Efficacy and safety of elobixibat in combination with or switched from conventional treatments of chronic constipation: A retrospective observational study.

Background and Aim: Elobixibat is a triple mode of action laxative that increases water secretion into the colon, promotes colonic motility, and reestablishes the defecation desire. This study aims to evaluate the effectivity and safety of elobixibat in chronic constipation (CC) patients refractory to conventional laxatives. Methods: A single-center retrospective observational study was conducted in refractory CC patients diagnosed according to the Rome IV criteria and received elobixibat between April 2018 and June 2022 at Osaka Saiseikai Nakatsu Hospital. Data were collected for spontaneous bowel movement (SBM), Bristol stool form scale (BSFS) scores, abdominal symptoms, and adverse events. Results: Eligible 311 patients were selected for the analysis. Two-week Elobixibat treatment significantly increased SBM (times/week) from 2.9 ± 1.9 to 4.3 ± 1.9 (P < 0.0001). The BSFS score improved significantly from 3.2 ± 1.7 to 4.4 ± 1.4 (P < 0.0001). The percentages of patients with hard stool were decrease and that with normal stools were increase. Improvements in abdominal symptoms (sensation of incomplete bowel evacuation, straining, abdominal pain and distention, and difficulty defecating) were also significant (P < 0.05). These constipation symptoms were improved irrespective of patient characteristics or previous laxatives. The 43.9% of previous laxatives were discontinued at the start of or after starting elobixibat treatment. A few adverse events were observed, elobixibat was well tolerated. Conclusion: Elobixibat was effective in patients who were refractory to other laxatives, irrespective of previous therapy or patient characteristics. Elobixibat may contribute to resolving polypharmacy with single mode of action laxatives.

Reciprocal suppression between TGFß signaling and TNF stimulation finetunes the macrophage inflammatory response.

Inflammation plays a crucial role in the development of various disease conditions or is closely associated with them. Inflammatory cytokines like TNF often engage in interactions with other cytokines and growth factors, including TGFß, to orchestrate inflammatory process. Basal/endogenous TGFß signaling is a universal presence, yet the precise way TNF communicates with TGFß signaling to regulate inflammation and influence inflammatory levels in macrophages has remained elusive. To address this question, this study utilized genetic approaches and a combination of molecular and cellular methods, including conditional TGFß receptor knockout mice, human cells, RNAseq, ATACseq and Cut & Run-seq. The results reveal that the TGFß signaling functions as a vital homeostatic pathway, curtailing uncontrolled inflammation in macrophages in response to TNF. Conversely, TNF employs two previously unrecognized mechanisms to suppress the TGFß signaling. These mechanisms encompass epigenetic inhibition and RBP-J-mediated inhibition of the TGFß signaling pathway by TNF. These mechanisms empower TNF to diminish the antagonistic influence exerted by the TGFß signaling pathway, ultimately enhancing TNF's capacity to induce heightened levels of inflammation. This reciprocal suppression dynamic between TNF and the TGFß signaling pathway holds unique physiopathological significance, as it serves as a crucial "braking" mechanism. The balance between TNF levels and the activity of the endogenous TGFß signaling pathway plays a pivotal role in determining the overall extent of inflammation. The potential for therapeutically augmenting the TGFß signaling pathway presents an intriguing avenue for countering the impact of TNF and, consequently, developing innovative strategies for inflammation control.

Bone marrow Adipoq-lineage progenitors are a major cellular source of M-CSF that dominates bone marrow macrophage development, osteoclastogenesis, and bone mass.

M-CSF is a critical growth factor for myeloid lineage cells, including monocytes, macrophages, and osteoclasts. Tissue-resident macrophages in most organs rely on local M-CSF. However, it is unclear what specific cells in the bone marrow produce M-CSF to maintain myeloid homeostasis. Here, we found that Adipoq-lineage progenitors but not mature adipocytes in bone marrow or in peripheral adipose tissue, are a major cellular source of M-CSF, with these Adipoq-lineage progenitors producing M-CSF at levels much higher than those produced by osteoblast lineage cells. The Adipoq-lineage progenitors with high CSF1 expression also exist in human bone marrow. Deficiency of M-CSF in bone marrow Adipoq-lineage progenitors drastically reduces the generation of bone marrow macrophages and osteoclasts, leading to severe osteopetrosis in mice. Furthermore, the osteoporosis in ovariectomized mice can be significantly alleviated by the absence of M-CSF in bone marrow Adipoq-lineage progenitors. Our findings identify bone marrow Adipoq-lineage progenitors as a major cellular source of M-CSF in bone marrow and reveal their crucial contribution to bone marrow macrophage development, osteoclastogenesis, bone homeostasis, and pathological bone loss.

Efficacy of a High-definition Three-dimensional Exoscope in Simultaneous Transcranial and Endoscopic Endonasal Surgery: A Case Report.

Owing to recent advances in medical optical technology, a high-definition (4K) three-dimensional (3D) exoscope has been developed as an alternative tool to using conventional microscopes for microscopic surgery, and its efficacy for neurosurgery has been reported. We report a case who underwent simultaneous surgery aiming for en bloc resection of an anterior skull base malignancy with concurrent exoscopic transcranial and endoscopic endonasal approaches using a 4K 3D exoscope. The patient was a 76-year-old woman who underwent en bloc resection for an anterior skull base olfactory neuroblastoma 13 years ago. After confirming the recurrence of progressive olfactory neuroblastoma, tumor resection was again decided to be performed. As with the first procedure, surgery was performed in an en bloc manner, using both transcranial and endonasal approaches. Exoscope provided enough space above the surgical field to allow us to perform transcranial and endonasal surgeries simultaneously. Moreover, the surgeons could maintain a comfortable posture throughout the procedure, and total tumor removal was successfully achieved without any abnormal event. To our knowledge, this is the first report of the introduction of an exoscope aiming for en bloc resection of an anterior skull base malignancy while performing simultaneous surgery with both transcranial and endonasal approaches. We believe that the more cases are accumulated, the more efficacy of a 4K 3D exoscope will be elucidated.

Hyper-Raman spectroscopy of benzene and pyridine revisited.

Hyper-Raman (HR) spectra of benzene-h6, benzene-d6, and pyridine in the liquid phase excited at 1064 nm were measured by a picosecond laser with a high repetition rate. Although benzene and pyridine are important aromatic molecules, the qualities of the HR spectra previously reported were not high enough to be compared with those of IR and Raman spectroscopy. Our HR spectroscopic system significantly improves sensitivity that enables the detection of HR bands of benzene and pyridine not observed before. In addition to band assignments, we interpret HR bands of benzene based on the vibronic coupling theory of (pre-) resonance hyper-Raman scattering. Depolarization ratios of HR bands of benzene and pyridine, obtained from polarized-HR measurements, are first examined from a theoretical point of view of HR spectroscopy. Moreover, we evaluate quantum chemical calculations for HR spectra by comparing experimental and computational spectra. We show that the frequency-dependent polarizability and hyperpolarizability calculations using time-dependent density functional theory well reproduce the HR experiments for bulk aromatic compounds.

TGFß reprograms TNF stimulation of macrophages towards a non-canonical pathway driving inflammatory osteoclastogenesis.

It is well-established that receptor activator of NF-κB ligand (RANKL) is the inducer of physiological osteoclast differentiation. However, the specific drivers and mechanisms driving inflammatory osteoclast differentiation under pathological conditions remain obscure. This is especially true given that inflammatory cytokines such as tumor necrosis factor (TNF) demonstrate little to no ability to directly drive osteoclast differentiation. Here, we found that transforming growth factor ß (TGFß) priming enables TNF to effectively induce osteoclastogenesis, independently of the canonical RANKL pathway. Lack of TGFß signaling in macrophages suppresses inflammatory, but not basal, osteoclastogenesis and bone resorption in vivo. Mechanistically, TGFß priming reprograms the macrophage response to TNF by remodeling chromatin accessibility and histone modifications, and enables TNF to induce a previously unrecognized non-canonical osteoclastogenic program, which includes suppression of the TNF-induced IRF1-IFNß-IFN-stimulated-gene axis, IRF8 degradation and B-Myb induction. These mechanisms are active in rheumatoid arthritis, in which TGFß level is elevated and correlates with osteoclast activity. Our findings identify a TGFß/TNF-driven inflammatory osteoclastogenic program, and may lead to development of selective treatments for inflammatory osteolysis.

Synthesis and photophysical properties of a new push-pull pyrene dye with green-to-far-red emission and its application to human cellular and skin tissue imaging.

Herein, we discuss a new pyrene-based push-pull dye (PC) and our investigation of its photophysical properties and applicability to biological studies. The newly synthesized dye exhibits highly polarity-sensitive fluorescence over a significantly wide range (i.e., the green to far-red region), accompanied by high fluorescence quantum yields (ΦFL > 0.70 in most organic solvents) and superior photostability to that of the commonly used Nile Red (NR) dye, which also fluoresces in the green to red region. When human prostate cancer cells stained with PC were imaged using a confocal laser scanning fluorescence microscope, PC was found to selectively stain the lipid droplets. Under the cell conditions where the formation of droplets was inhibited, PC could be distributed to both the remaining droplets and the intercellular membranes, which could be distinguished based on the fluorescence solvatochromic function of PC. Furthermore, PC efficiently stained normal human skin tissue blocks treated with a transparency-enhancing agent and enabled clear visualization of individual cells in each tissue architecture by means of two-photon fluorescence microscopy (2PM). Interestingly, PC provides bright 2PM images under tissue-penetrative 960 nm excitation, realizing much clearer and deeper tissue imaging than conventional pyrene dyes and NR. These results suggest that PC could replace several commonly used dyes in various biological applications, particularly the rapid and accurate diagnosis of tissue diseases, typified by biopsy.

Identification of a Novel Role for Foxo3 Isoform2 in Osteoclastic Inhibition.

Foxo3 acts as an important central regulator that integrates signaling pathways and coordinates cellular responses to environmental changes. Recent studies show the involvement of Foxo3 in osteoclastogenesis and rheumatoid arthritis, which prompted us to further investigate the FOXO3 locus. Several databases document FOXO3 isoform2, an N-terminal truncated mutation of the full-length FOXO3 However, the biological function of FOXO3 isoform2 is unclear. In this study, we established a conditional allele of Foxo3 in mice that deletes the full-length Foxo3 except isoform2, a close ortholog of the human FOXO3 isoform2. Expression of Foxo3 isoform2 specifically in macrophage/osteoclast lineage suppresses osteoclastogenesis and leads to the osteopetrotic phenotype in mice. Mechanistically, Foxo3 isoform2 enhances the expression of type I IFN response genes to RANKL stimulation and thus inhibits osteoclastogenesis via endogenous IFN-ß-mediated feedback inhibition. Our findings identify, to our knowledge, the first known biological function of Foxo3 isoform2 that acts as a novel osteoclastic inhibitor in bone remodeling.

[A Case Report of Pancreatic Neuroendocrine Tumor Resected with the Preoperative Diagnosis of Gastrointestinal Stromal Tumor of the Jejunum].

A 61-year-old man was examined for cervical pain and CT showed a 9 cm tumor to the third part of the duodenum and proximal jejunum. CT /MRI showed that the tumor was separated from the pancreas body. We scheduled a laparoscopic partial resection of the intestine with a suspected diagnosis of GIST of the intestine. The tumor was adhered to both the proximal jejunum and uncinate process of the pancreas. Therefore, we converted to an open surgery and resected part of the pancreas, duodenum, and proximal jejunum including the tumor. Histopathological examination showed the tumor capsule included the tissue of the pancreas and that the border between the intestine and the tumor was clear, suggesting that the origin of the tumor was the pancreas. We diagnosed the patient as having a grade 2 pancreatic neuroendocrine tumor based on the tumor growth pattern and immunohistochemistry findings. We examined the preoperative CT images retrospectively and found that the tumor had adhered to the uncinate process of the pancreas, which extends over the left side of the superior mesenteric artery. When GIST close to the proximal jejunum is suspected, the possibility of pancreatic neuroendocrine tumor should be considered.

The tumor suppressor menin prevents effector CD8 T-cell dysfunction by targeting mTORC1-dependent metabolic activation.

While menin plays an important role in preventing T-cell dysfunction, such as senescence and exhaustion, the regulatory mechanisms remain unclear. We found that menin prevents the induction of dysfunction in activated CD8 T cells by restricting the cellular metabolism. mTOR complex 1 (mTORC1) signaling, glycolysis, and glutaminolysis are augmented by menin deficiency. Rapamycin treatment prevents CD8 T-cell dysfunction in menin-deficient CD8 T cells. Limited glutamine availability also prevents CD8 T-cell dysfunction induced by menin deficiency, and its inhibitory effect is antagonized by α-ketoglutarate (α-KG), an intermediate metabolite of glutaminolysis. α-KG-dependent histone H3K27 demethylation seems to be involved in the dysfunction in menin-deficient CD8 T cells. We also found that α-KG activates mTORC1-dependent central carbon metabolism. These findings suggest that menin maintains the T-cell functions by limiting mTORC 1 activity and subsequent cellular metabolism.

Targeting skeletal endothelium to ameliorate bone loss.

Recent studies have identified a specialized subset of CD31hiendomucinhi (CD31hiEMCNhi) vascular endothelium that positively regulates bone formation. However, it remains unclear how CD31hiEMCNhi endothelium levels are coupled to anabolic bone formation. Mice with an osteoblast-specific deletion of Shn3, which have markedly elevated bone formation, demonstrated an increase in CD31hiEMCNhi endothelium. Transcriptomic analysis identified SLIT3 as an osteoblast-derived, SHN3-regulated proangiogenic factor. Genetic deletion of Slit3 reduced skeletal CD31hiEMCNhi endothelium, resulted in low bone mass because of impaired bone formation and partially reversed the high bone mass phenotype of Shn3-/- mice. This coupling between osteoblasts and CD31hiEMCNhi endothelium is essential for bone healing, as shown by defective fracture repair in SLIT3-mutant mice and enhanced fracture repair in SHN3-mutant mice. Finally, administration of recombinant SLIT3 both enhanced bone fracture healing and counteracted bone loss in a mouse model of postmenopausal osteoporosis. Thus, drugs that target the SLIT3 pathway may represent a new approach for vascular-targeted osteoanabolic therapy to treat bone loss.

[A Case of Epithelioid Sarcoma of the Sigmoid Mesocolon].

A 73-year-old man visited our hospital with the chief complaints of anorexia and weight loss. Computed tomography showed a 5 cm tumor(diameter)in the sigmoid mesocolon. We performed laparoscopic Hartmann operation; however, because of sacral invasion of tumor, curative surgery was difficult. Therefore, the tumor was excised together with the sigmoid colon. Histopathological examination of the tumor confirmed the diagnosis of epithelioid sarcoma. Postoperatively, the patient received heavy-particle radiotherapy at another facility as treatment for the residual tumor. The size of the residual tumor decreased 6 months after the surgery. Up until 1 year after surgery, the patient's condition has remained stable without any disease progression. Epithelioid sarcoma is a rare soft-tissue tumor and often leads to a poor prognosis. We present a case of epithelioid sarcoma occurring in the sigmoid mesocolon.

The HIV co-receptor CCR5 regulates osteoclast function.

C-C chemokine receptor 5 (CCR5) is a co-receptor of HIV. Epidemiological findings suggest that the functional loss of CCR5 is correlated with a lower incidence of bone-destructive diseases as well as of HIV transmission. However, it is not clear whether CCR5 is involved in regulation of the function of bone cells, in addition to that of immune cells. Here we show that blockade of CCR5 using specific antibodies impairs human osteoclast function in vitro. Ccr5-deficient (Ccr5 -/- ) mice presented with dysfunctional osteoclasts and were resistant to osteoporosis induced by receptor activator of nuclear factor kappa-B ligand (RANKL), which triggers osteoporosis independently of inflammatory and immunomodulatory pathways. Furthermore, Ccr5 deficiency impairs the cellular locomotion and bone-resorption activity of osteoclasts, which is associated with the disarrangement of podosomes and adhesion complex molecules including Pyk2. Overall, the data provides evidence that CCR5 has an essential role in bone-destructive conditions through the functional regulation of osteoclasts.

Def6 Restrains Osteoclastogenesis and Inflammatory Bone Resorption.

Inflammatory bone resorption mediated by osteoclasts is a major cause of morbidity and disability in many inflammatory disorders, including rheumatoid arthritis (RA). The mechanisms that regulate osteoclastogenesis and bone resorption in inflammatory settings are complex and have not been well elucidated. In this study, we identify the immunoregulator differentially expressed in FDCP 6 homolog (Def6) as a novel inhibitor of osteoclastogenesis in physiological and inflammatory conditions. Def6 deficiency in Def6-/- mice enhanced the sensitivity of osteoclast precursors to the physiological osteoclastogenic inducer receptor activator for NF-κB ligand, and Def6-/- osteoclasts formed actin rings. Furthermore, Def6 deficiency markedly increased TNF-α-induced osteoclastogenesis in vitro and in vivo and enhanced bone resorption in an inflammatory osteolysis mouse model. TNF-α serum levels correlated negatively with Def6 expression levels in osteoclast precursors obtained from RA patients, and the osteoclastogenic capacity of the osteoclast precursors was significantly inversely correlated with their Def6 expression levels, indicating that Def6 functions as an inhibitor of excessive osteoclast formation and bone destruction in RA. Mechanistically, Def6 suppressed osteoclastogenesis and the expression of key osteoclastogenic factors NFATc1, B lymphocyte-induced maturation protein-1, and c-Fos by regulating an endogenous IFN-ß-mediated autocrine feedback loop. The Def6-dependent pathway may represent a novel therapeutic target to prevent pathological bone destruction.

Identification of 2-methylthio cyclic N6-threonylcarbamoyladenosine (ms2ct6A) as a novel RNA modification at position 37 of tRNAs.

Transfer RNA modifications play pivotal roles in protein synthesis. N6-threonylcarbamoyladenosine (t6A) and its derivatives are modifications found at position 37, 3΄-adjacent to the anticodon, in tRNAs responsible for ANN codons. These modifications are universally conserved in all domains of life. t6A and its derivatives have pleiotropic functions in protein synthesis including aminoacylation, decoding and translocation. We previously discovered a cyclic form of t6A (ct6A) as a chemically labile derivative of t6A in tRNAs from bacteria, fungi, plants and protists. Here, we report 2-methylthio cyclic t6A (ms2ct6A), a novel derivative of ct6A found in tRNAs from Bacillus subtilis, plants and Trypanosoma brucei. In B. subtilis and T. brucei, ms2ct6A disappeared and remained to be ms2t6A and ct6A by depletion of tcdA and mtaB homologs, respectively, demonstrating that TcdA and MtaB are responsible for biogenesis of ms2ct6A.

Estrogen receptor α in osteocytes regulates trabecular bone formation in female mice.

Estrogens are well known steroid hormones necessary to maintain bone health. In addition, mechanical loading, in which estrogen signaling may intersect with the Wnt/ß-catenin pathway, is essential for bone maintenance. As osteocytes are known as the major mechanosensory cells embedded in mineralized bone matrix, osteocyte ERα deletion mice (ERα(ΔOcy/ΔOcy)) were generated by mating ERα floxed mice with Dmp1-Cre mice to determine the role of ERα in osteocytes. Trabecular bone mineral density of female, but not male ERα(ΔOcy/ΔOcy) mice was significantly decreased. Bone formation parameters in ERα(ΔOcy/ΔOcy) were significantly decreased while osteoclast parameters were unchanged. This suggests that ERα in osteocytes exerts osteoprotective function by positively controlling bone formation. To identify potential targets of ERα, gene array analysis of Dmp1-GFP osteocytes sorted by FACS from ERα(ΔOcy/ΔOcy) and control mice was performed. Gene expression microarray followed by gene ontology analyses revealed that osteocytes from ERα(ΔOcy/ΔOcy) highly expressed genes categorized in 'Secreted' when compared to control osteocytes. Among them, expression of Mdk and Sostdc1, both of which are Wnt inhibitors, was significantly increased without alteration of expression of the mature osteocyte markers such as Sost and ß-catenin. Moreover, hindlimb suspension experiments showed that trabecular bone loss due to unloading was greater in ERα(ΔOcy/ΔOcy) mice without cortical bone loss. These data suggest that ERα in osteocytes has osteoprotective functions in trabecular bone formation through regulating expression of Wnt antagonists, but conversely plays a negative role in cortical bone loss due to unloading.

Nuclear receptors in bone physiology and diseases.

During the last decade, our view on the skeleton as a mere solid physical support structure has been transformed, as bone emerged as a dynamic, constantly remodeling tissue with systemic regulatory functions including those of an endocrine organ. Reflecting this remarkable functional complexity, distinct classes of humoral and intracellular regulatory factors have been shown to control vital processes in the bone. Among these regulators, nuclear receptors (NRs) play fundamental roles in bone development, growth, and maintenance. NRs are DNA-binding transcription factors that act as intracellular transducers of the respective ligand signaling pathways through modulation of expression of specific sets of cognate target genes. Aberrant NR signaling caused by receptor or ligand deficiency may profoundly affect bone health and compromise skeletal functions. Ligand dependency of NR action underlies a major strategy of therapeutic intervention to correct aberrant NR signaling, and significant efforts have been made to design novel synthetic NR ligands with enhanced beneficial properties and reduced potential negative side effects. As an example, estrogen deficiency causes bone loss and leads to development of osteoporosis, the most prevalent skeletal disorder in postmenopausal women. Since administration of natural estrogens for the treatment of osteoporosis often associates with undesirable side effects, several synthetic estrogen receptor ligands have been developed with higher therapeutic efficacy and specificity. This review presents current progress in our understanding of the roles of various nuclear receptor-mediated signaling pathways in bone physiology and disease, and in development of advanced NR ligands for treatment of common skeletal disorders.

Female sex hormones ameliorate arthritis in SKG mice.

The pathology of rheumatoid arthritis (RA) is ameliorated during pregnancy and deteriorated after delivery. Thus, female sex hormones could be involved in the pathogenesis of RA. However, the effects of estrogen and progesterone on the development and progression of RA have been unclear. In this study, we analyzed the effects of female hormones on the pathogenesis of RA by performing ovariectomy (OVX) and hormone implantation in the SKG mouse model of human RA. OVX mice showed severe arthritis and cartilage destruction with increased serum levels of TNF-α and IL-6, when compared with sham-operated mice. In contrast, estrogen-treated mice exhibited remarkable suppression of arthritis, with no bone erosion, little synovial hyperplasia and little infiltration of immune cells. Moreover, serum levels of TNF-α and IL-6 were decreased. In progesterone-treated mice, mild synovial hyperplasia and no immune cell infiltration were observed, with decreased serum levels of IL-6. These results suggest that female hormones, estrogen and progesterone, can play roles in the remission of RA.

Noncanonical Wnt signaling mediates androgen-dependent tumor growth in a mouse model of prostate cancer.

Prostate cancer development is associated with hyperactive androgen signaling. However, the molecular link between androgen receptor (AR) function and humoral factors remains elusive. A prostate cancer mouse model was generated by selectively mutating the AR threonine 877 into alanine in prostatic epithelial cells through Cre-ERT2-mediated targeted somatic mutagenesis. Such AR point mutant mice (ARpe-T877A/Y) developed hypertrophic prostates with responses to both an androgen antagonist and estrogen, although no prostatic tumor was seen. In prostate cancer model transgenic mice, the onset of prostatic tumorigenesis as well as tumor growth was significantly potentiated by introduction of the AR T877A mutation into the prostate. Genetic screening of mice identified Wnt-5a as an activator. Enhanced Wnt-5a expression was detected in the malignant prostate tumors of patients, whereas in benign prostatic hyperplasia such aberrant up-regulation was not obvious. These findings suggest that a noncanonical Wnt signal stimulates development of prostatic tumors with AR hyperfunction.