NIP Chapter 1432 Can they reunite?
Chapter 1432 Can they reunite?
Chapter 1432 Can they reunite?
The data from the joint experiment reached an unexpected turning point.
It all started with a "mistake" by Hans. While performing proteomics analysis, he mistakenly mixed a set of control samples into the culture medium of the combined treatment group. According to standard procedure, this data should have been discarded. But Hans, being a meticulous person, insisted on running the erroneous samples on mass spectrometry as well, thinking they could at least be used as a negative control.
After the results came out, he stared at the screen for a long time, then rushed out of the cell culture room and bumped into Tang Shun, who was carrying a cup of coffee, in the corridor.
"Look at this!" Hans shoved the laptop in front of Tang Shun, almost spilling his coffee.
Tang Shun put down his cup and squinted at the heat map: the error sample, that is, the control culture medium that did not receive any treatment, actually detected three cytokines that were highly enriched in the combined treatment group—BDNF, GDNF, and a new secretory protein that they had never seen before.
“It might be too small,” Tang Shun said. “The control group didn’t have anything added, so how could these factors be present?”
"That's why I showed it to you!" Hans's eyes widened. "I repeated it three times, and the result was the same. In the control group's culture medium, something was spontaneously secreting these factors."
They told Yang Ping about their discovery. Yang Ping remained silent for a long time, then said something that stunned everyone: "Perhaps we've been looking in the wrong direction all along. It's not the exogenous stem cells that are secreting these factors, it's the original cells themselves."
“What do you mean?” Mainstein asked.
“It means,” Yang Ping walked to the whiteboard and drew a simple diagram, “that once the progenitor cells are activated, they can secrete neurotrophic factors. We thought that exogenous stem cells were ‘providing’ support, but in reality, they may just be ‘triggering’ the progenitor cells to do what they were already capable of doing.”
Weber called from Germany for a video conference. After listening to Hans's report, his first words were: "Hans, are you sure that sample was really mixed up?"
"Confirmed! I did the genotyping, and the SNP profile of that group of samples is completely different from that of the combined treatment group."
“Okay,” Weber nodded, “then this is a discovery even bigger than the synergistic effect. If the progenitor cells can secrete neurotrophic factors after activation, then much of what we’ve done in the last fifty years may have been unnecessary.”
“It’s not entirely superfluous,” Yang Ping corrected. “Exogenous stem cells may play a ‘starting’ role. Just like the ignition system in a car, the engine won’t turn on its own without it, but once it’s ignited, the engine can run on its own.”
“What we need to do,” Weber said, “is not to refuel the engine, but to find a better igniter.”
This discovery completely changed the direction of research.
Over the next two months, the team split into two groups: one group continued to optimize the combined approach and verify the autocrine ability of the progenitor cells; the other group began to search for the "minimum effective stimulus" that could activate the progenitor cells alone and induce them to differentiate into neurons.
Eva's electrophysiological data provided a crucial clue. She discovered that in the combined treatment group, the recovery of M7 motor evoked potentials exhibited a peculiar time curve: almost no change in the first four weeks, a sudden jump in the fifth week, and then a steady increase. This "jump" occurred precisely one week after the original cell markers reached their peak.
“There is a delay,” Eva said at the group meeting, “a four-week quiescent period, followed by a burst. This means that after the progenitor cells are activated, they need a period of time to ‘mature’ before they can function.”
“A four-week period of silence,” Yang Ping repeated the term, “but what if we could shorten that period of silence?”
How to shorten it?
"The reason why protocellular cells need four weeks to mature may be because the surrounding scar tissue inhibits them. If we can remove the scar tissue at the same time, or change the nature of the scar tissue, it may allow protocellular cells to mature faster."
This line of thought led to the exploration of a third direction: scar regulation.
Scar regulation is not a new concept. After spinal cord injury, the proliferation of astrocytes forms glial scars, which have long been considered an obstacle to regeneration. However, recent studies have found that scars are not entirely harmful. In the early stages, they have a protective function of isolating damage and preventing the spread of inflammation. It is only in the later stages that they become too dense, hindering axonal regeneration.
“The key issue isn’t whether there’s a scar or not,” Yang Ping said at the literature review meeting, “but the ‘texture’ of the scar. If it’s too loose, the inflammation will spread; if it’s too dense, the axon can’t pass through. What we need is a ‘permeable’ scar that allows the axon to pass through, but not the inflammation.”
Lena compiled all the literature on scar regulation from the past decade, creating a database that included 127 papers, 34 candidate molecules, and 12 biological materials. She conducted a network analysis and found that all effective scar regulation strategies pointed to the same pathway: TGF-β/Smad.
“TGF-β is the master switch for scar formation,” she said, presenting a complex signaling pathway diagram during her report. “Upregulating it thickens the scar; downregulating it thins the scar. But the problem is that TGF-β is protective in the early stages of injury, but becomes inhibitory in the later stages. Simply inhibiting it may worsen early-stage injury.”
“So we need to regulate the air quality in a timely manner,” Weber said on the other end of the video call, “preserving early and suppressing late.”
"Yes, but how do you control the air conditioning at any time?"
The meeting room was quiet for a long time before Fritz raised his hand, his first time speaking at a formal group meeting.
“I… have an idea,” he said softly, with a heavy German accent. “There’s a potted plant next to M7’s cage that I’ve been growing. It was almost dead when I was away last month. When I came back, I didn’t water it right away. I first cut off the dead leaves and then only watered it half the usual amount. Now it’s alive and growing better than before.”
Everyone was looking at him, wondering what he was going to say.
“What I mean is,” Fritz blushed, “sometimes help isn’t about giving more, it’s about giving less, but at the right time. The same goes for scars; maybe we don’t need to add any new medication, just reduce something a little at certain times.”
Yang Ping looked at him for a long time, then smiled: "Fritz, you're right, we need a 'pruning' strategy, not a 'fertilizing' strategy."
This analogy inspired Lena, who reanalyzed the database and discovered that all effective late-stage scar management programs shared a common characteristic: they did not inhibit TGF-β itself, but rather a specific molecule downstream of TGF-β, connective tissue growth factor (CTGF). CTGF begins to rise two weeks after injury, peaks at four weeks, and then remains at a high level. It is responsible for "compacting" loose scar tissue into a dense barrier.
“If we can specifically inhibit CTGF starting in the third week,” Lina said excitedly, “we can keep the scar loose and permeable without interfering with the protective effect of early TGF-β.”
"Are there any readily available inhibitors?" Yang Ping asked.
"There is a small molecule called FG-3019, which is an anti-CTGF antibody developed by FibroGen. It has been tested in clinical trials for pulmonary fibrosis and renal fibrosis, and the safety data are very good."
"Is it possible to get it?"
Lina did some research: "It's a clinical-grade reagent, which requires special channels. Moreover, using it for spinal cord injury is off-label use."
Yang Ping looked at Weber's video window. Weber was silent for a few seconds, then said, "I'll think of something. I have an old friend at FibroGen."
Three days later, Weber replied with an email, attaching a draft Material Transfer Agreement. FibroGen agreed to provide a small quantity of FG-3019 for preclinical studies, on the condition that it not be used in human trials.
“That’s enough,” Yang Ping said. “We’ll test it on animals first.”
The experimental design for FG-3019 was completed jointly by Hans and a Chinese PhD. They debated for a full week and finally reached a compromise: a three-factor design was adopted, involving progenitor cell activation, exogenous stem cell transplantation, and CTGF inhibition, with two levels for each factor, for a total of eight groups. The sample size was fifteen mice per group, for a total of one hundred and twenty mice.
"This is the largest mouse animal experiment in our institute's history," Tang Shun said at the experiment's launch meeting. "It will take three months to complete."
“Three months,” Yang Ping calculated, “plus data analysis and paper writing, it will take at least six months to get results.”
“But if we’re right,” Mainstein said, “these six months will be worth it.” After the experiment began, the atmosphere at the institute became tense and oppressive. Every morning, the first thing everyone did upon arriving at work was to check the data boards in the animal room: the survival rate, weight changes, and behavioral scores of each group of animals. For the first two weeks, there was almost no difference between the eight groups, and everyone was on tenterhooks.
In the third week, changes began to appear.
In the CTGF inhibition group, whether used alone or in combination, the scar area was significantly smaller than that in the control group. More importantly, the texture of these scars differed: immunostaining showed that in the scars of the CTGF inhibition group, astrocytes were loosely arranged with increased intercellular spaces, while the scars of the control group were dense and plate-like.
By the fourth week, motor function scores began to diverge. The combined treatment plus CTGF inhibition group performed significantly better than all other groups, scoring about 30 percent higher than the combined treatment alone group.
In week five, the "jump" point previously observed by Eva, the combined treatment + CTGF inhibition group showed explosive functional recovery. The BMS score jumped from an average of 2.5 to 4.8, approaching the 5.0 score of normal mice. Even more surprisingly, histological analysis showed that in this group, a large number of newly generated neurons and axons pierced through the scar tissue in the damaged area, forming continuous tissue bridges.
“They went right through,” Eva murmured to herself in front of the microscope. “The axons really did go through the scar.”
She projected the image onto the large screen in the conference room. Everyone held their breath. The green axonal markers, like thin lines, stretched from the head to the tail of the injury, passing through a pale blue area—the "softened" scar.
“This is the first time,” Weber said in the video, his voice trembling slightly, “that someone has allowed an axon to pass through a glial scar in an adult mammal.”
No one spoke in the meeting room. Then, someone started applause. At first, it was sparse, then it grew louder and louder. Tang Shun's eyes reddened, Hans was secretly wiping his eyes, and Lina, clutching her laptop, laughed like a child. Fritz stood in the corner, not clapping, but just looking at the thin green lines on the screen, and softly uttered a sentence in German. No one understood, but if M7 were there, perhaps they would.
Yang Ping sat in his office, laying out the data from eight sets of experiments one by one on the table, like arranging playing cards. Each graph told a story: some were sad, some were mundane, and some were full of hope.
He picked up the histological image of the combined treatment + CTGF inhibition group and stared at it under the lamp for a long time. Those green axonal threads shimmered under the light, like willow branches in spring, like spider webs after rain, like all fragile yet resilient life forms.
He wrote an email to Weber: "The data is out, and it's better than we expected."
Weber went back to Germany and replied, "I'll be back next week to continue working."
Weber brought an unexpected person with him this time—his wife, Elena.
Elena was a retired pediatrician in her seventies, with short, silver-white hair, and a gentle but authoritative voice. Everyone was stunned when she appeared at the institute's entrance. Weber had never mentioned having a wife, and no one expected her to bring him to the lab.
“Elena wanted to see M7,” Weber said simply. “She saw a rough cut of the documentary and was very interested in the monkey.”
"Just interested?" Mainstein asked Yang Ping in a low voice.
“It’s not just interest,” Elena seemed to hear her and turned around. “I’ve been a pediatrician for forty years and have seen many children lose their mobility due to illness or accidents. I’ve seen the look in their parents’ eyes. M7’s eyes are exactly the same as those of the children struggling to stand up in the rehabilitation room.”
She walked up to M7's cage, squatted down, and looked at M7 at eye level. M7 looked at her, tilted its head, and then stretched out its hand.
Elena grasped M7's fingers and gently shook them. M7 emitted a low, snoring sound, almost like humming.
“What is it saying?” Elena asked.
“It’s saying ‘thank you,’” Fritz replied from the side, “or ‘hello.’ The language of the M7 is very simple, with only a few syllables, but each syllable is meaningful.”
"Can you understand me?"
“I can’t understand everything,” Fritz said honestly, “but I can sense it.”
Elena smiled, a smile that softened the wrinkles on her face. She turned to Weber and said, "Carl, you're right, this is definitely a place worth working for."
Weber blushed slightly; this was the first time Mainstein had ever seen him embarrassed.
The combined treatment regimen for M7 was officially initiated in the second week after Weber's arrival.
This is the most crucial juncture in the entire project. Even the best data from mice is still just data from mice. M7 is a primate; its spinal cord structure, immune response, and neural plasticity are much closer to those of humans. If M7 is successful, we'll be just one step away from human clinical trials.
The surgery was performed by Yang Ping, with Mainstein assisting and Eva in charge of intraoperative electrophysiological monitoring. Tang Shun and Hans were in the preparation room next door, guarding the two precious tubes of cell suspension—one containing inducing factors that activate progenitor cells, the other containing exogenous neural stem cells, and the third containing FG-3019.
"Are you ready?" Yang Ping asked.
"Ready," everyone answered in unison.
After being anesthetized, M7 lay prone on the operating table. Its back had been shaved, revealing pink skin. Yang Ping made a longitudinal incision at the T8 segment with a scalpel to expose the lamina. He then carefully removed the lamina with a high-speed drill to expose the dura mater.
"The dura mater is intact," Yang Ping reported. "Prepare to cut it open."
He switched to a more precise scalpel and made a T-shaped incision in the dura mater. The spinal cord was exposed, grayish-white, with tiny pulsating blood vessels on its surface.
“The injury area is here,” he said, pointing to a dark red area on the back of the spinal cord, “about three millimeters long and half-cut deep.”
Weber leaned closer to the microscope, observed for a while, and then nodded: "It's consistent with the imaging; we can begin the transplant."
The first tube of inducing factor was slowly injected around the damaged area. Yang Ping used a special microinjector with a needle diameter of only 0.3 millimeters to minimize mechanical damage to the spinal cord. The pale yellow liquid spread across the surface of the spinal cord, like a drop of ink falling into clear water.
The second tube contained exogenous neural stem cells. These cells were suspended in a temperature-sensitive hydrogel, which solidified rapidly after injection to form a three-dimensional scaffold. Yang Ping's movements slowed even further, precisely controlling every microliter. The green cell suspension shimmered under the microscope, like flowing jade.
The third tube contained FG-3019. This time, Yang Ping did not inject it directly into the spinal cord, but rather into the epidural space surrounding the injury area. His reasoning was that CTGF is mainly secreted by subpiaural fibroblasts in the late stage of scar formation, and epidural administration can form a sustained-release reservoir, starting to take effect in the third week, which perfectly matches the time window of scar maturation.
The surgery lasted an hour. When the last stitch was completed, Yang Ping straightened up and let out a long breath.
For the first two weeks after surgery, M7 was placed in a special rehabilitation cage. This cage was twice the size of its original one, with a non-slip mat on the floor and soft railings around the edges. Fritz spent six hours a day with it, grooming it, giving it water, and performing passive joint exercises.
M7's condition was unexpectedly good. She started eating the day after surgery, was able to roll over in her cage on the third day, and began trying to support her body with her arms on the fifth day. These results surprised Eva, who had previously participated in several spinal cord surgeries on primates, where it usually takes more than a week to recover basic activities.
Yang Ping sat in his office, looking at the diagram he had drawn on the whiteboard. If there really was a mechanism behind it that unified stem cells and three-dimensional guide genes, there was a lot to study and many laboratories would need to participate.
The Germans are currently only researching a small part of the field; they are only trying to understand the theory from the perspective of stem cells.
The team led by Tang Shun at the Sanbo Research Institute is now starting from the three-dimensional guided gene theory, and many other teams around the world are gradually joining in, starting from their own areas of expertise.
Whether they will be able to reunite is anyone's guess.