Primo Vessels Research Articles

Fluorescent Pdots Facilitate High-Resolution Mapping of the Intact Meningeal Vascular Network and Eye-Brain Connections.

Meningeal vascular network is significant in neurology and neurosurgery. However, high-resolution imaging of intact meningeal vascular network is lacking. In this work, we develop a practical experimental method to ensure that the intact meninges are morphologically unfolded and fixed in an agarose gel. With the help of high-brightness polymer dots (Pdots) as probe, macroscopic and detailed imaging of the vascular network on the intact dorsal meninges can be performed. Meningeal vessels are symmetrically distributed along the superior sagittal sinus, and the distribution of meningeal vessels had a certain degree of hierarchy. The meninges are thicker blood vessels and capillary networks from the outside to the inside. Moreover, the diameter of the capillaries is 3.96 ± 0.89 μm. Interestingly, meningeal primo vessels in the central nervous system of mice is imaged with the diameter of 4.18 ± 1.18 μm, which has not been reported previously. It is worth mentioning that we found that orthotopic xenografts of brain tumors caused the appearance of corneal neovascularization and morphological changes in optic nerve microvessels. In conclusion, our work provides an effective Pdots-based imaging method for follow-up research on meningeal vascular-related diseases, and illustrates that the eye can serve as a window for the prevention and diagnosis of brain diseases.

The involvement of the primo vascular system in local enteritis and its modification by electroacupuncture.

The primo vascular system (PVS), an intensive network structure, has been claimed to be representative of the acupuncture meridian. Here, we explored the role of the PVS in local enteritis and its modification by acupuncture. Chronic cecitis in rabbits was induced by 2,4,6-trinitro-benzene-sulfonic acid (TNBS). The PVS on the cecum was visualized with trypan blue staining, and collected with the help of microsurgical forceps under an optical stereomicroscope. The increased primo vessels (PVs) and primo nodes (PNs) of the PVS on the surface of the cecum were induced by local inflammation, which was positively correlated with the inflammatory cells in the cecal mucosa. Tandem mass tag (TMT) based proteomic analysis revealed that 110 differentiated proteins of the PVS existed between TNBS-treated and control rabbits; 65 proteins were upregulated, while 45 proteins were downregulated. These proteins were mainly enriched in inflammation- and immunity-related processes, such as inflammatory cell proliferation, antigen presentation, and cell adhesion in the proliferated PVS (data are available via ProteomeXchange with the identifiers PXD034280). Importantly, TNBS-induced cecitis, the proliferated PVS and inflammation response-related proteins (CD40, CD45, HLA-DRA1, LAMP1, JAGN1 and FGL1) in the PVS were alleviated or reversed by repetitive electroacupuncture (EA) stimulations. These results suggest that the proliferated PVS and its active inclusions were related to the inflammatory process, which was modified by EA. Our study provides a new avenue for further exploration of the mechanism by which EA exerts anti-inflammatory effects.

Primo Vessels Inside Lymphatic Vessels Are Absent in an ALS Mouse Model.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by the selective death of motor neurons in the central nervous system. It is also a representative rare disease among degenerative diseases of the nervous system. Although many drugs for the treatment of degenerative brain diseases are being developed, they are not delivered correctly to the target due to the blood-brain barrier. The present study aimed to analyze changes in the primo vascular system (PVS) in ALS mice with symptoms and the partial oxygen pressure (pO2) in normal mice. In normal mice, we consistently observed primo vessels in lymphatic vessels (L-PVS). However, in ALS mice with symptoms, L-PVS were mostly lost, rendering them difficult to observe. The pO2 of the L-PVS in normal mice was significantly higher than that of normal dermis and lymph nodes.In conclusion, the relatively higher oxygen levels measured in the L-PVS than in normal dermis and lymph nodes suggest a role for the PVS in oxygen transport and enable a hypothesis that the L-PVS can function as a drug delivery pathway.

Injection Effect of Anti-CD3 Monoclonal Antibody on Primo Vessel in Lymph Vessel of Rabbit with Lipopolysaccharide-Induced Inflammation.

The primo vascular system can be viewed as a circulatory system that plays a therapeutic function in regenerating the body tissue. The anti-CD3 monoclonal antibody was used as an immunotherapeutic agent to treat the novel coronavirus infection (COVID-19). Objectives: In this study, we observed the effect of injecting lymph nodes with Foralumab, an anti- human CD3 epsilon therapeutic monoclonal antibody, on primo vessels. The structure and atomic stoichiometry of the antibody were determined by transmission electron microscopy and energy dispersive spectroscopy. Alcian blue dying solution was injected into the lymph nodes of the abdominal vena cava of rabbits, and the solution further flowed into the lymph vessels. A primo vessel with primo nodes stained with Alcian blue was clearly visible in the lymph vessel. By injecting Foralumab into lymph nodes of rabbits with lipopolysaccharide-induced inflammation, the floating primo vessel in the lymph vessel appeared thicker and was distinctly visible. The observation of the primo vessel post-treated with Foralumab in the inflamed lymphatic system suggests the possibility of a functional role of the primo vascular circulatory system in pathophysiological conditions.

The Cellular Architecture of the Primo Vascular System.

The primo vascular system (PVS) is of great interest to scientists in the last few years. The PVS plays a role in stem cell migration, immune function, erythropoiesis, tissue regeneration, and cancer metastasis. Discovered by Bong Han Kim in 1960, the PVS was described as a new, independent system that is distributed in the body of different animals. Since then, several cells have been discovered as important constituents of the PVS. Endothelial cells are hallmarks for the identification of the PVS, as they line the sinuses of the primo vessels and are characterized by their arrangement of rod-shaped nuclei in a parallel, broken-line fashion along the primo vessels. Immune cells as mast cells, eosinophils, neutrophils, and lymphocytes are also hallmarks for the identification of the PVS. One of the most interesting cells in the PVS are p-microcells. Primo nodes are a stem cell niche due to their p-microcells content, which express stem cell biomarkers CD133 and Oct 4. Mature erythrocytes and hematopoietic stem cells have also been observed in the PVS. Hematopoietic stem cells were observed in the PVS. Hematopoietic Stem Cells are the source of the cellular component of blood. Additionally, adrenaline and noradrenaline-producing cells, mesothelial cells, and smooth-muscle-like cells have also been described in the PVS.

Potential Mechanisms of Interior Lymphatic Vessel Primo Vessels in Tissue Repair

The Primo Vascular System was discovered by Bong Han Kim in the 1960s when searching for an anatomical correlate of the acupuncture meridians used in eastern medicine. The Primo Vascular System is a systemic network of thread-like Primo-vessels with intermittent enlargements known as Primo-nodes. Primo-vessels are difficult to view under a microscope due to their small diameters (20-50 µm) and translucent appearance. Primo-vessels have a porous outer membrane that encapsulates small channels named Primo sub-vessels filled with flowing fluid. Primo-vessels are classified into six sub-types based on their anatomical location. The physiological mechanisms of Primo-vessel function are not clear. There are multiple hypotheses based on Primo-vessel and Primo-node structure and cell content, however, supportive functional experimental data is lacking. This review focuses on the "interior" lymphatic vessel Primo-vessel (ILVPV) sub-type, the techniques that are used to visualize them, and experimental studies that attempt to unravel their physiological role after inflammatory stimulation. Speculative hypotheses are presented regarding the handling of signals by ILVPVs for intercellular communication between injured cells and cells stored within "interior" lymphatic vessel Primo-nodes (ILVPNs). One of the stored cell types that are of interest for tissue repair are very small embryonic-like cells. Very small embryonic-like cell activation may be induced by biophoton signals emitted by injured cells and transmitted to ILVPNs via Primo-vessel and/or ILVPV networks. An alternative or additional method for intercellular communication may involve the release of signaling proteins and/or extravesicular bodies carrying genetic messages (i.e., exosomes) by cells in injured tissues. As these signaling factors enter the lymphatic circulation, porous ILVPVs filter them out and transport them to ILVPNs where they initiate very small embryonic-like cell activation to start the tissue regenerative process. Primo Vascular System research will require more physiological functional studies to elucidate the role of ILVPVs and ILVPNs in tissue regeneration. To achieve this goal, future mechanistic studies will need novel biomarkers and animal models.

МОРФОЛОГИЧЕСКИЙ СУБСТРАТ ТОЧЕК ИГЛОУКАЛЫВАНИЯ И СИСТЕМЫ МЕРИДИАНОВ КИТАЙСКОЙ ТРАДИЦИОННОЙ МЕДИЦИНЫ

The review summarizes studies related to current issues and concepts of the neuroanatomic basis of the meridian system and acupuncture points. The proponents of their existence have not yet come to any consensus on how they might work or be tested in a scientific context. Kim Bonghan, a professor at Pyongyang Medical University of the Democratic People’s Republic of Korea, discovered the anatomical structure of meridian collaterals, which he called the Bonghan corpuscles (now known as primo nodes) and the the Bonghan ducts (primo vessels), and called it the Bonghan (Kyungrak) system. In 2010, it was renamed into the primo vascular system (PVS), which exists throughout the organism, including blood and lymph vessels. PVS is an anatomical structure being a network of ducts with fluid flowing in them. This system consists of primo-vessels and primo-nodes, corresponding to acupuncture meridians, and acupuncture points, respectively. Thus, the PVS can serve as a morphological substrate for acupuncture points and meridians of traditional Chinese medicine; however, since there is no scientific consensus on the neuroanatomical basis of acupuncture, further morphological, physiological, and clinical studies are needed to promote a broader mutual understanding of this issue in the research community and beyond.

Gene Expression of Prox-1 and Hif-1a in Primo Vessels Inside Lymph Vessels of the Rabbit.

The gene expression of Prox-1 and Hif-1a for the isolated primo vessels (PVs) and composite lymphatic vessels (LVs) containing PVs (LVs+PVs) was investigated by RNA-sequencing (Seq) and quantitative polymerase chain reaction (qRT-PCR) analysis. RNA-Seq on the passed 10 samples on RNA-QC for two experimental groups with PVs and PVs+LVs proceeded to the library construction stage automatically and analyzed differentially expressed genes (DEGs). From the real-time qRT-PCR analysis data, we found the marker genes of Prox-1 and Hif-1a were enriched and decreased in an isolated PVs compared to LVs, respectively. Based on mRNA transcriptional data, Prox-1 and Hif-1a were increased and decreased in PVs compared to LVs+PVs under lipopolysaccharide (LPS) treatment and relieved by acupuncture electric stimulation (AES), respectively. This finding indicates that high and low levels of Prox-1 and Hif-1a may be involved in the function of PVs and that pathophysiological and physiological condition could progress into inflamed lymphatic endothelial cells expanding the PV within the LV.

Primo Bundles Identified by Microcomputed Tomography in Primo Vascular Tissue on the Surface of Rat Abdominal Organs

BackgroundThe primo vascular system (PVS) is a novel network composed of primo nodes (PNs) and primo vessels (PVs). Currently, its anatomy is not fully understood. ObjectivesThe aim of this study was to elucidate the three-dimensional PN–PV structure. MethodsOrgan-surface PVS tissue was isolated from healthy and anemic rats. The tissues were analyzed by X-ray microcomputed tomography (CT), hematoxylin and eosin staining, and scanning electron microscopy. ResultsFrom CT images, we identified one or more bundles in a PV. In the PN, the bundles were enlarged and existed in isolation and/or in anastomosis. The transverse CT images revealed four areas of distinct intensities: zero, low, intermediate, and high. The first two were considered to be the sinuses and the subvessels of the PVS and were identified in the hematoxylin and eosin–stained PN sections. The enlargement of the PN from anemic rats was associated with an increase in the intermediate-intensity area. The high-intensity area demarcated the bundle and was overlapped with the mesothelial cells. In scanning electron microscopy, the PV bundles branched out, tapering down to a single bundle at some distance from the PN. Each bundle was composed of several subvessels (∼5 μm). Clustered round microcells (1–25 μm), scattered flat oval cells (∼15 μm), and amorphous extracellular matrix were observed on the surface of the PVS tissue. ConclusionsThe results newly showed that the primo bundle is a structural unit of both PVs and PNs. A bundle was demarcated by high CT intensity and mesothelial cells and consisted of multiple subvessels. The PN bundles contained also sinuses.

Analysis and Differential Expression of Primo Genes Using RNA-Seq and qRT-PCR Experiments.

Although the existence of the primo vasculature system has been shown in many species, including mice, rats, rabbits and humans, the biological role of this system, including expression of genes and proteins, has not yet been investigated. Especially the transcriptional action by mRNA, which is required for biological action, needs to be studied in primo vasculature biology. Differentially expressed genes in both isolated primo vessels and lymphatic vessels of rabbits were analyzed by RNA sequencing experiments. Primer efficiency and RNA purity of the primo vessels under lipopolysaccharides were confirmed prior to performing real-time qRT-PCR analysis following RNA extraction. We demonstrated that FLT4 was enriched in primo vessels and that several genes, including HSPH1 and EPHB2, were highly expressed in primo vessels compared with lymphatic vessels. Our data show that almost all genes, except HSPA4, were increased or sustained in isolated primo vessels compared with lymphatic vessels (FLT4 2.58 fold, HSPH1 1.83 fold, EPHB2 1.52 fold; whereas HSPA4 decreased 0.50 fold), suggesting primo vessels as a central regulator in diverse physiology. This implies that FLT4, HSPH1, and EPHB2 in high amounts may be involved in the functional activity of primo vessels. Our experimental data show that several genes are highly enriched in primo vessels in the lymphatic vessels of the rabbit.

Acute Anemia Induces Erythropoiesis in Rat Organ Surface Primo-Vascular Tissue.

The primo-vascular system (PVS) is a newly identified vascular tissue composed of primo-nodes (PNs) and primo-vessels (PVs). Previously, we reported erythropoietic activity in the organ-surface PVS (osPVS) tissue of rats with heart failure. In this study, we further investigated whether acute anemia could induce erythropoiesis in the PVS of rats, based on the hypothesis that erythropoiesis in osPVS tissue is due to anemia accompanying heart failure. Acute anemia was induced by an intraperitoneal injection of phenylhydrazine (PHZ). Circulating red blood cells (RBCs) and hematocrit decreased by 31.6%, whereas reticulocytes and white blood cells increased at day 3 and day 6 after PHZ treatment. All these parameters recovered to control levels at day 10. At days 3 and 6, we observed an increase in the size of the PNs (P<0.05), the number of the osPVS tissue samples per rat (P<0.01), and the proportion of osPVS tissue samples with red chromophore (P<0.001), which was from the RBCs in the PVS tissue. The number of RBCs, estimated from the PN sections stained with hematoxylin and eosin, increased at day 6 in the rats with anemia (P<0.01). All these anemia-induced changes in the osPVS tissue recovered to the control levels by day 10. Taken together, the results showed that the morphological and cytological changes in the osPVS tissue appear to be related to the erythropoietic activity induced by acute anemia in rats. This study confirmed the previous findings that the osPVS can exert erythropoietic activity in disease states accompanied by anemia, such as heart failure.

Mesothelial Cells Covering the Surface of Primo Vascular System Tissue

The primo vascular system (PVS) is reported to have a periductium composed of cells with spherical or spindle-shaped nuclei and abundant cytoplasm. However, little is known about these periductium cells. In this study, we examined the morphological features of cells covering the PVS tissue isolated from the surface of abdominal organs of rats. By hematoxylin and eosin (H&E) staining, we observed a layer of dark nuclei on the basement membrane at the borders of the sections of primo node (PN), primo vessel (PV), and their subunits. The nuclei appeared thin and linear (10-14 μm), elliptical (8-10 × 3-4 μm), and round (5-7 μm). The borders of the PVS tissue sections were immunostained with a selective antibody for mesothelial cells (MCs). Areas of immunoreactivity overlapped with the flattened cells are shown by hematoxylin and eosin staining. By scanning electron microscopy, we further identified elliptical (11 × 21 μm) and rectangular squamous MCs (length, 10 μm). There were numerous stomata (∼200 nm) and microparticles (20-200 nm) on the surface of the PVS MCs. In conclusion, this study presents the novel finding that the PVS periductium is composed of squamous MCs. These cells tightly line the luminal surface of the PVS tissue, including PNs, PVs, and small branches of the PVs in the abdominal cavity. These results will help us to understand the physiological roles such as hyaluronan secretion and the fine structure of PVS tissue.

Putative Primo-Vascular System in Rabbit Placenta

The primo vascular system (PVS) is a very important topic of study nowadays because of their role in transport and regeneration of tissue and in cell migration and cancer metastasis. The PVS was detected in different organs of the rabbit but not in the placenta. In this work, we observe the PVS inside the blood vessels of the placenta for the first time. The main characteristic features of the primo vessels (PVs) from the rabbit placenta were in agreement with the PVS in different organs of animals, including the rod-shaped nuclei and their arrangement.

Differential Gene Expression by RNA-Seq Analysis of the Primo Vessel in the Rabbit Lymph

For the connectome of primo vascular system, some long-type primo vessels dyed with Alcian blue injected into inguinal nodes, abdominal node, and axially nodes were visualized, which passed over around the vena cava of the rabbit. The Alcian blue dye revealed primo vessels and colored blue in the rabbit lymph vessels. The length of long-type primo vessels was 18 cm on average, of which diameters were about 20–30 μm, and the lymph vessels had diameters of 100–150 μm. Three different tissues of pure primo vessel, mixed primo + lymph vessel, and only lymph vessel were made to undergo RNA-Seq analysis by next-generation sequencing. We also analyzed differentially expressed genes (DEGs) from the RNA-Seq data, in which 30 genes of the primo vessels, primo + lymph vessels, and lymph vessels were selected for primo marker candidates. From the plot of DEG analysis, 10 genes had remarkably different expression pattern on the Group 1 (primo vessel) vs Group 3 (lymph vessel). With Fragments Per Kilobase of exon per Million the cutoff p-value for each gene was < 0.05. Fragments Per Kilobase of exon per Million of the 10 genes such as IGHM, HLA-DRA, HIST1H41, LPL, CD36, SRGN, DGAT2, SNCG, CD48, and GPD1 for primo vessels compared with those of lymph vessels increased twice or thrice. These results suggest that the selected genes could be used for the specific marker to construct primo connectome of circuit system in the rabbit.

알시안블루와 형광나노자성입자가 염색된 토끼의 림프내 프리모관의 자성특성 연구

토끼의 프리모 순환계(경락순환계로 불리움)의 연결망을 표시하기 위해, 형광 나노자성입자의 유체와 안정되게 혼합시킨 알시안블루 용액을 토끼의 복대정맥 근처의 림프노드에 주입하였다. 림프노드에 혼합 염색액을 주입한 후, 림프관 내부 프리모관의 색이 진한 청록색으로 표시되었다. 림프관 내부에 떠있는 프리모관 존재를 확인되었고, 채취된 림프관과 프리모관을 체외에서 생리식염수를 패트리디쉬에 담아 놓은 후 영구자석의 수평 운동에 따라 프리모관의 주기 운동을 사용하여 자기적 특성이 관찰되었다. 분리되어 채취한 프리모관의 휘어짐 정도는 알시안불루와 형광 나노자성입자를 흡착한 프리모관 내부를 통과하는 자기장의 세기에 의존함을 알 수 있었다.

The Primo Vascular System as a Possible Exosomal Route Across the Body: Implications for Tumor Proliferation and Metastasis

This literature study article will present the possibility of a correlation between the energy meridians of Traditional Chinese Medicine, which can be traced back to the recently described primo vessels (formerly known as Bong-Han ducts), their composition, and the ability of tumors to proliferate and metastasize. It is proposed that microvesicular bodies such as exosomes, known to be involved in cell-to-cell communication, immune response, and tumor proliferation, could be moving across the body via the primo vascular system. The ubiquity of the primo vascular system and its penetration through the blood–brain barrier could also explain the ability of some peripheral tumors (e.g., breast tumor) to metastasize in the brain.

A New Definition of an Acupuncture Meridian

This article provides a new definition of an acupuncture meridian. It suggests that a meridian consists of a distal tract of tissue that is affected by organ function. In the 1960s, Kim discovered the primo vascular system and regarded the superficial primo vessels as equating to the meridians. Instead, this article suggests that the superficial primo vessels merely underlie the meridians, in that they enable their creation, which is why some meridians are said to occur along the paths of superficial primo vessels. But the meridians themselves do not have a dedicated anatomical structure; instead they are merely tracts of tissue whose normal function is impeded when the related abdominal organ is stressed. It is hypothesized that the organ information is communicated in electrical waves that may travel through the connective tissue sheaths of the superficial primo vessels. Hence, the primo vessels serve as an inadvertent transport for this information, but the organ information is independent of the physiological purpose of the primo vascular system, as are the resultant meridians.

Expression of Genes in Primo Vasculature Floating in Lymphatic Endothelium Under Lipopolysaccharide and Acupuncture Electric Stimulation

It is known that the primo vascular system (PVS) includes the primo nodes and vessels. However, the relevant genes in the PVS system for both pathologic and physiologic condition are poorly understood. Here, we first examined the gene expression in primo vessels (PVs) floating in lymphatic endothelium by isolation of PVS and lymphatic vessels (LVs) containing PVS. To investigate therapeutic effects, both PVs and LVs containing PVS were isolated after lipopolysaccharide injection and acupuncture electric stimulation at two acupoints Joksamni (ST36) and Hapgok (LI04) following lipopolysaccharide injection. We used reverse transcriptase–polymerase chain reaction to examine expression of lymphatic endothelial cell markers and inflammatory related genes. We found that lymphatic endothelial cell markers such as fms-related tyrosine kinase 4 (Flt4), lymphatic vessel endothelial receptor (Lyve-1), prospero homeobox protein 1 (Prox-1), and podoplanin (Pdpn) were highly expressed in PV compared to that of lymphatic endothelium, suggesting pivotal roles of PV in LV under inflammation. Furthermore, lymphatic-related genes including metal-response element-binding transcription factor 2 (Mtf2), hypoxia inducible factor (Hif1a), angiotensin II type 1 receptor (Agtr1), and angiotensin II type 2 receptor (Agtr2) were also overall increased in PV, and remarkably increased and these genes except peroxisome proliferator–activated receptor gamma (Pparg) after acupuncture electric stimulation in two acupoints implying central role of PV by gene activation.

Sanal-Cell Cycle and Primo Vascular System: Regeneration via Sanals.

The Primo Vascular System (PVS) is new to most scientists despite that it was discovered in the 1960s by Bonghan Kim. Out of the many physiological functions reported, one of the most importantPVS functions appears to be its role in the regeneration via a small (~1μm) subcellular body called 'sanal.' According to Kim, a cell generates multiple sanals and the sanals arriving at the primo nodes (PNs) via primo vessels (PV) eventually produce new cells, by way of the 'Sanal-Cell Cycle.' Sanals express stem cell biomarkers. Appropriately differentiated sanals have been shown to perform non-marrow hematopoiesis and repair damaged tissues. However, many questions on sanals still remain: e.g., how sanals reside in the PN; whether sanalsare a new type of stem cells; and how exactly sanals produce cells and/or tissue. Our preliminary studies show that sanals reside inside the sinus formed by sub-PVs in the PNs;and in the PNs, there are more than one form of sanal-originated bodies of various sizes.

Potential Erythropoiesis in the Primo-Vascular System in Heart Failure.

The primo-vascular system (PVS), composed of primo-nodes (PNs) and primo-vessels (PVs), has been identified in various animal models. However, little is known about its function. Here, we investigated the changes in gross morphology and cellular composition of the organ-surface PVS (osPVS) in rats with heart failure (HF) induced by myocardial infarction. The size of the PNs in rats with HF was larger than in sham rats (1.87 vs. 0.80 mm2; P < 0.01) and the density of osPVS per rat was greater for the HF rats (28 of 6 rats vs. 19 of 9 rats; P < 0.01). In addition, the osPVS number containing red chromophore was greater in HF rats (P < 0.001). The chromophore was identified as hemoglobin. Transmission electron microscopy and H&E staining revealed that the osPVS of HF rats (P < 0.001) possessed more red blood cells (RBCs) than that of the sham rats. In particular, immature RBC number increased in the HF rats (90.7 vs. 42.3%; P < 0.001). Altogether, the results showed that the osPVS in HF rats increased in its size, density, and the proportion of immature RBCs in the PNs, which may indicate that the PVS has erythropoietic activity. Our study will help to elucidate the physiological roles of PVS in normal and disease states associated with HF.