The Hox-based positional memory in muscle stem cells.

The skeletal muscle is a contractile tissue distributed throughout the body with various anatomical sizes, shapes, and functions. In pathological conditions, such as muscular dystrophy, age-related sarcopenia, and cancer cachexia, skeletal muscles are not uniformly affected throughout the body. This region-specific vulnerability cannot be fully explained by known physiological classifications, including muscle fiber types. Accumulating evidence indicates that the expression patterns of topographic homeobox (Hox) genes provide a molecular signature of positional memory, reflecting the anatomical locations and embryonic history of muscles and their associated muscle stem cells in adult mice and humans. Hox-based positional memory is not merely a remnant of embryonic development but is expected to be an intrinsic determinant controlling muscle function because recent studies have shown that aberrant Hox genes affect muscle stem cells. In this review, we discuss the concept of Hox-based positional memory, which may offer a new perspective on the region-specific pathophysiology of muscle disorders.

Loss of Tob1 promotes muscle regeneration through muscle stem cell expansion.

Muscle stem cells (MuSCs) play an indispensable role in postnatal muscle growth and hypertrophy in adults. MuSCs also retain a highly regenerative capacity and are therefore considered a promising stem cell source for regenerative therapy for muscle diseases. In this study, we identify tumor-suppressor protein Tob1 as a Pax7 target protein that negatively controls the population expansion of MuSCs. Tob1 protein is undetectable in the quiescent state but is upregulated during activation in MuSCs. Tob1 ablation in mice accelerates MuSC population expansion and boosts muscle regeneration. Moreover, inactivation of Tob1 in MuSCs ameliorates the efficiency of MuSC transplantation in a murine muscular dystrophy model. Collectively, selective targeting of Tob1 might be a therapeutic option for the treatment of muscular diseases, including muscular dystrophy and age-related sarcopenia.

Three Molecular Developmental Pathways of Remnant Pancreatic Cancer after Resection: A Nationwide Project Study of Japan Pancreas Society.

OBJECTIVE: This study aimed to clarify the molecular mechanism of remnant pancreatic cancer (PC) development after primary PC resection. SUMMARY BACKGROUND DATA: Molecular mechanisms of the development of remnant PCs following primary PC resection are largely unknown. METHODS: Forty-three patients undergoing remnant PC resection after primary PC resection between 2001 and 2017 at 26 institutes were retrospectively analyzed. Clinicopathological features and molecular alterations detected by targeted amplicon sequencing of 36 PC-associated genes were evaluated. RESULTS: These patients showed significantly lower body mass indices and higher hemoglobin A1c values at remnant PC resection than at primary PC resection. A comparison of the molecular features between primary and remnant PCs indicated that remnant PCs were likely to develop via three different molecular pathways: successional, showing identical and accumulated alterations (n=14); phylogenic, showing identical and distinct alterations (n=26); and distinct, showing independent distinctive alterations (n=3). The similarity of gene alterations was associated with time to the remnant PC development (r=－0.384, P=0.0173). Phylogenic pathways were significantly associated with the intraductal spread of carcinoma (P=0.007). Patient survival did not differ significantly depending on these molecular pathways. CONCLUSION: Molecular profiling uncovered three pathways for the development of remnant PCs, namely, successional, phylogenic, and distinct pathways. The vast majority of remnant PCs are likely to be molecularly associated with primary PCs either in the successional or phylogenic way. This information could impact the design of a strategy for monitoring and treating remnant PCs.

Multilayered proteomics reveals that JAM-A promotes breast cancer progression via regulation of amino acid transporter LAT1.

Recent studies have shown that transmembrane-type tight junction proteins are upregulated in various cancers compared with their levels in normal tissues and are involved in cancer progression, suggesting that they are potential therapeutic targets. Here, we demonstrated the expression profile and a novel role of junctional adhesion molecule-A (JAM-A) in breast cancer. Immunohistochemistry of surgical specimens showed that JAM-A was highly expressed from carcinoma in situ lesions, as in other adenocarcinomas, with higher expression in invasive carcinomas. High expression of JAM-A contributed to malignant aspects such as lymph node metastasis and lymphatic involvement positivity. In breast cancer cells, JAM-A expression status affects malignant potentials including proliferation and migration. Multilayered proteomics revealed that JAM-A interacts with the amino acid transporter LAT1 in breast cancer cells. JAM-A regulates the expression of LAT1 and interacts with it on the whole cell membrane, leading to enhanced amino acid uptake to promote tumor growth. Double high expression of JAM-A and LAT1 predicts poor prognosis in patients with breast cancer. Of note, an antibody against an extracellular domain of JAM-A suppressed the proliferation of breast cancer cells. Our findings indicate the possibility of JAM-A-targeted therapy ideally combined with LAT1-targeted therapy as a new therapeutic strategy against breast cancer.

Decreased and Improved Movement Abilities in a Case of Myotonic Dystrophy Type 1: Examining Longitudinal Characteristics Based on Repeated Evaluations.

Several large longitudinal studies on myotonic dystrophy type 1 (DM1) patients have revealed that proximal muscles show more gradual muscle weakness than distal muscles and that the progression of muscle weakness might differ between the sexes. However, these longitudinal studies were based on two follow-up time points. The present report aimed to verify the longitudinal characteristics of muscle strength and various movement abilities in a case of DM1 by examining the results of 44 repeated evaluations for approximately two years. A 40-year-old male patient with DM1 could walk independently without any aid. We recorded the longitudinal changes in his muscle strength and movement ability during outpatient rehabilitation. During follow-up, he had a fall and was diagnosed with a right ankle sprain. To evaluate the effects of the fall, we examined his recorded data. He had a significant decrease in right knee extensor muscle strength after the fall, suggesting muscle weakness due to disuse syndrome. Although his right knee extensor muscle strength and walking speed decreased, the timed up-and-go test score was improved, and walking endurance in the 2-minute walk test was maintained. In the present case, there were some motor tasks in which the movement ability was maintained or improved, likely due to the use of compensation by residual function, even when muscle weakness was present. Regular and repeated evaluations of patients with DM1 lead to reveal longitudinal characteristics of their dysfunction and movement ability.

Vitamin D-metabolizing enzyme CYP24A1 affects oncogenic behaviors of oral squamous cell carcinoma and its prognostic implication.

Vitamin D is an essential molecule for cellular homeostasis, playing a critical role in cell fate decisions including cell proliferation, differentiation, and viability. Accumulating evidence has revealed that expression of the vitamin D-metabolizing enzyme CYP24A1 is dysregulated in different types of human malignancy. CYP24A1 has been shown to be involved in the oncogenic property of a variety of carcinoma cells. However, the pathological relevance of CYP24A1 expression level in human oral malignancy remains to be clarified. In the present study, suppression of CYP24A1 expression in oral squamous cell carcinoma (OSCC) cells increased cell proliferation, invasive activity, colony formation efficacy, and tumor growth in vivo. In addition, knockout of CYP24A1 expression inhibited cell death induced by two different types of anticancer drugs, i.e., fluorouracil and cisplatin. Gene clustering by RNA-sequence analysis revealed that several signaling molecules associated with MYC are involved in CYP24A1-mediated oncogenic behaviors. Furthermore, decreased expression level of CYP24A1 was observed in 124/204 cases (61%) of OSCC and was shown to be associated with short relapse-free and overall survival periods. The results showed that a low expression level of CYP24A1 promotes the oncogenic activity of OSCC and is significantly associated with poor prognosis in patients with this malignancy.

Carbon monoxide-loaded cell therapy as an exercise mimetic for sarcopenia treatment.

Sarcopenia is characterized by loss of muscle strength and muscle mass with aging. The growing number of sarcopenia patients as a result of the aging population has no viable treatment. Exercise maintains muscle strength and mass by increasing peroxisome growth factor activating receptor γ-conjugating factor-1α (PGC-1α) and Akt signaling in skeletal muscle. The present study focused on the carbon monoxide (CO), endogenous activator of PGC-1α and Akt, and investigated the therapeutic potential of CO-loaded red blood cells (CO-RBCs), which is bioinspired from in vivo CO delivery system, as an exercise mimetic for the treatment of sarcopenia. Treatment of C2C12 myoblasts with the CO-donor increased the protein levels of PGC-1α which enhanced mitochondrial biogenesis and energy production. The CO-donor treatment also activated Akt, indicating that CO promotes muscle synthesis. CO levels were significantly elevated in the skeletal muscle of normal mice after intravenous administration of CO-RBCs. Furthermore, CO-RBCs restored the mRNA expression levels of PGC-1α in the skeletal muscle of two experimental sarcopenia mouse models, denervated (Den) and hindlimb unloading (HU) models. CO-RBCs also restored muscle mass in Den mice by activating Akt signaling and suppressing the muscle atrophy factors myostatin and atrogin-1, and oxidative stress. Treadmill tests further showed that the reduced running distance in HU mice was significantly restored by CO-RBC administration. These findings suggest that CO-RBCs have potential as an exercise mimetic for sarcopenia treatment.

Clonal analysis of metachronous double biliary tract cancers.

The molecular mechanisms underpinning the development of metachronous tumors in the remnant bile duct following surgical resection of primary biliary tract carcinomas (BTCs) are unknown. This study aimed to elucidate these mechanisms by evaluating the clinicopathologic features of BTCs, the alterations to 31 BTC-related genes on targeted sequencing, and the aberrant expression of p53, p16, SMAD4, ARID1A and ß-catenin on immunohistochemistry. Twelve consecutive patients who underwent resection of metachronous BTCs following primary BTC resection with negative bile duct margins were enrolled. Among the 12 metachronous tumors, six exhibited anterograde growth in the lower portion and six exhibited retrograde growth in the upper portion of the biliary tree. Surgical resection of metachronous BTCs resulted in recurrence-free survival in seven, local recurrence in five, and death in two patients. Nine achieved 5-year overall survival after primary surgery. Molecular analyses revealed that recurrently altered genes were: TP53, SMAD4, CDKN2A, ELF3, ARID1A, GNAS, NF1, STK11, RNF43, KMT2D and ERBB3. Each of these was altered in at least three cases. A comparison of the molecular features between 12 paired primary and metachronous BTCs indicated that 10 (83%) metachronous tumors developed in clonal association with corresponding primary tumors either successionally or phylogenically. The remaining two (17%) developed distinctly. The successional tumors consisted of direct or evolved primary tumor clones that spread along the bile duct. The phylogenic tumors consisted of genetically unstable clones and conferred a poor prognosis. Metachronous tumors distinct from their primaries harbored fewer mutations than successional and phylogenic tumors. In conclusion, over 80% of metachronous BTCs that develop following primary BTC resection are probably molecularly associated with their primaries in either a successional or a phylogenetic manner. Comparison between the molecular features of a metachronous tumor and those of a preceding tumor may provide effective therapeutic clues for the treatment of metachronous BTC. © 2024 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Liquid Biopsy for Pancreatic Cancer by Serum Extracellular Vesicle-Encapsulated Long Noncoding RNA HEVEPA.

OBJECTIVES: The role of long noncoding RNAs (lncRNAs) in pancreatic ductal adenocarcinoma (PDAC) remain unclear. Extracellular vesicle (EV)-encapsulated RNAs could be effective targets for liquid biopsy. We aimed to identify previously unknown EV-encapsulated lncRNAs in PDAC and establish highly accurate methods for isolating EVs. MATERIALS AND METHODS: Extracellular vesicles were isolated using existing and newly developed methods, namely, PEViA-UC and PEViA-IP, from serum samples of 20 patients with PDAC, 22 patients with intraductal papillary mucinous neoplasms, and 21 healthy individuals. Extracellular vesicle lncRNA expression was analyzed using digital PCR. RESULTS: Gene expression analysis using cDNA microarray revealed a highly expressed lncRNA, HEVEPA , in serum EVs from patients with PDAC. We established PEViA-UC and PEViA-IP using PEViA reagent, ultracentrifugation, and immunoprecipitation. Although detection of EV-encapsulated HEVEPA using existing methods is challenging, PEViA-UC and PEViA-IP detected EV HEVEPA , which was highly expressed in patients with PDAC compared with non-PDAC patients. The detection sensitivity for discriminating PDAC from non-PDAC using the combination of HEVEPA and HULC , which are highly expressed lncRNAs in PDAC, and carbohydrate antigen 19-9 (CA19-9), was higher than that of HEVEPA , HULC , or CA19-9 alone. CONCLUSIONS: Extracellular vesicle lncRNAs isolated using PEViA-IP and CA19-9 together could be effective targets in liquid biopsy for PDAC diagnosis.

Comparison between hangeshashinto and dexamethasone for IL-1α and ß-defensin 1 production by human oral keratinocytes.

OBJECTIVE: Human ß-defensin 1 (hBD-1) is a antimicrobial peptide that is constantly secreted by oral tissues. Hangeshashinto (HST), a traditional Japanese medicine, has been reported to be effective against stomatitis. This study aimed to clarify the profile of HST by comparing the system of production of interleukin-1α (IL-1α) and hBD-1 in human oral mucosal epithelial cells with dexamethasone (DEX), a steroid used for the treatment of stomatitis. METHODS: Human oral keratinocytes (HOK) were treated with HST, DEX, or HST components (baicalein, baicalin, berberine, and glycyrrhizin) for 24 h, and subsequently cultured for 24 h with or without Pam3CSK4 or lipopolysaccharide (LPS). The cell supernatants, total RNA, and intracellular proteins were collected, and changes in IL-1α and hBD-1 protein production and gene expression were evaluated using ELISA and RT-PCR. The phosphorylation of NF-kB and the cell proliferative ability of HOK were evaluated by western blotting and XTT assay, respectively. RESULTS: DEX (0.01-10 µM) significantly suppressed IL-1α and hBD-1 production induced by either Pam3CSK4 or LPS, and also decreased cell growth. In contrast, HST inhibited Pam3CSK4- and LPS-induced IL-1α production at a concentration range of 12.5-100 µg/mL without affecting the cell proliferative capacity and hBD-1 production of HOK. Baicalein and baicalin, which are flavonoid ingredients of HST, showed anti-IL-1α production. CONCLUSION: HST may be useful as a therapeutic agent for stomatitis and other inflammatory diseases of the oral cavity.

Gene Rearrangement and Expression of PRKACA and PRKACB Govern Morphobiology of Pancreatobiliary Oncocytic Neoplasms.

Intraductal oncocytic papillary neoplasms (IOPNs) are distinct from intraductal papillary mucinous neoplasms based on characteristic morphologic and genetic features represented by fusion genes involving PRKACA or PRKACB (PRKACA/B). However, pancreatic and biliary tumors with partial oncocytic features are often encountered clinically, and their molecular features are yet to be clarified. This study included 80 intraductal papillary neoplasms: 32 tumors with mature IOPN morphology (typical), 28 with partial or subclonal oncocytic features (atypical), and 20 without oncocytic features (control). We analyzed PRKACA/B fusion genes, including ATP1B1::PRKACA, DNAJB1::PRKACA, and ATP1B1::PRKACB, by reverse-transcription PCR; mRNA expression of fusion genes and nonrearranged PRKACA/B genes by quantitative reverse-transcription PCR; mutations in KRAS, BRAF, and GNAS by targeted sequencing or droplet digital PCR; and the expression of cyclic adenosine monophosphate (cAMP)-dependent protein kinase catalytic subunits α (PRKACA) and ß (PRKACB), phosphorylated cAMP response element-binding protein, and aberrations of p16, p53, SMAD4, STK11, and ß-catenin by immunohistochemistry. PRKACA/B fusion genes were detected in 100% (32/32) of typical, 46% (13/28) of atypical, and 0% (0/20) of control (P < .05). Expression of PRKACA, PRKACB, and phosphorylated cAMP response element-binding protein was upregulated in neoplasms with PRKACA/B fusion genes (P < .05). mRNA expression of the PRKACA/B fusion genes and protein expression of PRKACA or PRKACB tended to be higher in typical than in atypical cases (mRNA, P = .002; protein expression, P = .054). In some atypical neoplasms with mixed subtypes, PRKACA/B fusion genes were superimposed exclusively on oncocytic components. Typical IOPNs harbored fewer KRAS and GNAS mutations than control samples and fewer alterations in p53 and STK11 than atypical samples (P < .05). In conclusion, PRKACA/B fusion genes not only are the characteristic drivers of IOPNs but also play a crucial role in the development of subclonal oncocytic neoplasms. Moreover, oncocytic morphology is strongly associated with upregulation of PRKACA/B, which may provide clues for potential therapeutic options.

Repeat bidirectional double-balloon enteroscopy 1 year later may be proper in Peutz-Jeghers patients with difficult-to-reach polyps.

Background and study aims Small-bowel polyps in patients with Peutz-Jeghers syndrome (PJS) are sometimes difficult to reach using double-balloon enteroscopy (DBE). However, they can induce intussusception, especially when ≧15 mm. This study aimed to review the outcomes of patients with such polyps. Patients and methods All patients with PJS with small-bowel polyps that bidirectional DBE failed to reach and were ≧5 mm as shown by DBE enterography at our institution from May 2006 to April 2022 were retrospectively evaluated. The endpoint was the earliest occurrence of symptomatic intussusception induced by the polyp, endoscopic removal by repeat DBE or intraoperative endoscopy, or the last medical record describing the patient's condition. Results This study included 27 polyps in 13 patients. All patients had extraluminal adhesions. None developed symptomatic intussusception, eight patients underwent endoscopic removal at repeat DBE without surgery, two patients underwent removal with intraoperative endoscopy, two patients were observed without polyp removal, and one patient had a polyp removed at repeat DBE and three unreachable polyps remained. Repeat DBE without surgery was able to remove 14 polyps (52%). Polyps ≧15 mm included 11 lesions in eight patients and were observed for a median of 14 months without symptomatic intussusception. Conclusions The difficult-to-reach polyps may have a low risk of immediate symptomatic intussusception, possibly due to limited bowel mobility by extraluminal adhesions, and the likelihood of reaching them at repeat DBE was substantial. Hence, repeat DBE 1 year later may be proper in such patients with PJS.

Pax7 reporter mouse models: a pocket guide for satellite cell research.

Since their discovery, satellite cells have showcased their need as primary contributors to skeletal muscle maintenance and repair. Satellite cells lay dormant, but when needed, activate, differentiate, fuse to fibres and self-renew, that has bestowed satellite cells with the title of muscle stem cells. The satellite cell specific transcription factor Pax7 has enabled researchers to develop animal models against the Pax7 locus in order to isolate and characterise satellite cell-mediated events. This review focuses specifically on describing Pax7 reporter mouse models. Here we describe how each model was generated and the key findings obtained. The strengths and limitations of each model are also discussed. The aim is to provide new and current satellite cell enthusiasts with a basic understanding of the available Pax7 reporter mice and hopefully guide selection of the most appropriate Pax7 model to answer a specific research question.

Evaluation of Eruption of Permanent Teeth in Beagle Dog Extraction Sites Filled with Carbonate Apatite.

Autologous bone grafting is the primary method for treating alveolar clefts. However, bone grafting materials are desired as alternatives to autogenous bone to reduce surgical invasiveness. Here, we present an animal study evaluating the effect of carbonate apatite (CA) on the spontaneous eruption of permanent teeth. The bone grafting materials included CA, natural bovine bone (BB), and hydroxyapatite (HA). In 15 8-week-old male beagle dogs, the left mandibular deciduous premolars (DP) two and three were extracted and subsequently filled with CA, BB, and HA. The animals were euthanized after a predetermined number of days, and samples were collected for microcomputed tomography and histological evaluation. Spontaneous eruption of the succeeding permanent teeth (P3 and P4) was observed in the CA group at 14 weeks. Delayed eruption of the succeeding permanent teeth was observed in the BB and HA groups. CA could serve as a viable alternative to autogenous bone for treating alveolar clefts.

Common pathological findings in the heart in COVID-19-related sudden death cases: An autopsy case series.

Background: Cardiomyopathy is a leading cause of sudden out-of-hospital death after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and coronavirus disease 2019 (COVID-19) vaccination. Such unexpected COVID-19-related cardiomyopathies are challenging to diagnose as specific pathological findings are not always identified. Case summary: We reported the autopsy findings of two cases of sudden death due to COVID-19-related cardiomyopathies. In one case, death occurred after SARS-CoV-2 infection, while in the other, after COVID-19 vaccination. We found common pathological findings in both hearts: decreased staining intensity with special stains, loss of rhabdomeres, and multivacuolation in cardiomyocytes without inflammatory cell infiltration. The remaining organs showed no findings that could have contributed to the deaths. Conclusion: In cases of sudden death after SARS-CoV-2 infection or COVID-19 vaccination, the decreased staining intensity with special stains may aid the diagnosis of sudden death due to COVID-19-related cardiomyopathy, even when H&E staining shows few findings.

Monitoring mutant KRAS in plasma cell-free DNA can predict disease progression in a patient with multiple myeloma: A case report.

BACKGROUND AND AIMS: Multiple myeloma (MM), a neoplasm of plasma cells (PCs), is a highly heterogeneous disease with multifocal dissemination throughout the body. Minimal residual disease (MRD) detected using PCs in bone marrow (BM) is important for MM management; however, frequent invasive examinations impose a significant burden on patients. METHODS: Analysis using plasma cell-free DNA (cfDNA) might represent an alternative tool for disease monitoring. In this study, we observed the disease status in a patient with MM by examining the KRAS mutation allele frequency (MAF) in plasma cfDNA using digital PCR. RESULTS: During treatment, the MAF was correlated with serum immunoglobulin A and free light chain-kappa levels. After the second autologous peripheral blood stem cell transplantation, the KRAS MAF became immediately positive after confirming MRD negativity using PCs from BM. Shortly thereafter, the patient experienced clinical relapse primarily involving bone lesions. CONCLUSION: Mutant KRAS monitoring in cfDNA using serial blood collection might reflect the disease status more accurately than invasive BM examinations, especially in patients with MM whose primary lesions have extra-BM locations. It could also help predict treatment responses and outcomes.

Successful endovascular embolization of the common hepatic artery for pseudoaneurysm associated with pancreatic fistula after liver transplantation: a case report.

BACKGROUND: After orthotopic liver transplantation (OLT), complications such as hepatic artery stenosis, thrombosis, and bleeding are possible. Hepatic artery pseudoaneurysms (HAP) are prone to rupture, rupture hemorrhage, and increased mortality risk. Endovascular treatment of HAP may result in recurrence, even after successful embolization with thrombin. Formation of a HAP in the common hepatic artery (CHA) is challenging because the CHA is the only artery in the liver graft after OLT. Therefore, CHA embolization in HAP is not an initial option. We report a case of HAP at the CHA after OLT that was treated with endovascular therapy, resulting in the occlusion of the CHA with coil embolization, achieving a radical cure. CASE PRESENTATION: A 59-year-old man with decompensated hepatitis C virus cirrhosis underwent deceased donor whole-liver transplantation after graft failure of a living donor liver transplantation. After the second transplantation, the patient developed infectious narrow-necked HAP at the CHA associated with postoperative pancreatic fistula. Repeated transcatheter arterial embolization with thrombin and n-butyl-2-cyanoacrylate was unsuccessful, as confirmed by postprocedure angiography, which revealed recanalization and regrowth of the HAP. Eight months after the first transcatheter arterial embolization, the patient presented with a chief complaint of abdominal pain due to an enlarged HAP. Angiography of the superior mesenteric artery (SMA) revealed a collateral bypass around the bile duct from the SMA to the liver graft. Coil embolization of the HAP in the CHA completely occluded the HAP without complications. More than 2 years after coil embolization, the liver graft function test results remained within normal limits without HAP recurrence. CONCLUSIONS: HAP at the CHA after liver transplantation can be fatal if ruptured. Because the liver is a highly angiogenic organ, even if initial treatment is not successful, radical treatment to occlude the CHA with HAP is possible if sufficient collateral vessels are developed.