Structural basis for ion selectivity in potassium-selective channelrhodopsins.

KCR channelrhodopsins (K+-selective light-gated ion channels) have received attention as potential inhibitory optogenetic tools but more broadly pose a fundamental mystery regarding how their K+ selectivity is achieved. Here, we present 2.5-2.7 Å cryo-electron microscopy structures of HcKCR1 and HcKCR2 and of a structure-guided mutant with enhanced K+ selectivity. Structural, electrophysiological, computational, spectroscopic, and biochemical analyses reveal a distinctive mechanism for K+ selectivity; rather than forming the symmetrical filter of canonical K+ channels achieving both selectivity and dehydration, instead, three extracellular-vestibule residues within each monomer form a flexible asymmetric selectivity gate, while a distinct dehydration pathway extends intracellularly. Structural comparisons reveal a retinal-binding pocket that induces retinal rotation (accounting for HcKCR1/HcKCR2 spectral differences), and design of corresponding KCR variants with increased K+ selectivity (KALI-1/KALI-2) provides key advantages for optogenetic inhibition in vitro and in vivo. Thus, discovery of a mechanism for ion-channel K+ selectivity also provides a framework for next-generation optogenetics.

Structural basis for channel conduction in the pump-like channelrhodopsin ChRmine.

ChRmine, a recently discovered pump-like cation-conducting channelrhodopsin, exhibits puzzling properties (large photocurrents, red-shifted spectrum, and extreme light sensitivity) that have created new opportunities in optogenetics. ChRmine and its homologs function as ion channels but, by primary sequence, more closely resemble ion pump rhodopsins; mechanisms for passive channel conduction in this family have remained mysterious. Here, we present the 2.0 Å resolution cryo-EM structure of ChRmine, revealing architectural features atypical for channelrhodopsins: trimeric assembly, a short transmembrane-helix 3, a twisting extracellular-loop 1, large vestibules within the monomer, and an opening at the trimer interface. We applied this structure to design three proteins (rsChRmine and hsChRmine, conferring further red-shifted and high-speed properties, respectively, and frChRmine, combining faster and more red-shifted performance) suitable for fundamental neuroscience opportunities. These results illuminate the conduction and gating of pump-like channelrhodopsins and point the way toward further structure-guided creation of channelrhodopsins for applications across biology.

Rational Engineering of XCaMPs, a Multicolor GECI Suite for In Vivo Imaging of Complex Brain Circuit Dynamics.

To decipher dynamic brain information processing, current genetically encoded calcium indicators (GECIs) are limited in single action potential (AP) detection speed, combinatorial spectral compatibility, and two-photon imaging depth. To address this, here, we rationally engineered a next-generation quadricolor GECI suite, XCaMPs. Single AP detection was achieved within 3-10 ms of spike onset, enabling measurements of fast-spike trains in parvalbumin (PV)-positive interneurons in the barrel cortex in vivo and recording three distinct (two inhibitory and one excitatory) ensembles during pre-motion activity in freely moving mice. In vivo paired recording of pre- and postsynaptic firing revealed spatiotemporal constraints of dendritic inhibition in layer 1 in vivo, between axons of somatostatin (SST)-positive interneurons and apical tufts dendrites of excitatory pyramidal neurons. Finally, non-invasive, subcortical imaging using red XCaMP-R uncovered somatosensation-evoked persistent activity in hippocampal CA1 neurons. Thus, the XCaMPs offer a critical enhancement of solution space in studies of complex neuronal circuit dynamics. VIDEO ABSTRACT.

Cardiogenic control of affective behavioural state.

Emotional states influence bodily physiology, as exemplified in the top-down process by which anxiety causes faster beating of the heart1-3. However, whether an increased heart rate might itself induce anxiety or fear responses is unclear3-8. Physiological theories of emotion, proposed over a century ago, have considered that in general, there could be an important and even dominant flow of information from the body to the brain9. Here, to formally test this idea, we developed a noninvasive optogenetic pacemaker for precise, cell-type-specific control of cardiac rhythms of up to 900 beats per minute in freely moving mice, enabled by a wearable micro-LED harness and the systemic viral delivery of a potent pump-like channelrhodopsin. We found that optically evoked tachycardia potently enhanced anxiety-like behaviour, but crucially only in risky contexts, indicating that both central (brain) and peripheral (body) processes may be involved in the development of emotional states. To identify potential mechanisms, we used whole-brain activity screening and electrophysiology to find brain regions that were activated by imposed cardiac rhythms. We identified the posterior insular cortex as a potential mediator of bottom-up cardiac interoceptive processing, and found that optogenetic inhibition of this brain region attenuated the anxiety-like behaviour that was induced by optical cardiac pacing. Together, these findings reveal that cells of both the body and the brain must be considered together to understand the origins of emotional or affective states. More broadly, our results define a generalizable approach for noninvasive, temporally precise functional investigations of joint organism-wide interactions among targeted cells during behaviour.

Single-Cell RNA Sequencing Reveals an Immune Landscape of CD4+ T Cells in Coronary Culprit Plaques With Acute Coronary Syndrome in Humans-Brief Report.

BACKGROUND: Acute coronary syndrome (ACS) involves plaque-related thrombosis, causing primary ischemic cardiomyopathy or lethal arrhythmia. We previously demonstrated a unique immune landscape of myeloid cells in the culprit plaques causing ACS by using single-cell RNA sequencing. Here, we aimed to characterize T cells in a single-cell level, assess clonal expansion of T cells, and find a therapeutic target to prevent ACS. METHODS: We obtained the culprit lesion plaques from 4 patients with chronic coronary syndrome (chronic coronary syndrome plaques) and the culprit lesion plaques from 3 patients with ACS (ACS plaques) who were candidates for percutaneous coronary intervention with directional coronary atherectomy. Live CD45+ immune cells were sorted from each pooled plaque samples and applied to the 10× platform for single-cell RNA sequencing analysis. We also extracted RNA from other 3 ACS plaque samples and conducted unbiased TCR (T-cell receptor) repertoire analysis. RESULTS: CD4+ T cells were divided into 5 distinct clusters: effector, naive, cytotoxic, CCR7+ (C-C chemokine receptor type 7) central memory, and FOXP3 (forkhead box P3)+ regulatory CD4+ T cells. The proportion of central memory CD4+ T cells was higher in the ACS plaques. Correspondingly, dendritic cells also tended to express more HLAs (human leukocyte antigens) and costimulatory molecules in the ACS plaques. The velocity analysis suggested the differentiation flow from central memory CD4+ T cells into effector CD4+ T cells and that from naive CD4+ T cells into central memory CD4+ T cells in the ACS plaques, which were not observed in the chronic coronary syndrome plaques. The bulk repertoire analysis revealed clonal expansion of TCRs in each patient with ACS and suggested that several peptides in the ACS plaques work as antigens and induced clonal expansion of CD4+ T cells. CONCLUSIONS: For the first time, we revealed single cell-level characteristics of CD4+ T cells in patients with ACS. CD4+ T cells could be therapeutic targets of ACS. REGISTRATION: URL: https://upload.umin.ac.jp/cgi-open-bin/icdr_e/ctr_view.cgi?recptno=R000046521; Unique identifier: UMIN000040747.

Drug Reaction With Eosinophilia and Systemic Symptoms (DRESS) Syndrome to Hemodialysis Polysulfone Membrane.

Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome is a severe and potentially life-threatening hypersensitivity reaction. Although commonly associated with specific drugs, there have been no reports of DRESS syndrome caused by medical devices. We report a unique case of DRESS syndrome linked to a particular hemodialysis membrane during treatment. An 83-year-old man on hemodialysis exhibited fever, rash, and elevated eosinophils. Despite medication changes and consultations with specialists, his condition persisted. A drug-induced lymphocyte stimulation test revealed a positive response to the dialysis membrane. His symptoms and lab results met DRESS syndrome diagnostic criteria. After substituting the membrane and administering glucocorticoids, the patient displayed early improvement. Diagnosing DRESS syndrome is complex due to its varied presentation and lack of specific benchmarks. This instance underscores the need to consider medical devices as potential DRESS syndrome triggers. Enhanced physician awareness can facilitate prompt detection and proper management, ultimately refining patient outcomes.

Kilohertz two-photon brain imaging in awake mice.

Two-photon microscopy is a mainstay technique for imaging in scattering media and normally provides frame-acquisition rates of ~10-30 Hz. To track high-speed phenomena, we created a two-photon microscope with 400 illumination beams that collectively sample 95,000-211,000 µm2 areas at rates up to 1 kHz. Using this microscope, we visualized microcirculatory flow, fast venous constrictions and neuronal Ca2+ spiking with millisecond-scale timing resolution in the brains of awake mice.

[A Resected Case of Angiomyolipoma Difficult to Be Distinguished from Hepatocellular Carcinoma].

A 42-year-old man complaining of left back pain was admitted to our hospital. The hepatis B and C surface antigens were negative. The serum levels of tumor markers were within the reference ranges. Abdominal ultrasound revealed an 8 cm-sized, primarily round and hyperechoic mass in the left lateral segment. Contrast-echo showed non-uniform enhancement in the arterial phase and uniform enhancement in the portal phase. This mass did not indicate"wash-out"on contrast- enhanced CT. It showed hypointensity in the hepatobiliary phase on MRI. The definitive diagnosis could not be obtained, and the patient was suspected with malignancy, such as hepatocellular carcinoma(HCC). Therefore, left hemi-hepatectomy was performed for the diagnostic treatment. Based on the immunochemical staining results, he was diagnosed with angiomyolipoma( AML). AML is composed of fat, blood vessels, and smooth muscles. It is regarded as a tumor of perivascular epithelioid cell tumor(PEComa). Early venous return and adipose tissues in the tumor were the distinctive features of this tumor. The preoperative diagnosis of AML without any fatty component as in this case is very difficult.

[A Case of Resected Peritoneal Metastasis from Hepatocellular Carcinoma after Surgery].

A 69-year-old woman with a hepatocellular carcinoma(HCC)was followed-up for type B chronic hepatitis and underwent partial hepatectomy(S6)at our hospital. Afterwards, she underwent radiofrequency ablation(RFA)therapy twice because of intrahepatic recurrence. Seven months after the first hepatectomy, a left adrenalectomy was performed for a left adrenal metastasis. Seventeen months after the first hepatectomy, a splenectomy was performed for a splenic metastasis. Forty-three months after the first hepatectomy, a second hepatectomy was performed for intrahepatic recurrence, and a right adrenalectomy was performed for an adrenal metastasis. Sixty-eight months after the first hepatectomy, an abdominal CT revealed a growing solitary lesion in the ascending colon, which was diagnosed as a peritoneal metastasis. The peritoneal dissemination was removed because there were no other extrahepatic or intrahepatic recurrences. Histologically, the resected specimen was diagnosed as a peritoneal metastasis from a HCC. The patient survived, and there were no recurrences for 6 months after the operation. We report this case of a peritoneal metastasis from a HCC after surgery with a review of the literature.

Simultaneous fast measurement of circuit dynamics at multiple sites across the mammalian brain.

Real-time activity measurements from multiple specific cell populations and projections are likely to be important for understanding the brain as a dynamical system. Here we developed frame-projected independent-fiber photometry (FIP), which we used to record fluorescence activity signals from many brain regions simultaneously in freely behaving mice. We explored the versatility of the FIP microscope by quantifying real-time activity relationships among many brain regions during social behavior, simultaneously recording activity along multiple axonal pathways during sensory experience, performing simultaneous two-color activity recording, and applying optical perturbation tuned to elicit dynamics that match naturally occurring patterns observed during behavior.

[Outcomes of FOLFIRINOX as First-Line Treatment for Recurrent or Unresectable Pancreatic Cancer].

We retrospectively analyzed adverse effects(AEs), overall survival(OS), and progression-free survival(PFS)in 15 consecutive patients treated with FOLFIRINOX as the first-line treatment for recurrent or unresectable pancreatic ductal adenocarcinoma( PDAC)between February 2014 and December 2017 in our hospital. Eleven patients were treated for unresectable PDAC with distant metastases(UR-M), and 4 were treated for locally advanced unresectable PDAC(UR-LA). The median age was 56(range: 40-75)years. Nine patients were male, and 6 were female. The performance status was 0 or 1 in all patients. Tumors were located in the pancreas head in 8 cases and in the body-tail in 7 cases. Grade 5 AEs were observed in 1 case in which liver abscess causing sepsis resulted in mortality. The response rate was 20.0%, and the disease control rate was 66.7%. Two patients underwent conversion surgery after FOLFIRINOX treatment. Seven patients received a nab-paclitaxel plus gemcitabine regimen as second-line treatment. The median OS and PFS were 17.0 and 8.4 months, respectively, and the 1-year survival rate was 66.7%. FOLFIRINOX for recurrent and unresectable PDAC showed relatively good tumor control. However, strict attention is required for severe AEs. Conversion surgery might be effective in patients who are good responders even if they have metastatic disease.

Rational design of a high-affinity, fast, red calcium indicator R-CaMP2.

Fluorescent Ca(2+) reporters are widely used as readouts of neuronal activities. Here we designed R-CaMP2, a high-affinity red genetically encoded calcium indicator (GECI) with a Hill coefficient near 1. Use of the calmodulin-binding sequence of CaMKK-α and CaMKK-ß in lieu of an M13 sequence resulted in threefold faster rise and decay times of Ca(2+) transients than R-CaMP1.07. These features allowed resolving single action potentials (APs) and recording fast AP trains up to 20-40 Hz in cortical slices. Somatic and synaptic activities of a cortical neuronal ensemble in vivo were imaged with similar efficacy as with previously reported sensitive green GECIs. Combining green and red GECIs, we successfully achieved dual-color monitoring of neuronal activities of distinct cell types, both in the mouse cortex and in freely moving Caenorhabditis elegans. Dual imaging using R-CaMP2 and green GECIs provides a powerful means to interrogate orthogonal and hierarchical neuronal ensembles in vivo.

Calmodulin kinases: essential regulators in health and disease.

Neuronal activity induces intracellular Ca2+ increase, which triggers activation of a series of Ca2+ -dependent signaling cascades. Among these, the multifunctional Ca2+ /calmodulin-dependent protein kinases (CaMKs, or calmodulin kinases) play key roles in neuronal transmission, synaptic plasticity, circuit development and cognition. The most investigated CaMKs for these roles in neuronal functions are CaMKI, CaMKII, CaMKIV and we will shed light on these neuronal CaMKs' functions in this review. Catalytically active members of CaMKs currently are CaMKI, CaMKII, CaMKIV and CaMKK. Although they all necessitate the binding of Ca2+ and calmodulin complex (Ca2+ /CaM) for releasing autoinhibition, each member of CaMK has distinct activation mechanisms-autophosphorylation mediated autonomy of multimeric CaMKII and CaMKK-dependent phosphoswitch-induced activation of CaMKI or CaMKIV. Furthermore, each CaMK shows distinct subcellular localization that underlies specific compartmentalized function in each activated neuron. In this review, we first summarize these molecular characteristics of each CaMK as to regulation and subcellular localization, and then describe each biological function. In the last section, we also focus on the emerging role of CaMKs in pathophysiological conditions by introducing the recent studies, especially focusing on drug addiction and depression, and discuss how dysfunctional CaMKs may contribute to the pathology of the neuropsychological disorders. This article is part of the mini review series "60th Anniversary of the Japanese Society for Neurochemistry".

Self-expanding metallic stent improves histopathologic edema compared with transanal drainage tube for malignant colorectal obstruction.

AIMS: To compare the usefulness of the self-expanding metallic stent (SEMS) with that of the transanal drainage tube (TDT) and emergency surgery after failure of decompression (ESFD) in patients with malignant colonic obstruction (MCO), and to evaluate post-decompression histopathologic changes. METHODS: From January 2010 to June 2015, 39 patients with MCO received SEMS, TDT, and ESFD. We evaluated the outcomes including success rates of placement, clinical outcomes after decompression, and histopathologic findings of the resected specimens. RESULTS: Technical success rates were 100% for SEMS and 78.9% for TDT. Clinical success rates were 100% for SEMS and 80.0% for TDT. Postoperative ileus was significantly less frequent after SEMS than after TDT (p = 0.014). Histopathologic edema grade was significantly lower for SEMS than for TDT and ESFD (p < 0.0001). There was no significant difference between edema grade and duration of decompression in the TDT group (p = 0.629), while all patients with SEMS were classified in a low edema grade (grade 0-2). The rate of stoma creation was significantly higher in patients with a high edema grade (grade 3) than in those with a low edema grade (grade 0-2) (p = 0.003). There was no microscopic perforation in any group. CONCLUSION: Significantly greater resolution of histopathologic edema was achieved after placement of SEMS than after placement of TDT. These findings provide an indication of favorable clinical outcomes of SEMS in comparison with TDT and ESFD. This article is protected by copyright. All rights reserved.

[Operational Management of Multidisciplinary Organ-Based Tumor Units in Our Cancer Center].

Owing to the advances in diagnosis and treatment, it is imperative to develop a multidisciplinary approach for the management of cancer patients. In our cancer center, multidisciplinary organ-based tumor units have been organized for team medical care. These units consist of cancer specialists from multiple departments including medical oncology, surgery, radiology, histopathology, and nursing. Members of each unit regularly conduct meetings to discuss diagnostic and therapeutic aspects, as well as to report the progress of cancer patients. Co-operation with the counseling and support center, utilization of the computerized medical record system, and using brochures for advertisement, all play important roles in adequate management of multidisciplinary organ-based tumor units.

[A Case of Collision Tumor of Gastric Malignant Lymphoma and Gastric Cancer].

A 71-year-old man with anemia, weight loss, and loss of appetite was admitted. Ultrasound examination found thickening of the wall of the stomach. A type 3 gastric tumor was detected in the greater curvature of the gastric corpus via upper gastrointestinal endoscopy. Total gastrectomy, transverse colon resection, and Roux-en-Y anastomosis reconstruction was performed. In the postoperative pathological results, adenocarcinoma, tub2, and diffuse large B cell lymphoma collision was found. The patient underwent chemotherapy for malignant lymphoma and although it was a relatively advanced neoplasia, he is alive without a recurrence.

Neuroprotective role of the basic leucine zipper transcription factor NFIL3 in models of amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by the loss of motor neurons. Here we show that the basic leucine zipper transcription factor NFIL3 (also called E4BP4) confers neuroprotection in models of ALS. NFIL3 is up-regulated in primary neurons challenged with neurotoxic insults and in a mouse model of ALS. Overexpression of NFIL3 attenuates excitotoxic neuronal damage and protects neurons against neurodegeneration in a cell-based ALS model. Conversely, reduction of NFIL3 exacerbates neuronal demise in adverse conditions. Transgenic neuronal expression of NFIL3 in ALS mice delays disease onset and attenuates motor axon and neuron degeneration. These results suggest that NFIL3 plays a neuroprotective role in neurons and constitutes a potential therapeutic target for neurodegeneration.

Comparison of gastric cancer surgery between patients aged >80 years and <79 years: complications and multivariate analysis of prognostic factors.

BACKGROUND/AIMS: To evaluate the clinicopathological features and results of surgery for gastric cancer in elderly patients aged ˃80 years relative to those aged ˂79 years, and to recommend the appropriate surgical treatment for elderly patients. METHODOLOGY: A total of 332 patients with gastric cancer who underwent gastrectomy in our department between 2002 and 2012 were evaluated. Of these, 81 were aged ˃80 years (Group A) and 251 were aged ˂79 years (Group B). We compared surgical outcomes and survival in these two groups. RESULTS; Postopeartive complications were associated with preoperative cormorbid disease(p<0.01). D2 and R0 resection was common in GroupB (p<0.01). Respiratory complications and hospital deaths were higher in Group A than in Group B. Overall survival (OS) was significantly lower in Group A than in Group B. Regarding Stage I disease, OS was significantly lower in Group A; however, cause-specific survival was similar between the two groups. Multivariate analysis showed that radicality and postoperative complications were independent prognostic factors for OS in elderly gastric cancer patients. CONCLUSIONS: These results indicate that postoperative respiratory complications and other causes of death worsened the prognosis of elderly. Preoperative accurate judgment of co-morbid disease, meticulous postoperative management and follow up might be improved survival of gastric cancer in elderly.

[Palliative surgery for malignant bowel obstruction in patients with advanced and recurrent gastroenterological cancer].

We report the outcomes of palliative surgery for the treatment of malignant bowel obstruction in patients with advanced gastroenterological cancer. We studied 20 patients who had undergone palliative surgery over 3 years. We analyzed the clinical findings, surgical procedure, postoperative clinical course, and prognosis. The origin of the patients was colorectal cancer( 9 cases), gastric cancer( 4 cases), uterine cancer( 3 cases), pancreatic cancer( 2 cases), bladder( 1 case), and anal cancer (1 case). Small bowel obstruction was noted in 8 cases and colorectal obstruction was noted in 14 cases. Colostomy was performed in 13 cases, resection and reconstruction were performed in 6 cases, and bypass was performed in 4 cases. Ninety percent of the patients were able to eat solid food following the surgery, but 20% of the patients were forced to have bowel obstruction. The median survival time after palliative surgery was 3 (range, 0-15) months, and 6 patients (30%) died within 2 months. We concluded that palliative surgery for the treatment of malignant bowel obstruction could improve the patients' quality of life. The decision for performing palliative surgery should be made while considering the patient's prognosis, wishes, and potential for symptom improvement.

[Four cases of double bypass surgery involving choledochojejunostomy and gastrojejunostomy for inoperable peripancreatic head cancer].

Peripancreatic head cancer often causes obstructive jaundice and duodenal obstruction, which reduces the quality of life and hinders the administration of anti-cancer drugs. Here, we report 4 cases of double bypass surgery( biliary and gastric) for the treatment of inoperable peripancreatic head cancer. The patients' ages ranged from 64 to 72 years. Two patients had pancreatic head cancer and 2 had ampullary cancer. No postoperative morbidity was observed and all 4 patients resumed oral intake within 5 days after surgery and began receiving chemotherapy within 1 month after surgery. There was immediate relief of biliary obstruction in all 3 patients with obstructive jaundice. None of the patients experienced recurrence of obstructive jaundice requiring biliary drainage. Two patients who died of cancer were able to consume food orally just before they died. Although bypass surgery is more invasive than endoscopic stenting, it may be safe and useful not only for palliation, but also for induction or continuation of chemotherapy.