TBK1 Suppresses RIPK1-Driven Apoptosis and Inflammation during Development and in Aging.

Aging is a major risk factor for both genetic and sporadic neurodegenerative disorders. However, it is unclear how aging interacts with genetic predispositions to promote neurodegeneration. Here, we investigate how partial loss of function of TBK1, a major genetic cause for amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) comorbidity, leads to age-dependent neurodegeneration. We show that TBK1 is an endogenous inhibitor of RIPK1 and the embryonic lethality of Tbk1-/- mice is dependent on RIPK1 kinase activity. In aging human brains, another endogenous RIPK1 inhibitor, TAK1, exhibits a marked decrease in expression. We show that in Tbk1+/- mice, the reduced myeloid TAK1 expression promotes all the key hallmarks of ALS/FTD, including neuroinflammation, TDP-43 aggregation, axonal degeneration, neuronal loss, and behavior deficits, which are blocked upon inhibition of RIPK1. Thus, aging facilitates RIPK1 activation by reducing TAK1 expression, which cooperates with genetic risk factors to promote the onset of ALS/FTD.

Modulating TRADD to restore cellular homeostasis and inhibit apoptosis.

Cell death in human diseases is often a consequence of disrupted cellular homeostasis. If cell death is prevented without restoring cellular homeostasis, it may lead to a persistent dysfunctional and pathological state. Although mechanisms of cell death have been thoroughly investigated1-3, it remains unclear how homeostasis can be restored after inhibition of cell death. Here we identify TRADD4-6, an adaptor protein, as a direct regulator of both cellular homeostasis and apoptosis. TRADD modulates cellular homeostasis by inhibiting K63-linked ubiquitination of beclin 1 mediated by TRAF2, cIAP1 and cIAP2, thereby reducing autophagy. TRADD deficiency inhibits RIPK1-dependent extrinsic apoptosis and proteasomal stress-induced intrinsic apoptosis. We also show that the small molecules ICCB-19 and Apt-1 bind to a pocket on the N-terminal TRAF2-binding domain of TRADD (TRADD-N), which interacts with the C-terminal domain (TRADD-C) and TRAF2 to modulate the ubiquitination of RIPK1 and beclin 1. Inhibition of TRADD by ICCB-19 or Apt-1 blocks apoptosis and restores cellular homeostasis by activating autophagy in cells with accumulated mutant tau, α-synuclein, or huntingtin. Treatment with Apt-1 restored proteostasis and inhibited cell death in a mouse model of proteinopathy induced by mutant tau(P301S). We conclude that pharmacological targeting of TRADD may represent a promising strategy for inhibiting cell death and restoring homeostasis to treat human diseases.

Sequential activation of necroptosis and apoptosis cooperates to mediate vascular and neural pathology in stroke.

Apoptosis and necroptosis are two regulated cell death mechanisms; however, the interaction between these cell death pathways in vivo is unclear. Here we used cerebral ischemia/reperfusion as a model to investigate the interaction between apoptosis and necroptosis. We show that the activation of RIPK1 sequentially promotes necroptosis followed by apoptosis in a temporally specific manner. Cerebral ischemia/reperfusion insult rapidly activates necroptosis to promote cerebral hemorrhage and neuroinflammation. Ripk3 deficiency reduces cerebral hemorrhage and delays the onset of neural damage mediated by inflammation. Reduced cerebral perfusion resulting from arterial occlusion promotes the degradation of TAK1, a suppressor of RIPK1, and the transition from necroptosis to apoptosis. Conditional knockout of TAK1 in microglial/infiltrated macrophages and neuronal lineages sensitizes to ischemic infarction by promoting apoptosis. Taken together, our results demonstrate the critical role of necroptosis in mediating neurovascular damage and hypoperfusion-induced TAK1 loss, which subsequently promotes apoptosis and cerebral pathology in stroke and neurodegeneration.

Immunohistochemical analysis of the distribution of RANKL: a case of disseminated carcinomatosis of bone marrow as the first presentation of relapse in curatively resected colorectal cancer.

Poorly differentiated adenocarcinoma of colorectal carcinoma (CRC) is a rare condition with poor prognosis. In this report, we describe a case of a 69-year-old man who underwent laparoscopic low anterior resection after being diagnosed with stage IIIB CRC. At 10 months post-operation, he developed fever and loss of appetite. Laboratory examination revealed > 120.0 µg/dL fibrin degradation products and > 60.0 µg/dL D-dimer. Bone marrow (BM) examination showed malignant epithelioid infiltrate with CK20 and CDX2 expression, leading to diagnosis of disseminated carcinomatosis of BM, which is rare in CRC and indicative of widespread disease throughout the body. Furthermore, immunohistochemistry revealed high expression of receptor activator of nuclear factor κB ligand (RANKL) in tumor cells, including budding cells of CRC and BM tissues. Thus, RANKL expression, which is known to indicate metastatic behavior of cancer cells, may play a critical role in promoting osteoclast formation, which has been associated with the pathogenesis of BM lesions.

[A Case of Rhabdomyolysis Caused by Oxaliplatin during Postoperative Adjuvant Chemotherapy].

The patient was a 50-year-old male. At the age of 48 years, he had undergone total gastrectomy and right hemicolectomy simultaneously for gastric and ascending colon cancers. Since adjuvant chemotherapy has become common practice for patients with ascending colon cancer, capecitabine was administered for 6 months. One year and 6 months after the surgery, he was diagnosed with recurrence of the ascending colon cancer at the anastomotic site and underwent local colectomy. Considering he was pathologically diagnosed as pT4a, mFOLFOX6 therapy was prescribed as postoperative adjuvant chemotherapy. On the day the 11th course of treatment was initiated, the patient complained of weakness; however, his blood test results showed no abnormalities; therefore, he was followed-up as an outpatient. Three days later, he presented to the hospital with exacerbated symptoms and was diagnosed with rhabdomyolysis due to a marked increase in CK(2,031 U/L). Rhabdomyolysis was determined to be the adverse effect of oxaliplatin because out of all the drugs prescribed to the patient, this condition is listed as a side effect only in oxaliplatin's package insert. Fortunately, outpatient treatment was enough to alleviate rhabdomyolysis. Subsequently, adjuvant chemotherapy was completed without oxaliplatin. The patient has been followed-up without recurrence for 9 months after the surgery.

[A Case of Extramural Growth-Type Ileocecal Colon Cancer].

A woman in her 80s was diagnosed with an abdominal mass during physical examination. Contrast-enhanced computed tomography(CT)revealed a tumor with contrast enhancement outside the ileocecal region of the intestine, and the ileocolic artery penetrated the tumor. No tumor was detected by colonoscopy. An endoscope could not be passed through due to an ileocecal valve stenosis. A biopsy of the ileocecal valve revealed only lymphocyte hyperplasia without adenocarcinoma components. Barium enema examination demonstrated no influx of the contrast medium from the cecum into the oral side of the intestine. Since a gastrointestinal stromal tumor in the ileocecal region was suspected, laparotomy was performed in the ileocecal region owing to the preoperative diagnosis of suspected malignant lymphoma, revealing a 5-cm elastic hard tumor outside the ileocecal wall. The tumor could not be separated from the intestinal tract. Histopathological examination revealed no lesion on the mucosal surface, although poorly differentiated adenocarcinoma infiltrated from the submucosa to the serosa. Thus, the patient was diagnosed with extramural growth-type ileocecal colon cancer. This disease is relatively rare but need to be kept in mind.

[A Case of Transverse Colon Cancer Complicated by Eosinophilic Granulomatosis with Polyangiitis].

A man in his 50s had undergone steroid therapy for eosinophilic granulomatosis with polyangiitis(EGPA). Since an examination for malignant tumors revealed type 0-Ⅰsp(cT1aN0M0)and type 2(cT2N0M0)lesions in the proximal and mid- transverse colon, respectively, he was referred to our department. Endoscopic resection was performed on the proximal lesion. After the confirmation of curative resection, laparoscopic partial colectomy(transverse colon)and D3 lymph node dissection were performed on the mid-transverse lesion. Because of the patient's favorable postoperative course, he was discharged from the hospital on POD17. Since steroids and immunosuppressants may cause immunological abnormalities and malignant tumors, such patients should be strictly followed up.

[An Analysis of Surgery for Colorectal Cancer Lung Metastasis].

OBJECTIVES: Resection of lung metastasis in colorectal cancer leads to a good prognosis; therefore, surgical treatment for resectable metastases is recommended by the Japanese Society for Cancer of the Colon and Rectum Guidelines for the treatment of colorectal cancer. In this study, we investigated the factors that affect the prognosis of resection of such lung cancers. RESULTS: Outcomes of 23 cases of lung resection performed from 2000 to 2019 were investigated. The 5-year overall survival rate after lung resection was 55.5%, and the 5-year relapse-free survival rate after liver resection was 27.0%. Univariate analysis identified sex(p=0.024), tumor size(p=0.0129)and complications(p=0.0129)as prognostic factors, while multivariate analysis revealed sex(p=0.0278, relative risk=5.38)to be a prognostic factor. CONCLUSION: In this study, sex was identified as a poor prognostic factor. Further evidence from cases is needed to ascertain the effects of other factors.

[Laparoscopic Partial Hepatectomy for the Liver Metastasis of Gastric Cancer after Nab-Paclitaxel plus Ramucirumab Combination Therapy-A Case Report].

We report a case of laparoscopic partial hepatectomy after nab-paclitaxel plus ramucirumab(nab-PTX plus RAM)combination therapy for postoperative liver recurrence of gastric cancer. The patient was a 50's man who underwent laparoscopic distal gastrectomy, D2 lymph node dissection, and Billroth-I reconstruction for gastric cancer. The pathological findings were L, Gre, Post, Type 3, por>tub2, pT3N3a, M1(CY1), fStage Ⅳ. Postoperative chemotherapy with S-1 was performed. The CT examination 6 months after the operation revealed a total of 3 tumors(maximum diameter of 5×4 cm)in liver segments S6, 7, and 8. We started nab-PTX plus RAM combination therapy for liver metastases and performed laparoscopic partial hepatectomy when 12 courses of the treatment were completed. The postoperative course was uneventful, and the patient was discharged on postoperative day 7. Pathological results suggested that the tumor was exposed on the cut surface, and 6 courses of nab-PTX plus RAM combination therapy were administered postoperatively. The patient has been recurrence-free 12 months after the operation.

A prospective multi-center registry concerning the clinical performance of laparoscopic colorectal surgery using an absorbable adhesion barrier (INTERCEED®) made of oxidized regenerated cellulose.

PURPOSE: The aim of this prospective multi-center registry was to evaluate the safety and clinical performance of INTERCEED® in laparoscopic colorectal surgery. METHODS: This study was a prospective, multi-center, single-arm registry wherein patients who received INTERCEED® in laparoscopic colorectal surgery were registered consecutively (UMIN-CTR 00001872). The primary outcome was the incidence rate of postoperative adhesive small intestinal obstruction within 6 months. The secondary outcomes were reoperation related to postoperative bleeding and anastomotic leak, surgical site infection (SSI) and anastomotic leak. RESULTS: Between March 2012 and March 2015, a total of 202 patients were enrolled from six institutions. INTERCEED® was not applied in two patients, so 200 patients were analyzed using the full analysis set population. The incidence rate of postoperative adhesive intestinal obstruction was 1.0% (2/200). The total SSI rate was 3.5% (7/200), the deep incisional SSI rate was 0.0% (0/200), and the organ SSI rate was 0.0% (0/200). The incidence of anastomotic leak was 1.0% (2/200). Reoperation was performed in two cases: one for anastomotic leak and the other as cardiac surgery due to heart disease. CONCLUSIONS: Using INTERCEED® in laparoscopic colorectal surgery is safe and may be useful for preventing postoperative adhesive small intestinal obstruction.