 was fixed at 80 mg/m2. The doses in the low- and high-dose oxaliplatin groups were 100 mg/m2 (low-dose group) and 130 mg/m2 (high-dose group), respectively. This treatment was repeated eight times. The primary endpoint was the rate of discontinuation owing to toxicity. The secondary endpoints were the relapse-free survival (RFS) and frequency of adverse events (AEs). RESULTS: Between August 2010 and March 2015, 44 patients (low-dose group: 31 patients and high-dose group: 13 patients) were enrolled in the study. Of these, one patient was excluded from the efficacy analysis. In the high-dose group, five of nine patients were unable to continue the study due to toxicity in February 2013. At that time, recruitment to the high-dose group was stopped from the protocol. The relative dose intensity (RDI) for S-1 in the low- and high-dose groups were 49.8 and 48.7% (p = 0.712), and that for oxaliplatin was 75.9 and 73.0% (p = 0.528), respectively. The rates of discontinuation due to toxicity were 60 and 53.8% in the low- and high-dose groups, respectively, with no marked difference noted between the groups (p = 0.747). The frequency of grade ≥ 3 common adverse events was neutropenia (23.3%/23.1%), diarrhea (13.3%/15.4%), and peripheral sensory neuropathy (6.7%/7.7%). The disease-free survival (DFS) at 3 years was 52.9% in the low-dose group, which was not significantly different from that in the high-dose group (46.2%; p = 0.705). CONCLUSIONS: SOX regimens as adjuvant therapy after hepatectomy for CRCLM had high rates of discontinuation due to toxicity in both groups. In particular, the RDI of S-1 was < 50%. Therefore, the SOX regimen is not recommended as adjuvant chemotherapy after hepatectomy for CRCLM.

Enhanced Clinical Utility of Molecular Budding Signature as a Recurrence Risk Determinant in Stage II and III Colon Cancer Patients.

BACKGROUND: A molecular budding signature (MBS), which consists of seven tumor budding-related genes, was recently presented as a prominent prognostic indicator in colon cancer (CC) using microarray data acquired from frozen specimens. This study aimed to confirm the predictive power of MBS for recurrence risk based on formalin-fixed, paraffin-embedded (FFPE) materials. METHODS: This research utilized the same microarray data from a prior multicenter study using FFPE whole tissue sections, which retrospectively reviewed 232 stage II CC patients without adjuvant chemotherapy and 302 stage III CC patients with adjuvant chemotherapy. All patients underwent upfront curative surgery without neoadjuvant therapy between 2009 and 2012. An MBS score was calculated using the mean of log2 [each signal] of seven genes (MSLN, SLC4A11, WNT11, SCEL, RUNX2, MGAT3, and FOXC1) as described before. RESULTS: The MBS-low group exhibited a better relapse-free survival (RFS) than the MBS-high group in stage II (P = 0.0077) and in stage III CC patients (P = 0.0003). Multivariate analyses revealed that the MBS score was an independent prognostic factor in both stage II (P = 0.0257) and stage III patients (P = 0.0022). Especially among T4, N2, or both (high-risk) stage III patients, the MBS-low group demonstrated markedly better RFS compared with the MBS-high group (P = 0.0013). CONCLUSIONS: This study confirmed the predictive power of the MBS for recurrence risk by employing FFPE materials in stage II/III CC patients.

Immunostimulatory effects of a subcritical water extract of Ganoderma.

Ganoderma, a medicinal mushroom with various physiological activities, has been extensively investigated regarding its effectiveness. The aim of the present study was to examine the effects of a subcritical water extract of Ganoderma (SWEG) on the immune system. The use of subcritical water with a higher temperature and pressure than hot water allows efficient elution of components from natural products. As an evaluation of the effectiveness of SWEG, a cell proliferation and a cell differentiation test were carried out using A-6 cells, a model of hematopoietic stem cells. Furthermore, an oral administration test in mice was conducted to examine the effects of SWEG on the number and function of immune cells. As a result, SWEG was revealed to promote both self-renewal and differentiation into immune cells such as T cells and natural killer (NK) cells in experiments with A-6 cells. These results were not obtained in experiments using hot water extract of Ganoderma lucidum and Ganoderma sinense. The oral administration test in mice demonstrated that SWEG increased hematopoietic precursor cells, immature B cells, and NK cells in the bone marrow, and T cells in the thymus. In addition, SWEG enhanced the immune functions in the spleen by promoting granzyme B expression and NK cell activity. SWEG was demonstrated to be a food material that acts on HSCs and regulates immunity in vivo.

[A Case of HER2-Positive Advanced Gastric Cancer with Liver Metastasis Treated by Laparoscopic Surgery after Chemotherapy and Achieved Pathological Complete Response].

A 77-year-old man presented to our hospital with diarrhea and weight loss. Upper gastrointestinal endoscopy revealed advanced Type 3 gastric cancer measuring 40 mm in the lower greater curvature of the stomach. Biopsy from a gastric tumor revealed moderately differentiated tubular adenocarcinoma overexpressing HER2. Abdominal contrast-enhanced computed tomography(CT)showed multiple liver metastases in S3 and S5. We diagnosed HER2-positive gastric cancer with liver metastasis. Systemic chemotherapy was administrated, with a total of 13 courses of combination therapy with S-1, oxaliplatin and trastuzumab. After chemotherapy, the primary tumor was significantly reduced and liver metastases were almost undetectable. Laparoscopic distal gastrectomy and partial hepatectomy were performed as conversion surgery. The patient was discharged on the 9th day without any postoperative complications. Postoperative pathological findings showed no residual tumor in either gastric and hepatic specimens, and the therapeutic effect of chemotherapy was diagnosed as pathological complete response. We report a case of HER2-positive advanced gastric cancer with multiple liver metastases that achieved a pathologically complete response to chemotherapy followed by conversion surgery. Laparoscopic surgery would be one of an effective option for conversion surgery.

[Indications and Outcomes of Laparoscopic Endoscopic Cooperative Surgery(LECS)for Gastric Gastrointestinal Stromal Tumor].

Laparoscopic and endoscopic cooperative surgery(LECS)for gastric gastrointestinal stromal tumor(GIST)has become a popular surgery with both curability and functional preservation. In this study, we examined the outcomes of 14 patients who underwent classical LECS or CLEAN-NET in our hospital. Until March 2022, classical LECS was performed in patients with intraluminal growth tumors or tumors close to the gastroesophageal junction. After April 2022, classical LECS was performed in patients with intraluminal growth tumors without ulceration, and CLEAN-NET was performed in patients with ulceration or intramural growth tumors. There were 10 males and 4 females with a median age of 80.5 years. Intraluminal growth tumor were 8 patients, close to the gastroesophageal junction tumor were 3, and intramural growth tumor were 4, respectively. Five of these patients had tumors with ulceration. Classical LECS was performed in 10 patients and CLEAN-NET in 4 patients, and the median operative time was 165.5 minutes. All patients underwent R0 resection, and no postoperative complications or recurrences were observed. LECS was performed safely, and it is important to select the surgical procedure according to the tumor site and growth type.

[A Case of Local Recurrence of Esophageal Cancer after Chemoradiation Therapy Successfully Treated with Nivolumab].

We report a case of a patient with locally recurrent esophageal cancer after chemoradiation therapy(CRT)who responded to nivolumab. The patient was an 86-year-old man with advanced esophageal cancer. Upper gastrointestinal endoscopy (EGD)revealed a type 2 lesion in the middle thoracic esophagus, and biopsy revealed squamous cell carcinoma(SCC). Contrast- enhanced CT showed invasion of the left main bronchi. The patient was diagnosed as Stage Ⅳa advanced esophageal cancer, and was treated with 5-FU plus cisplatin chemotherapy, and 60 Gy of radiation therapy. The tumor disappeared by CT and EGD, and the patient was followed up for observation. The patient experienced a feeling of tightness again, and EGD revealed an ulcerative lesion in the middle thoracic esophagus, and a biopsy detected SCC. Because of the early recurrence after CRT, the patient was judged to be resistant to 5-FU plus cisplatin chemotherapy, and 8 courses of nivolumab were administered as second-line treatment. Follow-up EGD confirmed disappearance of ulcerative lesions, and no tumors have been observed to date.

Enhanced Type I Collagen Synthesis in Fibroblasts by Dermal Stem/Progenitor Cell-Derived Exosomes.

The self-duplication and differentiation of dermal stem cells are essential for the maintenance of dermal homeostasis. Fibroblasts are derived from dermal stem cells and produce components of connective tissue, such as collagen, which maintains the structure of the dermis. Cell-cell communication is required for the maintenance of tissue homeostasis, and the role of exosomes in this process has recently been attracting increasing attention. Dermal stem cells and fibroblasts have been suggested to communicate with each other in the dermis; however, the underlying mechanisms remain unclear. In the present study, we investigated communication between dermal stem/progenitor cells (DSPCs) and fibroblasts via exosomes. We collected exosomes from DSPCs and added them to a culture of fibroblasts. With the exosomes, COL1A1 mRNA expression was up-regulated and dependent on the Akt phosphorylation. Exosomes collected from fibroblasts did not show the significant up-regulation of COL1A1 mRNA expression. We then performed a proteomic analysis and detected 74 proteins specific to DSPC-derived exosomes, including ANP32B related to Akt phosphorylation. We added exosomes in which ANP32B was knocked down to a fibroblast culture and observed neither Akt phosphorylation nor enhanced type I collagen synthesis. Additionally, an immunohistochemical analysis of skin tissues revealed that ANP32B expression levels in CD271-positive dermal stem cells were lower in old subjects than in young subjects. These results suggest that DSPCs promote type I collagen synthesis in fibroblasts by secreting exosomes containing ANP32B, which may contribute to the maintenance of skin homeostasis; however, this function of DSPCs may decrease with aging.

Increase in inhibin beta A/Activin-A expression in the human epidermis and the suppression of epidermal stem/progenitor cell proliferation with aging.

BACKGROUND: Age-related thinning and reduced cell proliferation in the human epidermis are associated with the accumulation of senescent cells and decreases in the number and function of epidermal stem cells. OBJECTIVE: This study examined the expression of INHBA/Activin-A in human epidermis and expression differences with age, and the effect of Activin-A on epidermal stem/progenitor cells. METHODS: Immunohistochemical staining was used to analyze age-related changes in the expression of INHBA/Activin-A in the epidermal tissue of young and old subjects. Epidermal INHBA/Activin-A expression levels, epidermal morphology, and the number of epidermal stem/progenitor cells or proliferating cells were investigated using older abdominal skin samples. The effects of Activin-A on the development of a three-dimensional (3D) reconstructed epidermis and cell proliferation were also assessed. RESULTS: INHBA/Activin-A expression levels in the human epidermis increased with age, although they varied among individuals. In the epidermis of older abdominal skin samples, INHBA/Activin-A expression levels negatively correlated with epidermal thickness, the rete ridge depth and the interdigitation index. The proportion of epidermal stem/progenitor cells and proliferating cells decreased with increases in INHBA/Activin-A expression levels. Activin-A had no effect on the differentiation of keratinocytes in the 3D-reconstructed epidermis; however, thinning of the 3D epidermis was noted. Moreover, the addition of Activin-A inhibited the proliferation of epidermal stem/progenitor cells in a concentration-dependent manner. CONCLUSIONS: Age-related increased in INHBA/Activin-A expression levels were observed in the human epidermis, and may contribute to epidermal thinning and decreases in the number of epidermal stem/progenitor cells and proliferative activity.

Age-related decrease in responsiveness of CD271-positive skin stem cells to growth factors.

Previous studies have demonstrated that the numbers of interfollicular epidermal stem cells (IFE-SCs) and dermal stem cells (DSCs) decrease with age and that this decrease is attributed to the age-related deterioration of skin homeostatic functions and the delay in wound healing. Meanwhile, functional decline in the stem cells is also considered to be responsible for the deteriorated skin homeostatic functions and the delayed wound healing associated with ageing. In the present study, we focused on epidermal growth factor/epidermal growth factor receptor (EGF/EGFR) signalling and fibroblast growth factor-2/fibroblast growth factor receptor (FGF2/FGFR) signalling to analyse the age-related changes. Immunohistological analysis revealed that the expressions of EGFR and FGFR1 declined in IFE-SCs and DSCs with age, respectively. Additionally, IFE-SCs and DSCs isolated from the skin samples of elderly subjects exhibited lowered responsiveness to EGF and FGF2, respectively. These results suggest that the lowered responsiveness of the skin stem cells to growth factors may be a factor involved in the age-related deterioration of skin regenerative functions during wound healing and skin homeostatic functions. We hope that homeostatic and wound healing functions in the skin could be maintained if the decreased expressions of EGFR and FGFR1 in IFE-SCs and DSCs, respectively, can be suppressed.

Characteristics of anal canal cancer in Japan.

Anal canal cancer (ACC) has been reported to be an uncommon cancer in Japan, as in the USA, Europe, and Australia. This retrospective multi-institutional study was conducted to clarify the characteristics of ACC in Japan. First, the histological ACC type cases treated between 1991 and 2015 were collected. A detailed analysis of the characteristics of anal canal squamous cell carcinoma (SCC) cases was then conducted. The results of the histological types revealed that of the 1781 ACC cases, 435 cases (24.4%) including seven cases of adenosquamous cell carcinomas were SCC and 1260 cases (70.7%) were adenocarcinoma. However, the most common histological type reported in the USA, Europe, and Australia is SCC. Most ACC cases are adenocarcinomas and there is a low incidence of SCC in Japan which is different from the above-mentioned countries. Moreover, we reclassified T4 into the following two groups based on tumor size: T4a (tumor diameter of 5 cm or less) and T4b (tumor diameter of more than 5 cm). The results of the TNM classification of SCC revealed that the hazard ratio (HR) to T1 of T2, T3, T4a, and T4b was 2.45, 2.28, 2.89, and 4.97, respectively. As T4b cases had a worse prognosis than T4a cases, we propose that T4 for anal canal SCC in Japan be subclassified into T4a and T4b.

Evaluation of a 55-gene classifier as a prognostic biomarker for adjuvant chemotherapy in stage III colon cancer patients.

BACKGROUND: Adjuvant chemotherapy reduces the risk of recurrence of stage III colon cancer (CC). However, more effective prognostic and predictive biomarkers are needed for better treatment stratification of affected patients. Here, we constructed a 55-gene classifier (55GC) and investigated its utility for classifying patients with stage III CC. METHODS: We retrospectively identified patients aged 20-79 years, with stage III CC, who received adjuvant chemotherapy with or without oxaliplatin, between the years 2009 and 2012. RESULTS: Among 938 eligible patients, 203 and 201 patients who received adjuvant chemotherapy with and without oxaliplatin, respectively, were selected by propensity score matching. Of these, 95 patients from each group were analyzed, and their 5-year relapse-free survival (RFS) rates with and without oxaliplatin were 73.7 and 77.1%, respectively. The hazard ratios for 5-year RFS following adjuvant chemotherapy (fluoropyrimidine), with and without oxaliplatin, were 1.241 (95% CI, 0.465-3.308; P = 0.67) and 0.791 (95% CI, 0.329-1.901; P = 0.60), respectively. Stratification using the 55GC revealed that 52 (27.3%), 78 (41.1%), and 60 (31.6%) patients had microsatellite instability (MSI)-like, chromosomal instability (CIN)-like, and stromal subtypes, respectively. The 5-year RFS rates were 84.3 and 72.0% in patients treated with and without oxaliplatin, respectively, for the MSI-like subtype (HR, 0.495; 95% CI, 0.145-1.692; P = 0.25). No differences in RFS rates were noted in the CIN-like or stromal subtypes. Stratification by cancer sidedness for each subtype showed improved RFS only in patients with left-sided primary cancer treated with oxaliplatin for the MSI-like subtype (P = 0.007). The 5-year RFS rates of the MSI-like subtype in left-sided cancer patients were 100 and 53.9% with and without oxaliplatin, respectively. CONCLUSIONS: Subclassification using 55GC and tumor sidedness revealed increased RFS in patients within the MSI-like subtype with stage III left-sided CC treated with fluoropyrimidine and oxaliplatin compared to those treated without oxaliplatin. However, the predictive power of 55GC subtyping alone did not reach statistical significance in this cohort, warranting larger prospective studies. TRIAL REGISTRATION: The study protocol was registered in the University Hospital Medical Education Network (UMIN) clinical trial registry (UMIN study ID: 000023879 ).

A nationwide, multi-institutional collaborative retrospective study of colorectal neuroendocrine tumors in Japan.

AIM: Neuroendocrine tumors (NETs) are one of the subtypes of neuroendocrine neoplasms and are defined as epithelial neoplasms with predominant neuroendocrine differentiation. The aim of this study was to clarify the clinicopathological characteristics of colorectal NETs through a nationwide retrospective study in Japan. METHODS: This multicenter retrospective cohort study of NETs in Japan was conducted by the study group of the Japanese Society for Cancer of the Colon and Rectum. In this study, we aimed to clarify the characteristics of Japanese patients with colorectal NETs. This cohort study included patients with colorectal NETs who were treated from January 2011 to December 2015. RESULTS: Most NETs developed in the lower rectum. Predictive factors of lymph node metastasis included size (>10 mm), depth of invasion (muscular propria or greater), NET grade (NET G2), depressed lesion of the tumor, and lymphovascular infiltration. In particular, depressed lesion of the tumor and lymphovascular infiltration were independent predictive factors of lymph node metastasis. The presence of an increased number of these predictive factors increased the lymph node metastasis rate. CONCLUSION: Surgical resection with lymph node dissection is considered in the colorectal NETs patients with predictive factors of lymph node metastasis, the number of which is correlated with incidence of lymph node metastasis.

SASP-induced macrophage dysfunction may contribute to accelerated senescent fibroblast accumulation in the dermis.

Recently, increasing attention has been paid to senescence-associated secretory phenotype (SASP), a phenomenon that senescent cells secrete molecules such as inflammatory cytokines and matrix metalloproteinases (MMPs), due to its noxious effects on the surrounding tissue. Senescent cells in the blood and liver are known to be properly depleted by macrophages. In the dermis, accumulation of senescent cells has been reported and is thought to be involved with skin ageing. In this study, to elucidate the clearance mechanism of senescent cells in the dermis, we focused on macrophage functions. Our co-culture experiments of senescent fibroblasts and macrophages revealed a two-step clearance mechanism: first, TNF-α secreted from macrophages induces apoptosis in senescent fibroblasts, and then, dead cells are phagocytosed by macrophages. Furthermore, it was suggested that SASP factors suppress both of the two steps of the senescent cell clearance by macrophages. From these findings, normally senescent cells in the dermis are thought to be removed by macrophages, but when senescent cells are excessively accumulated owing to oxidative stress, ultraviolet (UV) ray or other reasons, SASP was suggested to suppress the macrophage-dependent clearance functions and thereby cause further accumulation of senescent cells.

Rectal Cancer Surgery in Patients Older Than 80 Years: Is Hartmann's Procedure Safe?

BACKGROUND/AIM: The current study aimed to identify the safety and efficacy of Hartmann's procedure (HP) among elderly patients (age ≥80 years) with rectal cancer. PATIENTS AND METHODS: Data on surgical outcome, survival rate, and incidence of stoma reversal were retrospectively compared between patients aged over 80 years who underwent anterior resection (AR) and HP. RESULTS: In total, 79 elderly patients underwent rectal cancer surgery. Of these patients, 54 (68.4%) underwent AR and 25 (31.6%) HP. The two groups did not differ significantly in terms of age, nutrient status, and tumor characteristics. Eight (14.8%) patients who underwent AR and six (24.0%) who underwent HP presented with intra-abdominal complications (p=0.35). The overall survival and recurrent-free survival rates between the two groups did not differ. CONCLUSION: HP for elderly patients with rectal cancer has similar complication rates to AR, and achieved similar oncological outcomes.

UV irradiation-induced DNA hypomethylation around WNT1 gene: Implications for solar lentigines.

Wnt/ß-catenin signalling promotes melanogenesis in melanocytes and also induces melanocytogenesis from melanocyte stem cells (McSCs). Previous study reported that WNT1, a ligand which activates Wnt/ß-catenin signalling pathway, was more highly expressed in the epidermis at SLs than in normal skin areas, suggesting that WNT1 causes hyperpigmentation. To elucidate the mechanism by which WNT1 expression is increased in SLs, we examined the methylation of 5-carbon of cytosine (5mC), that is 5-methylcytosine (5mC) level, in a region within the WNT1 promoter; the methylation of the region was known to negatively regulate WNT1 gene expression. We used an immortalized cell line of human interfollicular epidermal stem cells to analyse the effect of UVB irradiation on DNA methylation level of WNT1 promoter and found that UVB irradiation caused demethylation of WNT1 promoter and promoted WNT1 mRNA expression. It was also found that UVB irradiation reduced the expression of DNA methyltransferase 1 (DNMT1), an enzyme responsible for maintaining methylation patterns during cell division. Pathological analysis of SLs and non-SL regions in the human skin revealed that both DNMT1 expression and 5mC level were decreased at SLs compared to non-SL skins. Furthermore, bisulphite sequencing showed that the methylated CpG level in WNT1 promoter was also lower at SLs than in non-SL skins. Thus, in the skin exposed to a high amount of UV rays, excessive expression of WNT1 is thought to be caused by the demethylation of WNT1 promoter, and the upregulated WNT1 promotes melanocytogenesis and melanogenesis, then resulting in SL formation.

Extracellular proteoglycan decorin maintains human hair follicle stem cells.

Hair follicle stem cells (HFSC) are localized in the bulge region of the hair follicle and play a role in producing hair. Recently, it has been shown that the number of HFSC decreases with age, which is thought to be a cause of senile alopecia. Therefore, maintaining HFSC may be key for the prevention of age-related hair loss, but the regulatory mechanisms of HFSC and the effects of aging on them are largely unknown. In general, stem cells are known to require regulatory factors in the pericellular microenvironment, termed the stem cell niche, to maintain their cell function. In this study, we focused on the extracellular matrix proteoglycan decorin (DCN) as a candidate factor for maintaining the human HFSC niche. Gene expression analysis showed that DCN was highly expressed in the bulge region. We observed decreases in DCN expression as well as the number of KRT15-positive HFSC with age. In vitro experiments with human plucked hair-derived HFSC revealed that HFSC lost their undifferentiated state with increasing passages, and prior to this change a decrease in DCN expression was observed. Furthermore, knockdown of DCN promoted HFSC differentiation. In contrast, when HFSC were cultured on DCN-coated plates, they showed an even more undifferentiated state. From these results, as a novel mechanism for maintaining HFSC, it was suggested that DCN functions as a stem cell niche component, and that the deficit of HFSC maintenance caused by a reduction in DCN expression could be a cause of age-related hair loss.

[Gallbladder Malignant Lymphoma Diagnosed after Surgery for Acute Cholecystitis - A Case Report].

An 84-year-old man visited our hospital with epigastralgia.Levels of hepatic and biliary enzymes and CRP were elevated, as detected by a blood test.On a CT scan, a swollen gallbladder with stones was detected.The patient was admitted to the hospital with a diagnosis of Grade I acute cholecystitis.Conservative treatment was continued with antibiotic administration and the patient was discharged from the hospital with improvement on day 6 after admission.Three months later, the patient underwent laparoscopic cholecystectomy.In the gallbladder, a 45×45 mm tumor was found.Upon pathological examination, diffuse proliferation of lymphocyte-like heterotypic cells and subserosal invasion were observed.Immunohistochemistry results were negative for MUM1 and positive for CD10 and Bcl6 markers.A malignant diffuse large B-cell lymphoma was diagnosed.We experienced a case of malignant lymphoma of the gallbladder diagnosed after surgery for acute cholecystitis, which we herein report with literature consideration.